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 "file.h"
  32 #include "thread.h"
  33 #include "request.h"
  34
  35 #include "async.h"
  36
  37 void destroy_async( struct async *async )
  38 {
  39     struct async_queue *aq = async->q;
  40
  41     /*fprintf(stderr,"destroyed async %p\n",async->overlapped); */
  42
  43     if(async->timeout)
  44         remove_timeout_user(async->timeout);
  45     async->timeout = NULL;
  46
  47     if(async->prev)
  48         async->prev->next = async->next;
  49     else
  50         aq->head = async->next;
  51
  52     if(async->next)
  53         async->next->prev = async->prev;
  54     else
  55         aq->tail = async->prev;
  56
  57     async->q = NULL;
  58     async->next = NULL;
  59     async->prev = NULL;
  60     release_object( async->thread );
  61     free(async);
  62 }
  63
  64 void async_notify(struct async *async, int status)
  65 {
  66     /* fprintf(stderr,"notifying %p!\n",async->overlapped); */
  67     async->status = status;
  68     thread_queue_apc(async->thread, NULL, NULL, APC_ASYNC_IO, 1,
  69                      async->overlapped, (void *)status, NULL );
  70 }
  71
  72 void destroy_async_queue( struct async_queue *q )
  73 {
  74     while(q->head)
  75     {
  76         async_notify(q->head, STATUS_CANCELLED);
  77         destroy_async(q->head);
  78     }
  79 }
  80
  81 struct async *find_async(struct async_queue *q, struct thread *thread, void *overlapped)
  82 {
  83     struct async *async;
  84
  85     /* fprintf(stderr,"find_async: %p\n",overlapped); */
  86
  87     if(!q)
  88         return NULL;
  89
  90     for(async = q->head; async; async = async->next)
  91         if((async->overlapped==overlapped) && (async->thread == thread))
  92              return async;
  93
  94     return NULL;
  95 }
  96
  97 void async_insert(struct async_queue *q, struct async *async)
  98 {
  99     async->q = q;
 100     async->prev = q->tail;
 101     async->next = NULL;
 102
 103     if(q->tail)
 104         q->tail->next = async;
 105     else
 106         q->head = async;
 107
 108     q->tail = async;
 109 }
 110
 111 static void async_callback(void *private)
 112 {
 113     struct async *async = (struct async *)private;
 114
 115     /* fprintf(stderr,"%p timeout out\n",async->overlapped); */
 116     async->timeout = NULL;
 117     async_notify(async, STATUS_TIMEOUT);
 118     destroy_async(async);
 119 }
 120
 121 struct async *create_async(struct object *obj, struct thread *thread,
 122                            void *overlapped)
 123 {
 124     struct async *async = (struct async *) malloc(sizeof(struct async));
 125     if(!async)
 126     {
 127         set_error(STATUS_NO_MEMORY);
 128         return NULL;
 129     }
 130
 131     async->obj = obj;
 132     async->thread = (struct thread *)grab_object(thread);
 133     async->overlapped = overlapped;
 134     async->next = NULL;
 135     async->prev = NULL;
 136     async->q = NULL;
 137     async->status = STATUS_PENDING;
 138     async->timeout = NULL;
 139
 140     return async;
 141 }
 142
 143 void async_add_timeout(struct async *async, int timeout)
 144 {
 145     if(timeout)
 146     {
 147         gettimeofday( &async->when, 0 );
 148         add_timeout( &async->when, timeout );
 149         async->timeout = add_timeout_user( &async->when, async_callback, async );
 150     }
 151 }