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  */
   8
   9 #include "config.h"
  10
  11 #include <assert.h>
  12 #include <string.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <stdio.h>
  16
  17 #include "handle.h"
  18 #include "thread.h"
  19 #include "request.h"
  20
  21 #include "async.h"
  22
  23 void destroy_async( struct async *async )
  24 {
  25     struct async_queue *aq = async->q;
  26
  27     /*fprintf(stderr,"destroyed async %p\n",async->overlapped); */
  28
  29     if(async->timeout)
  30         remove_timeout_user(async->timeout);
  31     async->timeout = NULL;
  32
  33     if(async->prev)
  34         async->prev->next = async->next;
  35     else
  36         aq->head = async->next;
  37
  38     if(async->next)
  39         async->next->prev = async->prev;
  40     else
  41         aq->tail = async->prev;
  42
  43     async->q = NULL;
  44     async->next = NULL;
  45     async->prev = NULL;
  46
  47     free(async);
  48 }
  49
  50 void async_notify(struct async *async, int status)
  51 {
  52     /* fprintf(stderr,"notifying %p!\n",async->overlapped); */
  53     async->status = status;
  54     thread_queue_apc(async->thread, NULL, async->func, APC_ASYNC, 1, 2, async->overlapped, status);
  55 }
  56
  57 void destroy_async_queue( struct async_queue *q )
  58 {
  59     while(q->head)
  60     {
  61         async_notify(q->head, STATUS_HANDLES_CLOSED);
  62         destroy_async(q->head);
  63     }
  64 }
  65
  66 struct async *find_async(struct async_queue *q, struct thread *thread, void *overlapped)
  67 {
  68     struct async *async;
  69
  70     /* fprintf(stderr,"find_async: %p\n",overlapped); */
  71
  72     if(!q)
  73         return NULL;
  74
  75     for(async = q->head; async; async = async->next)
  76         if((async->overlapped==overlapped) && (async->thread == thread))
  77              return async;
  78
  79     return NULL;
  80 }
  81
  82 void async_insert(struct async_queue *q, struct async *async)
  83 {
  84     async->q = q;
  85     async->prev = q->tail;
  86     async->next = NULL;
  87
  88     if(q->tail)
  89         q->tail->next = async;
  90     else
  91         q->head = async;
  92
  93     q->tail = async;
  94 }
  95
  96 static void async_callback(void *private)
  97 {
  98     struct async *async = (struct async *)private;
  99
 100     /* fprintf(stderr,"%p timeout out\n",async->overlapped); */
 101     async->timeout = NULL;
 102     async_notify(async, STATUS_TIMEOUT);
 103     destroy_async(async);
 104 }
 105
 106 struct async *create_async(struct object *obj, struct thread *thread, void *func,
 107                            void *overlapped)
 108 {
 109     struct async *async = (struct async *) malloc(sizeof(struct async));
 110     if(!async)
 111     {
 112         set_error(STATUS_NO_MEMORY);
 113         return NULL;
 114     }
 115
 116     async->obj = obj;
 117     async->thread = thread;
 118     async->func = func;
 119     async->overlapped = overlapped;
 120     async->next = NULL;
 121     async->prev = NULL;
 122     async->q = NULL;
 123     async->status = STATUS_PENDING;
 124     async->timeout = NULL;
 125
 126     return async;
 127 }
 128
 129 void async_add_timeout(struct async *async, int timeout)
 130 {
 131     if(timeout)
 132     {
 133         gettimeofday( &async->when, 0 );
 134         add_timeout( &async->when, timeout );
 135         async->timeout = add_timeout_user( &async->when, async_callback, async );
 136     }
 137 }
 138
 139 DECL_HANDLER(register_async)
 140 {
 141     struct object *obj;
 142
 143     if (!(obj = get_handle_obj( current->process, req->handle, 0, NULL)) )
 144         return;
 145
 146     if(obj->ops->queue_async)
 147     {
 148         struct async_queue *q = obj->ops->queue_async(obj, NULL, req->type, 0);
 149         struct async *async;
 150
 151         async = find_async(q, current, req->overlapped);
 152         if(req->status==STATUS_PENDING)
 153         {
 154             if(!async)
 155                 async = create_async(obj, current, req->func, req->overlapped);
 156
 157             if(async)
 158             {
 159                 async->status = req->status;
 160                 if(!obj->ops->queue_async(obj, async, req->type, req->count))
 161                     destroy_async(async);
 162             }
 163         }
 164         else
 165         {
 166             if(async)
 167                 destroy_async(async);
 168             else
 169                 set_error(STATUS_INVALID_PARAMETER);
 170         }
 171
 172         set_select_events(obj,obj->ops->get_poll_events(obj));
 173     }
 174     else
 175         set_error(STATUS_INVALID_HANDLE);
 176
 177     release_object(obj);
 178 }
 179