Merge "Rewrite the POSIX timer functions."
diff --git a/libc/Android.mk b/libc/Android.mk
index d2b67c1..0ad5af2 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -165,6 +165,7 @@
bionic/pipe.cpp \
bionic/poll.cpp \
bionic/posix_fallocate.cpp \
+ bionic/posix_timers.cpp \
bionic/pthread_atfork.cpp \
bionic/pthread_attr.cpp \
bionic/pthread_cond.cpp \
@@ -224,7 +225,6 @@
bionic/sys_signame.c \
bionic/tdestroy.cpp \
bionic/thread_atexit.cpp \
- bionic/timer.cpp \
bionic/tmpfile.cpp \
bionic/unlink.cpp \
bionic/utimes.cpp \
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 1928168..8d4b258 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -213,11 +213,11 @@
int clock_nanosleep(clockid_t clock_id, int flags, const struct timespec* req, struct timespec* rem) all
int getitimer(int, const struct itimerval*) all
int setitimer(int, const struct itimerval*, struct itimerval*) all
-int __timer_create:timer_create(clockid_t clockid, struct sigevent* evp, timer_t* timerid) all
-int __timer_settime:timer_settime(timer_t, int, const struct itimerspec*, struct itimerspec*) all
-int __timer_gettime:timer_gettime(timer_t, struct itimerspec*) all
-int __timer_getoverrun:timer_getoverrun(timer_t) all
-int __timer_delete:timer_delete(timer_t) all
+int __timer_create:timer_create(clockid_t clockid, struct sigevent* evp, __kernel_timer_t* timerid) all
+int __timer_settime:timer_settime(__kernel_timer_t, int, const struct itimerspec*, struct itimerspec*) all
+int __timer_gettime:timer_gettime(__kernel_timer_t, struct itimerspec*) all
+int __timer_getoverrun:timer_getoverrun(__kernel_timer_t) all
+int __timer_delete:timer_delete(__kernel_timer_t) all
int timerfd_create(clockid_t, int) all
int timerfd_settime(int, int, const struct itimerspec*, struct itimerspec*) all
int timerfd_gettime(int, struct itimerspec*) all
diff --git a/libc/bionic/fork.cpp b/libc/bionic/fork.cpp
index 9fa5fcf..a0f98e4 100644
--- a/libc/bionic/fork.cpp
+++ b/libc/bionic/fork.cpp
@@ -29,15 +29,9 @@
#include <unistd.h>
#include <sys/syscall.h>
-#include "private/libc_logging.h"
#include "pthread_internal.h"
int fork() {
- // POSIX mandates that the timers of a fork child process be
- // disarmed, but not destroyed. To avoid a race condition, we're
- // going to stop all timers now, and only re-start them in case
- // of error, or in the parent process
- __timer_table_start_stop(1);
__bionic_atfork_run_prepare();
pthread_internal_t* self = __get_thread();
@@ -50,7 +44,6 @@
if (result == 0) {
__bionic_atfork_run_child();
} else {
- __timer_table_start_stop(0);
__bionic_atfork_run_parent();
}
return result;
diff --git a/libc/bionic/posix_timers.cpp b/libc/bionic/posix_timers.cpp
new file mode 100644
index 0000000..ffe213c
--- /dev/null
+++ b/libc/bionic/posix_timers.cpp
@@ -0,0 +1,221 @@
+/*
+ * 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 "private/bionic_futex.h"
+#include "private/bionic_pthread.h"
+#include "private/kernel_sigset_t.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+// System calls.
+extern "C" int __rt_sigtimedwait(const sigset_t*, siginfo_t*, const struct timespec*, size_t);
+extern "C" int __timer_create(clockid_t, sigevent*, __kernel_timer_t*);
+extern "C" int __timer_delete(__kernel_timer_t);
+extern "C" int __timer_getoverrun(__kernel_timer_t);
+extern "C" int __timer_gettime(__kernel_timer_t, itimerspec*);
+extern "C" int __timer_settime(__kernel_timer_t, int, const itimerspec*, itimerspec*);
+
+// Most POSIX timers are handled directly by the kernel. We translate SIGEV_THREAD timers
+// into SIGEV_THREAD_ID timers so the kernel handles all the time-related stuff and we just
+// need to worry about running user code on a thread.
