mshtml: Added new EventTarget struct representing event targets.
[wine.git] / server / semaphore.c
blobd87325cf24df6d54e02242fe5d1c1297d06db3f4
1 /*
2 * Server-side semaphore management
4 * Copyright (C) 1998 Alexandre Julliard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
21 #include "config.h"
22 #include "wine/port.h"
24 #include <assert.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <stdarg.h>
29 #include "ntstatus.h"
30 #define WIN32_NO_STATUS
31 #include "windef.h"
32 #include "winternl.h"
34 #include "handle.h"
35 #include "thread.h"
36 #include "request.h"
37 #include "security.h"
39 struct semaphore
41 struct object obj; /* object header */
42 unsigned int count; /* current count */
43 unsigned int max; /* maximum possible count */
46 static void semaphore_dump( struct object *obj, int verbose );
47 static struct object_type *semaphore_get_type( struct object *obj );
48 static int semaphore_signaled( struct object *obj, struct wait_queue_entry *entry );
49 static void semaphore_satisfied( struct object *obj, struct wait_queue_entry *entry );
50 static unsigned int semaphore_map_access( struct object *obj, unsigned int access );
51 static int semaphore_signal( struct object *obj, unsigned int access );
53 static const struct object_ops semaphore_ops =
55 sizeof(struct semaphore), /* size */
56 semaphore_dump, /* dump */
57 semaphore_get_type, /* get_type */
58 add_queue, /* add_queue */
59 remove_queue, /* remove_queue */
60 semaphore_signaled, /* signaled */
61 semaphore_satisfied, /* satisfied */
62 semaphore_signal, /* signal */
63 no_get_fd, /* get_fd */
64 semaphore_map_access, /* map_access */
65 default_get_sd, /* get_sd */
66 default_set_sd, /* set_sd */
67 no_lookup_name, /* lookup_name */
68 no_open_file, /* open_file */
69 no_close_handle, /* close_handle */
70 no_destroy /* destroy */
74 static struct semaphore *create_semaphore( struct directory *root, const struct unicode_str *name,
75 unsigned int attr, unsigned int initial, unsigned int max,
76 const struct security_descriptor *sd )
78 struct semaphore *sem;
80 if (!max || (initial > max))
82 set_error( STATUS_INVALID_PARAMETER );
83 return NULL;
85 if ((sem = create_named_object_dir( root, name, attr, &semaphore_ops )))
87 if (get_error() != STATUS_OBJECT_NAME_EXISTS)
89 /* initialize it if it didn't already exist */
90 sem->count = initial;
91 sem->max = max;
92 if (sd) default_set_sd( &sem->obj, sd, OWNER_SECURITY_INFORMATION|
93 GROUP_SECURITY_INFORMATION|
94 DACL_SECURITY_INFORMATION|
95 SACL_SECURITY_INFORMATION );
98 return sem;
101 static int release_semaphore( struct semaphore *sem, unsigned int count,
102 unsigned int *prev )
104 if (prev) *prev = sem->count;
105 if (sem->count + count < sem->count || sem->count + count > sem->max)
107 set_error( STATUS_SEMAPHORE_LIMIT_EXCEEDED );
108 return 0;
110 else if (sem->count)
112 /* there cannot be any thread to wake up if the count is != 0 */
113 sem->count += count;
115 else
117 sem->count = count;
118 wake_up( &sem->obj, count );
120 return 1;
123 static void semaphore_dump( struct object *obj, int verbose )
125 struct semaphore *sem = (struct semaphore *)obj;
126 assert( obj->ops == &semaphore_ops );
127 fprintf( stderr, "Semaphore count=%d max=%d ", sem->count, sem->max );
128 dump_object_name( &sem->obj );
129 fputc( '\n', stderr );
132 static struct object_type *semaphore_get_type( struct object *obj )
134 static const WCHAR name[] = {'S','e','m','a','p','h','o','r','e'};
135 static const struct unicode_str str = { name, sizeof(name) };
136 return get_object_type( &str );
139 static int semaphore_signaled( struct object *obj, struct wait_queue_entry *entry )
141 struct semaphore *sem = (struct semaphore *)obj;
142 assert( obj->ops == &semaphore_ops );
143 return (sem->count > 0);
146 static void semaphore_satisfied( struct object *obj, struct wait_queue_entry *entry )
148 struct semaphore *sem = (struct semaphore *)obj;
149 assert( obj->ops == &semaphore_ops );
150 assert( sem->count );
151 sem->count--;
154 static unsigned int semaphore_map_access( struct object *obj, unsigned int access )
156 if (access & GENERIC_READ) access |= STANDARD_RIGHTS_READ | SEMAPHORE_QUERY_STATE;
157 if (access & GENERIC_WRITE) access |= STANDARD_RIGHTS_WRITE | SEMAPHORE_MODIFY_STATE;
158 if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE;
159 if (access & GENERIC_ALL) access |= STANDARD_RIGHTS_ALL | SEMAPHORE_ALL_ACCESS;
160 return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
163 static int semaphore_signal( struct object *obj, unsigned int access )
165 struct semaphore *sem = (struct semaphore *)obj;
166 assert( obj->ops == &semaphore_ops );
168 if (!(access & SEMAPHORE_MODIFY_STATE))
170 set_error( STATUS_ACCESS_DENIED );
171 return 0;
173 return release_semaphore( sem, 1, NULL );
176 /* create a semaphore */
177 DECL_HANDLER(create_semaphore)
179 struct semaphore *sem;
180 struct unicode_str name;
181 struct directory *root = NULL;
182 const struct object_attributes *objattr = get_req_data();
183 const struct security_descriptor *sd;
185 reply->handle = 0;
187 if (!objattr_is_valid( objattr, get_req_data_size() ))
188 return;
190 sd = objattr->sd_len ? (const struct security_descriptor *)(objattr + 1) : NULL;
191 objattr_get_name( objattr, &name );
193 if (objattr->rootdir && !(root = get_directory_obj( current->process, objattr->rootdir, 0 )))
194 return;
196 if ((sem = create_semaphore( root, &name, req->attributes, req->initial, req->max, sd )))
198 if (get_error() == STATUS_OBJECT_NAME_EXISTS)
199 reply->handle = alloc_handle( current->process, sem, req->access, req->attributes );
200 else
201 reply->handle = alloc_handle_no_access_check( current->process, sem, req->access, req->attributes );
202 release_object( sem );
205 if (root) release_object( root );
208 /* open a handle to a semaphore */
209 DECL_HANDLER(open_semaphore)
211 struct unicode_str name;
212 struct directory *root = NULL;
213 struct semaphore *sem;
215 get_req_unicode_str( &name );
216 if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
217 return;
219 if ((sem = open_object_dir( root, &name, req->attributes, &semaphore_ops )))
221 reply->handle = alloc_handle( current->process, &sem->obj, req->access, req->attributes );
222 release_object( sem );
225 if (root) release_object( root );
228 /* release a semaphore */
229 DECL_HANDLER(release_semaphore)
231 struct semaphore *sem;
233 if ((sem = (struct semaphore *)get_handle_obj( current->process, req->handle,
234 SEMAPHORE_MODIFY_STATE, &semaphore_ops )))
236 release_semaphore( sem, req->count, &reply->prev_count );
237 release_object( sem );
241 /* query details about the semaphore */
242 DECL_HANDLER(query_semaphore)
244 struct semaphore *sem;
246 if ((sem = (struct semaphore *)get_handle_obj( current->process, req->handle,
247 SEMAPHORE_QUERY_STATE, &semaphore_ops )))
249 reply->current = sem->count;
250 reply->max = sem->max;
251 release_object( sem );