diff options
Diffstat (limited to 'lib/glthread')
| -rw-r--r-- | lib/glthread/lock.c | 971 | ||||
| -rw-r--r-- | lib/glthread/lock.h | 565 | ||||
| -rw-r--r-- | lib/glthread/threadlib.c | 64 |
3 files changed, 471 insertions, 1129 deletions
diff --git a/lib/glthread/lock.c b/lib/glthread/lock.c index 9e148910..b650c219 100644 --- a/lib/glthread/lock.c +++ b/lib/glthread/lock.c @@ -1,31 +1,21 @@ /* Locking in multithreaded situations. - Copyright (C) 2005-2018 Free Software Foundation, Inc. + Copyright (C) 2005-2022 Free Software Foundation, Inc. - This program is free software: you can redistribute it and/or - modify it under the terms of either: + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. - * the GNU Lesser General Public License as published by the Free - Software Foundation; either version 3 of the License, or (at your - option) any later version. - - or - - * the GNU General Public License as published by the Free - Software Foundation; either version 2 of the License, or (at your - option) any later version. - - or both in parallel, as here. - This program is distributed in the hope that it will be useful, + This file is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. + GNU Lesser General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program; if not, see <https://www.gnu.org/licenses/>. */ + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ /* Written by Bruno Haible <bruno@clisp.org>, 2005. - Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h, - gthr-win32.h. */ + Based on GCC's gthr-posix.h, gthr-posix95.h. */ #include <config.h> @@ -33,6 +23,229 @@ /* ========================================================================= */ +#if USE_ISOC_THREADS || USE_ISOC_AND_POSIX_THREADS + +/* -------------------------- gl_lock_t datatype -------------------------- */ + +int +glthread_lock_init (gl_lock_t *lock) +{ + if (mtx_init (&lock->mutex, mtx_plain) != thrd_success) + return ENOMEM; + lock->init_needed = 0; + return 0; +} + +int +glthread_lock_lock (gl_lock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + if (mtx_lock (&lock->mutex) != thrd_success) + return EAGAIN; + return 0; +} + +int +glthread_lock_unlock (gl_lock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + if (mtx_unlock (&lock->mutex) != thrd_success) + return EINVAL; + return 0; +} + +int +glthread_lock_destroy (gl_lock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + mtx_destroy (&lock->mutex); + return 0; +} + +/* ------------------------- gl_rwlock_t datatype ------------------------- */ + +int +glthread_rwlock_init (gl_rwlock_t *lock) +{ + if (mtx_init (&lock->lock, mtx_plain) != thrd_success + || cnd_init (&lock->waiting_readers) != thrd_success + || cnd_init (&lock->waiting_writers) != thrd_success) + return ENOMEM; + lock->waiting_writers_count = 0; + lock->runcount = 0; + lock->init_needed = 0; + return 0; +} + +int +glthread_rwlock_rdlock (gl_rwlock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + if (mtx_lock (&lock->lock) != thrd_success) + return EAGAIN; + /* Test whether only readers are currently running, and whether the runcount + field will not overflow, and whether no writer is waiting. The latter + condition is because POSIX recommends that "write locks shall take + precedence over read locks", to avoid "writer starvation". */ + while (!(lock->runcount + 1 > 0 && lock->waiting_writers_count == 0)) + { + /* This thread has to wait for a while. Enqueue it among the + waiting_readers. */ + if (cnd_wait (&lock->waiting_readers, &lock->lock) != thrd_success) + { + mtx_unlock (&lock->lock); + return EINVAL; + } + } + lock->runcount++; + if (mtx_unlock (&lock->lock) != thrd_success) + return EINVAL; + return 0; +} + +int +glthread_rwlock_wrlock (gl_rwlock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + if (mtx_lock (&lock->lock) != thrd_success) + return EAGAIN; + /* Test whether no readers or writers are currently running. */ + while (!(lock->runcount == 0)) + { + /* This thread has to wait for a while. Enqueue it among the + waiting_writers. */ + lock->waiting_writers_count++; + if (cnd_wait (&lock->waiting_writers, &lock->lock) != thrd_success) + { + lock->waiting_writers_count--; + mtx_unlock (&lock->lock); + return EINVAL; + } + lock->waiting_writers_count--; + } + lock->runcount--; /* runcount becomes -1 */ + if (mtx_unlock (&lock->lock) != thrd_success) + return EINVAL; + return 0; +} + +int +glthread_rwlock_unlock (gl_rwlock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + if (mtx_lock (&lock->lock) != thrd_success) + return EAGAIN; + if (lock->runcount < 0) + { + /* Drop a writer lock. */ + if (!(lock->runcount == -1)) + { + mtx_unlock (&lock->lock); + return EINVAL; + } + lock->runcount = 0; + } + else + { + /* Drop a reader lock. */ + if (!(lock->runcount > 0)) + { + mtx_unlock (&lock->lock); + return EINVAL; + } + lock->runcount--; + } + if (lock->runcount == 0) + { + /* POSIX recommends that "write locks shall take precedence over read + locks", to avoid "writer starvation". */ + if (lock->waiting_writers_count > 0) + { + /* Wake up one of the waiting writers. */ + if (cnd_signal (&lock->waiting_writers) != thrd_success) + { + mtx_unlock (&lock->lock); + return EINVAL; + } + } + else + { + /* Wake up all waiting readers. */ + if (cnd_broadcast (&lock->waiting_readers) != thrd_success) + { + mtx_unlock (&lock->lock); + return EINVAL; + } + } + } + if (mtx_unlock (&lock->lock) != thrd_success) + return EINVAL; + return 0; +} + +int +glthread_rwlock_destroy (gl_rwlock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + mtx_destroy (&lock->lock); + cnd_destroy (&lock->waiting_readers); + cnd_destroy (&lock->waiting_writers); + return 0; +} + +/* --------------------- gl_recursive_lock_t datatype --------------------- */ + +int +glthread_recursive_lock_init (gl_recursive_lock_t *lock) +{ + if (mtx_init (&lock->mutex, mtx_plain | mtx_recursive) != thrd_success) + return ENOMEM; + lock->init_needed = 0; + return 0; +} + +int +glthread_recursive_lock_lock (gl_recursive_lock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + if (mtx_lock (&lock->mutex) != thrd_success) + return EAGAIN; + return 0; +} + +int +glthread_recursive_lock_unlock (gl_recursive_lock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + if (mtx_unlock (&lock->mutex) != thrd_success) + return EINVAL; + return 0; +} + +int +glthread_recursive_lock_destroy (gl_recursive_lock_t *lock) +{ + if (lock->init_needed) + call_once (&lock->init_once, lock->init_func); + mtx_destroy (&lock->mutex); + return 0; +} + +/* -------------------------- gl_once_t datatype -------------------------- */ + +#endif + +/* ========================================================================= */ + #if USE_POSIX_THREADS /* -------------------------- gl_lock_t datatype -------------------------- */ @@ -41,7 +254,7 @@ # if HAVE_PTHREAD_RWLOCK && (HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER || (defined PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP && (__GNU_LIBRARY__ > 1))) -# ifdef PTHREAD_RWLOCK_INITIALIZER +# if defined PTHREAD_RWLOCK_INITIALIZER || defined PTHREAD_RWLOCK_INITIALIZER_NP # if !HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER /* glibc with bug https://sourceware.org/bugzilla/show_bug.cgi?id=13701 */ @@ -505,726 +718,32 @@ glthread_once_singlethreaded (pthread_once_t *once_control) return 0; } -#endif - -/* ========================================================================= */ - -#if USE_PTH_THREADS - -/* Use the GNU Pth threads library. */ - -/* -------------------------- gl_lock_t datatype -------------------------- */ - -/* ------------------------- gl_rwlock_t datatype ------------------------- */ - -# if !HAVE_PTH_RWLOCK_ACQUIRE_PREFER_WRITER - -int -glthread_rwlock_init_multithreaded (gl_rwlock_t *lock) -{ - if (!pth_mutex_init (&lock->lock)) - return errno; - if (!pth_cond_init (&lock->waiting_readers)) - return errno; - if (!pth_cond_init (&lock->waiting_writers)) - return errno; - lock->waiting_writers_count = 0; - lock->runcount = 0; - lock->initialized = 1; - return 0; -} - -int -glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock) -{ - if (!lock->initialized) - glthread_rwlock_init_multithreaded (lock); - if (!pth_mutex_acquire (&lock->lock, 0, NULL)) - return errno; - /* Test whether only readers are currently running, and whether the runcount - field will not overflow, and whether no writer is waiting. The latter - condition is because POSIX recommends that "write locks shall take - precedence over read locks", to avoid "writer starvation". */ - while (!(lock->runcount + 1 > 0 && lock->waiting_writers_count == 0)) - { - /* This thread has to wait for a while. Enqueue it among the - waiting_readers. */ - if (!pth_cond_await (&lock->waiting_readers, &lock->lock, NULL)) - { - int err = errno; - pth_mutex_release (&lock->lock); - return err; - } - } - lock->runcount++; - return (!pth_mutex_release (&lock->lock) ? errno : 0); -} - -int -glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock) -{ - if (!lock->initialized) - glthread_rwlock_init_multithreaded (lock); - if (!pth_mutex_acquire (&lock->lock, 0, NULL)) - return errno; - /* Test whether no readers or writers are currently running. */ - while (!(lock->runcount == 0)) - { - /* This thread has to wait for a while. Enqueue it among the - waiting_writers. */ - lock->waiting_writers_count++; - if (!pth_cond_await (&lock->waiting_writers, &lock->lock, NULL)) - { - int err = errno; - lock->waiting_writers_count--; - pth_mutex_release (&lock->lock); - return err; - } - lock->waiting_writers_count--; - } - lock->runcount--; /* runcount becomes -1 */ - return (!pth_mutex_release (&lock->lock) ? errno : 0); -} +# if !(PTHREAD_IN_USE_DETECTION_HARD || USE_POSIX_THREADS_WEAK) int -glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock) +glthread_once_multithreaded (pthread_once_t *once_control, + void (*init_function) (void)) { - int err; - - if (!lock->initialized) - return EINVAL; - if (!pth_mutex_acquire (&lock->lock, 0, NULL)) - return errno; - if (lock->runcount < 0) - { - /* Drop a writer lock. */ - if (!(lock->runcount == -1)) - { - pth_mutex_release (&lock->lock); - return EINVAL; - } - lock->runcount = 0; - } - else + int err = pthread_once (once_control, init_function); + if (err == ENOSYS) { - /* Drop a reader lock. */ - if (!(lock->runcount > 0)) - { - pth_mutex_release (&lock->lock); - return EINVAL; - } - lock->runcount--; - } - if (lock->runcount == 0) - { - /* POSIX recommends that "write locks shall take precedence over read - locks", to avoid "writer starvation". */ - if (lock->waiting_writers_count > 0) - { - /* Wake up one of the waiting writers. */ - if (!pth_cond_notify (&lock->waiting_writers, FALSE)) - { - int err = errno; - pth_mutex_release (&lock->lock); - return err; - } - } - else - { - /* Wake up all waiting readers. */ - if (!pth_cond_notify (&lock->waiting_readers, TRUE)) - { - int err = errno; - pth_mutex_release (&lock->lock); - return err; - } - } + /* This happens on FreeBSD 11: The pthread_once function in libc returns + ENOSYS. */ + if (glthread_once_singlethreaded (once_control)) + init_function (); + return 0; } - return (!pth_mutex_release (&lock->lock) ? errno : 0); -} - -int -glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock) -{ - lock->initialized = 0; - return 0; + return err; } # endif -/* --------------------- gl_recursive_lock_t datatype --------------------- */ - -/* -------------------------- gl_once_t datatype -------------------------- */ - -static void -glthread_once_call (void *arg) -{ - void (**gl_once_temp_addr) (void) = (void (**) (void)) arg; - void (*initfunction) (void) = *gl_once_temp_addr; - initfunction (); -} - -int -glthread_once_multithreaded (pth_once_t *once_control, void (*initfunction) (void)) -{ - void (*temp) (void) = initfunction; - return (!pth_once (once_control, glthread_once_call, &temp) ? errno : 0); -} - -int -glthread_once_singlethreaded (pth_once_t *once_control) -{ - /* We know that pth_once_t is an integer type. */ - if (*once_control == PTH_ONCE_INIT) - { - /* First time use of once_control. Invert the marker. */ - *once_control = ~ PTH_ONCE_INIT; - return 1; - } - else - return 0; -} - -#endif - -/* ========================================================================= */ - -#if USE_SOLARIS_THREADS - -/* Use the old Solaris threads library. */ - -/* -------------------------- gl_lock_t datatype -------------------------- */ - -/* ------------------------- gl_rwlock_t datatype ------------------------- */ - -/* --------------------- gl_recursive_lock_t datatype --------------------- */ - -int -glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock) -{ - int err; - - err = mutex_init (&lock->mutex, USYNC_THREAD, NULL); - if (err != 0) - return err; - lock->owner = (thread_t) 0; - lock->depth = 0; - return 0; -} - -int -glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock) -{ - thread_t self = thr_self (); - if (lock->owner != self) - { - int err; - - err = mutex_lock (&lock->mutex); - if (err != 0) - return err; - lock->owner = self; - } - if (++(lock->depth) == 0) /* wraparound? */ - { - lock->depth--; - return EAGAIN; - } - return 0; -} - -int -glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock) -{ - if (lock->owner != thr_self ()) - return EPERM; - if (lock->depth == 0) - return EINVAL; - if (--(lock->depth) == 0) - { - lock->owner = (thread_t) 0; - return mutex_unlock (&lock->mutex); - } - else - return 0; -} - -int -glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock) -{ - if (lock->owner != (thread_t) 0) - return EBUSY; - return mutex_destroy (&lock->mutex); -} - -/* -------------------------- gl_once_t datatype -------------------------- */ - -int -glthread_once_multithreaded (gl_once_t *once_control, void (*initfunction) (void)) -{ - if (!once_control->inited) - { - int err; - - /* Use the mutex to guarantee that if another thread is already calling - the initfunction, this thread waits until it's finished. */ - err = mutex_lock (&once_control->mutex); - if (err != 0) - return err; - if (!once_control->inited) - { - once_control->inited = 1; - initfunction (); - } - return mutex_unlock (&once_control->mutex); - } - else - return 0; -} - -int -glthread_once_singlethreaded (gl_once_t *once_control) -{ - /* We know that gl_once_t contains an integer type. */ - if (!once_control->inited) - { - /* First time use of once_control. Invert the marker. */ - once_control->inited = ~ 0; - return 1; - } - else - return 0; -} - #endif /* ========================================================================= */ #if USE_WINDOWS_THREADS -/* -------------------------- gl_lock_t datatype -------------------------- */ - -void -glthread_lock_init_func (gl_lock_t *lock) -{ - InitializeCriticalSection (&lock->lock); - lock->guard.done = 1; -} - -int -glthread_lock_lock_func (gl_lock_t *lock) -{ - if (!lock->guard.done) - { - if (InterlockedIncrement (&lock->guard.started) == 0) - /* This thread is the first one to need this lock. Initialize it. */ - glthread_lock_init (lock); - else - /* Yield the CPU while waiting for another thread to finish - initializing this lock. */ - while (!lock->guard.done) - Sleep (0); - } - EnterCriticalSection (&lock->lock); - return 0; -} - -int -glthread_lock_unlock_func (gl_lock_t *lock) -{ - if (!lock->guard.done) - return EINVAL; - LeaveCriticalSection (&lock->lock); - return 0; -} - -int -glthread_lock_destroy_func (gl_lock_t *lock) -{ - if (!lock->guard.done) - return EINVAL; - DeleteCriticalSection (&lock->lock); - lock->guard.done = 0; - return 0; -} - -/* ------------------------- gl_rwlock_t datatype ------------------------- */ - -/* In this file, the waitqueues are implemented as circular arrays. */ -#define gl_waitqueue_t gl_carray_waitqueue_t - -static void -gl_waitqueue_init (gl_waitqueue_t *wq) -{ - wq->array = NULL; - wq->count = 0; - wq->alloc = 0; - wq->offset = 0; -} - -/* Enqueues the current thread, represented by an event, in a wait queue. - Returns INVALID_HANDLE_VALUE if an allocation failure occurs. */ -static HANDLE -gl_waitqueue_add (gl_waitqueue_t *wq) -{ - HANDLE event; - unsigned int index; - - if (wq->count == wq->alloc) - { - unsigned int new_alloc = 2 * wq->alloc + 1; - HANDLE *new_array = - (HANDLE *) realloc (wq->array, new_alloc * sizeof (HANDLE)); - if (new_array == NULL) - /* No more memory. */ - return INVALID_HANDLE_VALUE; - /* Now is a good opportunity to rotate the array so that its contents - starts at offset 0. */ - if (wq->offset > 0) - { - unsigned int old_count = wq->count; - unsigned int old_alloc = wq->alloc; - unsigned int old_offset = wq->offset; - unsigned int i; - if (old_offset + old_count > old_alloc) - { - unsigned int limit = old_offset + old_count - old_alloc; - for (i = 0; i < limit; i++) - new_array[old_alloc + i] = new_array[i]; - } - for (i = 0; i < old_count; i++) - new_array[i] = new_array[old_offset + i]; - wq->offset = 0; - } - wq->array = new_array; - wq->alloc = new_alloc; - } - /* Whether the created event is a manual-reset one or an auto-reset one, - does not matter, since we will wait on it only once. */ - event = CreateEvent (NULL, TRUE, FALSE, NULL); - if (event == INVALID_HANDLE_VALUE) - /* No way to allocate an event. */ - return INVALID_HANDLE_VALUE; - index = wq->offset + wq->count; - if (index >= wq->alloc) - index -= wq->alloc; - wq->array[index] = event; - wq->count++; - return event; -} - -/* Notifies the first thread from a wait queue and dequeues it. */ -static void -gl_waitqueue_notify_first (gl_waitqueue_t *wq) -{ - SetEvent (wq->array[wq->offset + 0]); - wq->offset++; - wq->count--; - if (wq->count == 0 || wq->offset == wq->alloc) - wq->offset = 0; -} - -/* Notifies all threads from a wait queue and dequeues them all. */ -static void -gl_waitqueue_notify_all (gl_waitqueue_t *wq) -{ - unsigned int i; - - for (i = 0; i < wq->count; i++) - { - unsigned int index = wq->offset + i; - if (index >= wq->alloc) - index -= wq->alloc; - SetEvent (wq->array[index]); - } - wq->count = 0; - wq->offset = 0; -} - -void -glthread_rwlock_init_func (gl_rwlock_t *lock) -{ - InitializeCriticalSection (&lock->lock); - gl_waitqueue_init (&lock->waiting_readers); - gl_waitqueue_init (&lock->waiting_writers); - lock->runcount = 0; - lock->guard.done = 1; -} - -int -glthread_rwlock_rdlock_func (gl_rwlock_t *lock) -{ - if (!lock->guard.done) - { - if (InterlockedIncrement (&lock->guard.started) == 0) - /* This thread is the first one to need this lock. Initialize it. */ - glthread_rwlock_init (lock); - else - /* Yield the CPU while waiting for another thread to finish - initializing this lock. */ - while (!lock->guard.done) - Sleep (0); - } - EnterCriticalSection (&lock->lock); - /* Test whether only readers are currently running, and whether the runcount - field will not overflow, and whether no writer is waiting. The latter - condition is because POSIX recommends that "write locks shall take - precedence over read locks", to avoid "writer starvation". */ - if (!(lock->runcount + 1 > 0 && lock->waiting_writers.count == 0)) - { - /* This thread has to wait for a while. Enqueue it among the - waiting_readers. */ - HANDLE event = gl_waitqueue_add (&lock->waiting_readers); - if (event != INVALID_HANDLE_VALUE) - { - DWORD result; - LeaveCriticalSection (&lock->lock); - /* Wait until another thread signals this event. */ - result = WaitForSingleObject (event, INFINITE); - if (result == WAIT_FAILED || result == WAIT_TIMEOUT) - abort (); - CloseHandle (event); - /* The thread which signalled the event already did the bookkeeping: - removed us from the waiting_readers, incremented lock->runcount. */ - if (!