+
+// We can't use SIGALRM because too many other C library functions throw that around, and since
+// they don't send to a specific thread, all threads are eligible to handle the signal and we can
+// end up with one of our POSIX timer threads handling it (meaning that the intended recipient
+// doesn't). glibc uses SIGRTMIN for its POSIX timer implementation, so in the absence of any
+// reason to use anything else, we use that too.
+static const int TIMER_SIGNAL = SIGRTMIN;
+
+struct PosixTimer {
+ __kernel_timer_t kernel_timer_id;
+
+ int sigev_notify;
+
+ // These fields are only needed for a SIGEV_THREAD timer.
+ pthread_t callback_thread;
+ void (*callback)(sigval_t);
+ sigval_t callback_argument;
+ volatile int exiting;
+};
+
+static __kernel_timer_t to_kernel_timer_id(timer_t timer) {
+ return reinterpret_cast<PosixTimer*>(timer)->kernel_timer_id;
+}
+
+static void* __timer_thread_start(void* arg) {
+ PosixTimer* timer = reinterpret_cast<PosixTimer*>(arg);
+
+ kernel_sigset_t sigset;
+ sigaddset(sigset.get(), TIMER_SIGNAL);
+
+ while (true) {
+ // Wait for a signal...
+ siginfo_t si;
+ memset(&si, 0, sizeof(si));
+ int rc = __rt_sigtimedwait(sigset.get(), &si, NULL, sizeof(sigset));
+ if (rc == -1) {
+ continue;
+ }
+
+ if (si.si_code == SI_TIMER) {
+ // This signal was sent because a timer fired, so call the callback.
+ timer->callback(timer->callback_argument);
+ } else if (si.si_code == SI_TKILL) {
+ // This signal was sent because someone wants us to exit.
+ timer->exiting = 1;
+ __futex_wake(&timer->exiting, INT32_MAX);
+ return NULL;
+ }
+ }
+}
+
+static void __timer_thread_stop(PosixTimer* timer) {
+ pthread_kill(timer->callback_thread, TIMER_SIGNAL);
+
+ // We can't pthread_join because POSIX says "the threads created in response to a timer
+ // expiration are created detached, or in an unspecified way if the thread attribute's
+ // detachstate is PTHREAD_CREATE_JOINABLE".
+ while (timer->exiting == 0) {
+ __futex_wait(&timer->exiting, 0, NULL);
+ }
+}
+
+// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_create.html
+int timer_create(clockid_t clock_id, sigevent* evp, timer_t* timer_id) {
+ PosixTimer* new_timer = reinterpret_cast<PosixTimer*>(malloc(sizeof(PosixTimer)));
+ if (new_timer == NULL) {
+ return -1;
+ }
+
+ new_timer->sigev_notify = (evp == NULL) ? SIGEV_SIGNAL : evp->sigev_notify;
+
+ // If not a SIGEV_THREAD timer, the kernel can handle it without our help.
+ if (new_timer->sigev_notify != SIGEV_THREAD) {
+ if (__timer_create(clock_id, evp, &new_timer->kernel_timer_id) == -1) {
+ free(new_timer);
+ return -1;
+ }
+
+ *timer_id = new_timer;
+ return 0;
+ }
+
+ // Otherwise, this must be SIGEV_THREAD timer...
+ new_timer->callback = evp->sigev_notify_function;
+ new_timer->callback_argument = evp->sigev_value;
+ new_timer->exiting = 0;
+
+ // Check arguments that the kernel doesn't care about but we do.
+ if (new_timer->callback == NULL) {
+ free(new_timer);
+ errno = EINVAL;
+ return -1;
+ }
+
+ // Create this timer's thread.
