143 lines
3.8 KiB
C
143 lines
3.8 KiB
C
/*
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* Server-side mutex management
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*
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* Copyright (C) 1998 Alexandre Julliard
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*/
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#include <assert.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include "winerror.h"
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#include "winnt.h"
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#include "server/thread.h"
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struct mutex
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{
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struct object obj; /* object header */
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struct thread *owner; /* mutex owner */
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unsigned int count; /* recursion count */
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int abandoned; /* has it been abandoned? */
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struct mutex *next;
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struct mutex *prev;
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};
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static void dump_mutex( struct object *obj, int verbose );
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static int mutex_signaled( struct object *obj, struct thread *thread );
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static int mutex_satisfied( struct object *obj, struct thread *thread );
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static void destroy_mutex( struct object *obj );
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static const struct object_ops mutex_ops =
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{
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dump_mutex,
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mutex_signaled,
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mutex_satisfied,
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destroy_mutex
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};
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struct object *create_mutex( const char *name, int owned )
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{
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struct mutex *mutex;
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if (!(mutex = (struct mutex *)create_named_object( name, &mutex_ops, sizeof(*mutex) )))
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return NULL;
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if (GET_ERROR() != ERROR_ALREADY_EXISTS)
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{
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/* initialize it if it didn't already exist */
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mutex->count = 0;
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mutex->owner = NULL;
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mutex->abandoned = 0;
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mutex->next = mutex->prev = NULL;
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if (owned) mutex_satisfied( &mutex->obj, current );
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}
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return &mutex->obj;
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}
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int open_mutex( unsigned int access, int inherit, const char *name )
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{
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return open_object( name, &mutex_ops, access, inherit );
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}
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/* release a mutex once the recursion count is 0 */
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static void do_release( struct mutex *mutex, struct thread *thread )
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{
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assert( !mutex->count );
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/* remove the mutex from the thread list of owned mutexes */
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if (mutex->next) mutex->next->prev = mutex->prev;
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if (mutex->prev) mutex->prev->next = mutex->next;
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else thread->mutex = mutex->next;
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mutex->owner = NULL;
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mutex->next = mutex->prev = NULL;
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wake_up( &mutex->obj, 0 );
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}
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int release_mutex( int handle )
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{
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struct mutex *mutex;
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if (!(mutex = (struct mutex *)get_handle_obj( current->process, handle,
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MUTEX_MODIFY_STATE, &mutex_ops )))
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return 0;
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if (!mutex->count || (mutex->owner != current))
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{
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SET_ERROR( ERROR_NOT_OWNER );
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return 0;
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}
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if (!--mutex->count) do_release( mutex, current );
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release_object( mutex );
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return 1;
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}
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void abandon_mutexes( struct thread *thread )
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{
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while (thread->mutex)
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{
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struct mutex *mutex = thread->mutex;
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assert( mutex->owner == thread );
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mutex->count = 0;
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mutex->abandoned = 1;
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do_release( mutex, thread );
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}
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}
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static void dump_mutex( struct object *obj, int verbose )
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{
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struct mutex *mutex = (struct mutex *)obj;
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assert( obj->ops == &mutex_ops );
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printf( "Mutex count=%u owner=%p\n", mutex->count, mutex->owner );
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}
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static int mutex_signaled( struct object *obj, struct thread *thread )
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{
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struct mutex *mutex = (struct mutex *)obj;
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assert( obj->ops == &mutex_ops );
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return (!mutex->count || (mutex->owner == thread));
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}
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static int mutex_satisfied( struct object *obj, struct thread *thread )
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{
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struct mutex *mutex = (struct mutex *)obj;
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assert( obj->ops == &mutex_ops );
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assert( !mutex->count || (mutex->owner == thread) );
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if (!mutex->count++) /* FIXME: avoid wrap-around */
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{
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assert( !mutex->owner );
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mutex->owner = thread;
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mutex->prev = NULL;
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if ((mutex->next = thread->mutex)) mutex->next->prev = mutex;
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thread->mutex = mutex;
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}
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if (!mutex->abandoned) return 0;
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mutex->abandoned = 0;
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return 1;
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}
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static void destroy_mutex( struct object *obj )
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{
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struct mutex *mutex = (struct mutex *)obj;
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assert( obj->ops == &mutex_ops );
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free( mutex );
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}
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