diff --git a/libc/bionic/pthread-timers.c b/libc/bionic/pthread-timers.c
new file mode 100644
index 0000000..a53d04b
--- /dev/null
+++ b/libc/bionic/pthread-timers.c
@@ -0,0 +1,625 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the 
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#include "pthread_internal.h"
+#include <linux/time.h>
+#include <string.h>
+#include <errno.h>
+
+/* This file implements the support required to implement SIGEV_THREAD posix 
+ * timers. See the following pages for additionnal details:
+ *
+ * www.opengroup.org/onlinepubs/000095399/functions/timer_create.html
+ * www.opengroup.org/onlinepubs/000095399/functions/timer_settime.html
+ * www.opengroup.org/onlinepubs/000095399/functions/xsh_chap02_04.html#tag_02_04_01
+ *
+ * The Linux kernel doesn't support these, so we need to implement them in the
+ * C library. We use a very basic scheme where each timer is associated to a
+ * thread that will loop, waiting for timeouts or messages from the program
+ * corresponding to calls to timer_settime() and timer_delete().
+ *
+ * Note also an important thing: Posix mandates that in the case of fork(),
+ * the timers of the child process should be disarmed, but not deleted.
+ * this is implemented by providing a fork() wrapper (see bionic/fork.c) which
+ * stops all timers before the fork, and only re-start them in case of error
+ * or in the parent process.
+ *
+ * the stop/start is implemented by the __timer_table_start_stop() function
+ * below.
+ */
+
+/* normal (i.e. non-SIGEV_THREAD) timer ids are created directly by the kernel
+ * and are passed as is to/from the caller.
+ *
+ * on the other hand, a SIGEV_THREAD timer ID will have its TIMER_ID_WRAP_BIT
+ * always set to 1. In this implementation, this is always bit 31, which is
+ * guaranteed to never be used by kernel-provided timer ids
+ *
+ * (see code in <kernel>/lib/idr.c, used to manage IDs, to see why)
+ */
+
+#define  TIMER_ID_WRAP_BIT        0x80000000
+#define  TIMER_ID_WRAP(id)        ((timer_t)((id) |  TIMER_ID_WRAP_BIT))
+#define  TIMER_ID_UNWRAP(id)      ((timer_t)((id) & ~TIMER_ID_WRAP_BIT))
+#define  TIMER_ID_IS_WRAPPED(id)  (((id) & TIMER_ID_WRAP_BIT) != 0)
+
+/* this value is used internally to indicate a 'free' or 'zombie' 
+ * thr_timer structure. Here, 'zombie' means that timer_delete()
+ * has been called, but that the corresponding thread hasn't
+ * exited yet.
+ */
+#define  TIMER_ID_NONE            ((timer_t)0xffffffff)
+
+/* True iff a timer id is valid */
+#define  TIMER_ID_IS_VALID(id)    ((id) != TIMER_ID_NONE)
+
+/* the maximum value of overrun counters */
+#define  DELAYTIMER_MAX    0x7fffffff
+
+#define  __likely(x)   __builtin_expect(!!(x),1)
+#define  __unlikely(x) __builtin_expect(!!(x),0)
+
+typedef struct thr_timer          thr_timer_t;
+typedef struct thr_timer_table    thr_timer_table_t;
+
+/* The Posix spec says the function receives an unsigned parameter, but
+ * it's really a 'union sigval' a.k.a. sigval_t */
+typedef void (*thr_timer_func_t)( sigval_t );
+
+struct thr_timer {
+    thr_timer_t*       next;     /* next in free list */
+    timer_t            id;       /* TIMER_ID_NONE iff free or dying */
+    clockid_t          clock;
+    pthread_t          thread;
+    pthread_attr_t     attributes;
+    thr_timer_func_t   callback;
+    sigval_t           value;
+
+    /* the following are used to communicate between
+     * the timer thread and the timer_XXX() functions
+     */
+    pthread_mutex_t           mutex;     /* lock */
+    pthread_cond_t            cond;      /* signal a state change to thread */
+    int volatile              done;      /* set by timer_delete */
+    int volatile              stopped;   /* set by _start_stop() */