+ pthread_attr_t thread_attributes;
+ if (evp->sigev_notify_attributes == NULL) {
+ pthread_attr_init(&thread_attributes);
+ } else {
+ thread_attributes = *reinterpret_cast<pthread_attr_t*>(evp->sigev_notify_attributes);
+ }
+ pthread_attr_setdetachstate(&thread_attributes, PTHREAD_CREATE_DETACHED);
+
+ // We start the thread with TIMER_SIGNAL blocked by blocking the signal here and letting it
+ // inherit. If it tried to block the signal itself, there would be a race.
+ kernel_sigset_t sigset;
+ sigaddset(sigset.get(), TIMER_SIGNAL);
+ kernel_sigset_t old_sigset;
+ pthread_sigmask(SIG_BLOCK, sigset.get(), old_sigset.get());
+
+ int rc = pthread_create(&new_timer->callback_thread, &thread_attributes, __timer_thread_start, new_timer);
+
+ pthread_sigmask(SIG_SETMASK, old_sigset.get(), NULL);
+
+ if (rc != 0) {
+ free(new_timer);
+ errno = rc;
+ return -1;
+ }
+
+ sigevent se = *evp;
+ se.sigev_signo = TIMER_SIGNAL;
+ se.sigev_notify = SIGEV_THREAD_ID;
+ se.sigev_notify_thread_id = __pthread_gettid(new_timer->callback_thread);
+ if (__timer_create(clock_id, &se, &new_timer->kernel_timer_id) == -1) {
+ __timer_thread_stop(new_timer);
+ free(new_timer);
+ return -1;
+ }
+
+ // Give the thread a meaningful name.
+ // It can't do this itself because the kernel timer isn't created until after it's running.
+ char name[32];
+ snprintf(name, sizeof(name), "POSIX interval timer %d", to_kernel_timer_id(new_timer));
+ pthread_setname_np(new_timer->callback_thread, name);
+
+ *timer_id = new_timer;
+ return 0;
+}
+
+// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_delete.html
+int timer_delete(timer_t id) {
+ int rc = __timer_delete(to_kernel_timer_id(id));
+ if (rc == -1) {
+ return -1;
+ }
+
+ PosixTimer* timer = reinterpret_cast<PosixTimer*>(id);
+
+ // Make sure the timer's thread has exited before we free the timer data.
+ if (timer->sigev_notify == SIGEV_THREAD) {
+ __timer_thread_stop(timer);
+ }
+
+ free(timer);
+
+ return 0;
+}
+
+// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_getoverrun.html
+int timer_gettime(timer_t id, itimerspec* ts) {
+ return __timer_gettime(to_kernel_timer_id(id), ts);
+}
+
+// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_getoverrun.html
+int timer_settime(timer_t id, int flags, const itimerspec* ts, itimerspec* ots) {
+ return __timer_settime(to_kernel_timer_id(id), flags, ts, ots);
+}
+
+// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_getoverrun.html
+int timer_getoverrun(timer_t id) {
+ return __timer_getoverrun(to_kernel_timer_id(id));
+}
diff --git a/libc/bionic/pthread_atfork.cpp b/libc/bionic/pthread_atfork.cpp
index 5bf63fb..c0664a9 100644
--- a/libc/bionic/pthread_atfork.cpp
+++ b/libc/bionic/pthread_atfork.cpp
@@ -48,14 +48,12 @@
static atfork_list_t gAtForkList = { NULL, NULL };
void __bionic_atfork_run_prepare() {
- // We will lock this here, and unlock it in the parent and child functions.
+ // We lock the atfork list here, unlock it in the parent, and reset it in the child.
// This ensures that nobody can modify the handler array between the calls
// to the prepare and parent/child handlers.
//
- // TODO: If a handler mucks with the list, it could cause problems. Right
- // now it's ok because all they can do is add new items to the end
- // of the list, but if/when we implement cleanup in dlclose() things
- // will get more interesting...
