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 list          queue;           /* queue of async objects */
  77 };
  78
  79 static void async_queue_dump( struct object *obj, int verbose );
  80
  81 static const struct object_ops async_queue_ops =
  82 {
  83     sizeof(struct async_queue),      /* size */
  84     async_queue_dump,                /* dump */
  85     no_get_type,                     /* get_type */
  86     no_add_queue,                    /* add_queue */
  87     NULL,                            /* remove_queue */
  88     NULL,                            /* signaled */
  89     NULL,                            /* satisfied */
  90     no_signal,                       /* signal */
  91     no_get_fd,                       /* get_fd */
  92     no_map_access,                   /* map_access */
  93     default_get_sd,                  /* get_sd */
  94     default_set_sd,                  /* set_sd */
  95     no_lookup_name,                  /* lookup_name */
  96     no_open_file,                    /* open_file */
  97     no_close_handle,                 /* close_handle */
  98     no_destroy                       /* destroy */
  99 };
 100
 101
 102 static inline void async_reselect( struct async *async )
 103 {
 104     if (async->queue->fd) fd_reselect_async( async->queue->fd, async->queue );
 105 }
 106
 107 static void async_dump( struct object *obj, int verbose )
 108 {
 109     struct async *async = (struct async *)obj;
 110     assert( obj->ops == &async_ops );
 111     fprintf( stderr, "Async thread=%p\n", async->thread );
 112 }
 113
 114 static void async_destroy( struct object *obj )
 115 {
 116     struct async *async = (struct async *)obj;
 117     assert( obj->ops == &async_ops );
 118
 119     list_remove( &async->queue_entry );
 120     async_reselect( async );
 121
 122     if (async->timeout) remove_timeout_user( async->timeout );
 123     if (async->event) release_object( async->event );
 124     release_object( async->queue );
 125     release_object( async->thread );
 126 }
 127
 128 static void async_queue_dump( struct object *obj, int verbose )
 129 {
 130     struct async_queue *async_queue = (struct async_queue *)obj;
 131     assert( obj->ops == &async_queue_ops );
 132     fprintf( stderr, "Async queue fd=%p\n", async_queue->fd );
 133 }
 134
 135 /* notifies client thread of new status of its async request */
 136 void async_terminate( struct async *async, unsigned int status )
 137 {
 138     apc_call_t data;
 139
 140     assert( status != STATUS_PENDING );
 141
 142     if (async->status != STATUS_PENDING)
 143     {
 144         /* already terminated, just update status */
 145         async->status = status;
 146         return;
 147     }
 148
 149     /* send error completion event */
 150     if (status != STATUS_ALERTED && async->data.cvalue && async->queue->fd)
 151         fd_add_completion( async->queue->fd, async->data.cvalue, status, 0 );
 152
 153     memset( &data, 0, sizeof(data) );
 154     data.type            = APC_ASYNC_IO;
 155     data.async_io.func   = async->data.callback;
 156     data.async_io.user   = async->data.arg;
 157     data.async_io.sb     = async->data.iosb;
 158     data.async_io.status = status;
 159     thread_queue_apc( async->thread, &async->obj, &data );
 160     async->status = status;
 161     async_reselect( async );
 162     release_object( async );  /* so that it gets destroyed when the async is done */
 163 }
 164
 165 /* callback for timeout on an async request */
 166 static void async_timeout( void *private )
 167 {
 168     struct async *async = private;
 169
 170     async->timeout = NULL;
 171     async_terminate( async, async->timeout_status );
 172 }
 173
 174 /* create a new async queue for a given fd */
 175 struct async_queue *create_async_queue( struct fd *fd )
 176 {
 177     struct async_queue *queue = alloc_object( &async_queue_ops );
 178
 179     if (queue)
 180     {
 181         queue->fd = fd;
 182         list_init( &queue->queue );
 183     }
 184     return queue;
 185 }
 186
 187 /* free an async queue, cancelling all async operations */
 188 void free_async_queue( struct async_queue *queue )
 189 {
 190     if (!queue) return;
 191     queue->fd = NULL;
 192     async_wake_up( queue, STATUS_HANDLES_CLOSED );
 193     release_object( queue );
 194 }
 195
 196 /* create an async on a given queue of a fd */
 197 struct async *create_async( struct thread *thread, struct async_queue *queue, const async_data_t *data )
 198 {
 199     struct event *event = NULL;
 200     struct async *async;
 201
 202     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 203         return NULL;
 204
 205     if (!(async = alloc_object( &async_ops )))
 206     {
 207         if (event) release_object( event );
 208         return NULL;
 209     }
 210
 211     async->thread  = (struct thread *)grab_object( thread );
 212     async->event   = event;
 213     async->status  = STATUS_PENDING;
 214     async->data    = *data;
 215     async->timeout = NULL;
 216     async->queue   = (struct async_queue *)grab_object( queue );
 217
 218     list_add_tail( &queue->queue, &async->queue_entry );
 219     grab_object( async );
 220
 221     if (queue->fd) set_fd_signaled( queue->fd, 0 );
 222     if (event) reset_event( event );
 223     return async;
 224 }
 225
 226 /* set the timeout of an async operation */
 227 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 228 {
 229     if (async->timeout) remove_timeout_user( async->timeout );
 230     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 231     else async->timeout = NULL;
 232     async->timeout_status = status;
 233 }
 234
 235 /* store the result of the client-side async callback */
 236 void async_set_result( struct object *obj, unsigned int status, unsigned long total )
 237 {
 238     struct async *async = (struct async *)obj;
 239
 240     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 241
 242     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 243
 244     if (status == STATUS_PENDING)  /* restart it */
 245     {
 246         status = async->status;
 247         async->status = STATUS_PENDING;
 248         grab_object( async );
 249
 250         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 251             async_terminate( async, status );
 252         else
 253             async_reselect( async );
 254     }
 255     else
 256     {
 257         if (async->timeout) remove_timeout_user( async->timeout );
 258         async->timeout = NULL;
 259         async->status = status;
 260         if (async->data.cvalue && async->queue->fd)
 261             fd_add_completion( async->queue->fd, async->data.cvalue, status, total );
 262         if (async->data.apc)
 263         {
 264             apc_call_t data;
 265             data.type         = APC_USER;
 266             data.user.func    = async->data.apc;
 267             data.user.args[0] = (unsigned long)async->data.arg;
 268             data.user.args[1] = (unsigned long)async->data.iosb;
 269             data.user.args[2] = 0;
 270             thread_queue_apc( async->thread, NULL, &data );
 271         }
 272         if (async->event) set_event( async->event );
 273         else if (async->queue->fd) set_fd_signaled( async->queue->fd, 1 );
 274     }
 275 }
 276
 277 /* check if an async operation is waiting to be alerted */
 278 int async_waiting( struct async_queue *queue )
 279 {
 280     struct list *ptr;
 281     struct async *async;
 282
 283     if (!queue) return 0;
 284     if (!(ptr = list_head( &queue->queue ))) return 0;
 285     async = LIST_ENTRY( ptr, struct async, queue_entry );
 286     return async->status == STATUS_PENDING;
 287 }
 288
 289 /* wake up async operations on the queue */
 290 void async_wake_up( struct async_queue *queue, unsigned int status )
 291 {
 292     struct list *ptr, *next;
 293
 294     if (!queue) return;
 295
 296     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 297     {
 298         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 299         async_terminate( async, status );
 300         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 301     }
 302 }