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     unsigned int         status;          /* current status */
  42     struct timeout_user *timeout;
  43     unsigned int         timeout_status;  /* status to report upon timeout */
  44     struct event        *event;
  45     async_data_t         data;            /* data for async I/O call */
  46 };
  47
  48 static void async_dump( struct object *obj, int verbose );
  49 static void async_destroy( struct object *obj );
  50
  51 static const struct object_ops async_ops =
  52 {
  53     sizeof(struct async),      /* size */
  54     async_dump,                /* dump */
  55     no_get_type,               /* get_type */
  56     no_add_queue,              /* add_queue */
  57     NULL,                      /* remove_queue */
  58     NULL,                      /* signaled */
  59     NULL,                      /* satisfied */
  60     no_signal,                 /* signal */
  61     no_get_fd,                 /* get_fd */
  62     no_map_access,             /* map_access */
  63     default_get_sd,            /* get_sd */
  64     default_set_sd,            /* set_sd */
  65     no_lookup_name,            /* lookup_name */
  66     no_open_file,              /* open_file */
  67     no_close_handle,           /* close_handle */
  68     async_destroy              /* destroy */
  69 };
  70
  71
  72 struct async_queue
  73 {
  74     struct object        obj;             /* object header */
  75     struct fd           *fd;              /* file descriptor owning this queue */
  76     struct completion   *completion;      /* completion associated with a recently closed file descriptor */
  77     apc_param_t          comp_key;        /* completion key associated with a recently closed file descriptor */
  78     struct list          queue;           /* queue of async objects */
  79 };
  80
  81 static void async_queue_dump( struct object *obj, int verbose );
  82 static void async_queue_destroy( struct object *obj );
  83
  84 static const struct object_ops async_queue_ops =
  85 {
  86     sizeof(struct async_queue),      /* size */
  87     async_queue_dump,                /* dump */
  88     no_get_type,                     /* get_type */
  89     no_add_queue,                    /* add_queue */
  90     NULL,                            /* remove_queue */
  91     NULL,                            /* signaled */
  92     NULL,                            /* satisfied */
  93     no_signal,                       /* signal */
  94     no_get_fd,                       /* get_fd */
  95     no_map_access,                   /* map_access */
  96     default_get_sd,                  /* get_sd */
  97     default_set_sd,                  /* set_sd */
  98     no_lookup_name,                  /* lookup_name */
  99     no_open_file,                    /* open_file */
 100     no_close_handle,                 /* close_handle */
 101     async_queue_destroy              /* destroy */
 102 };
 103
 104
 105 static inline void async_reselect( struct async *async )
 106 {
 107     if (async->queue->fd) fd_reselect_async( async->queue->fd, async->queue );
 108 }
 109
 110 static void async_dump( struct object *obj, int verbose )
 111 {
 112     struct async *async = (struct async *)obj;
 113     assert( obj->ops == &async_ops );
 114     fprintf( stderr, "Async thread=%p\n", async->thread );
 115 }
 116
 117 static void async_destroy( struct object *obj )
 118 {
 119     struct async *async = (struct async *)obj;
 120     assert( obj->ops == &async_ops );
 121
 122     list_remove( &async->queue_entry );
 123     async_reselect( async );
 124
 125     if (async->timeout) remove_timeout_user( async->timeout );
 126     if (async->event) release_object( async->event );
 127     release_object( async->queue );
 128     release_object( async->thread );
 129 }
 130
 131 static void async_queue_dump( struct object *obj, int verbose )
 132 {
 133     struct async_queue *async_queue = (struct async_queue *)obj;
 134     assert( obj->ops == &async_queue_ops );
 135     fprintf( stderr, "Async queue fd=%p\n", async_queue->fd );
 136 }
 137
 138 static void async_queue_destroy( struct object *obj )
 139 {
 140     struct async_queue *async_queue = (struct async_queue *)obj;
 141     assert( obj->ops == &async_queue_ops );
 142     if (async_queue->completion) release_object( async_queue->completion );
 143 }
 144
 145 /* notifies client thread of new status of its async request */
 146 void async_terminate( struct async *async, unsigned int status )
 147 {
 148     apc_call_t data;
 149
 150     assert( status != STATUS_PENDING );
 151
 152     if (async->status != STATUS_PENDING)
 153     {
 154         /* already terminated, just update status */
 155         async->status = status;
 156         return;
 157     }
 158
 159     memset( &data, 0, sizeof(data) );
 160     data.type            = APC_ASYNC_IO;
 161     data.async_io.func   = async->data.callback;
 162     data.async_io.user   = async->data.arg;
 163     data.async_io.sb     = async->data.iosb;
 164     data.async_io.status = status;
 165     thread_queue_apc( async->thread, &async->obj, &data );
 166     async->status = status;
 167     async_reselect( async );
 168     release_object( async );  /* so that it gets destroyed when the async is done */
 169 }
 170
 171 /* callback for timeout on an async request */
 172 static void async_timeout( void *private )
 173 {
 174     struct async *async = private;
 175
 176     async->timeout = NULL;
 177     async_terminate( async, async->timeout_status );
 178 }
 179
 180 /* create a new async queue for a given fd */
 181 struct async_queue *create_async_queue( struct fd *fd )
 182 {
 183     struct async_queue *queue = alloc_object( &async_queue_ops );
 184
 185     if (queue)
 186     {
 187         queue->fd = fd;
 188         queue->completion = NULL;
 189         list_init( &queue->queue );
 190     }
 191     return queue;
 192 }
 193
 194 /* free an async queue, cancelling all async operations */
