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_add_queue,              /* add_queue */
  56     NULL,                      /* remove_queue */
  57     NULL,                      /* signaled */
  58     NULL,                      /* satisfied */
  59     no_signal,                 /* signal */
  60     no_get_fd,                 /* get_fd */
  61     no_map_access,             /* map_access */
  62     default_get_sd,            /* get_sd */
  63     default_set_sd,            /* set_sd */
  64     no_lookup_name,            /* lookup_name */
  65     no_open_file,              /* open_file */
  66     no_close_handle,           /* close_handle */
  67     async_destroy              /* destroy */
  68 };
  69
  70
  71 struct async_queue
  72 {
  73     struct object        obj;             /* object header */
  74     struct fd           *fd;              /* file descriptor owning this queue */
  75     struct list          queue;           /* queue of async objects */
  76 };
  77
  78 static void async_queue_dump( struct object *obj, int verbose );
  79
  80 static const struct object_ops async_queue_ops =
  81 {
  82     sizeof(struct async_queue),      /* size */
  83     async_queue_dump,                /* dump */
  84     no_add_queue,                    /* add_queue */
  85     NULL,                            /* remove_queue */
  86     NULL,                            /* signaled */
  87     NULL,                            /* satisfied */
  88     no_signal,                       /* signal */
  89     no_get_fd,                       /* get_fd */
  90     no_map_access,                   /* map_access */
  91     default_get_sd,                  /* get_sd */
  92     default_set_sd,                  /* set_sd */
  93     no_lookup_name,                  /* lookup_name */
  94     no_open_file,                    /* open_file */
  95     no_close_handle,                 /* close_handle */
  96     no_destroy                       /* destroy */
  97 };
  98
  99
 100 static inline void async_reselect( struct async *async )
 101 {
 102     if (async->queue->fd) fd_reselect_async( async->queue->fd, async->queue );
 103 }
 104
 105 static void async_dump( struct object *obj, int verbose )
 106 {
 107     struct async *async = (struct async *)obj;
 108     assert( obj->ops == &async_ops );
 109     fprintf( stderr, "Async thread=%p\n", async->thread );
 110 }
 111
 112 static void async_destroy( struct object *obj )
 113 {
 114     struct async *async = (struct async *)obj;
 115     assert( obj->ops == &async_ops );
 116
 117     list_remove( &async->queue_entry );
 118     async_reselect( async );
 119
 120     if (async->timeout) remove_timeout_user( async->timeout );
 121     if (async->event) release_object( async->event );
 122     release_object( async->queue );
 123     release_object( async->thread );
 124 }
 125
 126 static void async_queue_dump( struct object *obj, int verbose )
 127 {
 128     struct async_queue *async_queue = (struct async_queue *)obj;
 129     assert( obj->ops == &async_queue_ops );
 130     fprintf( stderr, "Async queue fd=%p\n", async_queue->fd );
 131 }
 132
 133 /* notifies client thread of new status of its async request */
 134 void async_terminate( struct async *async, unsigned int status )
 135 {
 136     apc_call_t data;
 137
 138     assert( status != STATUS_PENDING );
 139
 140     if (async->status != STATUS_PENDING)
 141     {
 142         /* already terminated, just update status */
 143         async->status = status;
 144         return;
 145     }
 146
 147     memset( &data, 0, sizeof(data) );
 148     data.type            = APC_ASYNC_IO;
 149     data.async_io.func   = async->data.callback;
 150     data.async_io.user   = async->data.arg;
 151     data.async_io.sb     = async->data.iosb;
 152     data.async_io.status = status;
 153     thread_queue_apc( async->thread, &async->obj, &data );
 154     async->status = status;
 155     async_reselect( async );
 156     release_object( async );  /* so that it gets destroyed when the async is done */
 157 }
 158
 159 /* callback for timeout on an async request */
 160 static void async_timeout( void *private )
 161 {
 162     struct async *async = private;
 163
 164     async->timeout = NULL;
 165     async_terminate( async, async->timeout_status );
 166 }
 167
 168 /* create a new async queue for a given fd */
 169 struct async_queue *create_async_queue( struct fd *fd )
