From: Bruno Haible Date: Mon, 18 Jul 2005 11:35:09 +0000 (+0000) Subject: New gnulib module 'lock'. X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=76c867feaa6cca1cd900a33712f429474bcbd982;p=pspp New gnulib module 'lock'. --- diff --git a/ChangeLog b/ChangeLog index b2e63e468c..72a155fa1a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2005-07-18 Bruno Haible + + * modules/lock: New file. + * MODULES.html.sh (Multithreading): New section. + 2005-07-15 Paul Eggert * modules/xalloc (Depends-on): Add xalloc-die. diff --git a/MODULES.html.sh b/MODULES.html.sh index 0219150232..4e88998aa1 100755 --- a/MODULES.html.sh +++ b/MODULES.html.sh @@ -1901,6 +1901,16 @@ func_all_modules () func_module canon-host func_end_table + element="Multithreading" + element=`printf "%s" "$element" | sed -e "$sed_lt" -e "$sed_gt"` + func_section_wrap posix_ext_thread + func_wrap H3 + func_echo "$element" + + func_begin_table + func_module lock + func_end_table + element="Internationalization functions" element=`printf "%s" "$element" | sed -e "$sed_lt" -e "$sed_gt"` func_section_wrap posix_ext_i18n diff --git a/lib/ChangeLog b/lib/ChangeLog index bf60743ce8..d2d9c36ee9 100644 --- a/lib/ChangeLog +++ b/lib/ChangeLog @@ -1,3 +1,8 @@ +2005-07-18 Bruno Haible + + * lock.h: New file, from GNU gettext. + * lock.c: New file, from GNU gettext. + 2005-07-11 Paul Eggert * version-etc-fsf.c (version_etc_copyright): Parameterize the diff --git a/lib/lock.c b/lib/lock.c new file mode 100644 index 0000000000..cbf9f11632 --- /dev/null +++ b/lib/lock.c @@ -0,0 +1,769 @@ +/* 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. */ + +/* -------------------------- 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 + +#endif + +/* ========================================================================= */ + +#if USE_PTH_THREADS + +/* Use the GNU Pth threads library. */ + +/* -------------------------- gl_lock_t datatype -------------------------- */ + +/* ------------------------- gl_rwlock_t datatype ------------------------- */ + +/* --------------------- gl_recursive_lock_t datatype --------------------- */ + +#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 (); +} + +#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; +} + +#endif + +/* ========================================================================= */ diff --git a/lib/lock.h b/lib/lock.h new file mode 100644 index 0000000000..9ca33debcd --- /dev/null +++ b/lib/lock.h @@ -0,0 +1,641 @@ +/* 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. */ + +/* This file contains locking primitives for use with a given thread library. + It does not contain primitives for creating threads or for other + synchronization primitives. + + Normal (non-recursive) locks: + Type: gl_lock_t + Declaration: gl_lock_define(extern, name) + Initializer: gl_lock_define_initialized(, name) + Initialization: gl_lock_init (name); + Taking the lock: gl_lock_lock (name); + Releasing the lock: gl_lock_unlock (name); + De-initialization: gl_lock_destroy (name); + + Read-Write (non-recursive) locks: + Type: gl_rwlock_t + Declaration: gl_rwlock_define(extern, name) + Initializer: gl_rwlock_define_initialized(, name) + Initialization: gl_rwlock_init (name); + Taking the lock: gl_rwlock_rdlock (name); + gl_rwlock_wrlock (name); + Releasing the lock: gl_rwlock_unlock (name); + De-initialization: gl_rwlock_destroy (name); + + Recursive locks: + Type: gl_recursive_lock_t + Declaration: gl_recursive_lock_define(extern, name) + Initializer: gl_recursive_lock_define_initialized(, name) + Initialization: gl_recursive_lock_init (name); + Taking the lock: gl_recursive_lock_lock (name); + Releasing the lock: gl_recursive_lock_unlock (name); + De-initialization: