switch_time.c

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/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005-2014, Anthony Minessale II <anthm@freeswitch.org>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthm@freeswitch.org>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * 
 * Anthony Minessale II <anthm@freeswitch.org>
 * Massimo Cetra <devel@navynet.it> - Timezone functionality
 *
 *
 * softtimer.c -- Software Timer Module
 *
 */

#include <switch.h>
#include <stdio.h>
#include "private/switch_core_pvt.h"

#ifdef HAVE_TIMERFD_CREATE
#include <sys/timerfd.h>
#endif

//#if defined(DARWIN)
#define DISABLE_1MS_COND
//#endif

#ifndef UINT32_MAX
#define UINT32_MAX 0xffffffff
#endif

#define MAX_TICK UINT32_MAX - 1024

#define MAX_ELEMENTS 3600
#define IDLE_SPEED 100

/* In Windows, enable the montonic timer for better timer accuracy,
 * GetSystemTimeAsFileTime does not update on timeBeginPeriod on these OS.
 * Flag SCF_USE_WIN32_MONOTONIC must be enabled to activate it (start parameter -monotonic-clock).
 */

#if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
static int MONO = 1;
#else
static int MONO = 0;
#endif


static int SYSTEM_TIME = 0;

/* clock_nanosleep works badly on some kernels but really well on others.
   timerfd seems to work well as long as it exists so if you have timerfd we'll also enable clock_nanosleep by default.
*/
#if defined(HAVE_TIMERFD_CREATE)
static int TFD = 2;
#if defined(HAVE_CLOCK_NANOSLEEP)
static int NANO = 1;
#else
static int NANO = 0;
#endif
#else
static int TFD = 0;
static int NANO = 0;
#endif

static int OFFSET = 0;

static int COND = 1;

static int MATRIX = 1;

#ifdef WIN32
static CRITICAL_SECTION timer_section;
static switch_time_t win32_tick_time_since_start = -1;
static DWORD win32_last_get_time_tick = 0;

static uint8_t win32_use_qpc = 0;
static uint64_t win32_qpc_freq = 0;
#endif

static switch_memory_pool_t *module_pool = NULL;

static struct {
        int32_t RUNNING;
        int32_t STARTED;
        int32_t use_cond_yield;
        switch_mutex_t *mutex;
        uint32_t timer_count;
} globals;

#ifdef WIN32
#undef SWITCH_MOD_DECLARE_DATA
#define SWITCH_MOD_DECLARE_DATA __declspec(dllexport)
#endif

SWITCH_MODULE_LOAD_FUNCTION(softtimer_load);
SWITCH_MODULE_SHUTDOWN_FUNCTION(softtimer_shutdown);
SWITCH_MODULE_RUNTIME_FUNCTION(softtimer_runtime);
SWITCH_MODULE_DEFINITION(CORE_SOFTTIMER_MODULE, softtimer_load, softtimer_shutdown, softtimer_runtime);

struct timer_private {
        switch_size_t reference;
        switch_size_t start;
        uint32_t roll;
        uint32_t ready;
};
typedef struct timer_private timer_private_t;

struct timer_matrix {
        uint64_t tick;
        uint32_t count;
        uint32_t roll;
        switch_mutex_t *mutex;
        switch_thread_cond_t *cond;
        switch_thread_rwlock_t *rwlock;
};
typedef struct timer_matrix timer_matrix_t;

static timer_matrix_t TIMER_MATRIX[MAX_ELEMENTS + 1];

static switch_time_t time_now(int64_t offset);

SWITCH_DECLARE(void) switch_os_yield(void)
{
#if defined(WIN32)
        SwitchToThread();
#else
        sched_yield();
#endif
}

static void do_sleep(switch_interval_time_t t)
{
#if defined(HAVE_CLOCK_NANOSLEEP) || defined(DARWIN)
        struct timespec ts;
#endif

#if defined(WIN32)
        if (t < 1000) {
                t = 1000;
        }
#endif

#if !defined(DARWIN)
        if (t > 100000 || !NANO) {
                apr_sleep(t);
                return;
        }
#endif

#if defined(HAVE_CLOCK_NANOSLEEP)
        t -= OFFSET;
        ts.tv_sec = t / 1000000;
        ts.tv_nsec = ((t % 1000000) * 1000);
        clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL);

#elif defined(DARWIN)
        t -= OFFSET;
        ts.tv_sec = t / APR_USEC_PER_SEC;
        ts.tv_nsec = (t % APR_USEC_PER_SEC) * 850;
        nanosleep(&ts, NULL);
#else
        apr_sleep(t);
#endif

#if defined(DARWIN)
        sched_yield();
#endif

}

static switch_interval_time_t average_time(switch_interval_time_t t, int reps)
{
        int x = 0;
        switch_time_t start, stop, sum = 0;

        for (x = 0; x < reps; x++) {
                start = switch_time_ref();
                do_sleep(t);
                stop = switch_time_ref();
                sum += (stop - start);
        }

        return sum / reps;

}

#define calc_step() if (step > 11) step -= 10; else if (step > 1) step--
SWITCH_DECLARE(void) switch_time_calibrate_clock(void)
{
        int x;
        switch_interval_time_t avg, val = 1000, want = 1000;
        int over = 0, under = 0, good = 0, step = 50, diff = 0, retry = 0, lastgood = 0, one_k = 0;

#ifdef HAVE_CLOCK_GETRES
        struct timespec ts;
        long res = 0;
        clock_getres(CLOCK_MONOTONIC, &ts);
        res = ts.tv_nsec / 1000;


        if (res > 900 && res < 1100) {
                one_k = 1;
        }
        
        if (res > 1500) {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING,
                                                  "Timer resolution of %ld microseconds detected!\n"
                                                  "Do you have your kernel timer frequency set to lower than 1,000Hz? "
                                                  "You may experience audio problems. Step MS %d\n", ts.tv_nsec / 1000, runtime.microseconds_per_tick / 1000);
                do_sleep(5000000);
                switch_time_set_cond_yield(SWITCH_TRUE);
                return;
        }
#endif

  top:
        val = 1000;
        step = 50;
        over = under = good = 0;
        OFFSET = 0;

        for (x = 0; x < 100; x++) {
                avg = average_time(val, 50);
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Test: %ld Average: %ld Step: %d\n", (long) val, (long) avg, step);

                diff = abs((int) (want - avg));
                if (diff > 1500) {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING,
                                                          "Abnormally large timer gap %d detected!\n"
                                                          "Do you have your kernel timer frequency set to lower than 1,000Hz? You may experience audio problems.\n", diff);
                        do_sleep(5000000);
                        switch_time_set_cond_yield(SWITCH_TRUE);
                        return;
                }

                if (diff <= 100) {
                        lastgood = (int) val;
                }

                if (diff <= 2) {
                        under = over = 0;
                        lastgood = (int) val;
                        if (++good > 10) {
                                break;
                        }
                } else if (avg > want) {
                        if (under) {
                                calc_step();
                        }
                        under = good = 0;
                        if ((val - step) < 0) {
                                if (++retry > 2)
                                        break;
                                goto top;
                        }
                        val -= step;
                        over++;
                } else if (avg < want) {
                        if (over) {
                                calc_step();
                        }
                        over = good = 0;
                        if ((val - step) < 0) {
                                if (++retry > 2)
                                        break;
                                goto top;
                        }
                        val += step;
                        under++;
                }
        }

        if (good >= 10) {
                OFFSET = (int) (want - val);
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Timer offset of %d calculated\n", OFFSET);
        } else if (lastgood) {
                OFFSET = (int) (want - lastgood);
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Timer offset of %d calculated (fallback)\n", OFFSET);
                switch_time_set_cond_yield(SWITCH_TRUE);
        } else if (one_k) {
                OFFSET = 900;
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Timer offset CANNOT BE DETECTED, forcing OFFSET to 900\n");
                switch_time_set_cond_yield(SWITCH_TRUE);
        } else {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Timer offset NOT calculated\n");
                switch_time_set_cond_yield(SWITCH_TRUE);
        }
}


SWITCH_DECLARE(switch_time_t) switch_micro_time_now(void)
{
        return (globals.RUNNING == 1 && runtime.timestamp) ? runtime.timestamp : switch_time_now();
}

SWITCH_DECLARE(switch_time_t) switch_mono_micro_time_now(void)
{
        return time_now(-1);
}


SWITCH_DECLARE(time_t) switch_epoch_time_now(time_t *t)
{
        time_t now = switch_micro_time_now() / APR_USEC_PER_SEC;
        if (t) {
                *t = now;
        }
        return now;
}

SWITCH_DECLARE(void) switch_time_set_monotonic(switch_bool_t enable)
{
#if (defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)) || defined(WIN32)
        MONO = enable ? 1 : 0;
        switch_time_sync();
#else
        MONO = 0;
#endif
}


SWITCH_DECLARE(void) switch_time_set_use_system_time(switch_bool_t enable)
{
        SYSTEM_TIME = enable;
}


SWITCH_DECLARE(void) switch_time_set_timerfd(int enable)
{
#if defined(HAVE_TIMERFD_CREATE)
        TFD = enable;
        switch_time_sync();

#else
        TFD = 0;
#endif
}


SWITCH_DECLARE(void) switch_time_set_matrix(switch_bool_t enable)
{
        MATRIX = enable ? 1 : 0;
        switch_time_sync();
}

