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 <thread.h>
  30 #include <ntstatus.h>
  31 #include <wine/server.h>
  32 #include <winternl.h>
  33
  34 struct async_private;
  35
  36 typedef void (*async_handler)(struct async_private *ovp);
  37 typedef void (CALLBACK *async_call_completion_func)(ULONG_PTR data);
  38 typedef DWORD (*async_get_count)(const struct async_private *ovp);
  39 typedef void (*async_cleanup)(struct async_private *ovp);
  40
  41 typedef struct async_ops
  42 {
  43     async_get_count             get_count;
  44     async_call_completion_func  call_completion;
  45     async_cleanup               cleanup;
  46 } async_ops;
  47
  48 typedef struct async_private
  49 {
  50     struct async_ops*   ops;
  51     HANDLE              handle;
  52     HANDLE              event;
  53     int                 fd;
  54     async_handler       func;
  55     int                 type;
  56     IO_STATUS_BLOCK*    iosb;
  57     struct async_private* next;
  58     struct async_private* prev;
  59 } async_private;
  60
  61 /* All functions declared static for Dll separation purposes */
  62 static void CALLBACK call_user_apc( ULONG_PTR arg1, ULONG_PTR arg2, ULONG_PTR arg3 )
  63 {
  64     PAPCFUNC func = (PAPCFUNC)arg1;
  65     func( arg2 );
  66 }
  67
  68 inline static void finish_async( async_private *ovp )
  69 {
  70     if (ovp->prev)
  71         ovp->prev->next = ovp->next;
  72     else
  73         NtCurrentTeb()->pending_list = ovp->next;
  74
  75     if (ovp->next)
  76         ovp->next->prev = ovp->prev;
  77
  78     ovp->next = ovp->prev = NULL;
  79
  80     close(ovp->fd);
  81     if ( ovp->event != INVALID_HANDLE_VALUE )
  82         NtSetEvent( ovp->event, NULL );
  83
  84     if ( ovp->ops->call_completion )
  85         NtQueueApcThread( GetCurrentThread(), call_user_apc,
  86                           (ULONG_PTR)ovp->ops->call_completion, (ULONG_PTR)ovp, 0 );
  87     else
  88         ovp->ops->cleanup( ovp );
  89 }
  90
  91 inline static NTSTATUS __register_async( async_private *ovp, const DWORD status )
  92 {
  93     NTSTATUS    ret;
  94
  95     SERVER_START_REQ( register_async )
  96     {
  97         req->handle = ovp->handle;
  98         req->overlapped = ovp;
  99         req->type = ovp->type;
 100         req->count = ovp->ops->get_count( ovp );
 101         req->status = status;
 102         ret = wine_server_call( req );
 103     }
 104     SERVER_END_REQ;
 105
 106     if (ret) ovp->iosb->u.Status = ret;
 107
 108     if ( ovp->iosb->u.Status != STATUS_PENDING )
 109         finish_async(ovp);
 110
 111     return ret;
 112 }
 113
 114 #define register_old_async(ovp) \
 115     __register_async(ovp, ovp->iosb->u.Status);
 116
 117 inline static NTSTATUS register_new_async( async_private *ovp )
 118 {
 119     ovp->iosb->u.Status = STATUS_PENDING;
 120
 121     ovp->next = NtCurrentTeb()->pending_list;
 122     ovp->prev = NULL;
 123     if ( ovp->next ) ovp->next->prev = ovp;
 124     NtCurrentTeb()->pending_list = ovp;
 125
 126     return __register_async( ovp, STATUS_PENDING );
 127 }
 128
 129 inline static NTSTATUS cancel_async( async_private *ovp )
 130 {
 131      /* avoid multiple cancellations */
 132      if ( ovp->iosb->u.Status != STATUS_PENDING )
 133           return STATUS_SUCCESS;
 134      ovp->iosb->u.Status = STATUS_CANCELLED;
 135      return __register_async( ovp, STATUS_CANCELLED );
 136 }
 137
 138 #endif /* __WINE_ASYNC_H */