diff --git a/Makefile.pre.in b/Makefile.pre.in index f8216971958..1c536f813f8 100644 --- a/Makefile.pre.in +++ b/Makefile.pre.in @@ -939,7 +939,8 @@ regen-opcode-targets: $(srcdir)/Python/opcode_targets.h.new $(UPDATE_FILE) $(srcdir)/Python/opcode_targets.h $(srcdir)/Python/opcode_targets.h.new -Python/ceval.o: $(srcdir)/Python/opcode_targets.h $(srcdir)/Python/ceval_gil.h +Python/ceval.o: $(srcdir)/Python/opcode_targets.h $(srcdir)/Python/ceval_gil.h \ + $(srcdir)/Python/condvar.h Python/frozen.o: $(srcdir)/Python/importlib.h $(srcdir)/Python/importlib_external.h \ $(srcdir)/Python/importlib_zipimport.h @@ -1838,7 +1839,7 @@ patchcheck: @DEF_MAKE_RULE@ # Dependencies -Python/thread.o: @THREADHEADERS@ +Python/thread.o: @THREADHEADERS@ $(srcdir)/Python/condvar.h # Declare targets that aren't real files .PHONY: all build_all sharedmods check-clean-src oldsharedmods test quicktest diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-02-05-12-48-23.bpo-12822.0x2NDx.rst b/Misc/NEWS.d/next/Core and Builtins/2019-02-05-12-48-23.bpo-12822.0x2NDx.rst new file mode 100644 index 00000000000..a3de435f527 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2019-02-05-12-48-23.bpo-12822.0x2NDx.rst @@ -0,0 +1,2 @@ +Use monotonic clock for ``pthread_cond_timedwait`` when +``pthread_condattr_setclock`` and ``CLOCK_MONOTONIC`` are available. diff --git a/Python/ceval.c b/Python/ceval.c index 3db7c7c92a0..03456f6d2ab 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -171,6 +171,7 @@ PyEval_InitThreads(void) { if (gil_created()) return; + PyThread_init_thread(); create_gil(); take_gil(_PyThreadState_GET()); _PyRuntime.ceval.pending.main_thread = PyThread_get_thread_ident(); diff --git a/Python/condvar.h b/Python/condvar.h index 13517409aea..f54adc5ea8e 100644 --- a/Python/condvar.h +++ b/Python/condvar.h @@ -48,19 +48,9 @@ * POSIX support */ -#define PyCOND_ADD_MICROSECONDS(tv, interval) \ -do { /* TODO: add overflow and truncation checks */ \ - tv.tv_usec += (long) interval; \ - tv.tv_sec += tv.tv_usec / 1000000; \ - tv.tv_usec %= 1000000; \ -} while (0) - -/* We assume all modern POSIX systems have gettimeofday() */ -#ifdef GETTIMEOFDAY_NO_TZ -#define PyCOND_GETTIMEOFDAY(ptv) gettimeofday(ptv) -#else -#define PyCOND_GETTIMEOFDAY(ptv) gettimeofday(ptv, (struct timezone *)NULL) -#endif +/* These private functions are implemented in Python/thread_pthread.h */ +int _PyThread_cond_init(PyCOND_T *cond); +void _PyThread_cond_after(long long us, struct timespec *abs); /* The following functions return 0 on success, nonzero on error */ #define PyMUTEX_INIT(mut) pthread_mutex_init((mut), NULL) @@ -68,7 +58,7 @@ do { /* TODO: add overflow and truncation checks */ \ #define PyMUTEX_LOCK(mut) pthread_mutex_lock(mut) #define PyMUTEX_UNLOCK(mut) pthread_mutex_unlock(mut) -#define PyCOND_INIT(cond) pthread_cond_init((cond), NULL) +#define PyCOND_INIT(cond) _PyThread_cond_init(cond) #define PyCOND_FINI(cond) pthread_cond_destroy(cond) #define PyCOND_SIGNAL(cond) pthread_cond_signal(cond) #define PyCOND_BROADCAST(cond) pthread_cond_broadcast(cond) @@ -78,22 +68,16 @@ do { /* TODO: add overflow and truncation checks */ \ Py_LOCAL_INLINE(int) PyCOND_TIMEDWAIT(PyCOND_T *cond, PyMUTEX_T *mut, long long us) { - int r; - struct timespec ts; - struct timeval deadline; - - PyCOND_GETTIMEOFDAY(&deadline); - PyCOND_ADD_MICROSECONDS(deadline, us); - ts.tv_sec = deadline.tv_sec; - ts.tv_nsec = deadline.tv_usec * 1000; - - r = pthread_cond_timedwait((cond), (mut), &ts); - if (r == ETIMEDOUT) + struct timespec abs; + _PyThread_cond_after(us, &abs); + int ret = pthread_cond_timedwait(cond, mut, &abs); + if (ret == ETIMEDOUT) { return 1; - else if (r) + } + if (ret) { return -1; - else - return 0; + } + return 0; } #elif defined(NT_THREADS) diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h index 09e53a14aa4..25f58d9446d 100644 --- a/Python/thread_pthread.h +++ b/Python/thread_pthread.h @@ -56,16 +56,6 @@ #endif #endif -#if !defined(pthread_attr_default) -# define pthread_attr_default ((pthread_attr_t *)NULL) -#endif -#if !defined(pthread_mutexattr_default) -# define pthread_mutexattr_default ((pthread_mutexattr_t *)NULL) -#endif -#if !defined(pthread_condattr_default) -# define pthread_condattr_default ((pthread_condattr_t *)NULL) -#endif - /* Whether or not to use semaphores directly rather than emulating them with * mutexes and condition variables: @@ -110,6 +100,56 @@ do { \ } while(0) +/* + * pthread_cond support + */ + +#if defined(HAVE_PTHREAD_CONDATTR_SETCLOCK) && defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC) +// monotonic is supported statically. It doesn't mean it works on runtime. +#define CONDATTR_MONOTONIC +#endif + +// NULL when pthread_condattr_setclock(CLOCK_MONOTONIC) is not supported. +static pthread_condattr_t *condattr_monotonic = NULL; + +static void +init_condattr() +{ +#ifdef CONDATTR_MONOTONIC + static pthread_condattr_t ca; + pthread_condattr_init(&ca); + if (pthread_condattr_setclock(&ca, CLOCK_MONOTONIC) == 0) { + condattr_monotonic = &ca; // Use monotonic clock + } +#endif +} + +int +_PyThread_cond_init(PyCOND_T *cond) +{ + return pthread_cond_init(cond, condattr_monotonic); +} + +void +_PyThread_cond_after(long long us, struct timespec *abs) +{ +#ifdef CONDATTR_MONOTONIC + if (condattr_monotonic) { + clock_gettime(CLOCK_MONOTONIC, abs); + abs->tv_sec += us / 1000000; + abs->tv_nsec += (us % 1000000) * 1000; + abs->tv_sec += abs->tv_nsec / 1000000000; + abs->tv_nsec %= 1000000000; + return; + } +#endif + + struct timespec ts; + MICROSECONDS_TO_TIMESPEC(us, ts); + *abs = ts; +} + + /* A pthread mutex isn't sufficient to model the Python lock type * because, according to Draft 5 of the docs (P1003.4a/D5), both of the * following are undefined: @@ -146,6 +186,7 @@ PyThread__init_thread(void) extern void pthread_init(void); pthread_init(); #endif + init_condattr(); } /* @@ -462,8 +503,7 @@ PyThread_allocate_lock(void) memset((void *)lock, '\0', sizeof(pthread_lock)); lock->locked = 0; - status = pthread_mutex_init(&lock->mut, - pthread_mutexattr_default); + status = pthread_mutex_init(&lock->mut, NULL); CHECK_STATUS_PTHREAD("pthread_mutex_init"); /* Mark the pthread mutex underlying a Python mutex as pure happens-before. We can't simply mark the @@ -472,8 +512,7 @@ PyThread_allocate_lock(void) will