241 lines
7.8 KiB
C
241 lines
7.8 KiB
C
/*
|
|
* Server-side semaphore 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
|
|
*/
|
|
|
|
#include "config.h"
|
|
#include "wine/port.h"
|
|
|
|
#include <assert.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <stdarg.h>
|
|
|
|
#include "ntstatus.h"
|
|
#define WIN32_NO_STATUS
|
|
#include "windef.h"
|
|
#include "winternl.h"
|
|
|
|
#include "handle.h"
|
|
#include "thread.h"
|
|
#include "request.h"
|
|
#include "security.h"
|
|
|
|
struct semaphore
|
|
{
|
|
struct object obj; /* object header */
|
|
unsigned int count; /* current count */
|
|
unsigned int max; /* maximum possible count */
|
|
};
|
|
|
|
static void semaphore_dump( struct object *obj, int verbose );
|
|
static struct object_type *semaphore_get_type( struct object *obj );
|
|
static int semaphore_signaled( struct object *obj, struct thread *thread );
|
|
static int semaphore_satisfied( struct object *obj, struct thread *thread );
|
|
static unsigned int semaphore_map_access( struct object *obj, unsigned int access );
|
|
static int semaphore_signal( struct object *obj, unsigned int access );
|
|
|
|
static const struct object_ops semaphore_ops =
|
|
{
|
|
sizeof(struct semaphore), /* size */
|
|
semaphore_dump, /* dump */
|
|
semaphore_get_type, /* get_type */
|
|
add_queue, /* add_queue */
|
|
remove_queue, /* remove_queue */
|
|
semaphore_signaled, /* signaled */
|
|
semaphore_satisfied, /* satisfied */
|
|
semaphore_signal, /* signal */
|
|
no_get_fd, /* get_fd */
|
|
semaphore_map_access, /* map_access */
|
|
default_get_sd, /* get_sd */
|
|
default_set_sd, /* set_sd */
|
|
no_lookup_name, /* lookup_name */
|
|
no_open_file, /* open_file */
|
|
no_close_handle, /* close_handle */
|
|
no_destroy /* destroy */
|
|
};
|
|
|
|
|
|
static struct semaphore *create_semaphore( struct directory *root, const struct unicode_str *name,
|
|
unsigned int attr, unsigned int initial, unsigned int max,
|
|
const struct security_descriptor *sd )
|
|
{
|
|
struct semaphore *sem;
|
|
|
|
if (!max || (initial > max))
|
|
{
|
|
set_error( STATUS_INVALID_PARAMETER );
|
|
return NULL;
|
|
}
|
|
if ((sem = create_named_object_dir( root, name, attr, &semaphore_ops )))
|
|
{
|
|
if (get_error() != STATUS_OBJECT_NAME_EXISTS)
|
|
{
|
|
/* initialize it if it didn't already exist */
|
|
sem->count = initial;
|
|
sem->max = max;
|
|
if (sd) default_set_sd( &sem->obj, sd, OWNER_SECURITY_INFORMATION|
|
|
GROUP_SECURITY_INFORMATION|
|
|
DACL_SECURITY_INFORMATION|
|
|
SACL_SECURITY_INFORMATION );
|
|
}
|
|
}
|
|
return sem;
|
|
}
|
|
|
|
static int release_semaphore( struct semaphore *sem, unsigned int count,
|
|
unsigned int *prev )
|
|
{
|
|
if (prev) *prev = sem->count;
|
|
if (sem->count + count < sem->count || sem->count + count > sem->max)
|
|
{
|
|
set_error( STATUS_SEMAPHORE_LIMIT_EXCEEDED );
|
|
return 0;
|
|
}
|
|
else if (sem->count)
|
|
{
|
|
/* there cannot be any thread to wake up if the count is != 0 */
|
|
sem->count += count;
|
|
}
|
|
else
|
|
{
|
|
sem->count = count;
|
|
wake_up( &sem->obj, count );
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void semaphore_dump( struct object *obj, int verbose )
|
|
{
|
|
struct semaphore *sem = (struct semaphore *)obj;
|
|
assert( obj->ops == &semaphore_ops );
|
|
fprintf( stderr, "Semaphore count=%d max=%d ", sem->count, sem->max );
|
|
dump_object_name( &sem->obj );
|
|
fputc( '\n', stderr );
|
|
}
|
|
|
|
static struct object_type *semaphore_get_type( struct object *obj )
