wxWidgets/include/wx/unix/pipe.h
Vadim Zeitlin 3b81609771 Fix spurious errors when writing to the child process stdin under Unix.
Since the child pipe was made non-blocking in r65993, it became possible to
write to child process without deadlocking when the pipe became full. However
this still resulted in an error from wxFileOutputStream as it didn't handle
EAGAIN returned from write() any differently than any other error, even though
it is an expected situation in this particular case.

Change Unix wxExecute() to use wxPipeOutputStream which ignores EAGAIN unlike
wxFileOutputStream to fix this.

See #12636.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66152 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2010-11-14 14:04:37 +00:00

139 lines
3.5 KiB
C++

///////////////////////////////////////////////////////////////////////////////
// Name: wx/unix/pipe.h
// Purpose: wxPipe class
// Author: Vadim Zeitlin
// Modified by:
// Created: 24.06.2003 (extracted from src/unix/utilsunx.cpp)
// RCS-ID: $Id$
// Copyright: (c) 2003 Vadim Zeitlin <vadim@wxwidgets.org>
// Licence: wxWindows licence
///////////////////////////////////////////////////////////////////////////////
#ifndef _WX_UNIX_PIPE_H_
#define _WX_UNIX_PIPE_H_
#include <unistd.h>
#include "wx/log.h"
#include "wx/intl.h"
// ----------------------------------------------------------------------------
// wxPipe: this class encapsulates pipe() system call
// ----------------------------------------------------------------------------
class wxPipe
{
public:
// the symbolic names for the pipe ends
enum Direction
{
Read,
Write
};
enum
{
INVALID_FD = -1
};
// default ctor doesn't do anything
wxPipe() { m_fds[Read] = m_fds[Write] = INVALID_FD; }
// create the pipe, return TRUE if ok, FALSE on error
bool Create()
{
if ( pipe(m_fds) == -1 )
{
wxLogSysError(_("Pipe creation failed"));
return false;
}
return true;
}
// switch the given end of the pipe to non-blocking IO
bool MakeNonBlocking(Direction which)
{
const int flags = fcntl(m_fds[which], F_GETFL, 0);
if ( flags == -1 )
return false;
return fcntl(m_fds[which], F_SETFL, flags | O_NONBLOCK) == 0;
}
// return TRUE if we were created successfully
bool IsOk() const { return m_fds[Read] != INVALID_FD; }
// return the descriptor for one of the pipe ends
int operator[](Direction which) const { return m_fds[which]; }
// detach a descriptor, meaning that the pipe dtor won't close it, and
// return it
int Detach(Direction which)
{
int fd = m_fds[which];
m_fds[which] = INVALID_FD;
return fd;
}
// close the pipe descriptors
void Close()
{
for ( size_t n = 0; n < WXSIZEOF(m_fds); n++ )
{
if ( m_fds[n] != INVALID_FD )
{
close(m_fds[n]);
m_fds[n] = INVALID_FD;
}
}
}
// dtor closes the pipe descriptors
~wxPipe() { Close(); }
private:
int m_fds[2];
};
#if wxUSE_STREAMS && wxUSE_FILE
#include "wx/wfstream.h"
// ----------------------------------------------------------------------------
// wxPipeInputStream: stream for reading from a pipe
// ----------------------------------------------------------------------------
class wxPipeInputStream : public wxFileInputStream
{
public:
wxPipeInputStream(int fd) : wxFileInputStream(fd) { }
// return TRUE if the pipe is still opened
bool IsOpened() const { return !Eof(); }
// return TRUE if we have anything to read, don't block
virtual bool CanRead() const;
};
// ----------------------------------------------------------------------------
// wxPipeOutputStream: stream for writing to a pipe
// ----------------------------------------------------------------------------
class wxPipeOutputStream : public wxFileOutputStream
{
public:
wxPipeOutputStream(int fd) : wxFileOutputStream(fd) { }
// Override the base class version to ignore "pipe full" errors: this is
// not an error for this class.
size_t OnSysWrite(const void *buffer, size_t size);
};
#endif // wxUSE_STREAMS && wxUSE_FILE
#endif // _WX_UNIX_PIPE_H_