+ // TODO: If a handler tries to mutate the list, they'll block. We should probably copy
+ // the list before forking, and have prepare, parent, and child all work on the consistent copy.
pthread_mutex_lock(&gAtForkListMutex);
// Call pthread_atfork() prepare handlers. POSIX states that the prepare
@@ -75,10 +73,7 @@
}
}
- pthread_mutexattr_t attr;
- pthread_mutexattr_init(&attr);
- pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
- pthread_mutex_init(&gAtForkListMutex, &attr);
+ gAtForkListMutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER;
}
void __bionic_atfork_run_parent() {
diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
index 3825a4c..41f4636 100644
--- a/libc/bionic/pthread_internal.h
+++ b/libc/bionic/pthread_internal.h
@@ -91,8 +91,7 @@
__LIBC_HIDDEN__ int __timespec_from_absolute(timespec*, const timespec*, clockid_t);
-/* needed by fork.c */
-__LIBC_HIDDEN__ extern void __timer_table_start_stop(int);
+/* Needed by fork. */
__LIBC_HIDDEN__ extern void __bionic_atfork_run_prepare();
__LIBC_HIDDEN__ extern void __bionic_atfork_run_child();
__LIBC_HIDDEN__ extern void __bionic_atfork_run_parent();
diff --git a/libc/bionic/timer.cpp b/libc/bionic/timer.cpp
deleted file mode 100644
index ed73821..0000000
--- a/libc/bionic/timer.cpp
+++ /dev/null
@@ -1,636 +0,0 @@
-/*
- * 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 <errno.h>
-#include <stdio.h>
-#include <string.h>
-
-extern int __pthread_cond_timedwait(pthread_cond_t*, pthread_mutex_t*, const timespec*, clockid_t);
-extern int __pthread_cond_timedwait_relative(pthread_cond_t*, pthread_mutex_t*, const timespec*);
-
-// Normal (i.e. non-SIGEV_THREAD) timers are created directly by the kernel
-// and are passed as is to/from the caller.
-//
-// This file also implements the support required for SIGEV_THREAD ("POSIX interval")
-// timers. See the following pages for additional 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.
-//
-// This stop/start is implemented by the __timer_table_start_stop() function
-// below.
-//
-// A SIGEV_THREAD timer ID will always have its TIMER_ID_WRAP_BIT
-// 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
-
-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() */
- timespec volatile expires; /* next expiration time, or 0 */
- 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;
-
- if (t == NULL)
- return NULL;
-
- 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) {
- if (t == NULL) {
- return;
- }
-
- pthread_mutex_lock(&t->lock);
- for (int 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 (t == NULL || !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 - we only create it if the process
- * really wants to use SIGEV_THREAD timers, which should be
- * pretty infrequent
- */
-
-static pthread_once_t __timer_table_once = PTHREAD_ONCE_INIT;
-static thr_timer_table_t* __timer_table;
-
-static void __timer_table_init(void) {
- __timer_table = reinterpret_cast<thr_timer_table_t*>(calloc(1, sizeof(*__timer_table)));
- if (__timer_table != NULL) {
- 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) {
- // We access __timer_table directly so we don't create it if it doesn't yet exist.
