69 lines
2.6 KiB
C
69 lines
2.6 KiB
C
/* Read-write locks (native Windows implementation).
|
|
Copyright (C) 2005-2023 Free Software Foundation, Inc.
|
|
|
|
This file is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU Lesser General Public License as
|
|
published by the Free Software Foundation; either version 2.1 of the
|
|
License, or (at your option) any later version.
|
|
|
|
This file is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with this program. If not, see <https://www.gnu.org/licenses/>. */
|
|
|
|
/* Written by Bruno Haible <bruno@clisp.org>, 2005.
|
|
Based on GCC's gthr-win32.h. */
|
|
|
|
#ifndef _WINDOWS_RWLOCK_H
|
|
#define _WINDOWS_RWLOCK_H
|
|
|
|
#define WIN32_LEAN_AND_MEAN /* avoid including junk */
|
|
#include <windows.h>
|
|
|
|
#include "windows-initguard.h"
|
|
|
|
/* 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 */
|
|
}
|
|
glwthread_carray_waitqueue_t;
|
|
typedef struct
|
|
{
|
|
glwthread_initguard_t guard; /* protects the initialization */
|
|
CRITICAL_SECTION lock; /* protects the remaining fields */
|
|
glwthread_carray_waitqueue_t waiting_readers; /* waiting readers */
|
|
glwthread_carray_waitqueue_t waiting_writers; /* waiting writers */
|
|
int runcount; /* number of readers running, or -1 when a writer runs */
|
|
}
|
|
glwthread_rwlock_t;
|
|
|
|
#define GLWTHREAD_RWLOCK_INIT { GLWTHREAD_INITGUARD_INIT }
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
extern void glwthread_rwlock_init (glwthread_rwlock_t *lock);
|
|
extern int glwthread_rwlock_rdlock (glwthread_rwlock_t *lock);
|
|
extern int glwthread_rwlock_wrlock (glwthread_rwlock_t *lock);
|
|
extern int glwthread_rwlock_tryrdlock (glwthread_rwlock_t *lock);
|
|
extern int glwthread_rwlock_trywrlock (glwthread_rwlock_t *lock);
|
|
extern int glwthread_rwlock_unlock (glwthread_rwlock_t *lock);
|
|
extern int glwthread_rwlock_destroy (glwthread_rwlock_t *lock);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* _WINDOWS_RWLOCK_H */
|