server/async.c

   1 /*
   2  * Server-side async I/O support
   3  *
   4  * Copyright (C) 2007 Alexandre Julliard
   5  *
   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.
  10  *
  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.
  15  *
  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
  19  */
  20
  21 #include <assert.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <stdarg.h>
  25
  26 #include "ntstatus.h"
  27 #define WIN32_NO_STATUS
  28 #include "windef.h"
  29 #include "winternl.h"
  30
  31 #include "object.h"
  32 #include "file.h"
  33 #include "request.h"
  34
  35 struct async
  36 {
  37     struct object        obj;             /* object header */
  38     struct thread       *thread;          /* owning thread */
  39     struct list          queue_entry;     /* entry in async queue list */
  40     struct async_queue  *queue;           /* queue containing this async */
  41     struct timeout_user *timeout;
  42     unsigned int         timeout_status;  /* status to report upon timeout */
  43     struct event        *event;
  44     async_data_t         data;            /* data for async I/O call */
  45 };
  46
  47 static void async_dump( struct object *obj, int verbose );
  48 static void async_destroy( struct object *obj );
  49
  50 static const struct object_ops async_ops =
  51 {
  52     sizeof(struct async),      /* size */
  53     async_dump,                /* dump */
  54     no_add_queue,              /* add_queue */
  55     NULL,                      /* remove_queue */
  56     NULL,                      /* signaled */
  57     NULL,                      /* satisfied */
  58     no_signal,                 /* signal */
  59     no_get_fd,                 /* get_fd */
  60     no_map_access,             /* map_access */
  61     no_lookup_name,            /* lookup_name */
  62     no_open_file,              /* open_file */
  63     no_close_handle,           /* close_handle */
  64     async_destroy              /* destroy */
  65 };
  66
  67
  68 struct async_queue
  69 {
  70     struct object        obj;             /* object header */
  71     struct fd           *fd;              /* file descriptor owning this queue */
  72     struct list          queue;           /* queue of async objects */
  73 };
  74
  75 static void async_queue_dump( struct object *obj, int verbose );
  76
  77 static const struct object_ops async_queue_ops =
  78 {
  79     sizeof(struct async_queue),      /* size */
  80     async_queue_dump,                /* dump */
  81     no_add_queue,                    /* add_queue */
  82     NULL,                            /* remove_queue */
  83     NULL,                            /* signaled */
  84     NULL,                            /* satisfied */
  85     no_signal,                       /* signal */
  86     no_get_fd,                       /* get_fd */
  87     no_map_access,                   /* map_access */
  88     no_lookup_name,                  /* lookup_name */
  89     no_open_file,                    /* open_file */
  90     no_close_handle,                 /* close_handle */
  91     no_destroy                       /* destroy */
  92 };
  93
  94
  95 static void async_dump( struct object *obj, int verbose )
  96 {
  97     struct async *async = (struct async *)obj;
  98     assert( obj->ops == &async_ops );
  99     fprintf( stderr, "Async thread=%p\n", async->thread );
 100 }
 101
 102 static void async_destroy( struct object *obj )
 103 {
 104     struct async *async = (struct async *)obj;
 105     assert( obj->ops == &async_ops );
 106
 107     if (async->timeout) remove_timeout_user( async->timeout );
 108     if (async->event) release_object( async->event );
 109     release_object( async->queue );
 110     async->queue = NULL;
 111     release_object( async->thread );
 112 }
 113
 114 static void async_queue_dump( struct object *obj, int verbose )
 115 {
 116     struct async_queue *async_queue = (struct async_queue *)obj;
 117     assert( obj->ops == &async_queue_ops );
 118     fprintf( stderr, "Async queue fd=%p\n", async_queue->fd );
 119 }
 120
 121 /* notifies client thread of new status of its async request */
 122 /* destroys the server side of it */
 123 static void async_terminate( struct async *async, unsigned int status )
 124 {
 125     apc_call_t data;
 126
 127     memset( &data, 0, sizeof(data) );
