X-Git-Url: http://git.madism.org/?a=blobdiff_plain;f=intl%2Flock.c;fp=intl%2Flock.c;h=0000000000000000000000000000000000000000;hb=e7a772dca1b86e4036d25038ee67aa34dd217c07;hp=a860459d12153ab23017ce64ddebd293e081311c;hpb=366c938a78d928880c77bfe31a8715184c918d41;p=apps%2Fmadmutt.git diff --git a/intl/lock.c b/intl/lock.c deleted file mode 100644 index a860459..0000000 --- a/intl/lock.c +++ /dev/null @@ -1,924 +0,0 @@ -/* Locking in multithreaded situations. - Copyright (C) 2005 Free Software Foundation, Inc. - - This program is free software; you can redistribute it and/or modify it - under the terms of the GNU Library General Public License as published - by the Free Software Foundation; either version 2, or (at your option) - any later version. - - This program 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 - Library General Public License for more details. - - You should have received a copy of the GNU Library General Public - License along with this program; if not, write to the Free Software - Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, - USA. */ - -/* Written by Bruno Haible , 2005. - Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h, - gthr-win32.h. */ - -#ifdef HAVE_CONFIG_H -# include -#endif - -#include "lock.h" - -/* ========================================================================= */ - -#if USE_POSIX_THREADS - -/* Use the POSIX threads library. */ - -# if PTHREAD_IN_USE_DETECTION_HARD - -/* The function to be executed by a dummy thread. */ -static void * -dummy_thread_func (void *arg) -{ - return arg; -} - -int -glthread_in_use (void) -{ - static int tested; - static int result; /* 1: linked with -lpthread, 0: only with libc */ - - if (!tested) - { - pthread_t thread; - - if (pthread_create (&thread, NULL, dummy_thread_func, NULL) != 0) - /* Thread creation failed. */ - result = 0; - else - { - /* Thread creation works. */ - void *retval; - if (pthread_join (thread, &retval) != 0) - abort (); - result = 1; - } - tested = 1; - } - return result; -} - -# endif - -/* -------------------------- gl_lock_t datatype -------------------------- */ - -/* ------------------------- gl_rwlock_t datatype ------------------------- */ - -# if HAVE_PTHREAD_RWLOCK - -# if !defined PTHREAD_RWLOCK_INITIALIZER - -void -glthread_rwlock_init (gl_rwlock_t *lock) -{ - if (pthread_rwlock_init (&lock->rwlock, NULL) != 0) - abort (); - lock->initialized = 1; -} - -void -glthread_rwlock_rdlock (gl_rwlock_t *lock) -{ - if (!lock->initialized) - { - if (pthread_mutex_lock (&lock->guard) != 0) - abort (); - if (!lock->initialized) - glthread_rwlock_init (lock); - if (pthread_mutex_unlock (&lock->guard) != 0) - abort (); - } - if (pthread_rwlock_rdlock (&lock->rwlock) != 0) - abort (); -} - -void -glthread_rwlock_wrlock (gl_rwlock_t *lock) -{ - if (!lock->initialized) - { - if (pthread_mutex_lock (&lock->guard) != 0) - abort (); - if (!lock->initialized) - glthread_rwlock_init (lock); - if (pthread_mutex_unlock (&lock->guard) != 0) - abort (); - } - if (pthread_rwlock_wrlock (&lock->rwlock) != 0) - abort (); -} - -void -glthread_rwlock_unlock (gl_rwlock_t *lock) -{ - if (!lock->initialized) - abort (); - if (pthread_rwlock_unlock (&lock->rwlock) != 0) - abort (); -} - -void -glthread_rwlock_destroy (gl_rwlock_t *lock) -{ - if (!lock->initialized) - abort (); - if (pthread_rwlock_destroy (&lock->rwlock) != 0) - abort (); - lock->initialized = 0; -} - -# endif - -# else - -void -glthread_rwlock_init (gl_rwlock_t *lock) -{ - if (pthread_mutex_init (&lock->lock, NULL) != 0) - abort (); - if (pthread_cond_init (&lock->waiting_readers, NULL) != 0) - abort (); - if (pthread_cond_init (&lock->waiting_writers, NULL) != 0) - abort (); - lock->waiting_writers_count = 0; - lock->runcount = 0; -} - -void -glthread_rwlock_rdlock (gl_rwlock_t *lock) -{ - if (pthread_mutex_lock (&lock->lock) != 0) - abort (); - /* Test whether only readers are currently running, and whether the runcount - field will not overflow. */ - /* POSIX says: "It is implementation-defined whether the calling thread - acquires the lock when a writer does not hold the lock and there are - writers blocked on the lock." Let's say, no: give the writers a higher - priority. */ - 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 (pthread_cond_wait (&lock->waiting_readers, &lock->lock) != 0) - abort (); - } - lock->runcount++; - if (pthread_mutex_unlock (&lock->lock) != 0) - abort (); -} - -void -glthread_rwlock_wrlock (gl_rwlock_t *lock) -{ - if (pthread_mutex_lock (&lock->lock) != 0) - abort (); - /* 