(lock->runcount > 0)) - abort (); - return 0; - } - else - { - /* Allocation failure. Weird. */ - do - { - LeaveCriticalSection (&lock->lock); - Sleep (1); - EnterCriticalSection (&lock->lock); - } - while (!(lock->runcount + 1 > 0)); - } - } - lock->runcount++; - LeaveCriticalSection (&lock->lock); - return 0; -} - -int -glthread_rwlock_wrlock_func (gl_rwlock_t *lock) -{ - if (!lock->guard.done) - { - if (InterlockedIncrement (&lock->guard.started) == 0) - /* This thread is the first one to need this lock. Initialize it. */ - glthread_rwlock_init (lock); - else - /* Yield the CPU while waiting for another thread to finish - initializing this lock. */ - while (!lock->guard.done) - Sleep (0); - } - EnterCriticalSection (&lock->lock); - /* Test whether no readers or writers are currently running. */ - if (!(lock->runcount == 0)) - { - /* This thread has to wait for a while. Enqueue it among the - waiting_writers. */ - HANDLE event = gl_waitqueue_add (&lock->waiting_writers); - if (event != INVALID_HANDLE_VALUE) - { - DWORD result; - LeaveCriticalSection (&lock->lock); - /* Wait until another thread signals this event. */ - result = WaitForSingleObject (event, INFINITE); - if (result == WAIT_FAILED || result == WAIT_TIMEOUT) - abort (); - CloseHandle (event); - /* The thread which signalled the event already did the bookkeeping: - removed us from the waiting_writers, set lock->runcount = -1. */ - if (!(lock->runcount == -1)) - abort (); - return 0; - } - else - { - /* Allocation failure. Weird. */ - do - { - LeaveCriticalSection (&lock->lock); - Sleep (1); - EnterCriticalSection (&lock->lock); - } - while (!(lock->runcount == 0)); - } - } - lock->runcount--; /* runcount becomes -1 */ - LeaveCriticalSection (&lock->lock); - return 0; -} - -int -glthread_rwlock_unlock_func (gl_rwlock_t *lock) -{ - if (!lock->guard.done) - return EINVAL; - EnterCriticalSection (&lock->lock); - if (lock->runcount < 0) - { - /* Drop a writer lock. */ - if (!(lock->runcount == -1)) - abort (); - lock->runcount = 0; - } - else - { - /* Drop a reader lock. */ - if (!(lock->runcount > 0)) - { - LeaveCriticalSection (&lock->lock); - return EPERM; - } - lock->runcount--; - } - if (lock->runcount == 0) - { - /* POSIX recommends that "write locks shall take precedence over read - locks", to avoid "writer starvation". */ - if (lock->waiting_writers.count > 0) - { - /* Wake up one of the waiting writers. */ - lock->runcount--; - gl_waitqueue_notify_first (&lock->waiting_writers); - } - else - { - /* Wake up all waiting readers. */ - lock->runcount += lock->waiting_readers.count; - gl_waitqueue_notify_all (&lock->waiting_readers); - } - } - LeaveCriticalSection (&lock->lock); - return 0; -} - -int -glthread_rwlock_destroy_func (gl_rwlock_t *lock) -{ - if (!lock->guard.done) - return EINVAL; - if (lock->runcount != 0) - return EBUSY; - DeleteCriticalSection (&lock->lock); - if (lock->waiting_readers.array != NULL) - free (lock->waiting_readers.array); - if (lock->waiting_writers.array != NULL) - free (lock->waiting_writers.array); - lock->guard.done = 0; - return 0; -} - -/* --------------------- gl_recursive_lock_t datatype --------------------- */ - -void -glthread_recursive_lock_init_func (gl_recursive_lock_t *lock) -{ - lock->owner = 0; - lock->depth = 0; - InitializeCriticalSection (&lock->lock); - lock->guard.done = 1; -} - -int -glthread_recursive_lock_lock_func (gl_recursive_lock_t *lock) -{ - if (!lock->guard.done) - { - if (InterlockedIncrement (&lock->guard.started) == 0) - /* This thread is the first one to need this lock. Initialize it. */ - glthread_recursive_lock_init (lock); - else - /* Yield the CPU while waiting for another thread to finish - initializing this lock. */ - while (!lock->guard.done) - Sleep (0); - } - { - DWORD self = GetCurrentThreadId (); - if (lock->owner != self) - { - EnterCriticalSection (&lock->lock); - lock->owner = self; - } - if (++(lock->depth) == 0) /* wraparound? */ - { - lock->depth--; - return EAGAIN; - } - } - return 0; -} - -int -glthread_recursive_lock_unlock_func (gl_recursive_lock_t *lock) -{ - if (lock->owner != GetCurrentThreadId ()) - return EPERM; - if (lock->depth == 0) - return EINVAL; - if (--(lock->depth) == 0) - { - lock->owner = 0; - LeaveCriticalSection (&lock->lock); - } - return 0; -} - -int -glthread_recursive_lock_destroy_func (gl_recursive_lock_t *lock) -{ - if (lock->owner != 0) - return EBUSY; - DeleteCriticalSection (&lock->lock); - lock->guard.done = 0; - return 0; -} - -/* -------------------------- gl_once_t datatype -------------------------- */ - -void -glthread_once_func (gl_once_t *once_control, void (*initfunction) (void)) -{ - if (once_control->inited <= 0) - { - if (InterlockedIncrement (&once_control->started) == 0) - { - /* This thread is the first one to come to this once_control. */ - InitializeCriticalSection (&once_control->lock); - EnterCriticalSection (&once_control->lock); - once_control->inited = 0; - initfunction (); - once_control->inited = 1; - LeaveCriticalSection (&once_control->lock); - } - else - { - /* Undo last operation. */ - InterlockedDecrement (&once_control->started); - /* Some other thread has already started the initialization. - Yield the CPU while waiting for the other thread to finish - initializing and taking the lock. */ - while (once_control->inited < 0) - Sleep (0); - if (once_control->inited <= 0) - { - /* Take the lock. This blocks until the other thread has - finished calling the initfunction. */ - EnterCriticalSection (&once_control->lock); - LeaveCriticalSection (&once_control->lock); - if (!