xrootd
Main Page
Namespaces
Classes
Files
File List
File Members
src
XrdPosix
XrdPosixCallBack.hh
Go to the documentation of this file.
1
#ifndef __POSIX_CALLBACK_HH__
2
#define __POSIX_CALLBACK_HH__
3
/******************************************************************************/
4
/* */
5
/* X r d P o s i x C a l l B a c k . h h */
6
/* */
7
/* (c) 2010 by the Board of Trustees of the Leland Stanford, Jr., University */
8
/* All Rights Reserved */
9
/* Produced by Andrew Hanushevsky for Stanford University under contract */
10
/* DE-AC02-76-SFO0515 with the Department of Energy */
11
/* */
12
/* This file is part of the XRootD software suite. */
13
/* */
14
/* XRootD is free software: you can redistribute it and/or modify it under */
15
/* the terms of the GNU Lesser General Public License as published by the */
16
/* Free Software Foundation, either version 3 of the License, or (at your */
17
/* option) any later version. */
18
/* */
19
/* XRootD is distributed in the hope that it will be useful, but WITHOUT */
20
/* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or */
21
/* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public */
22
/* License for more details. */
23
/* */
24
/* You should have received a copy of the GNU Lesser General Public License */
25
/* along with XRootD in a file called COPYING.LESSER (LGPL license) and file */
26
/* COPYING (GPL license). If not, see <http://www.gnu.org/licenses/>. */
27
/* */
28
/* The copyright holder's institutional names and contributor's names may not */
29
/* be used to endorse or promote products derived from this software without */
30
/* specific prior written permission of the institution or contributor. */
31
/******************************************************************************/
32
33
// This abstract class defines the callback interface for file open() calls.
34
// It is passed when using the XrdPosixXrootd::Open() call. When passed, the
35
// open request will be done in the background. When a callback object is
36
// supplied, Open() will *always* return -1. However, if started successfully,
37
// Open() will return -1 with errno set to EINPROGRESS. Otherwise, errno will
38
// contain the reason the Open() request immediately failed. Upon completion,
39
// the callback's Compete() method is invoked. The Result parameter will either
40
// be a non-negative file descriptor or -errno indicating that the Open()
41
// failed. Note that the caller is responsible for deleting the callback object
42
// after it has been invoked. Note that callbacks will be executed in a
43
// separate thread unless open() is called with O_SYNC or maxThreads is zero.
44
// WARNING: If O_SYNC or maxThreads is zero, then the callback must *not*
45
// issue any filesystem calls using the supplied file descriptor.
46
// Ignoring this will produce undetermined results including possible
47
// deadlock. Synchrnous callbacks are only meant to support private
48
// thread management.
49
50
class
XrdPosixCallBack
51
{
52
public
:
53
54
virtual
void
Complete
(
int
Result) = 0;
55
56
XrdPosixCallBack
() {}
57
virtual
~XrdPosixCallBack
() {}
58
};
59
#endif
Generated by
1.8.3.1