 195 void free_async_queue( struct async_queue *queue )
 196 {
 197     if (!queue) return;
 198     if (queue->fd) queue->completion = fd_get_completion( queue->fd, &queue->comp_key );
 199     queue->fd = NULL;
 200     async_wake_up( queue, STATUS_HANDLES_CLOSED );
 201     release_object( queue );
 202 }
 203
 204 /* create an async on a given queue of a fd */
 205 struct async *create_async( struct thread *thread, struct async_queue *queue, const async_data_t *data )
 206 {
 207     struct event *event = NULL;
 208     struct async *async;
 209
 210     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 211         return NULL;
 212
 213     if (!(async = alloc_object( &async_ops )))
 214     {
 215         if (event) release_object( event );
 216         return NULL;
 217     }
 218
 219     async->thread  = (struct thread *)grab_object( thread );
 220     async->event   = event;
 221     async->status  = STATUS_PENDING;
 222     async->data    = *data;
 223     async->timeout = NULL;
 224     async->queue   = (struct async_queue *)grab_object( queue );
 225
 226     list_add_tail( &queue->queue, &async->queue_entry );
 227     grab_object( async );
 228
 229     if (queue->fd) set_fd_signaled( queue->fd, 0 );
 230     if (event) reset_event( event );
 231     return async;
 232 }
 233
 234 /* set the timeout of an async operation */
 235 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 236 {
 237     if (async->timeout) remove_timeout_user( async->timeout );
 238     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 239     else async->timeout = NULL;
 240     async->timeout_status = status;
 241 }
 242
 243 static void add_async_completion( struct async_queue *queue, apc_param_t cvalue, unsigned int status,
 244                                   apc_param_t information )
 245 {
 246     if (status == STATUS_MORE_PROCESSING_REQUIRED)
 247         return; /* The async callback has successfully finished but no completion should be reported */
 248
 249     if (queue->fd)
 250     {
 251         apc_param_t ckey;
 252         struct completion *completion = fd_get_completion( queue->fd, &ckey );
 253
 254         if (completion)
 255         {
 256             add_completion( completion, ckey, cvalue, status, information );
 257             release_object( completion );
 258         }
 259     }
 260     else if (queue->completion) add_completion( queue->completion, queue->comp_key,
 261                                                 cvalue, status, information );
 262 }
 263
 264 /* store the result of the client-side async callback */
 265 void async_set_result( struct object *obj, unsigned int status, apc_param_t total, client_ptr_t apc )
 266 {
 267     struct async *async = (struct async *)obj;
 268
 269     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 270
 271     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 272
 273     if (status == STATUS_PENDING)  /* restart it */
 274     {
 275         status = async->status;
 276         async->status = STATUS_PENDING;
 277         grab_object( async );
 278
 279         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 280             async_terminate( async, status );
 281         else
 282             async_reselect( async );
 283     }
 284     else
 285     {
 286         if (async->timeout) remove_timeout_user( async->timeout );
 287         async->timeout = NULL;
 288         async->status = status;
 289         if (async->data.cvalue) add_async_completion( async->queue, async->data.cvalue, status, total );
 290         if (apc)
 291         {
 292             apc_call_t data;
 293             memset( &data, 0, sizeof(data) );
 294             data.type         = APC_USER;
 295             data.user.func    = apc;
 296             data.user.args[0] = async->data.arg;
 297             data.user.args[1] = async->data.iosb;
 298             data.user.args[2] = 0;
 299             thread_queue_apc( async->thread, NULL, &data );
 300         }
 301         if (async->event) set_event( async->event );
 302         else if (async->queue->fd) set_fd_signaled( async->queue->fd, 1 );
 303     }
 304 }
 305
 306 /* check if there are any queued async operations */
 307 int async_queued( struct async_queue *queue )
 308 {
 309     return queue && list_head( &queue->queue );
 310 }
 311
 312 /* check if an async operation is waiting to be alerted */
 313 int async_waiting( struct async_queue *queue )
 314 {
 315     struct list *ptr;
 316     struct async *async;
 317
 318     if (!queue) return 0;
 319     if (!(ptr = list_head( &queue->queue ))) return 0;
 320     async = LIST_ENTRY( ptr, struct async, queue_entry );
 321     return async->status == STATUS_PENDING;
 322 }
 323
 324 int async_wake_up_by( struct async_queue *queue, struct process *process,
 325                       struct thread *thread, client_ptr_t iosb, unsigned int status )
 326 {
 327     struct list *ptr, *next;
 328     int woken = 0;
 329
 330     if (!queue || (!process && !thread && !iosb)) return 0;
 331
 332     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 333     {
 334         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 335         if ( (!process || async->thread->process == process) &&
 336              (!thread || async->thread == thread) &&
 337              (!iosb || async->data.iosb == iosb) )
 338         {
 339             async_terminate( async, status );
 340             woken++;
 341         }
 342     }
 343     return woken;
 344 }
 345
 346 /* wake up async operations on the queue */
 347 void async_wake_up( struct async_queue *queue, unsigned int status )
 348 {
 349     struct list *ptr, *next;
 350
 351     if (!queue) return;
 352
 353     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 354     {
 355         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 356         async_terminate( async, status );
 357         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 358     }
 359 }