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     struct completion   *completion;
  46     apc_param_t          comp_key;
  47     async_data_t         data;            /* data for async I/O call */
  48 };
  49
  50 static void async_dump( struct object *obj, int verbose );
  51 static void async_destroy( struct object *obj );
  52
  53 static const struct object_ops async_ops =
  54 {
  55     sizeof(struct async),      /* size */
  56     async_dump,                /* dump */
  57     no_get_type,               /* get_type */
  58     no_add_queue,              /* add_queue */
  59     NULL,                      /* remove_queue */
  60     NULL,                      /* signaled */
  61     NULL,                      /* satisfied */
  62     no_signal,                 /* signal */
  63     no_get_fd,                 /* get_fd */
  64     no_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     async_destroy              /* destroy */
  71 };
  72
  73
  74 struct async_queue
  75 {
  76     struct object        obj;             /* object header */
  77     struct fd           *fd;              /* file descriptor owning this queue */
  78     struct list          queue;           /* queue of async objects */
  79 };
  80
  81 static void async_queue_dump( struct object *obj, int verbose );
  82
  83 static const struct object_ops async_queue_ops =
  84 {
  85     sizeof(struct async_queue),      /* size */
  86     async_queue_dump,                /* dump */
  87     no_get_type,                     /* get_type */
  88     no_add_queue,                    /* add_queue */
  89     NULL,                            /* remove_queue */
  90     NULL,                            /* signaled */
  91     NULL,                            /* satisfied */
  92     no_signal,                       /* signal */
  93     no_get_fd,                       /* get_fd */
  94     no_map_access,                   /* map_access */
  95     default_get_sd,                  /* get_sd */
  96     default_set_sd,                  /* set_sd */
  97     no_lookup_name,                  /* lookup_name */
  98     no_open_file,                    /* open_file */
  99     no_close_handle,                 /* close_handle */
 100     no_destroy                       /* destroy */
 101 };
 102
 103
 104 static inline void async_reselect( struct async *async )
 105 {
 106     if (async->queue->fd) fd_reselect_async( async->queue->fd, async->queue );
 107 }
 108
 109 static void async_dump( struct object *obj, int verbose )
 110 {
 111     struct async *async = (struct async *)obj;
 112     assert( obj->ops == &async_ops );
 113     fprintf( stderr, "Async thread=%p\n", async->thread );
 114 }
 115
 116 static void async_destroy( struct object *obj )
 117 {
 118     struct async *async = (struct async *)obj;
 119     assert( obj->ops == &async_ops );
 120
 121     list_remove( &async->queue_entry );
 122     async_reselect( async );
 123
 124     if (async->timeout) remove_timeout_user( async->timeout );
 125     if (async->event) release_object( async->event );
 126     if (async->completion) release_object( async->completion );
 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 /* notifies client thread of new status of its async request */
 139 void async_terminate( struct async *async, unsigned int status )
 140 {
 141     apc_call_t data;
 142
 143     assert( status != STATUS_PENDING );
 144
 145     if (async->status != STATUS_PENDING)
 146     {
 147         /* already terminated, just update status */
 148         async->status = status;
 149         return;
 150     }
 151
 152     memset( &data, 0, sizeof(data) );
 153     data.type            = APC_ASYNC_IO;
 154     data.async_io.func   = async->data.callback;
 155     data.async_io.user   = async->data.arg;
 156     data.async_io.sb     = async->data.iosb;
 157     data.async_io.status = status;
 158     thread_queue_apc( async->thread, &async->obj, &data );
 159     async->status = status;
 160     async_reselect( async );
 161     release_object( async );  /* so that it gets destroyed when the async is done */
 162 }
 163
 164 /* callback for timeout on an async request */
 165 static void async_timeout( void *private )
 166 {
 167     struct async *async = private;
 168
 169     async->timeout = NULL;
 170     async_terminate( async, async->timeout_status );
 171 }
 172
 173 /* create a new async queue for a given fd */
 174 struct async_queue *create_async_queue( struct fd *fd )
 175 {