+    struct timespec volatile  expires;   /* next expiration time, or 0 */
+    struct timespec volatile  period;    /* reload value, or 0 */
+    int volatile              overruns;  /* current number of overruns */
+};
+
+#define  MAX_THREAD_TIMERS  32
+
+struct thr_timer_table {
+    pthread_mutex_t  lock;
+    thr_timer_t*     free_timer;
+    thr_timer_t      timers[ MAX_THREAD_TIMERS ];
+};
+
+/** GLOBAL TABLE OF THREAD TIMERS
+ **/
+
+static void
+thr_timer_table_init( thr_timer_table_t*  t )
+{
+    int  nn;
+
+    memset(t, 0, sizeof *t);
+    pthread_mutex_init( &t->lock, NULL );
+
+    for (nn = 0; nn < MAX_THREAD_TIMERS; nn++)
+        t->timers[nn].id = TIMER_ID_NONE;
+
+    t->free_timer = &t->timers[0];
+    for (nn = 1; nn < MAX_THREAD_TIMERS; nn++)
+        t->timers[nn-1].next = &t->timers[nn];
+}
+
+
+static thr_timer_t*
+thr_timer_table_alloc( thr_timer_table_t*  t )
+{
+    thr_timer_t*  timer;
+
+    pthread_mutex_lock(&t->lock);
+    timer = t->free_timer;
+    if (timer != NULL) {
+        t->free_timer = timer->next;
+        timer->next   = NULL;
+        timer->id     = TIMER_ID_WRAP((timer - t->timers));
+    }
+    pthread_mutex_unlock(&t->lock);
+    return timer;
+}
+
+
+static void
+thr_timer_table_free( thr_timer_table_t*  t, thr_timer_t*  timer )
+{
+    pthread_mutex_lock( &t->lock );
+    timer->id     = TIMER_ID_NONE;
+    timer->thread = 0;
+    timer->next   = t->free_timer;
+    t->free_timer = timer;
+    pthread_mutex_unlock( &t->lock );
+}
+
+
+static void
+thr_timer_table_start_stop( thr_timer_table_t*  t, int  stop )
+{
+    int  nn;
+
+    pthread_mutex_lock(&t->lock);
+
+    for (nn = 0; nn < MAX_THREAD_TIMERS; nn++) {
+        thr_timer_t*  timer  = &t->timers[nn];
+
+        if (TIMER_ID_IS_VALID(timer->id)) {
+            /* tell the thread to start/stop */
+            pthread_mutex_lock(&timer->mutex);
+            timer->stopped = stop;
+            pthread_cond_signal( &timer->cond );
+            pthread_mutex_unlock(&timer->mutex);
+        }
+    }
+    pthread_mutex_unlock(&t->lock);
+}
+
+
+/* convert a timer_id into the corresponding thr_timer_t* pointer
+ * returns NULL if the id is not wrapped or is invalid/free
+ */
+static thr_timer_t*
+thr_timer_table_from_id( thr_timer_table_t*  t,
+                         timer_t             id,
+                         int                 remove )
+{
+    unsigned      index;
+    thr_timer_t*  timer;
+
+    if (!TIMER_ID_IS_WRAPPED(id))
+        return NULL;
+
+    index = (unsigned) TIMER_ID_UNWRAP(id);
+    if (index >= MAX_THREAD_TIMERS)
+        return NULL;
+
+    pthread_mutex_lock(&t->lock);
+
+    timer = &t->timers[index];
+
+    if (!TIMER_ID_IS_VALID(timer->id)) {
+        timer = NULL;
+    } else {
+        /* if we're removing this timer, clear the id
+         * right now to prevent another thread to
+         * use the same id after the unlock */
+        if (remove)
+            timer->id = TIMER_ID_NONE;
+    }
+    pthread_mutex_unlock(&t->lock);
+
+    return timer;
+}
+
+/* the static timer table */
+
+static pthread_once_t      __timer_table_once = PTHREAD_ONCE_INIT;
+static thr_timer_table_t   __timer_table[1];
+
+static void
+__timer_table_init( void )
+{
+    thr_timer_table_init( __timer_table );
+}
+
+static thr_timer_table_t*
+__timer_table_get(void)
+{
+    pthread_once( &__timer_table_once, __timer_table_init );
+    return __timer_table;
+}
+
+/** POSIX THREAD TIMERS CLEANUP ON FORK
+ **
+ ** this should be called from the 'fork()' wrapper to stop/start
+ ** all active thread timers. this is used to implement a Posix
+ ** requirements: the timers of fork child processes must be
+ ** disarmed but not deleted.