gl_recursive_lock_destroy (name); +*/ + + +/* ========================================================================= */ + +#if USE_POSIX_THREADS + +/* Use the POSIX threads library. */ + +# include +# include + +# if USE_POSIX_THREADS_WEAK + +/* Use weak references to the POSIX threads library. */ + +/* Weak references avoid dragging in external libraries if the other parts + of the program don't use them. Here we use them, because we don't want + every program that uses libintl to depend on libpthread. This assumes + that libpthread would not be loaded after libintl; i.e. if libintl is + loaded first, by an executable that does not depend on libpthread, and + then a module is dynamically loaded that depends on libpthread, libintl + will not be multithread-safe. */ + +/* The way to test at runtime whether libpthread is present is to test + whether a function pointer's value, such as &pthread_mutex_init, is + non-NULL. However, some versions of GCC have a bug through which, in + PIC mode, &foo != NULL always evaluates to true if there is a direct + call to foo(...) in the same function. To avoid this, we test the + address of a function in libpthread that we don't use. */ + +# pragma weak pthread_mutex_init +# pragma weak pthread_mutex_lock +# pragma weak pthread_mutex_unlock +# pragma weak pthread_mutex_destroy +# pragma weak pthread_rwlock_init +# pragma weak pthread_rwlock_rdlock +# pragma weak pthread_rwlock_wrlock +# pragma weak pthread_rwlock_unlock +# pragma weak pthread_rwlock_destroy +# pragma weak pthread_cond_init +# pragma weak pthread_cond_wait +# pragma weak pthread_cond_signal +# pragma weak pthread_cond_broadcast +# pragma weak pthread_cond_destroy +# pragma weak pthread_mutexattr_init +# pragma weak pthread_mutexattr_settype +# pragma weak pthread_mutexattr_destroy +# ifndef pthread_self +# pragma weak pthread_self +# endif + +# pragma weak pthread_cancel +# define pthread_in_use() (pthread_cancel != NULL) + +# else + +# define pthread_in_use() 1 + +# endif + +/* -------------------------- gl_lock_t datatype -------------------------- */ + +typedef pthread_mutex_t gl_lock_t; +# define gl_lock_define(STORAGECLASS, NAME) \ + STORAGECLASS pthread_mutex_t NAME; +# define gl_lock_define_initialized(STORAGECLASS, NAME) \ + STORAGECLASS pthread_mutex_t NAME = PTHREAD_MUTEX_INITIALIZER; +# define gl_lock_init(NAME) \ + if (pthread_in_use () && pthread_mutex_init (&NAME, NULL) != 0) abort () +# define gl_lock_lock(NAME) \ + if (pthread_in_use () && pthread_mutex_lock (&NAME) != 0) abort () +# define gl_lock_unlock(NAME) \ + if (pthread_in_use () && pthread_mutex_unlock (&NAME) != 0) abort () +# define gl_lock_destroy(NAME) \ + if (pthread_in_use () && pthread_mutex_destroy (&NAME) != 0) abort () + +/* ------------------------- gl_rwlock_t datatype ------------------------- */ + +# if HAVE_PTHREAD_RWLOCK + +# ifdef PTHREAD_RWLOCK_INITIALIZER + +typedef pthread_rwlock_t gl_rwlock_t; +# define gl_rwlock_define(STORAGECLASS, NAME) \ + STORAGECLASS pthread_rwlock_t NAME; +# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \ + STORAGECLASS pthread_rwlock_t NAME = PTHREAD_RWLOCK_INITIALIZER; +# define gl_rwlock_init(NAME) \ + if (pthread_in_use () && pthread_rwlock_init (&NAME, NULL) != 0) abort () +# define gl_rwlock_rdlock(NAME) \ + if (pthread_in_use () && pthread_rwlock_rdlock (&NAME) != 0) abort () +# define gl_rwlock_wrlock(NAME) \ + if (pthread_in_use () && pthread_rwlock_wrlock (&NAME) != 0) abort () +# define gl_rwlock_unlock(NAME) \ + if (pthread_in_use () && pthread_rwlock_unlock (&NAME) != 0) abort () +# define gl_rwlock_destroy(NAME) \ + if (pthread_in_use () && pthread_rwlock_destroy (&NAME) != 0) abort () + +# else + +typedef struct + { + int initialized; + pthread_mutex_t