- thr_timer_table_start_stop(__timer_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);
-}
-
-
-static __inline__ void timespec_add(timespec* a, const timespec* b) {
- a->tv_sec += b->tv_sec;
- a->tv_nsec += b->tv_nsec;
- if (a->tv_nsec >= 1000000000) {
- a->tv_nsec -= 1000000000;
- a->tv_sec += 1;
- }
-}
-
-static __inline__ void timespec_sub(timespec* a, const timespec* b) {
- a->tv_sec -= b->tv_sec;
- a->tv_nsec -= b->tv_nsec;
- if (a->tv_nsec < 0) {
- a->tv_nsec += 1000000000;
- a->tv_sec -= 1;
- }
-}
-
-static __inline__ void timespec_zero(timespec* a) {
- a->tv_sec = a->tv_nsec = 0;
-}
-
-static __inline__ int timespec_is_zero(const timespec* a) {
- return (a->tv_sec == 0 && a->tv_nsec == 0);
-}
-
-static __inline__ int timespec_cmp(const timespec* a, const timespec* b) {
- if (a->tv_sec < b->tv_sec) return -1;
- if (a->tv_sec > b->tv_sec) return +1;
- if (a->tv_nsec < b->tv_nsec) return -1;
- if (a->tv_nsec > b->tv_nsec) return +1;
- return 0;
-}
-
-static __inline__ int timespec_cmp0(const timespec* a) {
- if (a->tv_sec < 0) return -1;
- if (a->tv_sec > 0) return +1;
- if (a->tv_nsec < 0) return -1;
- if (a->tv_nsec > 0) return +1;
- return 0;
-}
-
-/** POSIX TIMERS APIs */
-
-extern "C" int __timer_create(clockid_t, sigevent*, timer_t*);
-extern "C" int __timer_delete(timer_t);
-extern "C" int __timer_gettime(timer_t, itimerspec*);
-extern "C" int __timer_settime(timer_t, int, const itimerspec*, itimerspec*);
-extern "C" int __timer_getoverrun(timer_t);
-
-static void* timer_thread_start(void*);
-
-int timer_create(clockid_t clock_id, sigevent* evp, timer_t* timer_id) {
- // If not a SIGEV_THREAD timer, the kernel can handle it without our help.
- if (__predict_true(evp == NULL || evp->sigev_notify != SIGEV_THREAD)) {
- return __timer_create(clock_id, evp, timer_id);
- }
-
- // Check arguments.
- if (evp->sigev_notify_function == NULL) {
- errno = EINVAL;
- return -1;
- }
-
- // Check that the clock id is supported by the kernel.
- timespec dummy;
- if (clock_gettime(clock_id, &dummy) < 0 && errno == EINVAL) {
- return -1;
- }
-
- // Create a new timer and its thread.
- // TODO: use a single global thread for all timers.
- thr_timer_table_t* table = __timer_table_get();
- thr_timer_t* timer = thr_timer_table_alloc(table);
- 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 behavior.
- // 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 = clock_id;
-
- 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.
- int rc = pthread_create(&timer->thread, &timer->attributes, timer_thread_start, timer);
- if (rc != 0) {
- thr_timer_table_free(table, timer);
- errno = rc;
- return -1;
- }
-
- *timer_id = timer->id;
- return 0;
-}
-
-
-int
-timer_delete( timer_t id )
-{
- if ( __predict_true(!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, itimerspec* spec) {
- timespec diff = const_cast<timespec&>(timer->expires);
- if (!timespec_is_zero(&diff)) {
- 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 = const_cast<timespec&>(timer->period);
-}
-
-
-int timer_gettime(timer_t id, itimerspec* ospec) {
- if (ospec == NULL) {
- errno = EINVAL;
- return -1;
- }
-
- if ( __predict_true(!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 itimerspec* spec, itimerspec* ospec) {
- if (spec == NULL) {
- errno = EINVAL;
- return -1;
- }
-
- if ( __predict_true(!TIMER_ID_IS_WRAPPED(id)) ) {
- return __timer_settime( id, flags, spec, ospec );
- } else {
- thr_timer_t* timer = thr_timer_from_id(id);
- 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. note that if the
- * new it_interval is 0, we should disarm the timer
- */
- expires = spec->it_value;
- if (!timespec_is_zero(&expires)) {
- clock_gettime( timer->clock, &now );
- if (!(flags & TIMER_ABSTIME)) {
- timespec_add(&expires, &now);
- } else {
- if (timespec_cmp(&expires, &now) < 0)
- expires = now;
- }
- }
- const_cast<timespec&>(timer->expires) = expires;
- const_cast<timespec&>(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 ( __predict_true(!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 = reinterpret_cast<thr_timer_t*>(arg);
-
- thr_timer_lock(timer);
-
- // Give this thread a meaningful name.
