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Diffstat (limited to 'intl/lock.h')
| -rw-r--r-- | intl/lock.h | 801 |
1 files changed, 801 insertions, 0 deletions
diff --git a/intl/lock.h b/intl/lock.h new file mode 100644 index 0000000..be99139 --- /dev/null +++ b/intl/lock.h @@ -0,0 +1,801 @@ +/* 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 <bruno@clisp.org>, 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); + + Once-only execution: + Type: gl_once_t + Initializer: gl_once_define(extern, name) + Execution: gl_once (name, initfunction); +*/ + + +#ifndef _LOCK_H +#define _LOCK_H + +/* ========================================================================= */ + +#if USE_POSIX_THREADS + +/* Use the POSIX threads library. */ + +# include <pthread.h> +# include <stdlib.h> + +# if PTHREAD_IN_USE_DETECTION_HARD + +/* The pthread_in_use() detection needs to be done at runtime. */ +# define pthread_in_use() \ + glthread_in_use () +extern int glthread_in_use (void); + +# endif + +# 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_once +# 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 + +# if !PTHREAD_IN_USE_DETECTION_HARD +# pragma weak pthread_cancel +# define pthread_in_use() (pthread_cancel != NULL) +# endif + +# else + +# if !PTHREAD_IN_USE_DETECTION_HARD +# define pthread_in_use() 1 +# endif + +# 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 = gl_lock_initializer; +# define gl_lock_initializer \ + 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 = gl_rwlock_initializer; +# define gl_rwlock_initializer \ + 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 = gl_rwlock_initializer; +# define gl_rwlock_initializer \ + { 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 = gl_rwlock_initializer; +# define gl_rwlock_initializer \ + { 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; +# define gl_recursive_lock_define_initialized(STORAGECLASS, NAME) \ + STORAGECLASS pthread_mutex_t NAME = gl_recursive_lock_initializer; +# ifdef PTHREAD_RECURSIVE_MUTEX_INITIALIZER +# define gl_recursive_lock_initializer \ + PTHREAD_RECURSIVE_MUTEX_INITIALIZER +# else +# define gl_recursive_lock_initializer \ + 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 = gl_recursive_lock_initializer; +# define gl_recursive_lock_initializer \ + { 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 = gl_recursive_lock_initializer; +# define gl_recursive_lock_initializer \ + { 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 + +/* -------------------------- gl_once_t datatype -------------------------- */ + +typedef pthread_once_t gl_once_t; +# define gl_once_define(STORAGECLASS, NAME) \ + STORAGECLASS pthread_once_t NAME = PTHREAD_ONCE_INIT; +# define gl_once(NAME, INITFUNCTION) \ + do \ + { \ + if (pthread_in_use ()) \ + { \ + if (pthread_once (&NAME, INITFUNCTION) != 0) \ + abort (); \ + } \ + else \ + { \ + if (glthread_once_singlethreaded (&NAME)) \ + INITFUNCTION (); \ + } \ + } \ + while (0) +extern int glthread_once_singlethreaded (pthread_once_t *once_control); + +#endif + +/* ========================================================================= */ + +#if USE_PTH_THREADS + +/* Use the GNU Pth threads library. */ + +# include <pth.h> +# include <stdlib.h> + +# 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 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 = gl_rwlock_initializer; +# define gl_rwlock_initializer \ + 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 = gl_recursive_lock_initializer; +# define gl_recursive_lock_initializer \ + 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) + +/* -------------------------- 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 gl_once(NAME, INITFUNCTION) \ + do \ + { \ + if (pth_in_use ()) \ + { \ + void (*gl_once_temp) (void) = INITFUNCTION; \ + if (!pth_once (&NAME, glthread_once_call, &gl_once_temp)) \ + abort (); \ + } \ + else \ + { \ + if (glthread_once_singlethreaded (&NAME)) \ + INITFUNCTION (); \ + } \ + } \ + while (0) +extern void glthread_once_call (void *arg); +extern int glthread_once_singlethreaded (pth_once_t *once_control); + +#endif + +/* ========================================================================= */ + +#if USE_SOLARIS_THREADS + +/* Use the old Solaris threads library. */ + +# include <thread.h> +# include <synch.h> +# include <stdlib.h> + +# 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 = gl_lock_initializer; +# define gl_lock_initializer \ + 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 = gl_rwlock_initializer; +# define gl_rwlock_initializer \ + 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 = gl_recursive_lock_initializer; +# define gl_recursive_lock_initializer \ + { 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); + +/* -------------------------- 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 gl_once(NAME, INITFUNCTION) \ + do \ + { \ + if (thread_in_use ()) \ + { \ + glthread_once (&NAME, INITFUNCTION); \ + } \ + else \ + { \ + if (glthread_once_singlethreaded (&NAME)) \ + INITFUNCTION (); \ + } \ + } \ + while (0) +extern void glthread_once (gl_once_t *once_control, void (*initfunction) (void)); +extern int glthread_once_singlethreaded (gl_once_t *once_control); + +#endif + +/* ========================================================================= */ + +#if USE_WIN32_THREADS + +# include <windows.h> + +/* 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 = gl_lock_initializer; +# define gl_lock_initializer \ + { { 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 = gl_rwlock_initializer; +# define gl_rwlock_initializer \ + { { 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 = gl_recursive_lock_initializer; +# define gl_recursive_lock_initializer \ + { { 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); + +/* -------------------------- gl_once_t datatype -------------------------- */ + +typedef struct + { + volatile int inited; + volatile long started; + CRITICAL_SECTION lock; + } + gl_once_t; +# define gl_once_define(STORAGECLASS, NAME) \ + STORAGECLASS gl_once_t NAME = { -1, -1 }; +# define gl_once(NAME, INITFUNCTION) \ + glthread_once (&NAME, INITFUNCTION) +extern void glthread_once (gl_once_t *once_control, void (*initfunction) (void)); + +#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) + +/* -------------------------- gl_once_t datatype -------------------------- */ + +typedef int gl_once_t; +# define gl_once_define(STORAGECLASS, NAME) \ + STORAGECLASS gl_once_t NAME = 0; +# define gl_once(NAME, INITFUNCTION) \ + do \ + { \ + if (NAME == 0) \ + { \ + NAME = ~ 0; \ + INITFUNCTION (); \ + } \ + } \ + while (0) + +#endif + +/* ========================================================================= */ + +#endif /* _LOCK_H */ |