guard; /* protects the initialization */ + pthread_rwlock_t rwlock; /* read-write lock */ + } + 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 = { 0, PTHREAD_MUTEX_INITIALIZER }; +# define gl_rwlock_init(NAME) \ + if (pthread_in_use ()) glthread_rwlock_init (&NAME) +# define gl_rwlock_rdlock(NAME) \ + if (pthread_in_use ()) glthread_rwlock_rdlock (&NAME) +# define gl_rwlock_wrlock(NAME) \ + if (pthread_in_use ()) glthread_rwlock_wrlock (&NAME) +# define gl_rwlock_unlock(NAME) \ + if (pthread_in_use ()) glthread_rwlock_unlock (&NAME) +# define gl_rwlock_destroy(NAME) \ + if (pthread_in_use ()) glthread_rwlock_destroy (&NAME) +extern void glthread_rwlock_init (gl_rwlock_t *lock); +extern void glthread_rwlock_rdlock (gl_rwlock_t *lock); +extern void glthread_rwlock_wrlock (gl_rwlock_t *lock); +extern void glthread_rwlock_unlock (gl_rwlock_t *lock); +extern void glthread_rwlock_destroy (gl_rwlock_t *lock); + +# endif + +# else + +typedef struct + { + pthread_mutex_t lock; /* protects the remaining fields */ + pthread_cond_t waiting_readers; /* waiting readers */ + pthread_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 = \ + { PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, PTHREAD_COND_INITIALIZER, 0, 0 }; +# define gl_rwlock_init(NAME) \ + if (pthread_in_use ()) glthread_rwlock_init (&NAME) +# define gl_rwlock_rdlock(NAME) \ + if (pthread_in_use ()) glthread_rwlock_rdlock (&NAME) +# define gl_rwlock_wrlock(NAME) \ + if (pthread_in_use ()) glthread_rwlock_wrlock (&NAME) +# define gl_rwlock_unlock(NAME) \ + if (pthread_in_use ()) glthread_rwlock_unlock (&NAME) +# define gl_rwlock_destroy(NAME) \ + if (pthread_in_use ()) glthread_rwlock_destroy (&NAME) +extern void glthread_rwlock_init (gl_rwlock_t *lock); +extern void glthread_rwlock_rdlock (gl_rwlock_t *lock); +extern void glthread_rwlock_wrlock (gl_rwlock_t *lock); +extern void glthread_rwlock_unlock (gl_rwlock_t *lock); +extern void glthread_rwlock_destroy (gl_rwlock_t *lock); + +# endif + +/* --------------------- gl_recursive_lock_t datatype --------------------- */ + +# if HAVE_PTHREAD_MUTEX_RECURSIVE + +# if defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER || defined PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP + +typedef pthread_mutex_t gl_recursive_lock_t; +# define gl_recursive_lock_define(STORAGECLASS, NAME) \ + STORAGECLASS pthread_mutex_t NAME; +# ifdef PTHREAD_RECURSIVE_MUTEX_INITIALIZER +# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \ + STORAGECLASS pthread_mutex_t NAME = PTHREAD_RECURSIVE_MUTEX_INITIALIZER; +# else +# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \ + STORAGECLASS pthread_mutex_t NAME = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; +# endif +# define gl_recursive_lock_init(NAME) \ + if (pthread_in_use () && pthread_mutex_init (&NAME, NULL) != 0) abort () +# define gl_recursive_lock_lock(NAME) \ + if (pthread_in_use () && pthread_mutex_lock (&NAME) != 0) abort () +# define gl_recursive_lock_unlock(NAME) \ + if (pthread_in_use () && pthread_mutex_unlock (&NAME) != 0) abort () +# define gl_recursive_lock_destroy(NAME) \ + if (pthread_in_use () && pthread_mutex_destroy (&NAME) != 0) abort () + +# else + +typedef struct + { + pthread_mutex_t recmutex; /* recursive mutex */ + pthread_mutex_t guard; /* protects the initialization */ + int initialized; + } + 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 = \ + { PTHREAD_MUTEX_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, 0 }; +# define gl_recursive_lock_init(NAME) \ + if (pthread_in_use ()) glthread_recursive_lock_init (&NAME) +# define gl_recursive_lock_lock(NAME) \ + if (pthread_in_use ()) glthread_recursive_lock_lock (&NAME) +# define gl_recursive_lock_unlock(NAME) \ + if (pthread_in_use ()) glthread_recursive_lock_unlock (&NAME) +# define gl_recursive_lock_destroy(NAME) \ + if (pthread_in_use ()) glthread_recursive_lock_destroy (&NAME) +extern void glthread_recursive_lock_init (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_lock (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_unlock (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_destroy (gl_recursive_lock_t *lock); + +# endif + +# else + +/* Old versions of POSIX threads on Solaris did not have recursive locks. + We have to implement them ourselves. */ + +typedef struct + { + pthread_mutex_t mutex; + pthread_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 = \ + { PTHREAD_MUTEX_INITIALIZER, (pthread_t) 0, 0 }; +# define gl_recursive_lock_init(NAME) \ + if (pthread_in_use ()) glthread_recursive_lock_init (&NAME) +# define gl_recursive_lock_lock(NAME) \ + if (pthread_in_use ()) glthread_recursive_lock_lock (&NAME) +# define gl_recursive_lock_unlock(NAME) \ + if (pthread_in_use ()) glthread_recursive_lock_unlock (&NAME) +# define gl_recursive_lock_destroy(NAME) \ + if (pthread_in_use ()) glthread_recursive_lock_destroy (&NAME) +extern void glthread_recursive_lock_init (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_lock (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_unlock (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_destroy (gl_recursive_lock_t *lock); + +# endif + +#endif + +/* ========================================================================= */ + +#if USE_PTH_THREADS + +/* Use the GNU Pth threads library. */ + +# include +# include + +# 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_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 = PTH_MUTEX_INIT; +# define gl_lock_init(NAME) \ + if (pth_in_use() && !pth_mutex_init (&NAME)) abort () +# define gl_lock_lock(NAME) \ + if (pth_in_use() && !pth_mutex_acquire (&NAME, 0, NULL)) abort () +# define gl_lock_unlock(NAME) \ + if (pth_in_use() && !pth_mutex_release (&NAME)) abort () +# define gl_lock_destroy(NAME) \ + (void)(&NAME) + +/* ------------------------- gl_rwlock_t datatype ------------------------- */ + +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 = PTH_RWLOCK_INIT; +# define gl_rwlock_init(NAME) \ + if (pth_in_use() && !pth_rwlock_init (&NAME)) abort () +# define gl_rwlock_rdlock(NAME) \ + if (pth_in_use() && !pth_rwlock_acquire (&NAME, PTH_RWLOCK_RD, 0, NULL)) abort () +# define gl_rwlock_wrlock(NAME) \ + if (pth_in_use() && !pth_rwlock_acquire (&NAME, PTH_RWLOCK_RW, 0, NULL)) abort () +# define gl_rwlock_unlock(NAME) \ + if (pth_in_use() && !pth_rwlock_release (&NAME)) abort () +# define gl_rwlock_destroy(NAME) \ + (void)(&NAME) + +/* --------------------- 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 = PTH_MUTEX_INIT; +# define gl_recursive_lock_init(NAME) \ + if (pth_in_use() && !pth_mutex_init (&NAME)) abort () +# define gl_recursive_lock_lock(NAME) \ + if (pth_in_use() && !pth_mutex_acquire (&NAME, 0, NULL)) abort () +# define gl_recursive_lock_unlock(NAME) \ + if (pth_in_use() && !pth_mutex_release (&NAME)) abort () +# define gl_recursive_lock_destroy(NAME) \ + (void)(&NAME) + +#endif + +/* ========================================================================= */ + +#if USE_SOLARIS_THREADS + +/* Use the old Solaris threads library. */ + +# include +# include +# include + +# 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) + +# else + +# define thread_in_use() 1 + +# 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 = DEFAULTMUTEX; +# define gl_lock_init(NAME) \ + if (thread_in_use () && mutex_init (&NAME, USYNC_THREAD, NULL) != 0) abort () +# define gl_lock_lock(NAME) \ + if (thread_in_use () && mutex_lock (&NAME) != 