- char name[32];
- snprintf(name, sizeof(name), "POSIX interval timer 0x%08x", timer->id);
- pthread_setname_np(pthread_self(), name);
-
- // We loop until timer->done is set in timer_delete().
- while (!timer->done) {
- timespec expires = const_cast<timespec&>(timer->expires);
- timespec period = const_cast<timespec&>(timer->period);
-
- // 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.
- timespec now;
- clock_gettime(timer->clock, &now);
-
- if (timespec_cmp(&expires, &now) > 0) {
- // Cool, there was no overrun, so compute the
- // relative timeout as 'expires - now', then wait.
- timespec diff = expires;
- timespec_sub(&diff, &now);
-
- int ret = __pthread_cond_timedwait_relative(&timer->cond, &timer->mutex, &diff);
-
- // If we didn't time out, it means that a state change
- // occurred, so loop 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 timers, things are simple.
- timer->overruns = 1;
- }
- }
-
- // If we get here, a timeout was detected.
- // First reload/disarm the timer as needed.
- if (!timespec_is_zero(&period)) {
- timespec_add(&expires, &period);
- } else {
- timespec_zero(&expires);
- }
- const_cast<timespec&>(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.
- thr_timer_table_free(__timer_table_get(), timer);
-
- return NULL;
-}
diff --git a/libc/include/sys/types.h b/libc/include/sys/types.h
index 5340585..f8261f4 100644
--- a/libc/include/sys/types.h
+++ b/libc/include/sys/types.h
@@ -69,7 +69,7 @@
typedef __uint32_t __nlink_t;
typedef __nlink_t nlink_t;
-typedef int __timer_t;
+typedef void* __timer_t;
typedef __timer_t timer_t;
typedef __int32_t __suseconds_t;
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index 120bbc7..1e85a54 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -25,6 +25,8 @@
#include <time.h>
#include <unistd.h>
+#include "ScopedSignalHandler.h"
+
TEST(pthread, pthread_key_create) {
pthread_key_t key;
ASSERT_EQ(0, pthread_key_create(&key, NULL));
@@ -337,14 +339,8 @@
}
TEST(pthread, pthread_kill__in_signal_handler) {
- struct sigaction action;
- struct sigaction original_action;
- sigemptyset(&action.sa_mask);
- action.sa_flags = 0;
- action.sa_handler = pthread_kill__in_signal_handler_helper;
- ASSERT_EQ(0, sigaction(SIGALRM, &action, &original_action));
+ ScopedSignalHandler ssh(SIGALRM, pthread_kill__in_signal_handler_helper);
ASSERT_EQ(0, pthread_kill(pthread_self(), SIGALRM));
- ASSERT_EQ(0, sigaction(SIGALRM, &original_action, NULL));
}
TEST(pthread, pthread_detach__no_such_thread) {
diff --git a/tests/time_test.cpp b/tests/time_test.cpp
index 869ee4b..9563c78 100644
--- a/tests/time_test.cpp
+++ b/tests/time_test.cpp
@@ -14,11 +14,14 @@
* limitations under the License.
*/
-#include <sys/cdefs.h>
+#include <time.h>
+
+#include <errno.h>
#include <features.h>
#include <gtest/gtest.h>
+#include <signal.h>
-#include <time.h>
+#include "ScopedSignalHandler.h"
#if defined(__BIONIC__) // mktime_tz is a bionic extension.
