-/* 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 */