/* * Server-side mutex management * * Copyright (C) 1998 Alexandre Julliard * * This library 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 library 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 library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "config.h" #include "wine/port.h" #include <assert.h> #include <stdio.h> #include <stdlib.h> #include "windef.h" #include "handle.h" #include "thread.h" #include "request.h" struct mutex { struct object obj; /* object header */ struct thread *owner; /* mutex owner */ unsigned int count; /* recursion count */ int abandoned; /* has it been abandoned? */ struct list entry; /* entry in owner thread mutex list */ }; static void mutex_dump( struct object *obj, int verbose ); static int mutex_signaled( struct object *obj, struct thread *thread ); static int mutex_satisfied( struct object *obj, struct thread *thread ); static void mutex_destroy( struct object *obj ); static int mutex_signal( struct object *obj, unsigned int access ); static const struct object_ops mutex_ops = { sizeof(struct mutex), /* size */ mutex_dump, /* dump */ add_queue, /* add_queue */ remove_queue, /* remove_queue */ mutex_signaled, /* signaled */ mutex_satisfied, /* satisfied */ mutex_signal, /* signal */ no_get_fd, /* get_fd */ no_close_handle, /* close_handle */ mutex_destroy /* destroy */ }; static struct mutex *create_mutex( const WCHAR *name, size_t len, int owned ) { struct mutex *mutex; if ((mutex = create_named_object( sync_namespace, &mutex_ops, name, len ))) { if (get_error() != STATUS_OBJECT_NAME_COLLISION) { /* initialize it if it didn't already exist */ mutex->count = 0; mutex->owner = NULL; mutex->abandoned = 0; if (owned) mutex_satisfied( &mutex->obj, current ); } } return mutex; } /* release a mutex once the recursion count is 0 */ static void do_release( struct mutex *mutex ) { assert( !mutex->count ); /* remove the mutex from the thread list of owned mutexes */ list_remove( &mutex->entry ); mutex->owner = NULL; wake_up( &mutex->obj, 0 ); } void abandon_mutexes( struct thread *thread ) { struct list *ptr; while ((ptr = list_head( &thread->mutex_list )) != NULL) { struct mutex *mutex = LIST_ENTRY( ptr, struct mutex, entry ); assert( mutex->owner == thread ); mutex->count = 0; mutex->abandoned = 1; do_release( mutex ); } } static void mutex_dump( struct object *obj, int verbose ) { struct mutex *mutex = (struct mutex *)obj; assert( obj->ops == &mutex_ops ); fprintf( stderr, "Mutex count=%u owner=%p ", mutex->count, mutex->owner ); dump_object_name( &mutex->obj ); fputc( '\n', stderr ); } static int mutex_signaled( struct object *obj, struct thread *thread ) { struct mutex *mutex = (struct mutex *)obj; assert( obj->ops == &mutex_ops ); return (!mutex->count || (mutex->owner == thread)); } static int mutex_satisfied( struct object *obj, struct thread *thread ) { struct mutex *mutex = (struct mutex *)obj; assert( obj->ops == &mutex_ops ); assert( !mutex->count || (mutex->owner == thread) ); if (!mutex->count++) /* FIXME: avoid wrap-around */ { assert( !mutex->owner ); mutex->owner = thread; list_add_head( &thread->mutex_list, &mutex->entry ); } if (!mutex->abandoned) return 0; mutex->abandoned = 0; return 1; } static int mutex_signal( struct object *obj, unsigned int access ) { struct mutex *mutex = (struct mutex *)obj; assert( obj->ops == &mutex_ops ); if (!(access & SYNCHRONIZE)) /* FIXME: MUTEX_MODIFY_STATE? */ { set_error( STATUS_ACCESS_DENIED ); return 0; } if (!mutex->count || (mutex->owner != current)) { set_error( STATUS_MUTANT_NOT_OWNED ); return 0; } if (!--mutex->count) do_release( mutex ); return 1; } static void mutex_destroy( struct object *obj ) { struct mutex *mutex = (struct mutex *)obj; assert( obj->ops == &mutex_ops ); if (!mutex->count) return; mutex->count = 0; do_release( mutex ); } /* create a mutex */ DECL_HANDLER(create_mutex) { struct mutex *mutex; reply->handle = 0; if ((mutex = create_mutex( get_req_data(), get_req_data_size(), req->owned ))) { reply->handle = alloc_handle( current->process, mutex, req->access, req->inherit ); release_object( mutex ); } } /* open a handle to a mutex */ DECL_HANDLER(open_mutex) { reply->handle = open_object( sync_namespace, get_req_data(), get_req_data_size(), &mutex_ops, req->access, req->inherit ); } /* release a mutex */ DECL_HANDLER(release_mutex) { struct mutex *mutex; if ((mutex = (struct mutex *)get_handle_obj( current->process, req->handle, MUTEX_MODIFY_STATE, &mutex_ops ))) { if (!mutex->count || (mutex->owner != current)) set_error( STATUS_MUTANT_NOT_OWNED ); else { reply->prev_count = mutex->count; if (!--mutex->count) do_release( mutex ); } release_object( mutex ); } }