SWITCH_DECLARE(void) switch_time_set_nanosleep(switch_bool_t enable)
{
#if defined(HAVE_CLOCK_NANOSLEEP)
        NANO = enable ? 1 : 0;
#endif
}

SWITCH_DECLARE(void) switch_time_set_cond_yield(switch_bool_t enable)
{
        COND = enable ? 1 : 0;
        if (COND) {
                MATRIX = 1;
        }
        switch_time_sync();
}

static switch_status_t timer_generic_sync(switch_timer_t *timer)
{
        switch_time_t now = switch_time_now();
        int64_t elapsed = (now - timer->start);
        
        timer->tick = (elapsed / timer->interval) / 1000;
        timer->samplecount = (uint32_t)(timer->tick * timer->samples);

        return SWITCH_STATUS_SUCCESS;
}



/////////
#ifdef HAVE_TIMERFD_CREATE

#define MAX_INTERVAL            2000 /* ms */

struct interval_timer {
        int     fd;
};
typedef struct interval_timer interval_timer_t;

static switch_status_t timerfd_start_interval(interval_timer_t *it, int interval)
{
        struct itimerspec val;
        int fd, r;
        uint64_t exp;

        fd = timerfd_create(CLOCK_MONOTONIC, 0);

        if (fd < 0) {
                return SWITCH_STATUS_GENERR;
        }

        val.it_interval.tv_sec = interval / 1000;
        val.it_interval.tv_nsec = (interval % 1000) * 1000000;
        val.it_value.tv_sec = 0;
        val.it_value.tv_nsec = 100000;

        if (timerfd_settime(fd, 0, &val, NULL) < 0) {
                close(fd);
                return SWITCH_STATUS_GENERR;
        }

        if ((r = read(fd, &exp, sizeof(exp)) < 0)) {
                close(fd);
                return SWITCH_STATUS_GENERR;
        }

        it->fd = fd;
        
        return SWITCH_STATUS_SUCCESS;
}

static switch_status_t timerfd_stop_interval(interval_timer_t *it)
{
        close(it->fd);
        it->fd = -1;
        return SWITCH_STATUS_SUCCESS;
}

static switch_status_t _timerfd_init(switch_timer_t *timer)
{
        interval_timer_t *it;
        int rc;

        if (timer->interval < 1 || timer->interval > MAX_INTERVAL)
                return SWITCH_STATUS_GENERR;

        it = switch_core_alloc(timer->memory_pool, sizeof(*it));

        if ((rc = timerfd_start_interval(it, timer->interval)) == SWITCH_STATUS_SUCCESS) {
                timer->start = switch_micro_time_now();
                timer->private_info = it;
        }

        return rc;
}

static switch_status_t _timerfd_step(switch_timer_t *timer)
{
        timer->tick++;
        timer->samplecount += timer->samples;

        return SWITCH_STATUS_SUCCESS;
}

static switch_status_t _timerfd_next(switch_timer_t *timer)
{
        interval_timer_t *it = timer->private_info;
        uint64_t u64  = 0;

        if (read(it->fd, &u64, sizeof(u64)) < 0) {
                return SWITCH_STATUS_GENERR;
        } else {
                timer->tick += u64;
                timer->samplecount = timer->tick * timer->samples;
        }

        return SWITCH_STATUS_SUCCESS;
}

static switch_status_t _timerfd_check(switch_timer_t *timer, switch_bool_t step)
{
        interval_timer_t *it = timer->private_info;
        struct itimerspec val;
        int diff;

        timerfd_gettime(it->fd, &val);
        diff = val.it_interval.tv_nsec / 1000;
        
        if (diff > 0) {
                /* still pending */
                timer->diff = diff;
                return SWITCH_STATUS_FALSE;
        } else {
                /* timer pending */
                timer->diff = 0;
                if (step) {
                        _timerfd_step(timer);
                }
                return SWITCH_STATUS_SUCCESS;
        }
}

static switch_status_t _timerfd_destroy(switch_timer_t *timer)
{
        interval_timer_t *it = timer->private_info;
        int rc;

        rc = timerfd_stop_interval(it);
        return rc;
}

#endif
////////


static switch_time_t time_now(int64_t offset)
{
        switch_time_t now;

#if (defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)) || defined(WIN32)
        if (MONO) {
#ifndef WIN32
                struct timespec ts;
                clock_gettime(offset ? CLOCK_MONOTONIC : CLOCK_REALTIME, &ts);
                if (offset < 0) offset = 0;
                now = ts.tv_sec * APR_USEC_PER_SEC + (ts.tv_nsec / 1000) + offset;
#else
                if (offset == 0) {
                        return switch_time_now();
                } else if (offset < 0) offset = 0;
                

                if (win32_use_qpc) {
                        /* Use QueryPerformanceCounter */
                        uint64_t count = 0;
                        QueryPerformanceCounter((LARGE_INTEGER*)&count);
                        now = ((count * 1000000) / win32_qpc_freq) + offset;
                } else {
                        /* Use good old timeGetTime() */
                        DWORD tick_now;
                        DWORD tick_diff;

                        tick_now = timeGetTime();
                        if (win32_tick_time_since_start != -1) {
                                EnterCriticalSection(&timer_section);
                                /* just add diff (to make it work more than 50 days). */
                                tick_diff = tick_now - win32_last_get_time_tick;
                                win32_tick_time_since_start += tick_diff;

                                win32_last_get_time_tick = tick_now;
                                now = (win32_tick_time_since_start * 1000) + offset;
                                LeaveCriticalSection(&timer_section);
                        } else {
                                /* If someone is calling us before timer is initialized,
                                 * return the current tick + offset
                                 */
                                now = (tick_now * 1000) + offset;
                        }
                }
#endif
        } else {
#endif
                now = switch_time_now();

#if (defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)) || defined(WIN32)
        }
#endif

        return now;
}

SWITCH_DECLARE(switch_time_t) switch_time_ref(void)
{
        if (SYSTEM_TIME) {
                /* Return system time reference */
                return time_now(0);
        } else {
                /* Return monotonic time reference (when available) */
                return switch_mono_micro_time_now();
        }
}

static switch_time_t last_time = 0;

SWITCH_DECLARE(void) switch_time_sync(void)
{
        runtime.time_sync++; /* Indicate that we are syncing time right now */

        runtime.reference = switch_time_now();

        if (SYSTEM_TIME) {
                runtime.reference = time_now(0);
                runtime.offset = 0;
        } else {
                runtime.offset = runtime.reference - switch_mono_micro_time_now(); /* Get the offset between system time and the monotonic clock (when available) */
                runtime.reference = time_now(runtime.offset);
        }

        if (runtime.reference - last_time > 1000000 || last_time == 0) {
                if (SYSTEM_TIME) {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Clock is already configured to always report system time.\n");
                } else {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Clock synchronized to system time.\n");
                }
        }
        last_time = runtime.reference;

        runtime.time_sync++; /* Indicate that we are finished syncing time */
}

SWITCH_DECLARE(void) switch_micro_sleep(switch_interval_time_t t)
{
        do_sleep(t);
}

SWITCH_DECLARE(void) switch_sleep(switch_interval_time_t t)
{

        if (globals.RUNNING != 1 || t < 1000 || t >= 10000) {
                do_sleep(t);
                return;
        }
#ifndef DISABLE_1MS_COND
        if (globals.use_cond_yield == 1) {
                switch_cond_yield(t);
                return;
        }
#endif

        do_sleep(t);
}


SWITCH_DECLARE(void) switch_cond_next(void)
{
        if (runtime.tipping_point && globals.timer_count >= runtime.tipping_point) {
                switch_os_yield();
                return;
        }
#ifdef DISABLE_1MS_COND
        do_sleep(1000);
#else
        if (globals.RUNNING != 1 || !runtime.timestamp || globals.use_cond_yield != 1) {
                do_sleep(1000);
                return;
        }
        switch_mutex_lock(TIMER_MATRIX[1].mutex);
        switch_thread_cond_wait(TIMER_MATRIX[1].cond, TIMER_MATRIX[1].mutex);
        switch_mutex_unlock(TIMER_MATRIX[1].mutex);
#endif
}

SWITCH_DECLARE(void) switch_cond_yield(switch_interval_time_t t)
{
        switch_time_t want;
        if (!t)
                return;

        if (globals.RUNNING != 1 || !runtime.timestamp || globals.use_cond_yield != 1) {
                do_sleep(t);
                return;
        }
        want = runtime.timestamp + t;
        while (globals.RUNNING == 1 && globals.use_cond_yield == 1 && runtime.timestamp < want) {
                switch_mutex_lock(TIMER_MATRIX[1].mutex);
                if (runtime.timestamp < want) {
                        switch_thread_cond_wait(TIMER_MATRIX[1].cond, TIMER_MATRIX[1].mutex);
                }
                switch_mutex_unlock(TIMER_MATRIX[1].mutex);
        }


}

static switch_status_t timer_init(switch_timer_t *timer)
{
        timer_private_t *private_info;
        int sanity = 0;

        timer->start = switch_micro_time_now();

        if (timer->interval == 1) {
                runtime.microseconds_per_tick = 10000;
                switch_mutex_lock(globals.mutex);
                globals.timer_count++;
                switch_mutex_unlock(globals.mutex);
                return SWITCH_STATUS_SUCCESS;
        }