+ **/
+void
+__timer_table_start_stop( int  stop )
+{
+    thr_timer_table_t*  table = __timer_table_get();
+    thr_timer_table_start_stop(table, stop);
+}
+
+static thr_timer_t*
+thr_timer_from_id( timer_t   id )
+{
+    thr_timer_table_t*  table = __timer_table_get();
+    thr_timer_t*        timer = thr_timer_table_from_id( table, id, 0 );
+
+    return timer;
+}
+
+
+static __inline__ void
+thr_timer_lock( thr_timer_t*  t )
+{
+    pthread_mutex_lock(&t->mutex);
+}
+
+static __inline__ void
+thr_timer_unlock( thr_timer_t*  t )
+{
+    pthread_mutex_unlock(&t->mutex);
+}
+
+/** POSIX TIMERS APIs */
+
+/* first, declare the syscall stubs */
+extern int __timer_create( clockid_t, struct sigevent*, timer_t* );
+extern int __timer_delete( timer_t );
+extern int __timer_gettime( timer_t, struct itimerspec* );
+extern int __timer_settime( timer_t, int, const struct itimerspec*, struct itimerspec* );
+extern int __timer_getoverrun(timer_t);
+
+static void*  timer_thread_start( void* );
+
+/* then the wrappers themselves */
+int
+timer_create( clockid_t  clockid, struct sigevent*  evp, timer_t  *ptimerid)
+{
+    /* if not a SIGEV_THREAD timer, direct creation by the kernel */
+    if (__likely(evp == NULL || evp->sigev_notify != SIGEV_THREAD))
+        return __timer_create( clockid, evp, ptimerid );
+
+    // check arguments
+    if (evp->sigev_notify_function == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    {
+        struct timespec  dummy;
+
+        /* check that the clock id is supported by the kernel */
+        if (clock_gettime( clockid, &dummy ) < 0 && errno == EINVAL )
+            return -1;
+    }
+
+    /* create a new timer and its thread */
+    {
+        thr_timer_table_t*  table = __timer_table_get();
+        thr_timer_t*        timer = thr_timer_table_alloc( table );
+        struct sigevent     evp0;
+
+        if (timer == NULL) {
+            errno = ENOMEM;
+            return -1;
+        }
+
+        /* copy the thread attributes */
+        if (evp->sigev_notify_attributes == NULL) {
+            pthread_attr_init(&timer->attributes);
+        }
+        else {
+            timer->attributes = ((pthread_attr_t*)evp->sigev_notify_attributes)[0];
+        }
+
+        /* Posix says that the default is PTHREAD_CREATE_DETACHED and
+         * that PTHREAD_CREATE_JOINABLE has undefined behaviour.