(once_control->inited > 0)) - abort (); - } - } - } -} - #endif /* ========================================================================= */ diff --git a/lib/glthread/lock.h b/lib/glthread/lock.h index 2d8d5abb..47eed8fe 100644 --- a/lib/glthread/lock.h +++ b/lib/glthread/lock.h @@ -1,31 +1,21 @@ /* Locking in multithreaded situations. - Copyright (C) 2005-2018 Free Software Foundation, Inc. + Copyright (C) 2005-2022 Free Software Foundation, Inc. - This program is free software: you can redistribute it and/or - modify it under the terms of either: + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. - * the GNU Lesser General Public License as published by the Free - Software Foundation; either version 3 of the License, or (at your - option) any later version. - - or - - * the GNU General Public License as published by the Free - Software Foundation; either version 2 of the License, or (at your - option) any later version. - - or both in parallel, as here. - This program is distributed in the hope that it will be useful, + This file is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. + GNU Lesser General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program; if not, see <https://www.gnu.org/licenses/>. */ + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ /* Written by Bruno Haible <bruno@clisp.org>, 2005. - Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h, - gthr-win32.h. */ + Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-win32.h. */ /* This file contains locking primitives for use with a given thread library. It does not contain primitives for creating threads or for other @@ -90,6 +80,127 @@ #include <errno.h> #include <stdlib.h> +#if !defined c11_threads_in_use +# if HAVE_THREADS_H && USE_POSIX_THREADS_FROM_LIBC +# define c11_threads_in_use() 1 +# elif HAVE_THREADS_H && USE_POSIX_THREADS_WEAK +# include <threads.h> +# pragma weak thrd_exit +# define c11_threads_in_use() (thrd_exit != NULL) +# else +# define c11_threads_in_use() 0 +# endif +#endif + +/* ========================================================================= */ + +#if USE_ISOC_THREADS || USE_ISOC_AND_POSIX_THREADS + +/* Use the ISO C threads library. */ + +# include <threads.h> + +# ifdef __cplusplus +extern "C" { +# endif + +/* -------------------------- gl_lock_t datatype -------------------------- */ + +typedef struct + { + int volatile init_needed; + once_flag init_once; + void (*init_func) (void); + mtx_t mutex; + } + gl_lock_t; +# define gl_lock_define(STORAGECLASS, NAME) \ + STORAGECLASS gl_lock_t NAME; +# define gl_lock_define_initialized(STORAGECLASS, NAME) \ + static void _atomic_init_##NAME (void); \ + STORAGECLASS gl_lock_t NAME = \ + { 1, ONCE_FLAG_INIT, _atomic_init_##NAME }; \ + static void _atomic_init_##NAME (void) \ + { \ + if (glthread_lock_init (&(NAME))) \ + abort (); \ + } +extern int glthread_lock_init (gl_lock_t *lock); +extern int glthread_lock_lock (gl_lock_t *lock); +extern int glthread_lock_unlock (gl_lock_t *lock); +extern int glthread_lock_destroy (gl_lock_t *lock); + +/* ------------------------- gl_rwlock_t datatype ------------------------- */ + +typedef struct + { + int volatile init_needed; + once_flag init_once; + void (*init_func) (void); + mtx_t lock; /* protects the remaining fields */ + cnd_t waiting_readers; /* waiting readers */ + cnd_t waiting_writers; /* waiting writers */ + unsigned int waiting_writers_count; /* number of waiting writers */ + int runcount; /* number of readers running, or -1 when a writer runs */ + } + gl_rwlock_t; +# define gl_rwlock_define(STORAGECLASS, NAME) \ + STORAGECLASS gl_rwlock_t NAME; +# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \ + static void _atomic_init_##NAME (void); \ + STORAGECLASS gl_rwlock_t NAME = \ + { 1, ONCE_FLAG_INIT, _atomic_init_##NAME }; \ + static void _atomic_init_##NAME (void) \ + { \ + if (glthread_rwlock_init (&(NAME))) \ + abort (); \ + } +extern int glthread_rwlock_init (gl_rwlock_t *lock); +extern int glthread_rwlock_rdlock (gl_rwlock_t *lock); +extern int glthread_rwlock_wrlock (gl_rwlock_t *lock); +extern int glthread_rwlock_unlock (gl_rwlock_t *lock); +extern int glthread_rwlock_destroy (gl_rwlock_t *lock); + +/* --------------------- gl_recursive_lock_t datatype --------------------- */ + +typedef struct + { + int volatile init_needed; + once_flag init_once; + void (*init_func) (void); + mtx_t mutex; + } + gl_recursive_lock_t; +# define gl_recursive_lock_define(STORAGECLASS, NAME) \ + STORAGECLASS gl_recursive_lock_t NAME; +# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \ + static void _atomic_init_##NAME (void); \ + STORAGECLASS gl_recursive_lock_t NAME = \ + { 1, ONCE_FLAG_INIT, _atomic_init_##NAME }; \ + static void _atomic_init_##NAME (void) \ + { \ + if (glthread_recursive_lock_init (&(NAME))) \ + abort (); \ + } +extern int glthread_recursive_lock_init (gl_recursive_lock_t *lock); +extern int glthread_recursive_lock_lock (gl_recursive_lock_t *lock); +extern int glthread_recursive_lock_unlock (gl_recursive_lock_t *lock); +extern int glthread_recursive_lock_destroy (gl_recursive_lock_t *lock); + +/* -------------------------- gl_once_t datatype -------------------------- */ + +typedef once_flag gl_once_t; +# define gl_once_define(STORAGECLASS, NAME) \ + STORAGECLASS once_flag NAME = ONCE_FLAG_INIT; +# define glthread_once(ONCE_CONTROL, INITFUNCTION) \ + (call_once (ONCE_CONTROL, INITFUNCTION), 0) + +# ifdef __cplusplus +} +# endif + +#endif + /* ========================================================================= */ #if USE_POSIX_THREADS @@ -165,7 +276,8 @@ extern int glthread_in_use (void); pthread_rwlockattr_init */ # pragma weak pthread_mutexattr_gettype -# define pthread_in_use() (pthread_mutexattr_gettype != NULL) +# define pthread_in_use() \ + (pthread_mutexattr_gettype != NULL || c11_threads_in_use ()) # endif # else @@ -198,7 +310,7 @@ typedef pthread_mutex_t gl_lock_t; # if HAVE_PTHREAD_RWLOCK && (HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER || (defined PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP && (__GNU_LIBRARY__ > 1))) -# ifdef PTHREAD_RWLOCK_INITIALIZER +# if defined PTHREAD_RWLOCK_INITIALIZER || defined PTHREAD_RWLOCK_INITIALIZER_NP typedef pthread_rwlock_t gl_rwlock_t; # define gl_rwlock_define(STORAGECLASS, NAME) \ @@ -206,8 +318,13 @@ typedef pthread_rwlock_t gl_rwlock_t; # define gl_rwlock_define_initialized(STORAGECLASS, NAME) \ STORAGECLASS pthread_rwlock_t NAME = gl_rwlock_initializer; # if HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER -# define gl_rwlock_initializer \ - PTHREAD_RWLOCK_INITIALIZER +# if defined PTHREAD_RWLOCK_INITIALIZER +# define gl_rwlock_initializer \ + PTHREAD_RWLOCK_INITIALIZER +# else +# define gl_rwlock_initializer \ + PTHREAD_RWLOCK_INITIALIZER_NP +# endif # define glthread_rwlock_init(LOCK) \ (pthread_in_use () ? pthread_rwlock_init (LOCK, NULL) : 0) # else /* glibc with bug https://sourceware.org/bugzilla/show_bug.cgi?id=13701 */ @@ -390,287 +507,20 @@ extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *l typedef pthread_once_t gl_once_t; # define gl_once_define(STORAGECLASS, NAME) \ STORAGECLASS pthread_once_t NAME = PTHREAD_ONCE_INIT; -# define glthread_once(ONCE_CONTROL, INITFUNCTION) \ - (pthread_in_use () \ - ? pthread_once (ONCE_CONTROL, INITFUNCTION) \ - : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0)) -extern int glthread_once_singlethreaded (pthread_once_t *once_control); - -# ifdef __cplusplus -} -# endif - -#endif - -/* ========================================================================= */ - -#if USE_PTH_THREADS - -/* Use the GNU Pth threads library. */ - -# include <pth.h> - -# ifdef __cplusplus -extern "C" { -# endif - -# if USE_PTH_THREADS_WEAK - -/* Use weak references to the GNU Pth threads library. */ - -# pragma weak pth_mutex_init -# pragma weak pth_mutex_acquire -# pragma weak pth_mutex_release -# pragma weak pth_rwlock_init -# pragma weak pth_rwlock_acquire -# pragma weak pth_rwlock_release -# pragma weak pth_once - -# pragma weak pth_cancel -# define pth_in_use() (pth_cancel != NULL) - -# else - -# define pth_in_use() 1 - -# endif - -/* -------------------------- gl_lock_t datatype -------------------------- */ - -typedef pth_mutex_t gl_lock_t; -# define gl_lock_define(STORAGECLASS, NAME) \ - STORAGECLASS pth_mutex_t NAME; -# define gl_lock_define_initialized(STORAGECLASS, NAME) \ - STORAGECLASS pth_mutex_t NAME = gl_lock_initializer; -# define gl_lock_initializer \ - PTH_MUTEX_INIT -# define glthread_lock_init(LOCK) \ - (pth_in_use () && !pth_mutex_init (LOCK) ? errno : 0) -# define glthread_lock_lock(LOCK) \ - (pth_in_use () && !pth_mutex_acquire (LOCK, 0, NULL) ? errno : 0) -# define glthread_lock_unlock(LOCK) \ - (pth_in_use () && !pth_mutex_release (LOCK) ? errno : 0) -# define glthread_lock_destroy(LOCK) \ - ((void)(LOCK), 0) - -/* ------------------------- gl_rwlock_t datatype ------------------------- */ - -/* Pth pth_rwlock_acquire always prefers readers. No autoconf test so far. */ -# if HAVE_PTH_RWLOCK_ACQUIRE_PREFER_WRITER - -typedef pth_rwlock_t gl_rwlock_t; -# define gl_rwlock_define(STORAGECLASS, NAME) \ - STORAGECLASS pth_rwlock_t NAME; -# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \ - STORAGECLASS pth_rwlock_t NAME = gl_rwlock_initializer; -# define gl_rwlock_initializer \ - PTH_RWLOCK_INIT -# define glthread_rwlock_init(LOCK) \ - (pth_in_use () && !pth_rwlock_init (LOCK) ? errno : 0) -# define glthread_rwlock_rdlock(LOCK) \ - (pth_in_use () && !pth_rwlock_acquire (LOCK, PTH_RWLOCK_RD, 0, NULL) ? errno : 0) -# define glthread_rwlock_wrlock(LOCK) \ - (pth_in_use () && !pth_rwlock_acquire (LOCK, PTH_RWLOCK_RW, 0, NULL) ? errno : 0) -# define glthread_rwlock_unlock(LOCK) \ - (pth_in_use () && !pth_rwlock_release (LOCK) ? errno : 0) -# define glthread_rwlock_destroy(LOCK) \ - ((void)(LOCK), 0) - -# else - -typedef struct - { - int initialized; - pth_mutex_t lock; /* protects the remaining fields */ - pth_cond_t waiting_readers; /* waiting readers */ - pth_cond_t waiting_writers; /* waiting writers */ - unsigned int waiting_writers_count; /* number of waiting writers */ - int runcount; /* number of readers running, or -1 when a writer runs */ - } - gl_rwlock_t; -# define gl_rwlock_define(STORAGECLASS, NAME) \ - STORAGECLASS gl_rwlock_t NAME; -# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \ - STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer; -# define gl_rwlock_initializer \ - { 0 } -# define glthread_rwlock_init(LOCK) \ - (pth_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0) -# define glthread_rwlock_rdlock(LOCK) \ - (pth_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0) -# define glthread_rwlock_wrlock(LOCK) \ - (pth_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0) -# define glthread_rwlock_unlock(LOCK) \ - (pth_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0) -# define glthread_rwlock_destroy(LOCK) \ - (pth_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0) -extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock); -extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock); -extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock); -extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock); -extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock); - -# endif - -/* --------------------- gl_recursive_lock_t datatype --------------------- */ - -/* In Pth, mutexes are recursive by default. */ -typedef pth_mutex_t gl_recursive_lock_t; -# define gl_recursive_lock_define(STORAGECLASS, NAME) \ - STORAGECLASS pth_mutex_t NAME; -# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \ - STORAGECLASS pth_mutex_t NAME = gl_recursive_lock_initializer; -# define gl_recursive_lock_initializer \ - PTH_MUTEX_INIT -# define glthread_recursive_lock_init(LOCK) \ - (pth_in_use () && !pth_mutex_init (LOCK) ? errno : 0) -# define glthread_recursive_lock_lock(LOCK) \ - (pth_in_use () && !pth_mutex_acquire (LOCK, 0, NULL) ? errno : 0) -# define glthread_recursive_lock_unlock(LOCK) \ - (pth_in_use () && !pth_mutex_release (LOCK) ? errno : 0) -# define glthread_recursive_lock_destroy(LOCK) \ - ((void)(LOCK), 0) - -/* -------------------------- gl_once_t datatype -------------------------- */ - -typedef pth_once_t gl_once_t; -# define gl_once_define(STORAGECLASS, NAME) \ - STORAGECLASS pth_once_t NAME = PTH_ONCE_INIT; -# define glthread_once(ONCE_CONTROL, INITFUNCTION) \ - (pth_in_use () \ - ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION) \ - : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0)) -extern int glthread_once_multithreaded (pth_once_t *once_control, void (*initfunction) (void)); -extern int glthread_once_singlethreaded (pth_once_t *once_control); - -# ifdef __cplusplus -} -# endif - -#endif - -/* ========================================================================= */ - -#if USE_SOLARIS_THREADS - -/* Use the old Solaris threads library. */ - -# include <thread.h> -# include <synch.h> - -# ifdef __cplusplus -extern "C" { -# endif - -# if USE_SOLARIS_THREADS_WEAK - -/* Use weak references to the old Solaris threads library. */ - -# pragma weak mutex_init -# pragma weak mutex_lock -# pragma weak mutex_unlock -# pragma weak mutex_destroy -# pragma weak rwlock_init -# pragma weak rw_rdlock -# pragma weak rw_wrlock -# pragma weak rw_unlock -# pragma weak rwlock_destroy -# pragma weak thr_self - -# pragma weak thr_suspend -# define thread_in_use() (thr_suspend != NULL) - +# if PTHREAD_IN_USE_DETECTION_HARD || USE_POSIX_THREADS_WEAK +# define glthread_once(ONCE_CONTROL, INITFUNCTION) \ + (pthread_in_use () \ + ? pthread_once (ONCE_CONTROL, INITFUNCTION) \ + : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0)) # else - -# define thread_in_use() 1 - +# define glthread_once(ONCE_CONTROL, INITFUNCTION) \ + (pthread_in_use () \ + ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION) \ + : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0)) +extern int glthread_once_multithreaded (pthread_once_t *once_control, + void (*init_function) (void)); # endif - -/* -------------------------- gl_lock_t datatype -------------------------- */ - -typedef mutex_t gl_lock_t; -# define gl_lock_define(STORAGECLASS, NAME) \ - STORAGECLASS mutex_t NAME; -# define gl_lock_define_initialized(STORAGECLASS, NAME) \ - STORAGECLASS mutex_t NAME = gl_lock_initializer; -# define gl_lock_initializer \ - DEFAULTMUTEX -# define glthread_lock_init(LOCK) \ - (thread_in_use () ? mutex_init (LOCK, USYNC_THREAD, NULL) : 0) -# define glthread_lock_lock(LOCK) \ - (thread_in_use () ? mutex_lock (LOCK) : 0) -# define glthread_lock_unlock(LOCK) \ - (thread_in_use () ? mutex_unlock (LOCK) : 0) -# define glthread_lock_destroy(LOCK) \ - (thread_in_use () ? mutex_destroy (LOCK) : 0) - -/* ------------------------- gl_rwlock_t datatype ------------------------- */ - -typedef rwlock_t gl_rwlock_t; -# define gl_rwlock_define(STORAGECLASS, NAME) \ - STORAGECLASS rwlock_t NAME; -# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \ - STORAGECLASS rwlock_t NAME = gl_rwlock_initializer; -# define gl_rwlock_initializer \ - DEFAULTRWLOCK -# define glthread_rwlock_init(LOCK) \ - (thread_in_use () ? rwlock_init (LOCK, USYNC_THREAD, NULL) : 0) -# define glthread_rwlock_rdlock(LOCK) \ - (thread_in_use () ? rw_rdlock (LOCK) : 0) -# define glthread_rwlock_wrlock(LOCK) \ - (thread_in_use () ? rw_wrlock (LOCK) : 0) -# define glthread_rwlock_unlock(LOCK) \ - (thread_in_use () ? rw_unlock (LOCK) : 0) -# define glthread_rwlock_destroy(LOCK) \ - (thread_in_use () ? rwlock_destroy (LOCK) : 0) - -/* --------------------- gl_recursive_lock_t datatype --------------------- */ - -/* Old Solaris threads did not have recursive locks. - We have to implement them ourselves. */ - -typedef struct - { - mutex_t mutex; - thread_t owner; - unsigned long depth; - } - gl_recursive_lock_t; -# define gl_recursive_lock_define(STORAGECLASS, NAME) \ - STORAGECLASS gl_recursive_lock_t NAME; -# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \ - STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer; -# define gl_recursive_lock_initializer \ - { DEFAULTMUTEX, (thread_t) 0, 0 } -# define glthread_recursive_lock_init(LOCK) \ - (thread_in_use () ? glthread_recursive_lock_init_multithreaded (LOCK) : 0) -# define glthread_recursive_lock_lock(LOCK) \ - (thread_in_use () ? glthread_recursive_lock_lock_multithreaded (LOCK) : 0) -# define glthread_recursive_lock_unlock(LOCK) \ - (thread_in_use () ? glthread_recursive_lock_unlock_multithreaded (LOCK) : 0) -# define glthread_recursive_lock_destroy(LOCK) \ - (thread_in_use () ? glthread_recursive_lock_destroy_multithreaded (LOCK) : 0) -extern int glthread_recursive_lock_init_multithreaded (gl_recursive_lock_t *lock); -extern int glthread_recursive_lock_lock_multithreaded (gl_recursive_lock_t *lock); -extern int glthread_recursive_lock_unlock_multithreaded (gl_recursive_lock_t *lock); -extern int glthread_recursive_lock_destroy_multithreaded (gl_recursive_lock_t *lock); - -/* -------------------------- gl_once_t datatype -------------------------- */ - -typedef struct - { - volatile int inited; - mutex_t mutex; - } - gl_once_t; -# define gl_once_define(STORAGECLASS, NAME) \ - STORAGECLASS gl_once_t NAME = { 0, DEFAULTMUTEX }; -# define glthread_once(ONCE_CONTROL, INITFUNCTION) \ - (thread_in_use () \ - ? glthread_once_multithreaded (ONCE_CONTROL, INITFUNCTION) \ - : (glthread_once_singlethreaded (ONCE_CONTROL) ? (INITFUNCTION (), 0) : 0)) -extern int glthread_once_multithreaded (gl_once_t *once_control, void (*initfunction) (void)); -extern int glthread_once_singlethreaded (gl_once_t *once_control); +extern int glthread_once_singlethreaded (pthread_once_t *once_control); # ifdef __cplusplus } @@ -685,6 +535,11 @@ extern int glthread_once_singlethreaded (gl_once_t *once_control); # define WIN32_LEAN_AND_MEAN /* avoid including junk */ # include <windows.h> +# include "windows-mutex.h" +# include "windows-rwlock.h" +# include "windows-recmutex.h" +# include "windows-once.h" + # ifdef __cplusplus extern "C" { # endif @@ -700,127 +555,69 @@ extern "C" { /* There is no way to statically initialize a CRITICAL_SECTION. It needs to be done lazily, once only. For this we need spinlocks. */ -typedef struct { volatile int done; volatile long started; } gl_spinlock_t; - /* -------------------------- gl_lock_t datatype -------------------------- */ -typedef struct - { - gl_spinlock_t guard; /* protects the initialization */ - CRITICAL_SECTION lock; - } - gl_lock_t; +typedef glwthread_mutex_t gl_lock_t; # define gl_lock_define(STORAGECLASS, NAME) \ STORAGECLASS gl_lock_t NAME; # define gl_lock_define_initialized(STORAGECLASS, NAME) \ STORAGECLASS gl_lock_t NAME = gl_lock_initializer; # define gl_lock_initializer \ - { { 0, -1 } } + GLWTHREAD_MUTEX_INIT # define glthread_lock_init(LOCK) \ - (glthread_lock_init_func (LOCK), 0) + (glwthread_mutex_init (LOCK), 0) # define glthread_lock_lock(LOCK) \ - glthread_lock_lock_func (LOCK) + glwthread_mutex_lock (LOCK) # define glthread_lock_unlock(LOCK) \ - glthread_lock_unlock_func (LOCK) + glwthread_mutex_unlock (LOCK) # define glthread_lock_destroy(LOCK) \ - glthread_lock_destroy_func (LOCK) -extern void glthread_lock_init_func (gl_lock_t *lock); -extern int glthread_lock_lock_func (gl_lock_t *lock); -extern int glthread_lock_unlock_func (gl_lock_t *lock); -extern int glthread_lock_destroy_func (gl_lock_t *lock); + glwthread_mutex_destroy (LOCK) /* ------------------------- gl_rwlock_t datatype ------------------------- */ -/* It is impossible to implement read-write locks using plain locks, without - introducing an extra thread dedicated to managing read-write locks. - Therefore here we need to use the low-level Event type. */ - -typedef struct - { - HANDLE *array; /* array of waiting threads, each represented by an event */ - unsigned int count; /* number of waiting threads */ - unsigned int alloc; /* length of allocated array */ - unsigned int offset; /* index of first waiting thread in array */ - } - gl_carray_waitqueue_t; -typedef struct - { - gl_spinlock_t