#ifdef HAVE_TIMERFD_CREATE
        if (TFD == 2) {
                return _timerfd_init(timer);
        }
#endif

        while (globals.STARTED == 0) {
                do_sleep(100000);
                if (++sanity == 300) {
                        abort();
                }
        }

        if (globals.RUNNING != 1 || !globals.mutex || timer->interval < 1) {
                return SWITCH_STATUS_FALSE;
        }

        if ((private_info = switch_core_alloc(timer->memory_pool, sizeof(*private_info)))) {
                switch_mutex_lock(globals.mutex);
                if (!TIMER_MATRIX[timer->interval].mutex) {
                        switch_mutex_init(&TIMER_MATRIX[timer->interval].mutex, SWITCH_MUTEX_NESTED, module_pool);
                        switch_thread_cond_create(&TIMER_MATRIX[timer->interval].cond, module_pool);
                }
                TIMER_MATRIX[timer->interval].count++;
                switch_mutex_unlock(globals.mutex);
                timer->private_info = private_info;
                private_info->start = private_info->reference = (switch_size_t)TIMER_MATRIX[timer->interval].tick;
                private_info->start -= 2; /* switch_core_timer_init sets samplecount to samples, this makes first next() step once */
                private_info->roll = TIMER_MATRIX[timer->interval].roll;
                private_info->ready = 1;

                if (runtime.microseconds_per_tick > 10000  && (timer->interval % (int)(runtime.microseconds_per_tick / 1000)) != 0 && (timer->interval % 10) == 0) {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Increasing global timer resolution to 10ms to handle interval %d\n", timer->interval);
                        runtime.microseconds_per_tick = 10000;
                }

                if (timer->interval > 0 && (timer->interval < (int)(runtime.microseconds_per_tick / 1000) || (timer->interval % 10) != 0)) {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Increasing global timer resolution to 1ms to handle interval %d\n", timer->interval);
                        runtime.microseconds_per_tick = 1000;
                        switch_time_sync();
                }

                switch_mutex_lock(globals.mutex);
                globals.timer_count++;
                if (runtime.tipping_point && globals.timer_count == (runtime.tipping_point + 1)) {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Crossed tipping point of %u, shifting into high-gear.\n", runtime.tipping_point);
                }
                switch_mutex_unlock(globals.mutex);

                return SWITCH_STATUS_SUCCESS;
        }

        return SWITCH_STATUS_MEMERR;
}

#define check_roll() if (private_info->roll < TIMER_MATRIX[timer->interval].roll) {     \
                private_info->roll++;                                                                                   \
                private_info->reference = private_info->start = (switch_size_t)TIMER_MATRIX[timer->interval].tick;      \
                private_info->start--; /* Must have a diff */                                   \
        }                                                                                                                                       \


static switch_status_t timer_step(switch_timer_t *timer)
{
        timer_private_t *private_info;
        uint64_t samples;

        if (timer->interval == 1) {
                return SWITCH_STATUS_FALSE;
        }

#ifdef HAVE_TIMERFD_CREATE
        if (TFD == 2) {
                return _timerfd_step(timer);
        }
#endif

        private_info = timer->private_info;

        if (globals.RUNNING != 1 || private_info->ready == 0) {
                return SWITCH_STATUS_FALSE;
        }

        check_roll();
        samples = (uint64_t)timer->samples * (private_info->reference - private_info->start);

        if (samples > UINT32_MAX) {
                private_info->start = private_info->reference - 1; /* Must have a diff */
                samples = timer->samples;
        }

        timer->samplecount = (uint32_t) samples;
        private_info->reference++;

        return SWITCH_STATUS_SUCCESS;
}

static switch_status_t timer_sync(switch_timer_t *timer)
{
        timer_private_t *private_info;

        if (timer->interval == 1) {
                return timer_generic_sync(timer);
        }

#ifdef HAVE_TIMERFD_CREATE
        if (TFD == 2) {
                return timer_generic_sync(timer);
        }
#endif

        private_info = timer->private_info;

        if (globals.RUNNING != 1 || private_info->ready == 0) {
                return SWITCH_STATUS_FALSE;
        }

        /* sync the clock */
        private_info->reference = (switch_size_t)(timer->tick = TIMER_MATRIX[timer->interval].tick);

        /* apply timestamp */
        timer_step(timer);

        return SWITCH_STATUS_SUCCESS;
}


static switch_status_t timer_next(switch_timer_t *timer)
{
        timer_private_t *private_info;

#ifdef DISABLE_1MS_COND
        int cond_index = timer->interval;
#else
        int cond_index = 1;
#endif
        int delta;

        if (timer->interval == 1) {
                return SWITCH_STATUS_FALSE;
        }

#ifdef HAVE_TIMERFD_CREATE
        if (TFD == 2) {
                return _timerfd_next(timer);
        }
#endif

        private_info = timer->private_info;

        delta = (int) (private_info->reference - TIMER_MATRIX[timer->interval].tick);



        /* sync up timer if it's not been called for a while otherwise it will return instantly several times until it catches up */
        if (delta < -1) {
                private_info->reference = (switch_size_t)(timer->tick = TIMER_MATRIX[timer->interval].tick);
        }
        timer_step(timer);

        if (!MATRIX) {
                do_sleep(1000 * timer->interval);
                goto end;
        }

        while (globals.RUNNING == 1 && private_info->ready && TIMER_MATRIX[timer->interval].tick < private_info->reference) {
                check_roll();

                switch_os_yield();


                if (runtime.tipping_point && globals.timer_count >= runtime.tipping_point) {
                        globals.use_cond_yield = 0;
                } else {
                        if (globals.use_cond_yield == 1) {
                                switch_mutex_lock(TIMER_MATRIX[cond_index].mutex);
                                if (TIMER_MATRIX[timer->interval].tick < private_info->reference) {
                                        switch_thread_cond_wait(TIMER_MATRIX[cond_index].cond, TIMER_MATRIX[cond_index].mutex);
                                }
                                switch_mutex_unlock(TIMER_MATRIX[cond_index].mutex);
                        } else {
                                do_sleep(1000);
                        }
                }
        }

  end:
        return globals.RUNNING == 1 ? SWITCH_STATUS_SUCCESS : SWITCH_STATUS_FALSE;
}

static switch_status_t timer_check(switch_timer_t *timer, switch_bool_t step)
{
        timer_private_t *private_info;
        switch_status_t status = SWITCH_STATUS_SUCCESS;

        if (timer->interval == 1) {
                return SWITCH_STATUS_FALSE;
        }

#ifdef HAVE_TIMERFD_CREATE
        if (TFD == 2) {
                return _timerfd_check(timer, step);
        }
#endif

        private_info = timer->private_info;

        if (globals.RUNNING != 1 || !private_info->ready) {
                return SWITCH_STATUS_SUCCESS;
        }

        check_roll();

        timer->tick = TIMER_MATRIX[timer->interval].tick;

        if (timer->tick < private_info->reference) {
                timer->diff = (switch_size_t)(private_info->reference - timer->tick);
        } else {
                timer->diff = 0;
        }

        if (timer->diff) {
                status = SWITCH_STATUS_FALSE;
        } else if (step) {
                timer_step(timer);
        }


        return status;
}

static switch_status_t timer_destroy(switch_timer_t *timer)
{
        timer_private_t *private_info;

        if (timer->interval == 1) {
                switch_mutex_lock(globals.mutex);
                if (globals.timer_count) {
                        globals.timer_count--;
                }
                switch_mutex_unlock(globals.mutex);
                return SWITCH_STATUS_SUCCESS;
        }

#ifdef HAVE_TIMERFD_CREATE
        if (TFD == 2) {
                return _timerfd_destroy(timer);
        }
#endif

        private_info = timer->private_info;

        if (timer->interval < MAX_ELEMENTS) {
                switch_mutex_lock(globals.mutex);
                TIMER_MATRIX[timer->interval].count--;
                if (TIMER_MATRIX[timer->interval].count == 0) {
                        TIMER_MATRIX[timer->interval].tick = 0;
                }
                switch_mutex_unlock(globals.mutex);
        }
        if (private_info) {
                private_info->ready = 0;
        }

        switch_mutex_lock(globals.mutex);
        if (globals.timer_count) {
                globals.timer_count--;
                if (runtime.tipping_point && globals.timer_count == (runtime.tipping_point - 1)) {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Fell Below tipping point of %u, shifting into low-gear.\n", runtime.tipping_point);
                }
        }
        switch_mutex_unlock(globals.mutex);

        return SWITCH_STATUS_SUCCESS;
}

static void win32_init_timers(void)
{
#ifdef WIN32
        OSVERSIONINFOEX version_info; /* Used to fetch current OS version from Windows */

        EnterCriticalSection(&timer_section);

        ZeroMemory(&version_info, sizeof(OSVERSIONINFOEX));
        version_info.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);

