server/async.c

   1 /*
   2  * Server-side support for async i/o operations
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  * Copyright (C) 2000 Mike McCormack
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include "config.h"
  23
  24 #include <assert.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <stdio.h>
  29
  30 #include "handle.h"
  31 #include "thread.h"
  32 #include "request.h"
  33
  34 #include "async.h"
  35
  36 void destroy_async( struct async *async )
  37 {
  38     struct async_queue *aq = async->q;
  39
  40     /*fprintf(stderr,"destroyed async %p\n",async->overlapped); */
  41
  42     if(async->timeout)
  43         remove_timeout_user(async->timeout);
  44     async->timeout = NULL;
  45
  46     if(async->prev)
  47         async->prev->next = async->next;
  48     else
  49         aq->head = async->next;
  50
  51     if(async->next)
  52         async->next->prev = async->prev;
  53     else
  54         aq->tail = async->prev;
  55
  56     async->q = NULL;
  57     async->next = NULL;
  58     async->prev = NULL;
  59
  60     free(async);
  61 }
  62
  63 void async_notify(struct async *async, int status)
  64 {
  65     /* fprintf(stderr,"notifying %p!\n",async->overlapped); */
  66     async->status = status;
  67     thread_queue_apc(async->thread, NULL, NULL, APC_ASYNC_IO, 1, 2, async->overlapped, status);
  68 }
  69
  70 void destroy_async_queue( struct async_queue *q )
  71 {
  72     while(q->head)
  73     {
  74         async_notify(q->head, STATUS_CANCELLED);
  75         destroy_async(q->head);
  76     }
  77 }
  78
  79 struct async *find_async(struct async_queue *q, struct thread *thread, void *overlapped)
  80 {
  81     struct async *async;
  82
  83     /* fprintf(stderr,"find_async: %p\n",overlapped); */
  84
  85     if(!q)
  86         return NULL;
  87
  88     for(async = q->head; async; async = async->next)
  89         if((async->overlapped==overlapped) && (async->thread == thread))
  90              return async;
  91
  92     return NULL;
  93 }
  94
  95 void async_insert(struct async_queue *q, struct async *async)
  96 {
  97     async->q = q;
  98     async->prev = q->tail;
  99     async->next = NULL;
 100
 101     if(q->tail)
 102         q->tail->next = async;
 103     else
 104         q->head = async;
 105
 106     q->tail = async;
 107 }
 108
 109 static void async_callback(void *private)
 110 {
 111     struct async *async = (struct async *)private;
 112
 113     /* fprintf(stderr,"%p timeout out\n",async->overlapped); */
 114     async->timeout = NULL;
 115     async_notify(async, STATUS_TIMEOUT);
 116     destroy_async(async);
 117 }
 118
 119 struct async *create_async(struct object *obj, struct thread *thread,
 120                            void *overlapped)
 121 {
 122     struct async *async = (struct async *) malloc(sizeof(struct async));
 123     if(!async)
 124     {
 125         set_error(STATUS_NO_MEMORY);
 126         return NULL;
 127     }
 128
 129     async->obj = obj;
 130     async->thread = thread;
 131     async->overlapped = overlapped;
 132     async->next = NULL;
 133     async->prev = NULL;
 134     async->q = NULL;
 135     async->status = STATUS_PENDING;
 136     async->timeout = NULL;
 137
 138     return async;
 139 }
 140
 141 void async_add_timeout(struct async *async, int timeout)
 142 {
 143     if(timeout)
 144     {
 145         gettimeofday( &async->when, 0 );
 146         add_timeout( &async->when, timeout );
 147         async->timeout = add_timeout_user( &async->when, async_callback, async );
 148     }
 149 }
 150
 151 DECL_HANDLER(register_async)
 152 {
 153     struct object *obj;
 154
 155     if (!(obj = get_handle_obj( current->process, req->handle, 0, NULL)) )
 156         return;
 157
 158     if(obj->ops->queue_async)
 159     {
 160         struct async_queue *q = obj->ops->queue_async(obj, NULL, req->type, 0);
 161         struct async *async;
 162
 163         async = find_async(q, current, req->overlapped);
 164         if(req->status==STATUS_PENDING)
 165         {
 166             if(!async)
 167                 async = create_async(obj, current, req->overlapped);
 168
 169             if(async)
 170             {
 171                 async->status = req->status;
 172                 if(!obj->ops->queue_async(obj, async, req->type, req->count))
 173                     destroy_async(async);
 174             }
 175         }
 176         else
 177         {
 178             if(async)
 179                 destroy_async(async);
 180             else
 181                 set_error(STATUS_INVALID_PARAMETER);
 182         }
 183
 184         set_select_events(obj,obj->ops->get_poll_events(obj));
 185     }
 186     else
 187         set_error(STATUS_INVALID_HANDLE);
 188
 189     release_object(obj);
 190 }
 191