guard; /* protects the initialization */ - CRITICAL_SECTION lock; /* protects the remaining fields */ - gl_carray_waitqueue_t waiting_readers; /* waiting readers */ - gl_carray_waitqueue_t waiting_writers; /* waiting writers */ - int runcount; /* number of readers running, or -1 when a writer runs */ - } - gl_rwlock_t; +typedef glwthread_rwlock_t gl_rwlock_t; # define gl_rwlock_define(STORAGECLASS, NAME) \ STORAGECLASS gl_rwlock_t NAME; # define gl_rwlock_define_initialized(STORAGECLASS, NAME) \ STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer; # define gl_rwlock_initializer \ - { { 0, -1 } } + GLWTHREAD_RWLOCK_INIT # define glthread_rwlock_init(LOCK) \ - (glthread_rwlock_init_func (LOCK), 0) + (glwthread_rwlock_init (LOCK), 0) # define glthread_rwlock_rdlock(LOCK) \ - glthread_rwlock_rdlock_func (LOCK) + glwthread_rwlock_rdlock (LOCK) # define glthread_rwlock_wrlock(LOCK) \ - glthread_rwlock_wrlock_func (LOCK) + glwthread_rwlock_wrlock (LOCK) # define glthread_rwlock_unlock(LOCK) \ - glthread_rwlock_unlock_func (LOCK) + glwthread_rwlock_unlock (LOCK) # define glthread_rwlock_destroy(LOCK) \ - glthread_rwlock_destroy_func (LOCK) -extern void glthread_rwlock_init_func (gl_rwlock_t *lock); -extern int glthread_rwlock_rdlock_func (gl_rwlock_t *lock); -extern int glthread_rwlock_wrlock_func (gl_rwlock_t *lock); -extern int glthread_rwlock_unlock_func (gl_rwlock_t *lock); -extern int glthread_rwlock_destroy_func (gl_rwlock_t *lock); + glwthread_rwlock_destroy (LOCK) /* --------------------- gl_recursive_lock_t datatype --------------------- */ -/* The native Windows documentation says that CRITICAL_SECTION already - implements a recursive lock. But we need not rely on it: It's easy to - implement a recursive lock without this assumption. */ - -typedef struct - { - gl_spinlock_t guard; /* protects the initialization */ - DWORD owner; - unsigned long depth; - CRITICAL_SECTION lock; - } - gl_recursive_lock_t; +typedef glwthread_recmutex_t gl_recursive_lock_t; # define gl_recursive_lock_define(STORAGECLASS, NAME) \ STORAGECLASS gl_recursive_lock_t NAME; # define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \ STORAGECLASS gl_recursive_lock_t NAME = gl_recursive_lock_initializer; # define gl_recursive_lock_initializer \ - { { 0, -1 }, 0, 0 } + GLWTHREAD_RECMUTEX_INIT # define glthread_recursive_lock_init(LOCK) \ - (glthread_recursive_lock_init_func (LOCK), 0) + (glwthread_recmutex_init (LOCK), 0) # define glthread_recursive_lock_lock(LOCK) \ - glthread_recursive_lock_lock_func (LOCK) + glwthread_recmutex_lock (LOCK) # define glthread_recursive_lock_unlock(LOCK) \ - glthread_recursive_lock_unlock_func (LOCK) + glwthread_recmutex_unlock (LOCK) # define glthread_recursive_lock_destroy(LOCK) \ - glthread_recursive_lock_destroy_func (LOCK) -extern void glthread_recursive_lock_init_func (gl_recursive_lock_t *lock); -extern int glthread_recursive_lock_lock_func (gl_recursive_lock_t *lock); -extern int glthread_recursive_lock_unlock_func (gl_recursive_lock_t *lock); -extern int glthread_recursive_lock_destroy_func (gl_recursive_lock_t *lock); + glwthread_recmutex_destroy (LOCK) /* -------------------------- gl_once_t datatype -------------------------- */ -typedef struct - { - volatile int inited; - volatile long started; - CRITICAL_SECTION lock; - } - gl_once_t; +typedef glwthread_once_t gl_once_t; # define gl_once_define(STORAGECLASS, NAME) \ - STORAGECLASS gl_once_t NAME = { -1, -1 }; + STORAGECLASS gl_once_t NAME = GLWTHREAD_ONCE_INIT; # define glthread_once(ONCE_CONTROL, INITFUNCTION) \ - (glthread_once_func (ONCE_CONTROL, INITFUNCTION), 0) -extern void glthread_once_func (gl_once_t *once_control, void (*initfunction) (void)); + (glwthread_once (ONCE_CONTROL, INITFUNCTION), 0) # ifdef __cplusplus } @@ -830,7 +627,7 @@ extern void glthread_once_func (gl_once_t *once_control, void (*initfunction) (v /* ========================================================================= */ -#if !(USE_POSIX_THREADS || USE_PTH_THREADS || USE_SOLARIS_THREADS || USE_WINDOWS_THREADS) +#if !(USE_ISOC_THREADS || USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS || USE_WINDOWS_THREADS) /* Provide dummy implementation if threads are not supported. */ diff --git a/lib/glthread/threadlib.c b/lib/glthread/threadlib.c index 3534b61e..88a76bad 100644 --- a/lib/glthread/threadlib.c +++ b/lib/glthread/threadlib.c @@ -1,27 +1,18 @@ /* Multithreading primitives. - Copyright (C) 2005-2018 Free Software Foundation, Inc. + Copyright (C) 2005-2022 Free Software Foundation, Inc. - This program is free software: you can redistribute it and/or - modify it under the terms of either: + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. - * the GNU Lesser General Public License as published by the Free - Software Foundation; either version 3 of the License, or (at your - option) any later version. - - or - - * the GNU General Public License as published by the Free - Software Foundation; either version 2 of the License, or (at your - option) any later version. - - or both in parallel, as here. - This program is distributed in the hope that it will be useful, + This file is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. + GNU Lesser General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program; if not, see <https://www.gnu.org/licenses/>. */ + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ /* Written by Bruno Haible <bruno@clisp.org>, 2005. */ @@ -29,15 +20,48 @@ /* ========================================================================= */ -#if USE_POSIX_THREADS +#if USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS /* Use the POSIX threads library. */ +# include <errno.h> # include <pthread.h> # include <stdlib.h> # if PTHREAD_IN_USE_DETECTION_HARD +# if defined __FreeBSD__ || defined __DragonFly__ /* FreeBSD */ + +/* Test using pthread_key_create. */ + +int +glthread_in_use (void) +{ + static int tested; + static int result; /* 1: linked with -lpthread, 0: only with libc */ + + if (!tested) + { + pthread_key_t key; + int err = pthread_key_create (&key, NULL); + + if (err == ENOSYS) + result = 0; + else + { + result = 1; + if (err == 0) + pthread_key_delete (key); + } + tested = 1; + } + return result; +} + +# else /* Solaris, HP-UX */ + +/* Test using pthread_create. */ + /* The function to be executed by a dummy thread. */ static void * dummy_thread_func (void *arg) @@ -71,6 +95,8 @@ glthread_in_use (void) return result; } +# endif + # endif #endif |