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