#include <libc/private/bionic_time.h>
@@ -92,3 +95,208 @@
#endif
#endif
}
+
+void SetTime(timer_t t, time_t value_s, time_t value_ns, time_t interval_s, time_t interval_ns) {
+ itimerspec ts;
+ ts.it_value.tv_sec = value_s;
+ ts.it_value.tv_nsec = value_ns;
+ ts.it_interval.tv_sec = interval_s;
+ ts.it_interval.tv_nsec = interval_ns;
+ ASSERT_EQ(0, timer_settime(t, TIMER_ABSTIME, &ts, NULL));
+}
+
+static void NoOpNotifyFunction(sigval_t) {
+}
+
+TEST(time, timer_create) {
+ sigevent_t se;
+ memset(&se, 0, sizeof(se));
+ se.sigev_notify = SIGEV_THREAD;
+ se.sigev_notify_function = NoOpNotifyFunction;
+ timer_t timer_id;
+ ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, &se, &timer_id));
+
+ int pid = fork();
+ ASSERT_NE(-1, pid) << strerror(errno);
+
+ if (pid == 0) {
+ // Timers are not inherited by the child.
+ ASSERT_EQ(-1, timer_delete(timer_id));
+ ASSERT_EQ(EINVAL, errno);
+ _exit(0);
+ }
+
+ int status;
+ ASSERT_EQ(pid, waitpid(pid, &status, 0));
+ ASSERT_TRUE(WIFEXITED(status));
+ ASSERT_EQ(0, WEXITSTATUS(status));
+
+ ASSERT_EQ(0, timer_delete(timer_id));
+}
+
+static int timer_create_SIGEV_SIGNAL_signal_handler_invocation_count = 0;
+static void timer_create_SIGEV_SIGNAL_signal_handler(int signal_number) {
+ ++timer_create_SIGEV_SIGNAL_signal_handler_invocation_count;
+ ASSERT_EQ(SIGUSR1, signal_number);
+}
+
+TEST(time, timer_create_SIGEV_SIGNAL) {
+ sigevent_t se;
+ memset(&se, 0, sizeof(se));
+ se.sigev_notify = SIGEV_SIGNAL;
+ se.sigev_signo = SIGUSR1;
+
+ timer_t timer_id;
+ ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, &se, &timer_id));
+
+ ScopedSignalHandler ssh(SIGUSR1, timer_create_SIGEV_SIGNAL_signal_handler);
+
+ ASSERT_EQ(0, timer_create_SIGEV_SIGNAL_signal_handler_invocation_count);
+
+ itimerspec ts;
+ ts.it_value.tv_sec = 0;
+ ts.it_value.tv_nsec = 1;
+ ts.it_interval.tv_sec = 0;
+ ts.it_interval.tv_nsec = 0;
+ ASSERT_EQ(0, timer_settime(timer_id, TIMER_ABSTIME, &ts, NULL));
+
+ usleep(500000);
+ ASSERT_EQ(1, timer_create_SIGEV_SIGNAL_signal_handler_invocation_count);
+}
+
+struct Counter {
+ volatile int value;
+ timer_t timer_id;
+ sigevent_t se;
+
+ Counter(void (*fn)(sigval_t)) : value(0) {
+ memset(&se, 0, sizeof(se));
+ se.sigev_notify = SIGEV_THREAD;
+ se.sigev_notify_function = fn;
+ se.sigev_value.sival_ptr = this;
+ }
+
+ void Create() {
+ ASSERT_EQ(0, timer_create(CLOCK_REALTIME, &se, &timer_id));
+ }
+
+ ~Counter() {
+ if (timer_delete(timer_id) != 0) {
+ abort();
+ }
+ }
+
+ static void CountNotifyFunction(sigval_t value) {
+ Counter* cd = reinterpret_cast<Counter*>(value.sival_ptr);
+ ++cd->value;
+ }
+
+ static void CountAndDisarmNotifyFunction(sigval_t value) {
+ Counter* cd = reinterpret_cast<Counter*>(value.sival_ptr);
+ ++cd->value;
+
+ // Setting the initial expiration time to 0 disarms the timer.