+         * So simply always use DETACHED :-)
+         */
+        pthread_attr_setdetachstate(&timer->attributes, PTHREAD_CREATE_DETACHED);
+
+        timer->callback = evp->sigev_notify_function;
+        timer->value    = evp->sigev_value;
+        timer->clock    = clockid;
+
+        pthread_mutex_init( &timer->mutex, NULL );
+        pthread_cond_init( &timer->cond, NULL );
+
+        timer->done           = 0;
+        timer->stopped        = 0;
+        timer->expires.tv_sec = timer->expires.tv_nsec = 0;
+        timer->period.tv_sec  = timer->period.tv_nsec  = 0;
+        timer->overruns       = 0;
+
+        /* create the thread */
+        if (pthread_create( &timer->thread, &timer->attributes, timer_thread_start, timer ) < 0) {
+            thr_timer_table_free( __timer_table, timer );
+            errno = ENOMEM;
+            return -1;
+        }
+
+        *ptimerid = timer->id;
+        return 0;
+    }
+}
+
+
+int
+timer_delete( timer_t  id )
+{
+    if ( __likely(!TIMER_ID_IS_WRAPPED(id)) )
+        return __timer_delete( id );
+    else
+    {
+        thr_timer_table_t*  table = __timer_table_get();
+        thr_timer_t*        timer = thr_timer_table_from_id(table, id, 1);
+
+        if (timer == NULL) {
+            errno = EINVAL;
+            return -1;
+        }
+
+        /* tell the timer's thread to stop */
+        thr_timer_lock(timer);
+        timer->done = 1;
+        pthread_cond_signal( &timer->cond );
+        thr_timer_unlock(timer);
+
+        /* NOTE: the thread will call __timer_table_free() to free the
+         * timer object. the '1' parameter to thr_timer_table_from_id
+         * above ensured that the object and its timer_id cannot be
+         * reused before that.
+         */
+        return 0;
+    }
+}
+
+/* return the relative time until the next expiration, or 0 if
+ * the timer is disarmed */
+static void
+timer_gettime_internal( thr_timer_t*        timer,
+                        struct itimerspec*  spec)
+{
+    struct timespec  diff;
+
+    diff = timer->expires;
+    if (!timespec_is_zero(&diff)) 
+    {
+        struct timespec  now;
+
+        clock_gettime( timer->clock, &now );
+        timespec_sub(&diff, &now);
+
+        /* in case of overrun, return 0 */
+        if (timespec_cmp0(&diff) < 0) {
+            timespec_zero(&diff);
+        }
+    }
+
+    spec->it_value    = diff;
+    spec->it_interval = timer->period;
+}
+
+
+int
+timer_gettime( timer_t  id, struct itimerspec*  ospec )
+{
+    if (ospec == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    if ( __likely(!TIMER_ID_IS_WRAPPED(id)) ) {
+        return __timer_gettime( id, ospec );
+    } else {
+        thr_timer_t*  timer = thr_timer_from_id(id);
+
+        if (timer == NULL) {
+            errno = EINVAL;
+            return -1;
+        }
+        thr_timer_lock(timer);
+        timer_gettime_internal( timer, ospec );
+        thr_timer_unlock(timer);
+    }
+    return 0;
+}
+
+
+int
+timer_settime( timer_t                   id,
+               int                       flags,
+               const struct itimerspec*  spec,
+               struct itimerspec*        ospec )
+{
+    if (spec == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    if ( __likely(!TIMER_ID_IS_WRAPPED(id)) ) {
+        return __timer_gettime( id, ospec );
+    } else {
+        thr_timer_t*        timer = thr_timer_from_id(id);
+        struct timespec     expires, now;
+
+        if (timer == NULL) {
+            errno = EINVAL;
+            return -1;
+        }
+        thr_timer_lock(timer);
+
+        /* return current timer value if ospec isn't NULL */
+        if (ospec != NULL) {
+            timer_gettime_internal(timer, ospec );
+        }
+
+        /* compute next expiration time */
+        expires = spec->it_value;
+        clock_gettime( timer->clock, &now );
+        if (!(flags & TIMER_ABSTIME)) {
+            timespec_add(&expires, &now);
+        } else {
+            if (timespec_cmp(&expires, &now) < 0)
+                expires = now;
+        }
+
+        timer->expires = expires;
+        timer->period  = spec->it_interval;