cause errors. */ _Py_ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX(&lock->mut); - status = pthread_cond_init(&lock->lock_released, - pthread_condattr_default); + status = _PyThread_cond_init(&lock->lock_released); CHECK_STATUS_PTHREAD("pthread_cond_init"); if (error) { @@ -532,9 +571,10 @@ PyThread_acquire_lock_timed(PyThread_type_lock lock, PY_TIMEOUT_T microseconds, success = PY_LOCK_ACQUIRED; } else if (microseconds != 0) { - struct timespec ts; - if (microseconds > 0) - MICROSECONDS_TO_TIMESPEC(microseconds, ts); + struct timespec abs; + if (microseconds > 0) { + _PyThread_cond_after(microseconds, &abs); + } /* continue trying until we get the lock */ /* mut must be locked by me -- part of the condition @@ -543,10 +583,13 @@ PyThread_acquire_lock_timed(PyThread_type_lock lock, PY_TIMEOUT_T microseconds, if (microseconds > 0) { status = pthread_cond_timedwait( &thelock->lock_released, - &thelock->mut, &ts); + &thelock->mut, &abs); + if (status == 1) { + break; + } if (status == ETIMEDOUT) break; - CHECK_STATUS_PTHREAD("pthread_cond_timed_wait"); + CHECK_STATUS_PTHREAD("pthread_cond_timedwait"); } else { status = pthread_cond_wait( diff --git a/configure b/configure index b78a7b22610..867e2fc28c4 100755 --- a/configure +++ b/configure @@ -11448,7 +11448,8 @@ for ac_func in alarm accept4 setitimer getitimer bind_textdomain_codeset chown \ memrchr mbrtowc mkdirat mkfifo \ mkfifoat mknod mknodat mktime mremap nice openat pathconf pause pipe2 plock poll \ posix_fallocate posix_fadvise posix_spawn posix_spawnp pread preadv preadv2 \ - pthread_init pthread_kill putenv pwrite pwritev pwritev2 readlink readlinkat readv realpath renameat \ + pthread_condattr_setclock pthread_init pthread_kill putenv pwrite pwritev pwritev2 \ + readlink readlinkat readv realpath renameat \ sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \ setgid sethostname \ setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \ diff --git a/configure.ac b/configure.ac index eeedfedd236..bb7861bc0da 100644 --- a/configure.ac +++ b/configure.ac @@ -3506,7 +3506,8 @@ AC_CHECK_FUNCS(alarm accept4 setitimer getitimer bind_textdomain_codeset chown \ memrchr mbrtowc mkdirat mkfifo \ mkfifoat mknod mknodat mktime mremap nice openat pathconf pause pipe2 plock poll \ posix_fallocate posix_fadvise posix_spawn posix_spawnp pread preadv preadv2 \ - pthread_init pthread_kill putenv pwrite pwritev pwritev2 readlink readlinkat readv realpath renameat \ + pthread_condattr_setclock pthread_init pthread_kill putenv pwrite pwritev pwritev2 \ + readlink readlinkat readv realpath renameat \ sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \ setgid sethostname \ setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \ diff --git a/pyconfig.h.in b/pyconfig.h.in index ab9e9e10f7c..8db06d91006 100644 --- a/pyconfig.h.in +++ b/pyconfig.h.in @@ -765,6 +765,9 @@ /* Define if your compiler supports function prototype */ #undef HAVE_PROTOTYPES +/* Define to 1 if you have the `pthread_condattr_setclock' function. */ +#undef HAVE_PTHREAD_CONDATTR_SETCLOCK + /* Defined for Solaris 2.6 bug in pthread header. */ #undef HAVE_PTHREAD_DESTRUCTOR