+ SetTime(cd->timer_id, 0, 0, 1, 0);
+ }
+};
+
+TEST(time, timer_settime_0) {
+ Counter counter(Counter::CountAndDisarmNotifyFunction);
+ counter.Create();
+
+ ASSERT_EQ(0, counter.value);
+
+ SetTime(counter.timer_id, 0, 1, 1, 0);
+ usleep(500000);
+
+ // The count should just be 1 because we disarmed the timer the first time it fired.
+ ASSERT_EQ(1, counter.value);
+}
+
+TEST(time, timer_settime_repeats) {
+ Counter counter(Counter::CountNotifyFunction);
+ counter.Create();
+
+ ASSERT_EQ(0, counter.value);
+
+ SetTime(counter.timer_id, 0, 1, 0, 10);
+ usleep(500000);
+
+ // The count should just be > 1 because we let the timer repeat.
+ ASSERT_GT(counter.value, 1);
+}
+
+static int timer_create_NULL_signal_handler_invocation_count = 0;
+static void timer_create_NULL_signal_handler(int signal_number) {
+ ++timer_create_NULL_signal_handler_invocation_count;
+ ASSERT_EQ(SIGALRM, signal_number);
+}
+
+TEST(time, timer_create_NULL) {
+ // A NULL sigevent* is equivalent to asking for SIGEV_SIGNAL for SIGALRM.
+ timer_t timer_id;
+ ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, NULL, &timer_id));
+
+ ScopedSignalHandler ssh(SIGALRM, timer_create_NULL_signal_handler);
+
+ ASSERT_EQ(0, timer_create_NULL_signal_handler_invocation_count);
+
+ SetTime(timer_id, 0, 1, 0, 0);
+ usleep(500000);
+
+ ASSERT_EQ(1, timer_create_NULL_signal_handler_invocation_count);
+}
+
+TEST(time, timer_create_EINVAL) {
+ clockid_t invalid_clock = 16;
+
+ // A SIGEV_SIGNAL timer is easy; the kernel does all that.
+ timer_t timer_id;
+ ASSERT_EQ(-1, timer_create(invalid_clock, NULL, &timer_id));
+ ASSERT_EQ(EINVAL, errno);
+
+ // A SIGEV_THREAD timer is more interesting because we have stuff to clean up.
+ sigevent_t se;
+ memset(&se, 0, sizeof(se));
+ se.sigev_notify = SIGEV_THREAD;
+ se.sigev_notify_function = NoOpNotifyFunction;
+ ASSERT_EQ(-1, timer_create(invalid_clock, &se, &timer_id));
+ ASSERT_EQ(EINVAL, errno);
+}
+
+TEST(time, timer_delete_multiple) {
+ timer_t timer_id;
+ ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, NULL, &timer_id));
+ ASSERT_EQ(0, timer_delete(timer_id));
+ ASSERT_EQ(-1, timer_delete(timer_id));
+ ASSERT_EQ(EINVAL, errno);
+
+ sigevent_t se;
+ memset(&se, 0, sizeof(se));
+ se.sigev_notify = SIGEV_THREAD;
+ se.sigev_notify_function = NoOpNotifyFunction;
+ ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, &se, &timer_id));
+ ASSERT_EQ(0, timer_delete(timer_id));
+ ASSERT_EQ(-1, timer_delete(timer_id));
+ ASSERT_EQ(EINVAL, errno);
+}
+
+TEST(time, timer_create_multiple) {
+ Counter counter1(Counter::CountNotifyFunction);
+ counter1.Create();
+ Counter counter2(Counter::CountNotifyFunction);
+ counter2.Create();
+ Counter counter3(Counter::CountNotifyFunction);
+ counter3.Create();
+
+ ASSERT_EQ(0, counter1.value);
+ ASSERT_EQ(0, counter2.value);
+ ASSERT_EQ(0, counter3.value);
+
+ SetTime(counter2.timer_id, 0, 1, 0, 0);
+ usleep(500000);
+
+ EXPECT_EQ(0, counter1.value);
+ EXPECT_EQ(1, counter2.value);
+ EXPECT_EQ(0, counter3.value);
+}