        /* Check if we should use timeGetTime() (pre-Vista) or QueryPerformanceCounter() (Vista and later) */

        if (GetVersionEx((OSVERSIONINFO*) &version_info)) {
                if (version_info.dwPlatformId == VER_PLATFORM_WIN32_NT && version_info.dwMajorVersion >= 6) {
                        if (QueryPerformanceFrequency((LARGE_INTEGER*)&win32_qpc_freq) && win32_qpc_freq > 0) {
                                /* At least Vista, and QueryPerformanceFrequency() suceeded, enable qpc */
                                win32_use_qpc = 1;
                        } else {
                                /* At least Vista, but QueryPerformanceFrequency() failed, disable qpc */
                                win32_use_qpc = 0;
                        }
                } else {
                        /* Older then Vista, disable qpc */
                        win32_use_qpc = 0;
                }
        } else {
                /* Unknown version - we want at least Vista, disable qpc */
                win32_use_qpc = 0;
        }

        if (win32_use_qpc) {
                uint64_t count = 0;

                if (!QueryPerformanceCounter((LARGE_INTEGER*)&count) || count == 0) {
                        /* Call to QueryPerformanceCounter() failed, disable qpc again */
                        win32_use_qpc = 0;
                }
        }

        if (!win32_use_qpc) {
                /* This will enable timeGetTime() instead, qpc init failed */
                win32_last_get_time_tick = timeGetTime();
                win32_tick_time_since_start = win32_last_get_time_tick;
        }

        LeaveCriticalSection(&timer_section);
#endif
}

SWITCH_MODULE_RUNTIME_FUNCTION(softtimer_runtime)
{
        switch_time_t too_late = runtime.microseconds_per_tick * 1000;
        uint32_t current_ms = 0;
        uint32_t x, tick = 0, sps_interval_ticks = 0;
        switch_time_t ts = 0, last = 0;
        int fwd_errs = 0, rev_errs = 0;
        int profile_tick = 0;
        int tfd = -1;
        uint32_t time_sync = runtime.time_sync;

#ifdef HAVE_TIMERFD_CREATE
        int last_MICROSECONDS_PER_TICK = runtime.microseconds_per_tick;

        struct itimerspec spec = { { 0 } };

        if (MONO && TFD) {
                tfd = timerfd_create(CLOCK_MONOTONIC, 0);

                if (tfd > -1) {
                        spec.it_interval.tv_sec = 0;
                        spec.it_interval.tv_nsec = runtime.microseconds_per_tick * 1000;
                        spec.it_value.tv_sec = 0;
                        spec.it_value.tv_nsec = 100000;
                
                        if (timerfd_settime(tfd, 0, &spec, NULL)) {
                                close(tfd);
                                tfd = -1;
                        }
                }

                if (tfd > -1) MATRIX = 0;
        }
#else
        tfd = -1;
#endif

        runtime.profile_timer = switch_new_profile_timer();
        switch_get_system_idle_time(runtime.profile_timer, &runtime.profile_time);

        if (runtime.timer_affinity > -1) { 
                switch_core_thread_set_cpu_affinity(runtime.timer_affinity);
        }

        switch_time_sync();
        time_sync = runtime.time_sync;

        globals.STARTED = globals.RUNNING = 1;
        switch_mutex_lock(runtime.throttle_mutex);
        runtime.sps = runtime.sps_total;
        switch_mutex_unlock(runtime.throttle_mutex);

        if (MONO) {
                int loops;
                for (loops = 0; loops < 3; loops++) {
                        ts = switch_time_ref();
                        /* if it returns the same value every time it won't be of much use. */
                        if (ts == last) {
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Broken MONOTONIC Clock Detected!, Support Disabled.\n");
                                MONO = 0;
                                NANO = 0;
                                runtime.reference = switch_time_now();
                                runtime.initiated = runtime.reference;
                                break;
                        }
                        do_sleep(runtime.microseconds_per_tick);
                        last = ts;
                }
        }

        ts = 0;
        last = 0;
        fwd_errs = rev_errs = 0;

#ifndef DISABLE_1MS_COND
        if (!NANO) {
                switch_mutex_init(&TIMER_MATRIX[1].mutex, SWITCH_MUTEX_NESTED, module_pool);
                switch_thread_cond_create(&TIMER_MATRIX[1].cond, module_pool);
        }
#endif


        switch_time_sync();
        time_sync = runtime.time_sync;

        globals.use_cond_yield = COND;
        globals.RUNNING = 1;

        while (globals.RUNNING == 1) {

#ifdef HAVE_TIMERFD_CREATE
                if (last_MICROSECONDS_PER_TICK != runtime.microseconds_per_tick) {
                        spec.it_interval.tv_nsec = runtime.microseconds_per_tick * 1000;
                        timerfd_settime(tfd, 0, &spec, NULL);
                }
                
                last_MICROSECONDS_PER_TICK = runtime.microseconds_per_tick;
#endif

                runtime.reference += runtime.microseconds_per_tick;

                while (((ts = time_now(runtime.offset)) + 100) < runtime.reference) {
                        if (ts < last) {
                                if (MONO) {
                                        runtime.initiated = switch_mono_micro_time_now() - ((last - runtime.offset) - runtime.initiated);

                                        if (time_sync == runtime.time_sync) { /* Only resync if not in the middle of switch_time_sync() already */
                                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Virtual Migration Detected! Syncing Clock\n");
                                                win32_init_timers(); /* Make sure to reinit timers on WIN32 */
                                                switch_time_sync();
                                                time_sync = runtime.time_sync;
                                        }
                                } else {
                                        int64_t diff = (int64_t) (ts - last);
                                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Reverse Clock Skew Detected!\n");
                                        runtime.reference = switch_time_now();
                                        current_ms = 0;
                                        tick = 0;
                                        runtime.initiated += diff;
                                        rev_errs++;
                                }

                                if (!MONO || time_sync == runtime.time_sync) {
#if defined(HAVE_CLOCK_NANOSLEEP)
                                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT,
                                                                          "If you see this message many times try setting the param enable-clock-nanosleep to true in switch.conf.xml or consider a nicer machine to run me on. I AM *FREE* afterall.\n");
#else
                                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT,
                                                                          "If you see this message many times consider a nicer machine to run me on. I AM *FREE* afterall.\n");
#endif
                                }
                        } else {
                                rev_errs = 0;
                        }

                        if (runtime.tipping_point && globals.timer_count >= runtime.tipping_point) {
                                switch_os_yield();
                        } else {
                                if (tfd > -1 && globals.RUNNING == 1) {
                                        uint64_t exp;
                                        int r;
                                        r = read(tfd, &exp, sizeof(exp));
                                        r++;
                                } else {
                                        switch_time_t timediff = runtime.reference - ts;

                                        if (runtime.microseconds_per_tick < timediff) {
                                                /* Only sleep for runtime.microseconds_per_tick if this value is lower then the actual time diff we need to sleep */
                                                do_sleep(runtime.microseconds_per_tick);
                                        } else {
#ifdef WIN32
                                                /* Windows only sleeps in ms precision, try to round the usec value as good as possible */
                                                do_sleep((switch_interval_time_t)floor((timediff / 1000.0) + 0.5) * 1000);
#else
                                                do_sleep(timediff);
#endif
                                        }
                                }
                        }

                        last = ts;
                }

                if (ts > (runtime.reference + too_late)) {
                        if (MONO) {
                                runtime.initiated = switch_mono_micro_time_now() - (((runtime.reference - runtime.microseconds_per_tick) - runtime.offset) - runtime.initiated);

                                if (time_sync == runtime.time_sync) { /* Only resync if not in the middle of switch_time_sync() already */
                                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Virtual Migration Detected! Syncing Clock\n");
                                        win32_init_timers(); /* Make sure to reinit timers on WIN32 */
                                        switch_time_sync();
                                        time_sync = runtime.time_sync;
                                }
                        } else {
                                switch_time_t diff = ts - (runtime.reference - runtime.microseconds_per_tick);
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Forward Clock Skew Detected!\n");
                                fwd_errs++;
                                runtime.reference = switch_time_now();
                                current_ms = 0;
                                tick = 0;
                                runtime.initiated += diff;
                        }
                } else {
                        fwd_errs = 0;
                }

                if (fwd_errs > 9 || rev_errs > 9) {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Auto Re-Syncing clock.\n");
                        switch_time_sync();
                        time_sync = runtime.time_sync;
                        fwd_errs = rev_errs = 0;
                }

                runtime.timestamp = ts;
                current_ms += (runtime.microseconds_per_tick / 1000);
                tick++;

                if (time_sync < runtime.time_sync) {
                        time_sync++; /* Only step once for each loop, we want to make sure to keep this thread safe */
                }

                if (tick >= (1000000 / runtime.microseconds_per_tick)) {
                        if (++profile_tick == 1) {
                                switch_get_system_idle_time(runtime.profile_timer, &runtime.profile_time);
                                profile_tick = 0;
                        }
                        
                        if (runtime.sps <= 0) {
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Over Session Rate of %d!\n", runtime.sps_total);
                        }
                        switch_mutex_lock(runtime.throttle_mutex);
                        runtime.sps_last = runtime.sps_total - runtime.sps;

                        if (sps_interval_ticks >= 300) {
                                runtime.sps_peak_fivemin = 0;
                                sps_interval_ticks = 0;
                                switch_mutex_lock(runtime.session_hash_mutex);
                                runtime.sessions_peak_fivemin = session_manager.session_count;
                                switch_mutex_unlock(runtime.session_hash_mutex);
                        }

                        sps_interval_ticks++;
                        
                        if (runtime.sps_last > runtime.sps_peak_fivemin) {
                                runtime.sps_peak_fivemin = runtime.sps_last;
                        }