0) abort () +# define gl_lock_unlock(NAME) \ + if (thread_in_use () && mutex_unlock (&NAME) != 0) abort () +# define gl_lock_destroy(NAME) \ + if (thread_in_use () && mutex_destroy (&NAME) != 0) abort () + +/* ------------------------- 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 = DEFAULTRWLOCK; +# define gl_rwlock_init(NAME) \ + if (thread_in_use () && rwlock_init (&NAME, USYNC_THREAD, NULL) != 0) abort () +# define gl_rwlock_rdlock(NAME) \ + if (thread_in_use () && rw_rdlock (&NAME) != 0) abort () +# define gl_rwlock_wrlock(NAME) \ + if (thread_in_use () && rw_wrlock (&NAME) != 0) abort () +# define gl_rwlock_unlock(NAME) \ + if (thread_in_use () && rw_unlock (&NAME) != 0) abort () +# define gl_rwlock_destroy(NAME) \ + if (thread_in_use () && rwlock_destroy (&NAME) != 0) abort () + +/* --------------------- 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 = { DEFAULTMUTEX, (thread_t) 0, 0 }; +# define gl_recursive_lock_init(NAME) \ + if (thread_in_use ()) glthread_recursive_lock_init (&NAME) +# define gl_recursive_lock_lock(NAME) \ + if (thread_in_use ()) glthread_recursive_lock_lock (&NAME) +# define gl_recursive_lock_unlock(NAME) \ + if (thread_in_use ()) glthread_recursive_lock_unlock (&NAME) +# define gl_recursive_lock_destroy(NAME) \ + if (thread_in_use ()) glthread_recursive_lock_destroy (&NAME) +extern void glthread_recursive_lock_init (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_lock (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_unlock (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_destroy (gl_recursive_lock_t *lock); + +#endif + +/* ========================================================================= */ + +#if USE_WIN32_THREADS + +# include + +/* We can use CRITICAL_SECTION directly, rather than the Win32 Event, Mutex, + Semaphore types, because + - we need only to synchronize inside a single process (address space), + not inter-process locking, + - we don't need to support trylock operations. (TryEnterCriticalSection + does not work on Windows 95/98/ME. Packages that need trylock usually + define their own mutex type.) */ + +/* 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; +# define gl_lock_define(STORAGECLASS, NAME) \ + STORAGECLASS gl_lock_t NAME; +# define gl_lock_define_initialized(STORAGECLASS, NAME) \ + STORAGECLASS gl_lock_t NAME = { { 0, -1 } }; +# define gl_lock_init(NAME) \ + glthread_lock_init (&NAME) +# define gl_lock_lock(NAME) \ + glthread_lock_lock (&NAME) +# define gl_lock_unlock(NAME) \ + glthread_lock_unlock (&NAME) +# define gl_lock_destroy(NAME) \ + glthread_lock_destroy (&NAME) +extern void glthread_lock_init (gl_lock_t *lock); +extern void glthread_lock_lock (gl_lock_t *lock); +extern void glthread_lock_unlock (gl_lock_t *lock); +extern void glthread_lock_destroy (gl_lock_t *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_waitqueue_t; +typedef struct + { + gl_spinlock_t guard; /* protects the initialization */ + CRITICAL_SECTION lock; /* protects the remaining fields */ + gl_waitqueue_t waiting_readers; /* waiting readers */ + gl_waitqueue_t waiting_writers; /* 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 = { { 0, -1 } }; +# define gl_rwlock_init(NAME) \ + glthread_rwlock_init (&NAME) +# define gl_rwlock_rdlock(NAME) \ + glthread_rwlock_rdlock (&NAME) +# define gl_rwlock_wrlock(NAME) \ + glthread_rwlock_wrlock (&NAME) +# define gl_rwlock_unlock(NAME) \ + glthread_rwlock_unlock (&NAME) +# define gl_rwlock_destroy(NAME) \ + glthread_rwlock_destroy (&NAME) +extern void glthread_rwlock_init (gl_rwlock_t *lock); +extern void glthread_rwlock_rdlock (gl_rwlock_t *lock); +extern void glthread_rwlock_wrlock (gl_rwlock_t *lock); +extern void glthread_rwlock_unlock (gl_rwlock_t *lock); +extern void glthread_rwlock_destroy (gl_rwlock_t *lock); + +/* --------------------- gl_recursive_lock_t datatype --------------------- */ + +/* The Win32 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; +# 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 = { { 0, -1 }, 0, 0 }; +# define gl_recursive_lock_init(NAME) \ + glthread_recursive_lock_init (&NAME) +# define gl_recursive_lock_lock(NAME) \ + glthread_recursive_lock_lock (&NAME) +# define gl_recursive_lock_unlock(NAME) \ + glthread_recursive_lock_unlock (&NAME) +# define gl_recursive_lock_destroy(NAME) \ + glthread_recursive_lock_destroy (&NAME) +extern void glthread_recursive_lock_init (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_lock (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_unlock (gl_recursive_lock_t *lock); +extern void glthread_recursive_lock_destroy (gl_recursive_lock_t *lock); + +#endif + +/* ========================================================================= */ + +#if !(USE_POSIX_THREADS || USE_PTH_THREADS || USE_SOLARIS_THREADS || USE_WIN32_THREADS) + +/* Provide dummy implementation if threads are not supported. */ + +/* -------------------------- gl_lock_t datatype -------------------------- */ + +typedef int gl_lock_t; +# define gl_lock_define(STORAGECLASS, NAME) +# define gl_lock_define_initialized(STORAGECLASS, NAME) +# define gl_lock_init(NAME) +# define gl_lock_lock(NAME) +# define gl_lock_unlock(NAME) + +/* ------------------------- gl_rwlock_t datatype ------------------------- */ + +typedef int gl_rwlock_t; +# define gl_rwlock_define(STORAGECLASS, NAME) +# define gl_rwlock_define_initialized(STORAGECLASS, NAME) +# define gl_rwlock_init(NAME) +# define gl_rwlock_rdlock(NAME) +# define gl_rwlock_wrlock(NAME) +# define gl_rwlock_unlock(NAME) + +/* --------------------- gl_recursive_lock_t datatype --------------------- */ + +typedef int gl_recursive_lock_t; +# define gl_recursive_lock_define(STORAGECLASS, NAME) +# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) +# define gl_recursive_lock_init(NAME) +# define gl_recursive_lock_lock(NAME) +# define gl_recursive_lock_unlock(NAME) + +#endif diff --git a/m4/ChangeLog b/m4/ChangeLog index 11756981ba..cce430ee90 100644 --- a/m4/ChangeLog +++ b/m4/ChangeLog @@ -1,3 +1,7 @@ +2005-07-18 Bruno Haible + + * lock.m4: New file, from GNU gettext. + 2005-06-01 Bruno Haible * poll.m4 (gl_FUNC_POLL): Check against MacOS X 10.4 poll() bug. diff --git a/m4/lock.m4 b/m4/lock.m4 new file mode 100644 index 0000000000..be6a7176d6 --- /dev/null +++ b/m4/lock.m4 @@ -0,0 +1,259 @@ +# lock.m4 serial 1 (gettext-0.15) +dnl Copyright (C) 2005 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +dnl From Bruno Haible. + +dnl Tests for a multithreading library to be used. +dnl Defines at most one of the macros USE_POSIX_THREADS, USE_SOLARIS_THREADS, +dnl USE_PTH_THREADS, USE_WIN32_THREADS +dnl Sets the variables LIBTHREAD and LTLIBTHREAD to the linker options for use +dnl in a Makefile (LIBTHREAD for use without libtool, LTLIBTHREAD for use with +dnl libtool). +dnl Sets the variables LIBMULTITHREAD and LTLIBMULTITHREAD similarly, for +dnl programs that really need multithread functionality. The difference +dnl between LIBTHREAD and LIBMULTITHREAD is that on platforms supporting weak +dnl symbols, typically LIBTHREAD="" whereas LIBMULTITHREAD="-lpthread". + +AC_DEFUN([gl_LOCK], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([AC_GNU_SOURCE]) dnl needed for pthread_rwlock_t on glibc systems + dnl Check for multithreading. + AC_ARG_ENABLE(threads, +AC_HELP_STRING([--enable-threads={posix|solaris|pth|win32}], [specify multithreading API]) +AC_HELP_STRING([--disable-threads], [build without multithread