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 (pthread_cond_wait (&lock->waiting_writers, &lock->lock) != 0) - abort (); - lock->waiting_writers_count--; - } - lock->runcount--; /* runcount becomes -1 */ - if (pthread_mutex_unlock (&lock->lock) != 0) - abort (); -} - -void -glthread_rwlock_unlock (gl_rwlock_t *lock) -{ - if (pthread_mutex_lock (&lock->lock) != 0) - abort (); - 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)) - abort (); - 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 (pthread_cond_signal (&lock->waiting_writers) != 0) - abort (); - } - else - { - /* Wake up all waiting readers. */ - if (pthread_cond_broadcast (&lock->waiting_readers) != 0) - abort (); - } - } - if (pthread_mutex_unlock (&lock->lock) != 0) - abort (); -} - -void -glthread_rwlock_destroy (gl_rwlock_t *lock) -{ - if (pthread_mutex_destroy (&lock->lock) != 0) - abort (); - if (pthread_cond_destroy (&lock->waiting_readers) != 0) - abort (); - if (pthread_cond_destroy (&lock->waiting_writers) != 0) - abort (); -} - -# endif - -/* --------------------- gl_recursive_lock_t datatype --------------------- */ - -# if HAVE_PTHREAD_MUTEX_RECURSIVE - -# if !(defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER || defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP) - -void -glthread_recursive_lock_init (gl_recursive_lock_t *lock) -{ - pthread_mutexattr_t attributes; - - if (pthread_mutexattr_init (&attributes) != 0) - abort (); - if (pthread_mutexattr_settype (&attributes, PTHREAD_MUTEX_RECURSIVE) != 0) - abort (); - if (pthread_mutex_init (&lock->recmutex, &attributes) != 0) - abort (); - if (pthread_mutexattr_destroy (&attributes) != 0) - abort (); - lock->initialized = 1; -} - -void -glthread_recursive_lock_lock (gl_recursive_lock_t *lock) -{ - if (!lock->initialized) - { - if (pthread_mutex_lock (&lock->guard) != 0) - abort (); - if (!lock->initialized) - glthread_recursive_lock_init (lock); - if (pthread_mutex_unlock (&lock->guard) != 0) - abort (); - } - if (pthread_mutex_lock (&lock->recmutex) != 0) - abort (); -} - -void -glthread_recursive_lock_unlock (gl_recursive_lock_t *lock) -{ - if (!lock->initialized) - abort (); - if (pthread_mutex_unlock (&lock->recmutex) != 0) - abort (); -} - -void -glthread_recursive_lock_destroy (gl_recursive_lock_t *lock) -{ - if (!lock->initialized) - abort (); - if (pthread_mutex_destroy (&lock->recmutex) != 0) - abort (); - lock->initialized = 0; -} - -# endif - -# else - -void -glthread_recursive_lock_init (gl_recursive_lock_t *lock) -{ - if (pthread_mutex_init (&lock->mutex, NULL) != 0) - abort (); - lock->owner = (pthread_t) 0; - lock->depth = 0; -} - -void -glthread_recursive_lock_lock (gl_recursive_lock_t *lock) -{ - pthread_t self = pthread_self (); - if (lock->owner != self) - { - if (pthread_mutex_lock (&lock->mutex) != 0) - abort (); - lock->owner = self; - } - if (++(lock->depth) == 0) /* wraparound? */ - abort (); -} - -void -glthread_recursive_lock_unlock (gl_recursive_lock_t *lock) -{ - if (lock->owner != pthread_self ()) - abort (); - if (lock->depth == 0) - abort (); - if (--(lock->depth) == 0) - { - lock->owner = (pthread_t) 0; - if (pthread_mutex_unlock (&lock->mutex) != 0) - abort (); - } -} - -void -glthread_recursive_lock_destroy (gl_recursive_lock_t *lock) -{ - if (lock->owner != (pthread_t) 0) - abort (); - if (pthread_mutex_destroy (&lock->mutex) != 0) - abort (); -} - -# endif - -/* -------------------------- gl_once_t datatype -------------------------- */ - -static const pthread_once_t fresh_once = PTHREAD_ONCE_INIT; - -int -glthread_once_singlethreaded (pthread_once_t *once_control) -{ - /* We don't know whether pthread_once_t is an integer type, a floating-point - type, a pointer type, or a structure type. */ - char *firstbyte = (char *)once_control; - if (*firstbyte == *(const char *)&fresh_once) - { - /* First time use of once_control. Invert the first byte. */ - *firstbyte = ~ *(const char *)&fresh_once; - return 1; - } - else - return 0; -} - -#endif - -/* ========================================================================= */ - -#if USE_PTH_THREADS - -/* Use the GNU Pth threads library. */ - -/* -------------------------- gl_lock_t datatype -------------------------- */ - -/* ------------------------- gl_rwlock_t datatype ------------------------- */ - -/* --------------------- gl_recursive_lock_t datatype --------------------- */ - -/* -------------------------- gl_once_t datatype -------------------------- */ - -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_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 --------------------- */ - -void -glthread_recursive_lock_init (gl_recursive_lock_t *lock) -{ - if (mutex_init (&lock->mutex, USYNC_THREAD, NULL) != 0) - abort (); - lock->owner = (thread_t) 0; - lock->depth = 0; -} - -void -glthread_recursive_lock_lock (gl_recursive_lock_t *lock) -{ - thread_t self = thr_self (); - if (lock->owner != self) - { - if (mutex_lock (&lock->mutex) != 0) - abort (); - lock->owner = self; - } - if (++(lock->depth) == 0) /* wraparound? */ - abort (); -} - -void -glthread_recursive_lock_unlock (gl_recursive_lock_t *lock) -{ - if (lock->owner != thr_self ()) - abort (); - if (lock->depth == 0) - abort (); - if (--(lock->depth) == 0) - { - lock->owner = (thread_t) 0; - if (mutex_unlock (&lock->mutex) != 0) - abort (); - } -} - -void -glthread_recursive_lock_destroy (gl_recursive_lock_t *lock) -{ - if (lock->owner != (thread_t) 0) - abort (); - if (mutex_destroy (&lock->mutex) != 0) - abort (); -} - -/* -------------------------- gl_once_t datatype -------------------------- */ - -void -glthread_once (gl_once_t *once_control, void (*initfunction) (void)) -{ - if (!once_control->inited) - { - /* Use the mutex to guarantee that if another thread is already calling - the initfunction, this thread waits until it's finished. */ - if (mutex_lock (&once_control->mutex) != 0) - abort (); - if (!once_control->inited) - { - once_control->inited = 1; - initfunction (); - } - if (mutex_unlock (&once_control->mutex) != 0) - abort (); - } -} - -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_WIN32_THREADS - -/* -------------------------- gl_lock_t datatype -------------------------- */ - -void -glthread_lock_init (gl_lock_t *lock) -{ - InitializeCriticalSection (&lock->lock); - lock->guard.done = 1; -} - -void -glthread_lock_lock (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); -} - -void -glthread_lock_unlock (gl_lock_t *lock) -{ - if (!lock->guard.done) - abort (); - LeaveCriticalSection (&lock->lock); -} - -void -glthread_lock_destroy (gl_lock_t *lock) -{ - if (!lock->guard.done) - abort (); - DeleteCriticalSection (&lock->lock); - lock->guard.done = 0; -} - -/* ------------------------- gl_rwlock_t datatype ------------------------- */ - -static inline 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; - } - 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 inline 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 inline 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 (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; -} - -void -glthread_rwlock_rdlock (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. */ - if (!(lock->runcount + 1 > 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; - } - else - { - /* Allocation failure. Weird. */ - do - { - LeaveCriticalSection (&lock->lock); - Sleep (1); - EnterCriticalSection (&lock->lock); - } - while (!(lock->runcount + 1 > 0)); - } - } - lock->runcount++; - LeaveCriticalSection (&lock->lock); -} - -void -glthread_rwlock_wrlock (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; - } - 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); -} - -void -glthread_rwlock_unlock (gl_rwlock_t *lock) -{ - if (!lock->guard.done) - abort (); - 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)) - abort (); - 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); -} - -void -glthread_rwlock_destroy (gl_rwlock_t *lock) -{ - if (!lock->guard.done) - abort (); - if (lock->runcount != 0) - abort (); - 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; -} - -/* --------------------- gl_recursive_lock_t datatype --------------------- */ - -void -glthread_recursive_lock_init (gl_recursive_lock_t *lock) -{ - lock->owner = 0; - lock->depth = 0; - InitializeCriticalSection (&lock->lock); - lock->guard.done = 1; -} - -void -glthread_recursive_lock_lock (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? */ - abort (); - } -} - -void -glthread_recursive_lock_unlock (gl_recursive_lock_t *lock) -{ - if (lock->owner != GetCurrentThreadId ()) - abort (); - if (lock->depth == 0) - abort (); - if (--(lock->depth) == 0) - { - lock->owner = 0; - LeaveCriticalSection (&lock->lock); - } -} - -void -glthread_recursive_lock_destroy (gl_recursive_lock_t *lock) -{ - if (lock->owner != 0) - abort (); - DeleteCriticalSection (&lock->lock); - lock->guard.done = 0; -} - -/* -------------------------- gl_once_t datatype -------------------------- */ - -void -glthread_once (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 - -/* ========================================================================= */