include/async.h

   1 /*
   2  * Structures and static functions for handling asynchronous I/O.
   3  *
   4  * Copyright (C) 2002 Mike McCormack,  Martin Wilck
   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /*
  22  * This file declares static functions.
  23  * It should only be included by those source files that implement async I/O requests.
  24  */
  25
  26 #ifndef __WINE_ASYNC_H
  27 #define __WINE_ASYNC_H
  28
  29 #include "wine/server.h"
  30
  31 struct async_private;
  32
  33 typedef void (*async_handler)(struct async_private *ovp);
  34 typedef void (CALLBACK *async_call_completion_func)(ULONG_PTR data);
  35 typedef DWORD (*async_get_status)(const struct async_private *ovp);
  36 typedef DWORD (*async_get_count)(const struct async_private *ovp);
  37 typedef void (*async_set_status)(struct async_private *ovp, const DWORD status);
  38 typedef void (*async_cleanup)(struct async_private *ovp);
  39
  40 typedef struct async_ops
  41 {
  42     async_get_status            get_status;
  43     async_set_status            set_status;
  44     async_get_count             get_count;
  45     async_call_completion_func  call_completion;
  46     async_cleanup               cleanup;
  47 } async_ops;
  48
  49 typedef struct async_private
  50 {
  51     struct async_ops     *ops;
  52     HANDLE        handle;
  53     HANDLE        event;
  54     int           fd;
  55     async_handler func;
  56     int           type;
  57     struct async_private *next;
  58     struct async_private *prev;
  59 } async_private;
  60
  61 /* All functions declared static for Dll separation purposes */
  62
  63 inline static void finish_async( async_private *ovp )
  64 {
  65     if(ovp->prev)
  66         ovp->prev->next = ovp->next;
  67     else
  68         NtCurrentTeb()->pending_list = ovp->next;
  69
  70     if(ovp->next)
  71         ovp->next->prev = ovp->prev;
  72
  73     ovp->next = ovp->prev = NULL;
  74
  75     close( ovp->fd );
  76     if( ovp->event != INVALID_HANDLE_VALUE )
  77         NtSetEvent( ovp->event, NULL );
  78
  79     if ( ovp->ops->call_completion )
  80         QueueUserAPC( ovp->ops->call_completion, GetCurrentThread(), (ULONG_PTR)ovp );
  81     else
  82         ovp->ops->cleanup ( ovp );
  83 }
  84
  85 inline static BOOL __register_async( async_private *ovp, const DWORD status )
  86 {
  87     BOOL ret;
  88
  89     SERVER_START_REQ( register_async )
  90     {
  91         req->handle = ovp->handle;
  92         req->overlapped = ovp;
  93         req->type = ovp->type;
  94         req->count = ovp->ops->get_count( ovp );
  95         req->status = status;
  96         ret = wine_server_call( req );
  97     }
  98     SERVER_END_REQ;
  99
 100     if ( ret ) {
 101         SetLastError( RtlNtStatusToDosError(ret) );
 102         ovp->ops->set_status ( ovp, ret );
 103     }
 104
 105     if ( ovp->ops->get_status (ovp) != STATUS_PENDING )
 106         finish_async (ovp);
 107
 108     return ret;
 109 }
 110
 111 #define register_old_async(ovp) \
 112     __register_async (ovp, ovp->ops->get_status( ovp ));
 113
 114 inline static BOOL register_new_async( async_private *ovp )
 115 {
 116     ovp->ops->set_status ( ovp, STATUS_PENDING );
 117
 118     ovp->next = NtCurrentTeb()->pending_list;
 119     ovp->prev = NULL;
 120     if ( ovp->next ) ovp->next->prev = ovp;
 121     NtCurrentTeb()->pending_list = ovp;
 122
 123     return __register_async( ovp, STATUS_PENDING );
 124 }
 125
 126 inline static BOOL cancel_async ( async_private *ovp )
 127 {
 128      /* avoid multiple cancellations */
 129      if ( ovp->ops->get_status( ovp ) != STATUS_PENDING )
 130           return 0;
 131      ovp->ops->set_status ( ovp, STATUS_CANCELLED );
 132      return __register_async ( ovp, STATUS_CANCELLED );
 133 }
 134
 135 #endif /* __WINE_ASYNC_H */