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