|
|
{
|
|
static const WCHAR name[] = {'S','e','m','a','p','h','o','r','e'};
|
|
static const struct unicode_str str = { name, sizeof(name) };
|
|
return get_object_type( &str );
|
|
}
|
|
|
|
static int semaphore_signaled( struct object *obj, struct thread *thread )
|
|
{
|
|
struct semaphore *sem = (struct semaphore *)obj;
|
|
assert( obj->ops == &semaphore_ops );
|
|
return (sem->count > 0);
|
|
}
|
|
|
|
static int semaphore_satisfied( struct object *obj, struct thread *thread )
|
|
{
|
|
struct semaphore *sem = (struct semaphore *)obj;
|
|
assert( obj->ops == &semaphore_ops );
|
|
assert( sem->count );
|
|
sem->count--;
|
|
return 0; /* not abandoned */
|
|
}
|
|
|
|
static unsigned int semaphore_map_access( struct object *obj, unsigned int access )
|
|
{
|
|
if (access & GENERIC_READ) access |= STANDARD_RIGHTS_READ | SYNCHRONIZE;
|
|
if (access & GENERIC_WRITE) access |= STANDARD_RIGHTS_WRITE | SEMAPHORE_MODIFY_STATE;
|
|
if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE;
|
|
if (access & GENERIC_ALL) access |= STANDARD_RIGHTS_ALL | SEMAPHORE_ALL_ACCESS;
|
|
return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
|
|
}
|
|
|
|
static int semaphore_signal( struct object *obj, unsigned int access )
|
|
{
|
|
struct semaphore *sem = (struct semaphore *)obj;
|
|
assert( obj->ops == &semaphore_ops );
|
|
|
|
if (!(access & SEMAPHORE_MODIFY_STATE))
|
|
{
|
|
set_error( STATUS_ACCESS_DENIED );
|
|
return 0;
|
|
}
|
|
return release_semaphore( sem, 1, NULL );
|
|
}
|
|
|
|
/* create a semaphore */
|
|
DECL_HANDLER(create_semaphore)
|
|
{
|
|
struct semaphore *sem;
|
|
struct unicode_str name;
|
|
struct directory *root = NULL;
|
|
const struct object_attributes *objattr = get_req_data();
|
|
const struct security_descriptor *sd;
|
|
|
|
reply->handle = 0;
|
|
|
|
if (!objattr_is_valid( objattr, get_req_data_size() ))
|
|
return;
|
|
|
|
sd = objattr->sd_len ? (const struct security_descriptor *)(objattr + 1) : NULL;
|
|
objattr_get_name( objattr, &name );
|
|
|
|
if (objattr->rootdir && !(root = get_directory_obj( current->process, objattr->rootdir, 0 )))
|
|
return;
|
|
|
|
if ((sem = create_semaphore( root, &name, req->attributes, req->initial, req->max, sd )))
|
|
{
|
|
if (get_error() == STATUS_OBJECT_NAME_EXISTS)
|
|
reply->handle = alloc_handle( current->process, sem, req->access, req->attributes );
|
|
else
|
|
reply->handle = alloc_handle_no_access_check( current->process, sem, req->access, req->attributes );
|
|
release_object( sem );
|
|
}
|
|
|
|
if (root) release_object( root );
|
|
}
|
|
|
|
/* open a handle to a semaphore */
|
|
DECL_HANDLER(open_semaphore)
|
|
{
|
|
struct unicode_str name;
|
|
struct directory *root = NULL;
|
|
struct semaphore *sem;
|
|
|
|
get_req_unicode_str( &name );
|
|
if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
|
|
return;
|
|
|
|
if ((sem = open_object_dir( root, &name, req->attributes, &semaphore_ops )))
|
|
{
|
|
reply->handle = alloc_handle( current->process, &sem->obj, req->access, req->attributes );
|
|
release_object( sem );
|
|
}
|
|
|
|
if (root) release_object( root );
|
|
}
|
|
|
|
/* release a semaphore */
|
|
DECL_HANDLER(release_semaphore)
|
|
{
|
|
struct semaphore *sem;
|
|
|
|
if ((sem = (struct semaphore *)get_handle_obj( current->process, req->handle,
|
|
SEMAPHORE_MODIFY_STATE, &semaphore_ops )))
|
|
{
|
|
release_semaphore( sem, req->count, &reply->prev_count );
|
|
release_object( sem );
|
|
}
|
|
}
|