 176     struct async_queue *queue = alloc_object( &async_queue_ops );
 177
 178     if (queue)
 179     {
 180         queue->fd = fd;
 181         list_init( &queue->queue );
 182     }
 183     return queue;
 184 }
 185
 186 /* free an async queue, cancelling all async operations */
 187 void free_async_queue( struct async_queue *queue )
 188 {
 189     if (!queue) return;
 190     queue->fd = NULL;
 191     async_wake_up( queue, STATUS_HANDLES_CLOSED );
 192     release_object( queue );
 193 }
 194
 195 /* create an async on a given queue of a fd */
 196 struct async *create_async( struct thread *thread, struct async_queue *queue, const async_data_t *data )
 197 {
 198     struct event *event = NULL;
 199     struct async *async;
 200
 201     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 202         return NULL;
 203
 204     if (!(async = alloc_object( &async_ops )))
 205     {
 206         if (event) release_object( event );
 207         return NULL;
 208     }
 209
 210     async->thread  = (struct thread *)grab_object( thread );
 211     async->event   = event;
 212     async->status  = STATUS_PENDING;
 213     async->data    = *data;
 214     async->timeout = NULL;
 215     async->queue   = (struct async_queue *)grab_object( queue );
 216     async->completion = NULL;
 217     if (queue->fd) async->completion = fd_get_completion( queue->fd, &async->comp_key );
 218
 219     list_add_tail( &queue->queue, &async->queue_entry );
 220     grab_object( async );
 221
 222     if (queue->fd) set_fd_signaled( queue->fd, 0 );
 223     if (event) reset_event( event );
 224     return async;
 225 }
 226
 227 /* set the timeout of an async operation */
 228 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 229 {
 230     if (async->timeout) remove_timeout_user( async->timeout );
 231     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 232     else async->timeout = NULL;
 233     async->timeout_status = status;
 234 }
 235
 236 /* store the result of the client-side async callback */
 237 void async_set_result( struct object *obj, unsigned int status, unsigned int total, client_ptr_t apc )
 238 {
 239     struct async *async = (struct async *)obj;
 240
 241     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 242
 243     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 244
 245     if (status == STATUS_PENDING)  /* restart it */
 246     {
 247         status = async->status;
 248         async->status = STATUS_PENDING;
 249         grab_object( async );
 250
 251         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 252             async_terminate( async, status );
 253         else
 254             async_reselect( async );
 255     }
 256     else
 257     {
 258         if (async->timeout) remove_timeout_user( async->timeout );
 259         async->timeout = NULL;
 260         async->status = status;
 261         if (async->completion && async->data.cvalue)
 262             add_completion( async->completion, async->comp_key, async->data.cvalue, status, total );
 263         if (apc)
 264         {
 265             apc_call_t data;
 266             memset( &data, 0, sizeof(data) );
 267             data.type         = APC_USER;
 268             data.user.func    = apc;
 269             data.user.args[0] = async->data.arg;
 270             data.user.args[1] = async->data.iosb;
 271             data.user.args[2] = 0;
 272             thread_queue_apc( async->thread, NULL, &data );
 273         }
 274         if (async->event) set_event( async->event );
 275         else if (async->queue->fd) set_fd_signaled( async->queue->fd, 1 );
 276     }
 277 }
 278
 279 /* check if an async operation is waiting to be alerted */
 280 int async_waiting( struct async_queue *queue )
 281 {
 282     struct list *ptr;
 283     struct async *async;
 284
 285     if (!queue) return 0;
 286     if (!(ptr = list_head( &queue->queue ))) return 0;
 287     async = LIST_ENTRY( ptr, struct async, queue_entry );
 288     return async->status == STATUS_PENDING;
 289 }
 290
 291 /* wake up async operations on the queue */
 292 void async_wake_up( struct async_queue *queue, unsigned int status )
 293 {
 294     struct list *ptr, *next;
 295
 296     if (!queue) return;
 297
 298     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 299     {
 300         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 301         async_terminate( async, status );
 302         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 303     }
 304 }