                        if (runtime.sps_last > runtime.sps_peak) {
                                runtime.sps_peak = runtime.sps_last;
                        }
                        runtime.sps = runtime.sps_total;
                        switch_mutex_unlock(runtime.throttle_mutex);
                        tick = 0;
                }
#ifndef DISABLE_1MS_COND
                TIMER_MATRIX[1].tick++;
                if (switch_mutex_trylock(TIMER_MATRIX[1].mutex) == SWITCH_STATUS_SUCCESS) {
                        switch_thread_cond_broadcast(TIMER_MATRIX[1].cond);
                        switch_mutex_unlock(TIMER_MATRIX[1].mutex);
                }
                if (TIMER_MATRIX[1].tick == MAX_TICK) {
                        TIMER_MATRIX[1].tick = 0;
                        TIMER_MATRIX[1].roll++;
                }
#endif


                if (MATRIX && (current_ms % (runtime.microseconds_per_tick / 1000)) == 0) {
                        for (x = (runtime.microseconds_per_tick / 1000); x <= MAX_ELEMENTS; x += (runtime.microseconds_per_tick / 1000)) {
                                if ((current_ms % x) == 0) {
                                        if (TIMER_MATRIX[x].count) {
                                                TIMER_MATRIX[x].tick++;
#ifdef DISABLE_1MS_COND

                                                if (TIMER_MATRIX[x].mutex && switch_mutex_trylock(TIMER_MATRIX[x].mutex) == SWITCH_STATUS_SUCCESS) {
                                                        switch_thread_cond_broadcast(TIMER_MATRIX[x].cond);
                                                        switch_mutex_unlock(TIMER_MATRIX[x].mutex);
                                                }
#endif
                                                if (TIMER_MATRIX[x].tick == MAX_TICK) {
                                                        TIMER_MATRIX[x].tick = 0;
                                                        TIMER_MATRIX[x].roll++;
                                                }
                                        }
                                }
                        }
                }

                if (current_ms == MAX_ELEMENTS) {
                        current_ms = 0;
                }
        }

        globals.use_cond_yield = 0;
        
        for (x = (runtime.microseconds_per_tick / 1000); x <= MAX_ELEMENTS; x += (runtime.microseconds_per_tick / 1000)) {
                if (TIMER_MATRIX[x].mutex && switch_mutex_trylock(TIMER_MATRIX[x].mutex) == SWITCH_STATUS_SUCCESS) {
                        switch_thread_cond_broadcast(TIMER_MATRIX[x].cond);
                        switch_mutex_unlock(TIMER_MATRIX[x].mutex);
                }
        }

        if (tfd > -1) {
                close(tfd);
                tfd = -1;
        }


        switch_mutex_lock(globals.mutex);
        globals.RUNNING = 0;
        switch_mutex_unlock(globals.mutex);

        switch_delete_profile_timer(&runtime.profile_timer);

        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Soft timer thread exiting.\n");

        return SWITCH_STATUS_TERM;
}

/* 
   This converts a struct tm to a switch_time_exp_t
   We have to use UNIX structures to do our exams
   and use switch_* functions for the output.
*/

static void tm2switchtime(struct tm *tm, switch_time_exp_t *xt)
{

        if (!xt || !tm) {
                return;
        }
        memset(xt, 0, sizeof(*xt));

        xt->tm_sec = tm->tm_sec;
        xt->tm_min = tm->tm_min;
        xt->tm_hour = tm->tm_hour;
        xt->tm_mday = tm->tm_mday;
        xt->tm_mon = tm->tm_mon;
        xt->tm_year = tm->tm_year;
        xt->tm_wday = tm->tm_wday;
        xt->tm_yday = tm->tm_yday;
        xt->tm_isdst = tm->tm_isdst;

#if defined(HAVE_STRUCT_TM_TM_GMTOFF)
        xt->tm_gmtoff = tm->tm_gmtoff;
#endif

        return;
}

/* **************************************************************************
   LOADING OF THE XML DATA - HASH TABLE & MEMORY POOL MANAGEMENT
   ************************************************************************** */

typedef struct {
        switch_memory_pool_t *pool;
        switch_hash_t *hash;
} switch_timezones_list_t;

static switch_timezones_list_t TIMEZONES_LIST = { 0 };
static switch_event_node_t *NODE = NULL;

SWITCH_DECLARE(const char *) switch_lookup_timezone(const char *tz_name)
{
        char *value = NULL;

        if (zstr(tz_name) || !TIMEZONES_LIST.hash) {
                return NULL;
        }
        
        if ((value = switch_core_hash_find(TIMEZONES_LIST.hash, tz_name)) == NULL) {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Timezone '%s' not found!\n", tz_name);
        }

        return value;
}

void switch_load_timezones(switch_bool_t reload)
{
        switch_xml_t xml = NULL, x_lists = NULL, x_list = NULL, cfg = NULL;
        unsigned total = 0;

        if (TIMEZONES_LIST.hash) {
                switch_core_hash_destroy(&TIMEZONES_LIST.hash);
        }

        if (TIMEZONES_LIST.pool) {
                switch_core_destroy_memory_pool(&TIMEZONES_LIST.pool);
        }

        memset(&TIMEZONES_LIST, 0, sizeof(TIMEZONES_LIST));
        switch_core_new_memory_pool(&TIMEZONES_LIST.pool);
        switch_core_hash_init(&TIMEZONES_LIST.hash);

        if ((xml = switch_xml_open_cfg("timezones.conf", &cfg, NULL))) {
                if ((x_lists = switch_xml_child(cfg, "timezones"))) {
                        for (x_list = switch_xml_child(x_lists, "zone"); x_list; x_list = x_list->next) {
                                const char *name = switch_xml_attr(x_list, "name");
                                const char *value = switch_xml_attr(x_list, "value");

                                if (zstr(name)) {
                                        continue;
                                }

                                if (zstr(value)) {
                                        continue;
                                }

                                switch_core_hash_insert(TIMEZONES_LIST.hash, name, switch_core_strdup(TIMEZONES_LIST.pool, value));
                                total++;
                        }
                }

                switch_xml_free(xml);
        }

        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Timezone %sloaded %d definitions\n", reload ? "re" : "", total);
}

static void event_handler(switch_event_t *event)
{
        switch_mutex_lock(globals.mutex);
        switch_load_timezones(1);
        switch_mutex_unlock(globals.mutex);
}

static void tztime(const time_t *const timep, const char *tzstring, struct tm *const tmp);

SWITCH_DECLARE(switch_status_t) switch_time_exp_tz_name(const char *tz, switch_time_exp_t *tm, switch_time_t thetime)
{
        struct tm xtm = { 0 };
        const char *tz_name = tz;
        const char *tzdef;
        time_t timep;

        if (!thetime) {
                thetime = switch_micro_time_now();
        }

        timep = (thetime) / (int64_t) (1000000);

        if (!zstr(tz_name)) {
                tzdef = switch_lookup_timezone(tz_name);
        } else {
                /* We set the default timezone to GMT. */
                tz_name = "GMT";
                tzdef = "GMT";
        }

        if (tzdef) {                            /* The lookup of the zone may fail. */
                tztime(&timep, tzdef, &xtm);
                tm2switchtime(&xtm, tm);
                return SWITCH_STATUS_SUCCESS;
        }

        return SWITCH_STATUS_FALSE;

}

SWITCH_DECLARE(switch_status_t) switch_strftime_tz(const char *tz, const char *format, char *date, size_t len, switch_time_t thetime)
{
        time_t timep;

        const char *tz_name = tz;
        const char *tzdef;

        switch_size_t retsize;

        struct tm tm = { 0 };
        switch_time_exp_t stm;

        if (!thetime) {
                thetime = switch_micro_time_now();
        }

        timep = (thetime) / (int64_t) (1000000);

        if (!zstr(tz_name)) {
                tzdef = switch_lookup_timezone(tz_name);
        } else {
                /* We set the default timezone to GMT. */
                tz_name = "GMT";
                tzdef = "GMT";
        }

        if (tzdef) {                            /* The lookup of the zone may fail. */
                tztime(&timep, tzdef, &tm);
                tm2switchtime(&tm, &stm);
                switch_strftime_nocheck(date, &retsize, len, zstr(format) ? "%Y-%m-%d %T" : format, &stm);
                if (!zstr_buf(date)) {
                        return SWITCH_STATUS_SUCCESS;
                }
        }
        return SWITCH_STATUS_FALSE;
}

SWITCH_MODULE_LOAD_FUNCTION(softtimer_load)
{
        switch_timer_interface_t *timer_interface;
        module_pool = pool;

#ifdef WIN32
        timeBeginPeriod(1);

        InitializeCriticalSection(&timer_section);

        win32_init_timers(); /* Init timers for Windows, if we should use timeGetTime() or QueryPerformanceCounters() */
#endif

        memset(&globals, 0, sizeof(globals));
        switch_mutex_init(&globals.mutex, SWITCH_MUTEX_NESTED, module_pool);

        if ((switch_event_bind_removable(modname, SWITCH_EVENT_RELOADXML, NULL, event_handler, NULL, &NODE) != SWITCH_STATUS_SUCCESS)) {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't bind!\n");
        }
        switch_load_timezones(0);