+        thr_timer_unlock( timer );
+
+        /* signal the change to the thread */
+        pthread_cond_signal( &timer->cond );
+    }
+    return 0;
+}
+
+
+int
+timer_getoverrun(timer_t  id)
+{
+    if ( __likely(!TIMER_ID_IS_WRAPPED(id)) ) {
+        return __timer_getoverrun( id );
+    } else {
+        thr_timer_t*  timer = thr_timer_from_id(id);
+        int           result;
+
+        if (timer == NULL) {
+            errno = EINVAL;
+            return -1;
+        }
+
+        thr_timer_lock(timer);
+        result = timer->overruns;
+        thr_timer_unlock(timer);
+
+        return result;
+    }
+}
+
+
+static void*
+timer_thread_start( void*  _arg )
+{
+    thr_timer_t*  timer = _arg;
+
+    thr_timer_lock( timer );
+
+    /* we loop until timer->done is set in timer_delete() */
+    while (!timer->done) 
+    {
+        struct timespec   expires = timer->expires;
+        struct timespec   period  = timer->period;
+        struct timespec   now;
+
+        /* if the timer is stopped or disarmed, wait indefinitely
+         * for a state change from timer_settime/_delete/_start_stop
+         */
+        if ( timer->stopped || timespec_is_zero(&expires) )
+        {
+            pthread_cond_wait( &timer->cond, &timer->mutex );
+            continue;
+        }
+
+        /* otherwise, we need to do a timed wait until either a
+        * state change of the timer expiration time.
+        */
+        clock_gettime(timer->clock, &now);
+
+        if (timespec_cmp( &expires, &now ) > 0)
+        {
+            /* cool, there was no overrun, so compute the
+             * relative timeout as 'now - expires', then wait
+             */
+            int              ret;
+            struct timespec  diff = now;
+            timespec_sub( &diff, &expires );
+
+            ret = __pthread_cond_timedwait_relative(
+                        &timer->cond, &timer->mutex, &diff);
+
+            /* if we didn't timeout, it means that a state change
+                * occured, so reloop to take care of it.
+                */
+            if (ret != ETIMEDOUT)
+                continue;
+        }
+        else
+        {
+            /* overrun was detected before we could wait ! */
+            if (!timespec_is_zero( &period ) )
+            {
+                /* for periodic timers, compute total overrun count */
+                do {
+                    timespec_add( &expires, &period );
+                    if (timer->overruns < DELAYTIMER_MAX)
+                        timer->overruns += 1;
+                } while ( timespec_cmp( &expires, &now ) < 0 );
+
+                /* backtrack the last one, because we're going to
+                 * add the same value just a bit later */
+                timespec_sub( &expires, &period );
+            }
+            else
+            {
+                /* for non-periodic timer, things are simple */
+                timer->overruns = 1;
+            }
+        }
+
+        /* if we get there, a timeout was detected.
+         * first reload/disarm the timer has needed
+         */
+        if ( !timespec_is_zero(&period) ) {
+            timespec_add( &expires, &period );
+        } else {
+            timespec_zero( &expires );
+        }
+        timer->expires = expires;
+
+        /* now call the timer callback function. release the
+         * lock to allow the function to modify the timer setting
+         * or call timer_getoverrun().
+         *
+         * NOTE: at this point we trust the callback not to be a
+         *       total moron and pthread_kill() the timer thread
+         */
+        thr_timer_unlock(timer);
+        timer->callback( timer->value );
+        thr_timer_lock(timer);
+
+        /* now clear the overruns counter. it only makes sense
+         * within the callback */
+        timer->overruns = 0;
+    }
+
+    thr_timer_unlock( timer );
+
+    /* free the timer object now. there is no need to call
+     * __timer_table_get() since we're guaranteed that __timer_table
+     * is initialized in this thread
+     */
+    thr_timer_table_free(__timer_table, timer);
+
+    return NULL;
+}