 170 {
 171     struct async_queue *queue = alloc_object( &async_queue_ops );
 172
 173     if (queue)
 174     {
 175         queue->fd = fd;
 176         list_init( &queue->queue );
 177     }
 178     return queue;
 179 }
 180
 181 /* free an async queue, cancelling all async operations */
 182 void free_async_queue( struct async_queue *queue )
 183 {
 184     if (!queue) return;
 185     queue->fd = NULL;
 186     async_wake_up( queue, STATUS_HANDLES_CLOSED );
 187     release_object( queue );
 188 }
 189
 190 /* create an async on a given queue of a fd */
 191 struct async *create_async( struct thread *thread, struct async_queue *queue, const async_data_t *data )
 192 {
 193     struct event *event = NULL;
 194     struct async *async;
 195
 196     if (data->event && !(event = get_event_obj( thread->process, data->event, EVENT_MODIFY_STATE )))
 197         return NULL;
 198
 199     if (!(async = alloc_object( &async_ops )))
 200     {
 201         if (event) release_object( event );
 202         return NULL;
 203     }
 204
 205     async->thread  = (struct thread *)grab_object( thread );
 206     async->event   = event;
 207     async->status  = STATUS_PENDING;
 208     async->data    = *data;
 209     async->timeout = NULL;
 210     async->queue   = (struct async_queue *)grab_object( queue );
 211
 212     list_add_tail( &queue->queue, &async->queue_entry );
 213     grab_object( async );
 214
 215     if (queue->fd) set_fd_signaled( queue->fd, 0 );
 216     if (event) reset_event( event );
 217     return async;
 218 }
 219
 220 /* set the timeout of an async operation */
 221 void async_set_timeout( struct async *async, timeout_t timeout, unsigned int status )
 222 {
 223     if (async->timeout) remove_timeout_user( async->timeout );
 224     if (timeout != TIMEOUT_INFINITE) async->timeout = add_timeout_user( timeout, async_timeout, async );
 225     else async->timeout = NULL;
 226     async->timeout_status = status;
 227 }
 228
 229 /* store the result of the client-side async callback */
 230 void async_set_result( struct object *obj, unsigned int status )
 231 {
 232     struct async *async = (struct async *)obj;
 233
 234     if (obj->ops != &async_ops) return;  /* in case the client messed up the APC results */
 235
 236     assert( async->status != STATUS_PENDING );  /* it must have been woken up if we get a result */
 237
 238     if (status == STATUS_PENDING)  /* restart it */
 239     {
 240         status = async->status;
 241         async->status = STATUS_PENDING;
 242         grab_object( async );
 243
 244         if (status != STATUS_ALERTED)  /* it was terminated in the meantime */
 245             async_terminate( async, status );
 246         else
 247             async_reselect( async );
 248     }
 249     else
 250     {
 251         if (async->timeout) remove_timeout_user( async->timeout );
 252         async->timeout = NULL;
 253         async->status = status;
 254         if (async->data.apc)
 255         {
 256             apc_call_t data;
 257             data.type         = APC_USER;
 258             data.user.func    = async->data.apc;
 259             data.user.args[0] = (unsigned long)async->data.arg;
 260             data.user.args[1] = (unsigned long)async->data.iosb;
 261             data.user.args[2] = 0;
 262             thread_queue_apc( async->thread, NULL, &data );
 263         }
 264         if (async->event) set_event( async->event );
 265         else if (async->queue->fd) set_fd_signaled( async->queue->fd, 1 );
 266     }
 267 }
 268
 269 /* check if an async operation is waiting to be alerted */
 270 int async_waiting( struct async_queue *queue )
 271 {
 272     struct list *ptr;
 273     struct async *async;
 274
 275     if (!queue) return 0;
 276     if (!(ptr = list_head( &queue->queue ))) return 0;
 277     async = LIST_ENTRY( ptr, struct async, queue_entry );
 278     return async->status == STATUS_PENDING;
 279 }
 280
 281 /* wake up async operations on the queue */
 282 void async_wake_up( struct async_queue *queue, unsigned int status )
 283 {
 284     struct list *ptr, *next;
 285
 286     if (!queue) return;
 287
 288     LIST_FOR_EACH_SAFE( ptr, next, &queue->queue )
 289     {
 290         struct async *async = LIST_ENTRY( ptr, struct async, queue_entry );
 291         async_terminate( async, status );
 292         if (status == STATUS_ALERTED) break;  /* only wake up the first one */
 293     }
 294 }