        /* connect my internal structure to the blank pointer passed to me */
        *module_interface = switch_loadable_module_create_module_interface(pool, modname);
        timer_interface = switch_loadable_module_create_interface(*module_interface, SWITCH_TIMER_INTERFACE);
        timer_interface->interface_name = "soft";
        timer_interface->timer_init = timer_init;
        timer_interface->timer_next = timer_next;
        timer_interface->timer_step = timer_step;
        timer_interface->timer_sync = timer_sync;
        timer_interface->timer_check = timer_check;
        timer_interface->timer_destroy = timer_destroy;

        if (!switch_test_flag((&runtime), SCF_USE_CLOCK_RT)) {
                switch_time_set_nanosleep(SWITCH_FALSE);
        }

        if (switch_test_flag((&runtime), SCF_USE_HEAVY_TIMING)) {
                switch_time_set_cond_yield(SWITCH_FALSE);
        }

        if (TFD) {
                switch_clear_flag((&runtime), SCF_CALIBRATE_CLOCK);
        }

#ifdef WIN32
        if (switch_test_flag((&runtime), SCF_USE_WIN32_MONOTONIC)) {
                MONO = 1;

                if (win32_use_qpc) {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Enabled Windows monotonic clock, using QueryPerformanceCounter()\n");
                } else {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Enabled Windows monotonic clock, using timeGetTime()\n");
                }

                runtime.initiated = switch_mono_micro_time_now(); /* Update mono_initiated, since now is the first time the real clock is enabled */
        }

        /* No need to calibrate clock in Win32, we will only sleep ms anyway, it's just not accurate enough */
        switch_clear_flag((&runtime), SCF_CALIBRATE_CLOCK);
#endif

        if (switch_test_flag((&runtime), SCF_CALIBRATE_CLOCK)) {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Calibrating timer, please wait...\n");
                switch_time_calibrate_clock();
        } else {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CONSOLE, "Clock calibration disabled.\n");
        }

        /* indicate that the module should continue to be loaded */
        return SWITCH_STATUS_SUCCESS;
}

SWITCH_MODULE_SHUTDOWN_FUNCTION(softtimer_shutdown)
{
        globals.use_cond_yield = 0;

        if (globals.RUNNING == 1) {
                switch_mutex_lock(globals.mutex);
                globals.RUNNING = -1;
                switch_mutex_unlock(globals.mutex);

                while (globals.RUNNING == -1) {
                        do_sleep(10000);
                }
        }
#if defined(WIN32)
        timeEndPeriod(1);
        win32_tick_time_since_start = -1; /* we are not initialized anymore */
        DeleteCriticalSection(&timer_section);
#endif

        if (TIMEZONES_LIST.hash) {
                switch_core_hash_destroy(&TIMEZONES_LIST.hash);
        }

        if (TIMEZONES_LIST.pool) {
                switch_core_destroy_memory_pool(&TIMEZONES_LIST.pool);
        }

        if (NODE) {
                switch_event_unbind(&NODE);
        }

        return SWITCH_STATUS_SUCCESS;
}




/*
 *    This file was originally written for NetBSD and is in the public domain, 
 *    so clarified as of 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
 *    
 *    Iw was modified by Massimo Cetra in order to be used with Callweaver and Freeswitch.
 */

//#define TESTING_IT 1

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <assert.h>


#ifdef TESTING_IT
#include <sys/time.h>
#endif


#ifndef TRUE
#define TRUE    1
#endif /* !defined TRUE */

#ifndef FALSE
#define FALSE   0
#endif /* !defined FALSE */



#ifndef TZ_MAX_TIMES
/*
** The TZ_MAX_TIMES value below is enough to handle a bit more than a
** year's worth of solar time (corrected daily to the nearest second) or
** 138 years of Pacific Presidential Election time
** (where there are three time zone transitions every fourth year).
*/
#define TZ_MAX_TIMES    370
#endif /* !defined TZ_MAX_TIMES */

#ifndef TZ_MAX_TYPES

#ifndef NOSOLAR
#define TZ_MAX_TYPES    256             /* Limited by what (unsigned char)'s can hold */
#endif /* !defined NOSOLAR */

#ifdef NOSOLAR
/*
** Must be at least 14 for Europe/Riga as of Jan 12 1995,
** as noted by Earl Chew <earl@hpato.aus.hp.com>.
*/
#define TZ_MAX_TYPES    20              /* Maximum number of local time types */
#endif /* !defined NOSOLAR */

#endif /* !defined TZ_MAX_TYPES */

#ifndef TZ_MAX_CHARS
#define TZ_MAX_CHARS    50              /* Maximum number of abbreviation characters */
                                /* (limited by what unsigned chars can hold) */
#endif /* !defined TZ_MAX_CHARS */

#ifndef TZ_MAX_LEAPS
#define TZ_MAX_LEAPS    50              /* Maximum number of leap second corrections */
#endif /* !defined TZ_MAX_LEAPS */

#ifdef TZNAME_MAX
#define MY_TZNAME_MAX   TZNAME_MAX
#endif /* defined TZNAME_MAX */

#ifndef TZNAME_MAX
#define MY_TZNAME_MAX   255
#endif /* !defined TZNAME_MAX */


#define SECSPERMIN      60
#define MINSPERHOUR     60
#define HOURSPERDAY     24
#define DAYSPERWEEK     7
#define DAYSPERNYEAR    365
#define DAYSPERLYEAR    366
#define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY      ((long) SECSPERHOUR * HOURSPERDAY)
#define MONSPERYEAR     12

#define JULIAN_DAY              0               /* Jn - Julian day */
#define DAY_OF_YEAR             1               /* n - day of year */
#define MONTH_NTH_DAY_OF_WEEK   2       /* Mm.n.d - month, week, day of week */

#define EPOCH_YEAR      1970
#define EPOCH_WDAY      TM_THURSDAY


#ifndef TZ_MAX_TIMES
/*
** The TZ_MAX_TIMES value below is enough to handle a bit more than a
** year's worth of solar time (corrected daily to the nearest second) or
** 138 years of Pacific Presidential Election time
** (where there are three time zone transitions every fourth year).
*/
#define TZ_MAX_TIMES    370
#endif /* !defined TZ_MAX_TIMES */

#ifndef TZDEFRULES
#define TZDEFRULES      "posixrules"
#endif /* !defined TZDEFRULES */

/*
** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
** We default to US rules as of 1999-08-17.
** POSIX 1003.1 section 8.1.1 says that the default DST rules are
** implementation dependent; for historical reasons, US rules are a
** common default.
*/
#ifndef TZDEFRULESTRING
#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
#endif /* !defined TZDEFDST */

/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX.  */
#define is_digit(c) ((unsigned)(c) - '0' <= 9)

#define BIGGEST(a, b)   (((a) > (b)) ? (a) : (b))

#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))



/*
** INITIALIZE(x)
*/

#ifndef GNUC_or_lint
#ifdef lint
#define GNUC_or_lint
#endif /* defined lint */
#ifndef lint
#ifdef __GNUC__
#define GNUC_or_lint
#endif /* defined __GNUC__ */
#endif /* !defined lint */
#endif /* !defined GNUC_or_lint */
#ifdef WIN32
#define GNUC_or_lint
#endif

#ifndef INITIALIZE
#ifdef GNUC_or_lint
#define INITIALIZE(x)   ((x) = 0)
#endif /* defined GNUC_or_lint */
#ifndef GNUC_or_lint
#define INITIALIZE(x)
#endif /* !defined GNUC_or_lint */
#endif /* !defined INITIALIZE */


#define TM_SUNDAY       0
#define TM_MONDAY       1
#define TM_TUESDAY      2
#define TM_WEDNESDAY    3
#define TM_THURSDAY     4
#define TM_FRIDAY       5
#define TM_SATURDAY     6

#define TM_JANUARY      0
#define TM_FEBRUARY     1
#define TM_MARCH        2
#define TM_APRIL        3
#define TM_MAY          4
#define TM_JUNE         5
#define TM_JULY         6
#define TM_AUGUST       7
#define TM_SEPTEMBER    8
#define TM_OCTOBER      9
#define TM_NOVEMBER     10
#define TM_DECEMBER     11

#define TM_YEAR_BASE    1900

#define EPOCH_YEAR      1970
#define EPOCH_WDAY      TM_THURSDAY


/* **************************************************************************
            
   ************************************************************************** */

static const char gmt[] = "GMT";

#define CHARS_DEF BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt), (2 * (MY_TZNAME_MAX + 1)))

struct rule {
        int r_type;                                     /* type of rule--see below */
        int r_day;                                      /* day number of rule */
        int r_week;                                     /* week number of rule */
        int r_mon;                                      /* month number of rule */
        long r_time;                            /* transition time of rule */
};

struct ttinfo {                                 /* time type information */
        long tt_gmtoff;                         /* UTC offset in seconds */
        int tt_isdst;                           /* used to set tm_isdst */
        int tt_abbrind;                         /* abbreviation list index */
        int tt_ttisstd;                         /* TRUE if transition is std time */
        int tt_ttisgmt;                         /* TRUE if transition is UTC */
};

struct lsinfo {                                 /* leap second information */
        time_t ls_trans;                        /* transition time */
        long ls_corr;                           /* correction to apply */
};


struct state {
        int leapcnt;
        int timecnt;
        int typecnt;
        int charcnt;
        time_t ats[TZ_MAX_TIMES];
        unsigned char types[TZ_MAX_TIMES];
        struct ttinfo ttis[TZ_MAX_TYPES];
        char chars[ /* LINTED constant */ CHARS_DEF];
        struct lsinfo lsis[TZ_MAX_LEAPS];
};


static const int mon_lengths[2][MONSPERYEAR] = {
        {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
        {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
};

static const int year_lengths[2] = {
        DAYSPERNYEAR, DAYSPERLYEAR
};