 128     data.type            = APC_ASYNC_IO;
 129     data.async_io.func   = async->data.callback;
 130     data.async_io.user   = async->data.arg;
 131     data.async_io.sb     = async->data.iosb;
 132     data.async_io.status = status;
 133     thread_queue_apc( async->thread, &async->obj, &data );
 134
 135     if (async->timeout) remove_timeout_user( async->timeout );
 136     async->timeout = NULL;
 137     list_remove( &async->queue_entry );
 138     release_object( async );
 139 }
 140
 141 /* callback for timeout on an async request */
 142 static void async_timeout( void *private )
 143 {
 144     struct async *async = private;
 145
 146     async->timeout = NULL;
 147     async_terminate( async, async->timeout_status );
 148 }
 149
 150 /* create a new async queue for a given fd */
 151 struct async_queue *create_async_queue( struct fd *fd )
 152 {
 153     struct async_queue *queue = alloc_object( &async_queue_ops );
 154
 155     if (queue)
 156     {
 157         queue->fd = fd;
 158         list_init( &queue->queue );
 159     }
 160     return queue;
 161 }
 162
 163 /* free an async queue, cancelling all async operations */
 164 void free_async_queue( struct async_queue *queue )
 165 {
 166     if (!queue) return;
 167     queue->fd = NULL;
 168     async_wake_up( queue, STATUS_HANDLES_CLOSED );
 169     release_object( queue );
 170 }
 171
 172 /* create an async on a given queue of a fd */
 173 struct async *create_async( struct thread *thread, struct async_queue *queue, const async_data_t *data )
 174 {
 175     struct event *event = NULL;
 176     struct async *async;
 177
 178     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 179         return NULL;
 180
 181     if (!(async = alloc_object( &async_ops )))
 182     {
 183         if (event) release_object( event );
 184         return NULL;
 185     }
 186
 187     async->thread = (struct thread *)grab_object( thread );
 188     async->event = event;
 189     async->data = *data;
 190     async->timeout = NULL;
 191     async->queue = (struct async_queue *)grab_object( queue );
 192
 193     list_add_tail( &queue->queue, &async->queue_entry );
 194     grab_object( async );
 195
 196     if (queue->fd) set_fd_signaled( queue->fd, 0 );
 197     if (event) reset_event( event );
 198     return async;
 199 }
 200
 201 /* set the timeout of an async operation */
 202 void async_set_timeout( struct async *async, const struct timeval *timeout, unsigned int status )
 203 {
 204     if (async->timeout) remove_timeout_user( async->timeout );
 205     if (timeout) async->timeout = add_timeout_user( timeout, async_timeout, async );
 206     else async->timeout = NULL;
 207     async->timeout_status = status;
 208 }
 209
 210 /* store the result of the client-side async callback */
 211 void async_set_result( struct object *obj, unsigned int status )
 212 {
 213     struct async *async = (struct async *)obj;
 214
 215     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 216
 217     if (status == STATUS_PENDING)
 218     {
 219         /* FIXME: restart the async operation */
 220     }
 221     else
 222     {
 223         if (async->data.apc)
 224         {
 225             apc_call_t data;
 226             data.type         = APC_USER;
 227             data.user.func    = async->data.apc;
 228             data.user.args[0] = (unsigned long)async->data.apc_arg;
 229             data.user.args[1] = (unsigned long)async->data.iosb;
 230             data.user.args[2] = 0;
 231             thread_queue_apc( async->thread, NULL, &data );
 232         }
 233         if (async->event) set_event( async->event );
 234         else if (async->queue->fd) set_fd_signaled( async->queue->fd, 1 );
 235     }
 236 }
 237
 238 /* check if an async operation is waiting to be alerted */
 239 int async_waiting( struct async_queue *queue )
 240 {
 241     return queue && !list_empty( &queue->queue );
 242 }
 243
 244 /* wake up async operations on the queue */
 245 void async_wake_up( struct async_queue *queue, unsigned int status )
 246 {
 247     struct list *ptr, *next;
 248
 249     if (!queue) return;
 250
 251     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 252     {
 253         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 254         async_terminate( async, status );
 255         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 256     }
 257 }