safety]), + gl_use_threads=$enableval, gl_use_threads=yes) + gl_threads_api=none + LIBTHREAD= + LTLIBTHREAD= + LIBMULTITHREAD= + LTLIBMULTITHREAD= + if test "$gl_use_threads" != no; then + dnl Check whether the compiler and linker support weak declarations. + AC_MSG_CHECKING([whether imported symbols can be declared weak]) + gl_have_weak=no + AC_TRY_LINK([extern void xyzzy (); +#pragma weak xyzzy], [xyzzy();], [gl_have_weak=yes]) + AC_MSG_RESULT([$gl_have_weak]) + if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then + # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that + # it groks . + gl_save_CPPFLAGS="$CPPFLAGS" + CPPFLAGS="$CPPFLAGS -D_REENTRANT" + AC_CHECK_HEADER(pthread.h, gl_have_pthread_h=yes, gl_have_pthread_h=no) + CPPFLAGS="$gl_save_CPPFLAGS" + if test "$gl_have_pthread_h" = yes; then + # Other possible tests: + # -lpthreads (FSU threads, PCthreads) + # -lgthreads + case "$host_os" in + osf*) + # On OSF/1, the compiler needs the flag -pthread so that it groks + # . For the linker, it is equivalent to -lpthread. + if test -n "$GCC"; then + # gcc-2.95 doesn't understand -pthread, only -D_REENTRANT. + CPPFLAGS="$CPPFLAGS -D_REENTRANT" + else + CPPFLAGS="$CPPFLAGS -pthread" + fi + ;; + esac + gl_have_pthread= + AC_TRY_LINK([#include ], + [pthread_mutex_lock((pthread_mutex_t*)0);], + [gl_have_pthread=yes]) + # Test for libpthread by looking for pthread_kill. (Not pthread_self, + # since it is defined as a macro on OSF/1.) + if test -n "$gl_have_pthread"; then + # The program links fine without libpthread. But it may actually + # need to link with libpthread in order to create multiple threads. + AC_CHECK_LIB(pthread, pthread_kill, + [LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread]) + else + # Some library is needed. Try libpthread and libc_r. + AC_CHECK_LIB(pthread, pthread_kill, + [gl_have_pthread=yes + LIBTHREAD=-lpthread LTLIBTHREAD=-lpthread + LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread]) + if test -z "$gl_have_pthread"; then + # For FreeBSD 4. + AC_CHECK_LIB(c_r, pthread_kill, + [gl_have_pthread=yes + LIBTHREAD=-lc_r LTLIBTHREAD=-lc_r + LIBMULTITHREAD=-lc_r LTLIBMULTITHREAD=-lc_r]) + fi + fi + if test -n "$gl_have_pthread"; then + gl_threads_api=posix + AC_DEFINE([USE_POSIX_THREADS], 1, + [Define if the POSIX multithreading library can be used.]) + if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then + if test $gl_have_weak = yes; then + AC_DEFINE([USE_POSIX_THREADS_WEAK], 1, + [Define if references to the POSIX multithreading library should be made weak.]) + LIBTHREAD= + LTLIBTHREAD= + fi + fi + # OSF/1 4.0 and MacOS X 10.1 lack the pthread_rwlock_t type and the + # pthread_rwlock_* functions. + AC_CHECK_TYPE([pthread_rwlock_t], + [AC_DEFINE([HAVE_PTHREAD_RWLOCK], 1, + [Define if the POSIX multithreading library has read/write locks.])], + [], + [#include ]) + # glibc defines PTHREAD_MUTEX_RECURSIVE as enum, not as a macro. + AC_TRY_COMPILE([#include ], + [#if __FreeBSD__ == 4 +error "No, in FreeBSD 4.0 recursive mutexes actually don't work." +#else +int x = (int)PTHREAD_MUTEX_RECURSIVE; +#endif], + [AC_DEFINE([HAVE_PTHREAD_MUTEX_RECURSIVE], 1, + [Define if the defines PTHREAD_MUTEX_RECURSIVE.])]) + # Some systems optimize for single-threaded programs by default, and + # need special flags to disable these optimizations. + case "$host_os" in + aix* | freebsd*) CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE" ;; + solaris*) CPPFLAGS="$CPPFLAGS -D_REENTRANT" ;; + esac + fi + fi + fi + if test -z "$gl_have_pthread"; then + if test "$gl_use_threads" = yes || test "$gl_use_threads" = solaris; then + gl_have_solaristhread= + gl_save_LIBS="$LIBS" + LIBS="$LIBS -lthread" + AC_TRY_LINK([#include +#include ], + [thr_self();], + [gl_have_solaristhread=yes]) + LIBS="$gl_save_LIBS" + if