/* **************************************************************************
            
   ************************************************************************** */


/*
    Given a pointer into a time zone string, scan until a character that is not
    a valid character in a zone name is found.  Return a pointer to that
    character.
*/

static const char *getzname(register const char *strp)
{
        register char c;

        while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && c != '+')
                ++strp;
        return strp;
}


/*
    Given a pointer into a time zone string, extract a number from that string.
    Check that the number is within a specified range; if it is not, return
    NULL.
    Otherwise, return a pointer to the first character not part of the number.
*/

static const char *getnum(register const char *strp, int *const nump, const int min, const int max)
{
        register char c;
        register int num;

        if (strp == NULL || !is_digit(c = *strp))
                return NULL;
        num = 0;
        do {
                num = num * 10 + (c - '0');
                if (num > max)
                        return NULL;            /* illegal value */
                c = *++strp;
        } while (is_digit(c));
        if (num < min)
                return NULL;                    /* illegal value */
        *nump = num;
        return strp;
}

/*
    Given a pointer into a time zone string, extract a number of seconds,
    in hh[:mm[:ss]] form, from the string.
    If any error occurs, return NULL.
    Otherwise, return a pointer to the first character not part of the number
    of seconds.
*/

static const char *getsecs(register const char *strp, long *const secsp)
{
        int num;

        /*
         ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
         ** "M10.4.6/26", which does not conform to Posix,
         ** but which specifies the equivalent of
         ** ``02:00 on the first Sunday on or after 23 Oct''.
         */
        strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
        if (strp == NULL)
                return NULL;
        *secsp = num * (long) SECSPERHOUR;
        if (*strp == ':') {
                ++strp;
                strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
                if (strp == NULL)
                        return NULL;
                *secsp += num * SECSPERMIN;
                if (*strp == ':') {
                        ++strp;
                        /* `SECSPERMIN' allows for leap seconds.  */
                        strp = getnum(strp, &num, 0, SECSPERMIN);
                        if (strp == NULL)
                                return NULL;
                        *secsp += num;
                }
        }
        return strp;
}

/*
    Given a pointer into a time zone string, extract an offset, in
    [+-]hh[:mm[:ss]] form, from the string.
    If any error occurs, return NULL.
    Otherwise, return a pointer to the first character not part of the time.
*/

static const char *getoffset(register const char *strp, long *const offsetp)
{
        register int neg = 0;

        if (*strp == '-') {
                neg = 1;
                ++strp;
        } else if (*strp == '+')
                ++strp;
        strp = getsecs(strp, offsetp);
        if (strp == NULL)
                return NULL;                    /* illegal time */
        if (neg)
                *offsetp = -*offsetp;
        return strp;
}

/*
    Given a pointer into a time zone string, extract a rule in the form
    date[/time].  See POSIX section 8 for the format of "date" and "time".
    If a valid rule is not found, return NULL.
    Otherwise, return a pointer to the first character not part of the rule.
*/

static const char *getrule(const char *strp, register struct rule *const rulep)
{
        if (*strp == 'J') {
                /*
                 ** Julian day.
                 */
                rulep->r_type = JULIAN_DAY;
                ++strp;
                strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
        } else if (*strp == 'M') {
                /*
                 ** Month, week, day.
                 */
                rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
                ++strp;
                strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
                if (strp == NULL)
                        return NULL;
                if (*strp++ != '.')
                        return NULL;
                strp = getnum(strp, &rulep->r_week, 1, 5);
                if (strp == NULL)
                        return NULL;
                if (*strp++ != '.')
                        return NULL;
                strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
        } else if (is_digit(*strp)) {
                /*
                 ** Day of year.
                 */
                rulep->r_type = DAY_OF_YEAR;
                strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
        } else
                return NULL;                    /* invalid format */
        if (strp == NULL)
                return NULL;
        if (*strp == '/') {
                /*
                 ** Time specified.
                 */
                ++strp;
                strp = getsecs(strp, &rulep->r_time);
        } else
                rulep->r_time = 2 * SECSPERHOUR;        /* default = 2:00:00 */
        return strp;
}


/*
    Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
    year, a rule, and the offset from UTC at the time that rule takes effect,
    calculate the Epoch-relative time that rule takes effect.
*/

static time_t transtime(const time_t janfirst, const int year, register const struct rule *const rulep, const long offset)
{
        register int leapyear;
        register time_t value;
        register int i;
        int d, m1, yy0, yy1, yy2, dow;

        INITIALIZE(value);
        leapyear = isleap(year);
        switch (rulep->r_type) {

        case JULIAN_DAY:
                /*
                 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
                 ** years.
                 ** In non-leap years, or if the day number is 59 or less, just
                 ** add SECSPERDAY times the day number-1 to the time of
                 ** January 1, midnight, to get the day.
                 */
                value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
                if (leapyear && rulep->r_day >= 60)
                        value += SECSPERDAY;
                break;

        case DAY_OF_YEAR:
                /*
                 ** n - day of year.
                 ** Just add SECSPERDAY times the day number to the time of
                 ** January 1, midnight, to get the day.
                 */
                value = janfirst + rulep->r_day * SECSPERDAY;
                break;

        case MONTH_NTH_DAY_OF_WEEK:
                /*
                 ** Mm.n.d - nth "dth day" of month m.
                 */
                value = janfirst;
                for (i = 0; i < rulep->r_mon - 1; ++i)
                        value += mon_lengths[leapyear][i] * SECSPERDAY;

                /*
                 ** Use Zeller's Congruence to get day-of-week of first day of
                 ** month.
                 */
                m1 = (rulep->r_mon + 9) % 12 + 1;
                yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
                yy1 = yy0 / 100;
                yy2 = yy0 % 100;
                dow = ((26 * m1 - 2) / 10 + 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
                if (dow < 0)
                        dow += DAYSPERWEEK;

                /*
                 ** "dow" is the day-of-week of the first day of the month.  Get
                 ** the day-of-month (zero-origin) of the first "dow" day of the
                 ** month.
                 */
                d = rulep->r_day - dow;
                if (d < 0)
                        d += DAYSPERWEEK;
                for (i = 1; i < rulep->r_week; ++i) {
                        if (d + DAYSPERWEEK >= mon_lengths[leapyear][rulep->r_mon - 1])
                                break;
                        d += DAYSPERWEEK;
                }

                /*
                 ** "d" is the day-of-month (zero-origin) of the day we want.
                 */
                value += d * SECSPERDAY;
                break;
        }

        /*
         ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
         ** question.  To get the Epoch-relative time of the specified local
         ** time on that day, add the transition time and the current offset
         ** from UTC.
         */
        return value + rulep->r_time + offset;
}



/*
    Given a POSIX section 8-style TZ string, fill in the rule tables as
    appropriate.
*/

static int tzparse(const char *name, register struct state *const sp, const int lastditch)
{
        const char *stdname;
        const char *dstname;
        size_t stdlen;
        size_t dstlen;
        long stdoffset;
        long dstoffset;
        register time_t *atp;
        register unsigned char *typep;
        register char *cp;


        INITIALIZE(dstname);
        stdname = name;

        if (lastditch) {
                stdlen = strlen(name);  /* length of standard zone name */
                name += stdlen;
                if (stdlen >= sizeof sp->chars)
                        stdlen = (sizeof sp->chars) - 1;
                stdoffset = 0;
        } else {
                name = getzname(name);
                stdlen = name - stdname;
                if (stdlen < 3)
                        return -1;
                if (*name == '\0')
                        return -1;
                name = getoffset(name, &stdoffset);
                if (name == NULL)
                        return -1;
        }

        sp->leapcnt = 0;                        /* so, we're off a little */

        if (*name != '\0') {
                dstname = name;
                name = getzname(name);
                dstlen = name - dstname;        /* length of DST zone name */
                if (dstlen < 3)
                        return -1;
                if (*name != '\0' && *name != ',' && *name != ';') {
                        name = getoffset(name, &dstoffset);
                        if (name == NULL)
                                return -1;
                } else
                        dstoffset = stdoffset - SECSPERHOUR;

                /* Go parsing the daylight saving stuff */
                if (*name == ',' || *name == ';') {
                        struct rule start;
                        struct rule end;
                        register int year;
                        register time_t janfirst;
                        time_t starttime;
                        time_t endtime;

                        ++name;
                        if ((name = getrule(name, &start)) == NULL)
                                return -1;
                        if (*name++ != ',')
                                return -1;
                        if ((name = getrule(name, &end)) == NULL)
                                return -1;
                        if (*name != '\0')
                                return -1;

                        sp->typecnt = 2;        /* standard time and DST */

                        /*
                         ** Two transitions per year, from EPOCH_YEAR to 2037.
                         */
                        sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);

                        if (sp->timecnt > TZ_MAX_TIMES)
                                return -1;

                        sp->ttis[0].tt_gmtoff = -dstoffset;
                        sp->ttis[0].tt_isdst = 1;
                        sp->ttis[0].tt_abbrind = (int) (stdlen + 1);
                        sp->ttis[1].tt_gmtoff = -stdoffset;
                        sp->ttis[1].tt_isdst = 0;
                        sp->ttis[1].tt_abbrind = 0;

                        atp = sp->ats;
                        typep = sp->types;
                        janfirst = 0;