test -n "$gl_have_solaristhread"; then + gl_threads_api=solaris + LIBTHREAD=-lthread + LTLIBTHREAD=-lthread + LIBMULTITHREAD="$LIBTHREAD" + LTLIBMULTITHREAD="$LTLIBTHREAD" + AC_DEFINE([USE_SOLARIS_THREADS], 1, + [Define if the old Solaris multithreading library can be used.]) + if test $gl_have_weak = yes; then + AC_DEFINE([USE_SOLARIS_THREADS_WEAK], 1, + [Define if references to the old Solaris multithreading library should be made weak.]) + LIBTHREAD= + LTLIBTHREAD= + fi + fi + fi + fi + if test "$gl_use_threads" = pth; then + gl_save_CPPFLAGS="$CPPFLAGS" + AC_LIB_LINKFLAGS(pth) + gl_have_pth= + gl_save_LIBS="$LIBS" + LIBS="$LIBS -lpth" + AC_TRY_LINK([#include ], [pth_self();], gl_have_pth=yes) + LIBS="$gl_save_LIBS" + if test -n "$gl_have_pth"; then + gl_threads_api=pth + LIBTHREAD="$LIBPTH" + LTLIBTHREAD="$LTLIBPTH" + LIBMULTITHREAD="$LIBTHREAD" + LTLIBMULTITHREAD="$LTLIBTHREAD" + AC_DEFINE([USE_PTH_THREADS], 1, + [Define if the GNU Pth multithreading library can be used.]) + if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then + if test $gl_have_weak = yes; then + AC_DEFINE([USE_PTH_THREADS_WEAK], 1, + [Define if references to the GNU Pth multithreading library should be made weak.]) + LIBTHREAD= + LTLIBTHREAD= + fi + fi + else + CPPFLAGS="$gl_save_CPPFLAGS" + fi + fi + if test -z "$gl_have_pthread"; then + if test "$gl_use_threads" = yes || test "$gl_use_threads" = win32; then + if { case "$host_os" in + mingw*) true;; + *) false;; + esac + }; then + gl_threads_api=win32 + AC_DEFINE([USE_WIN32_THREADS], 1, + [Define if the Win32 multithreading API can be used.]) + fi + fi + fi + fi + AC_MSG_CHECKING([for multithread API to use]) + AC_MSG_RESULT([$gl_threads_api]) + AC_SUBST(LIBTHREAD) + AC_SUBST(LTLIBTHREAD) + AC_SUBST(LIBMULTITHREAD) + AC_SUBST(LTLIBMULTITHREAD) + gl_PREREQ_LOCK +]) + +# Prerequisites of lib/lock.c. +AC_DEFUN([gl_PREREQ_LOCK], [ + AC_REQUIRE([AC_C_INLINE]) +]) + +dnl Survey of platforms: +dnl +dnl Platform Available Compiler Supports test-lock +dnl flavours option weak result +dnl --------------- --------- --------- -------- --------- +dnl Linux 2.4/glibc posix -lpthread Y OK +dnl +dnl GNU Hurd/glibc posix +dnl +dnl FreeBSD 5.3 posix -lc_r Y +dnl posix -lkse ? Y +dnl posix -lpthread ? Y +dnl posix -lthr Y +dnl +dnl FreeBSD 5.2 posix -lc_r Y +dnl posix -lkse Y +dnl posix -lthr Y +dnl +dnl FreeBSD 4.0,4.10 posix -lc_r Y OK +dnl +dnl NetBSD 1.6 -- +dnl +dnl OpenBSD 3.4 posix -lpthread Y OK +dnl +dnl MacOS X 10.[123] posix -lpthread Y OK +dnl +dnl Solaris 7,8,9 posix -lpthread Y Sol 7,8: 0.0; Sol 9: OK +dnl solaris -lthread Y Sol 7,8: 0.0; Sol 9: OK +dnl +dnl HP-UX 11 posix -lpthread Y OK +dnl +dnl IRIX 6.5 posix -lpthread Y 0.5 +dnl +dnl AIX 4.3,5.1 posix -lpthread N AIX 4: 0.5; AIX 5: OK +dnl +dnl OSF/1 4.0,5.1 posix -pthread (cc) Y OK +dnl -lpthread (gcc) Y +dnl +dnl Cygwin posix -lpthread Y OK +dnl +dnl Any of the above pth -lpth 0.0 +dnl +dnl Mingw win32 N OK +dnl +dnl BeOS 5 -- +dnl +dnl The test-lock result shows what happens if in test-lock.c EXPLICIT_YIELD is +dnl turned off: +dnl OK if all three tests terminate OK, +dnl 0.5 if the first test terminates OK but the second one loops endlessly, +dnl 0.0 if the first test already loops endlessly. diff --git a/modules/lock b/modules/lock new file mode 100644 index 0000000000..e66bd8a432 --- /dev/null +++ b/modules/lock @@ -0,0 +1,29 @@ +Description: +Locking in multithreaded situations. + +Files: +lib/lock.h +lib/lock.c +m4/lock.m4 +m4/lib-ld.m4 +m4/lib-link.m4 +m4/lib-prefix.m4 +build-aux/config.rpath + +Depends-on: + +configure.ac: +gl_LOCK + +Makefile.am: +lib_SOURCES += lock.h lock.c + +Include: +"lock.h" + +License: +LGPL + +Maintainer: +Bruno Haible +