                        for (year = EPOCH_YEAR; year <= 2037; ++year) {
                                starttime = transtime(janfirst, year, &start, stdoffset);
                                endtime = transtime(janfirst, year, &end, dstoffset);
                                if (starttime > endtime) {
                                        *atp++ = endtime;
                                        *typep++ = 1;   /* DST ends */
                                        *atp++ = starttime;
                                        *typep++ = 0;   /* DST begins */
                                } else {
                                        *atp++ = starttime;
                                        *typep++ = 0;   /* DST begins */
                                        *atp++ = endtime;
                                        *typep++ = 1;   /* DST ends */
                                }

                                janfirst += year_lengths[isleap(year)] * SECSPERDAY;
                        }

                } else {
                        register long theirstdoffset;
                        register long theirdstoffset;
                        register long theiroffset;
                        register int isdst;
                        register int i;
                        register int j;

                        if (*name != '\0')
                                return -1;
                        /*
                           Initial values of theirstdoffset and theirdstoffset.
                         */
                        theirstdoffset = 0;
                        for (i = 0; i < sp->timecnt; ++i) {
                                j = sp->types[i];
                                if (!sp->ttis[j].tt_isdst) {
                                        theirstdoffset = -sp->ttis[j].tt_gmtoff;
                                        break;
                                }
                        }
                        theirdstoffset = 0;
                        for (i = 0; i < sp->timecnt; ++i) {
                                j = sp->types[i];
                                if (sp->ttis[j].tt_isdst) {
                                        theirdstoffset = -sp->ttis[j].tt_gmtoff;
                                        break;
                                }
                        }
                        /*
                         ** Initially we're assumed to be in standard time.
                         */
                        isdst = FALSE;
                        theiroffset = theirstdoffset;
                        /*
                         ** Now juggle transition times and types
                         ** tracking offsets as you do.
                         */
                        for (i = 0; i < sp->timecnt; ++i) {
                                j = sp->types[i];
                                sp->types[i] = (unsigned char) sp->ttis[j].tt_isdst;
                                if (sp->ttis[j].tt_ttisgmt) {
                                        /* No adjustment to transition time */
                                } else {
                                        /*
                                         ** If summer time is in effect, and the
                                         ** transition time was not specified as
                                         ** standard time, add the summer time
                                         ** offset to the transition time;
                                         ** otherwise, add the standard time
                                         ** offset to the transition time.
                                         */
                                        /*
                                         ** Transitions from DST to DDST
                                         ** will effectively disappear since
                                         ** POSIX provides for only one DST
                                         ** offset.
                                         */
                                        if (isdst && !sp->ttis[j].tt_ttisstd) {
                                                sp->ats[i] += dstoffset - theirdstoffset;
                                        } else {
                                                sp->ats[i] += stdoffset - theirstdoffset;
                                        }
                                }
                                theiroffset = -sp->ttis[j].tt_gmtoff;
                                if (sp->ttis[j].tt_isdst)
                                        theirdstoffset = theiroffset;
                                else
                                        theirstdoffset = theiroffset;
                        }
                        /*
                         ** Finally, fill in ttis.
                         ** ttisstd and ttisgmt need not be handled.
                         */
                        sp->ttis[0].tt_gmtoff = -stdoffset;
                        sp->ttis[0].tt_isdst = FALSE;
                        sp->ttis[0].tt_abbrind = 0;
                        sp->ttis[1].tt_gmtoff = -dstoffset;
                        sp->ttis[1].tt_isdst = TRUE;
                        sp->ttis[1].tt_abbrind = (int) (stdlen + 1);
                        sp->typecnt = 2;
                }
        } else {
                dstlen = 0;
                sp->typecnt = 1;                /* only standard time */
                sp->timecnt = 0;
                sp->ttis[0].tt_gmtoff = -stdoffset;
                sp->ttis[0].tt_isdst = 0;
                sp->ttis[0].tt_abbrind = 0;
        }

        sp->charcnt = (int) (stdlen + 1);
        if (dstlen != 0)
                sp->charcnt += (int) (dstlen + 1);
        if ((size_t) sp->charcnt > sizeof sp->chars)
                return -1;
        cp = sp->chars;
        (void) strncpy(cp, stdname, stdlen);
        cp += stdlen;
        *cp++ = '\0';
        if (dstlen != 0) {
                (void) strncpy(cp, dstname, dstlen);
                *(cp + dstlen) = '\0';
        }
        return 0;
}

/* **************************************************************************
            
   ************************************************************************** */
#if (_MSC_VER >= 1400)                  // VC8+
#define switch_assert(expr) assert(expr);__analysis_assume( expr )
#else
#define switch_assert(expr) assert(expr)
#endif

static void timesub(const time_t *const timep, const long offset, register const struct state *const sp, register struct tm *const tmp)
{
        register const struct lsinfo *lp;
        register long days;
        register time_t rem;
        register int y;
        register int yleap;
        register const int *ip;
        register long corr;
        register int hit;
        register int i;

        switch_assert(timep != NULL);
        switch_assert(sp != NULL);
        switch_assert(tmp != NULL);

        corr = 0;
        hit = 0;
        i = (sp == NULL) ? 0 : sp->leapcnt;

        while (--i >= 0) {
                lp = &sp->lsis[i];
                if (*timep >= lp->ls_trans) {
                        if (*timep == lp->ls_trans) {
                                hit = ((i == 0 && lp->ls_corr > 0) || (i > 0 && lp->ls_corr > sp->lsis[i - 1].ls_corr));
                                if (hit)
                                        while (i > 0 && sp->lsis[i].ls_trans == sp->lsis[i - 1].ls_trans + 1 && sp->lsis[i].ls_corr == sp->lsis[i - 1].ls_corr + 1) {
                                                ++hit;
                                                --i;
                                        }
                        }
                        corr = lp->ls_corr;
                        break;
                }
        }
        days = (long) (*timep / SECSPERDAY);
        rem = *timep % SECSPERDAY;


#ifdef mc68k
        /* If this is for CPU bugs workarounds, i would remove this anyway. Who would use it on an old mc68k ? */
        if (*timep == 0x80000000) {
                /*
                 ** A 3B1 muffs the division on the most negative number.
                 */
                days = -24855;
                rem = -11648;
        }
#endif

        rem += (offset - corr);
        while (rem < 0) {
                rem += SECSPERDAY;
                --days;
        }
        while (rem >= SECSPERDAY) {
                rem -= SECSPERDAY;
                ++days;
        }
        tmp->tm_hour = (int) (rem / SECSPERHOUR);
        rem = rem % SECSPERHOUR;
        tmp->tm_min = (int) (rem / SECSPERMIN);

        /*
         ** A positive leap second requires a special
         ** representation.  This uses "... ??:59:60" et seq.
         */
        tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
        tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);

        if (tmp->tm_wday < 0)
                tmp->tm_wday += DAYSPERWEEK;

        y = EPOCH_YEAR;

#define LEAPS_THRU_END_OF(y)    ((y) / 4 - (y) / 100 + (y) / 400)

        while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
                register int newy;

                newy = (int) (y + days / DAYSPERNYEAR);
                if (days < 0)
                        --newy;
                days -= (newy - y) * DAYSPERNYEAR + LEAPS_THRU_END_OF(newy - 1) - LEAPS_THRU_END_OF(y - 1);
                y = newy;
        }

        tmp->tm_year = y - TM_YEAR_BASE;
        tmp->tm_yday = (int) days;

        ip = mon_lengths[yleap];

        for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
                days = days - (long) ip[tmp->tm_mon];

        tmp->tm_mday = (int) (days + 1);
        tmp->tm_isdst = 0;
#if defined(HAVE_STRUCT_TM_TM_GMTOFF)
        tmp->tm_gmtoff = offset;
#endif
}

/* **************************************************************************
            
   ************************************************************************** */

static void tztime(const time_t *const timep, const char *tzstring, struct tm *const tmp)
{
        struct state *tzptr, *sp;
        const time_t t = *timep;
        register int i;
        register const struct ttinfo *ttisp;

        if (tzstring == NULL)
                tzstring = gmt;

        tzptr = (struct state *) malloc(sizeof(struct state));
        sp = tzptr;

        if (tzptr != NULL) {

                memset(tzptr, 0, sizeof(struct state));

                (void) tzparse(tzstring, tzptr, FALSE);

                if (sp->timecnt == 0 || t < sp->ats[0]) {
                        i = 0;
                        while (sp->ttis[i].tt_isdst)
                                if (++i >= sp->typecnt) {
                                        i = 0;
                                        break;
                                }
                } else {
                        for (i = 1; i < sp->timecnt; ++i)
                                if (t < sp->ats[i])
                                        break;
                        i = sp->types[i - 1];   // DST begin or DST end
                }
                ttisp = &sp->ttis[i];

                /*
                   To get (wrong) behavior that's compatible with System V Release 2.0
                   you'd replace the statement below with
                   t += ttisp->tt_gmtoff;
                   timesub(&t, 0L, sp, tmp);
                 */
                if (tmp != NULL) {              /* Just a check not to assert */
                        timesub(&t, ttisp->tt_gmtoff, sp, tmp);
                        tmp->tm_isdst = ttisp->tt_isdst;
#if defined(HAVE_STRUCT_TM_TM_ZONE)
                        tmp->tm_zone = &sp->chars[ttisp->tt_abbrind];
#endif
                }

                free(tzptr);
        }

}

/* For Emacs:
 * Local Variables:
 * mode:c
 * indent-tabs-mode:t
 * tab-width:4
 * c-basic-offset:4
 * End:
 * For VIM:
 * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
 */