# include <sys/select.h>
#endif
-#define HAS_PIPE_INPUT_STREAM (wxUSE_STREAMS && wxUSE_FILE)
+#define HAS_PIPE_STREAMS (wxUSE_STREAMS && wxUSE_FILE)
-#if HAS_PIPE_INPUT_STREAM
+#if HAS_PIPE_STREAMS
// define this to let wxexec.cpp know that we know what we're doing
#define _WX_USED_BY_WXEXECUTE_
#include "../common/execcmn.cpp"
-#endif // HAS_PIPE_INPUT_STREAM
+#endif // HAS_PIPE_STREAMS
#if defined(__MWERKS__) && defined(__MACH__)
#ifndef WXWIN_OS_DESCRIPTION
// wxStream classes to support IO redirection in wxExecute
// ----------------------------------------------------------------------------
-#if HAS_PIPE_INPUT_STREAM
+#if HAS_PIPE_STREAMS
bool wxPipeInputStream::CanRead() const
{
}
}
-#endif // HAS_PIPE_INPUT_STREAM
+size_t wxPipeOutputStream::OnSysWrite(const void *buffer, size_t size)
+{
+ // We need to suppress error logging here, because on writing to a pipe
+ // which is full, wxFile::Write reports a system error. However, this is
+ // not an extraordinary situation, and it should not be reported to the
+ // user (but if really needed, the program can recognize it by checking
+ // whether LastRead() == 0.) Other errors will be reported below.
+ size_t ret;
+ {
+ wxLogNull logNo;
+ ret = m_file->Write(buffer, size);
+ }
+
+ switch ( m_file->GetLastError() )
+ {
+ // pipe is full
+#ifdef EAGAIN
+ case EAGAIN:
+#endif
+#if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN)
+ case EWOULDBLOCK:
+#endif
+ // do not treat it as an error
+ m_file->ClearLastError();
+ // fall through
+
+ // no error
+ case 0:
+ break;
+
+ // some real error
+ default:
+ wxLogSysError(_("Can't write to child process's stdin"));
+ m_lasterror = wxSTREAM_WRITE_ERROR;
+ }
+
+ return ret;
+}
+
+#endif // HAS_PIPE_STREAMS
// ----------------------------------------------------------------------------
// wxShell
}
#endif // !__VMS
- // reading side can be safely closed but we should keep the write one
- // opened, it will be only closed when the process terminates resulting
- // in a read notification to the parent
- execData.pipeEndProcDetect.Detach(wxPipe::Write);
- execData.pipeEndProcDetect.Close();
-
// redirect stdin, stdout and stderr
if ( pipeIn.IsOk() )
{
pipeErr.Close();
}
+ // Close all (presumably accidentally) inherited file descriptors to
+ // avoid descriptor leaks. This means that we don't allow inheriting
+ // them purposefully but this seems like a lesser evil in wx code.
+ // Ideally we'd provide some flag to indicate that none (or some?) of
+ // the descriptors do not need to be closed but for now this is better
+ // than never closing them at all as wx code never used FD_CLOEXEC.
+
+ // Note that while the reading side of the end process detection pipe
+ // can be safely closed, we should keep the write one opened, it will
+ // be only closed when the process terminates resulting in a read
+ // notification to the parent
+ const int fdEndProc = execData.pipeEndProcDetect.Detach(wxPipe::Write);
+ execData.pipeEndProcDetect.Close();
+
+ // TODO: Iterating up to FD_SETSIZE is both inefficient (because it may
+ // be quite big) and incorrect (because in principle we could
+ // have more opened descriptions than this number). Unfortunately
+ // there is no good portable solution for closing all descriptors
+ // above a certain threshold but non-portable solutions exist for
+ // most platforms, see [http://stackoverflow.com/questions/899038/
+ // getting-the-highest-allocated-file-descriptor]
+ for ( int fd = 0; fd < (int)FD_SETSIZE; ++fd )
+ {
+ if ( fd != STDIN_FILENO &&
+ fd != STDOUT_FILENO &&
+ fd != STDERR_FILENO &&
+ fd != fdEndProc )
+ {
+ close(fd);
+ }
+ }
+
+
// Process additional options if we have any
if ( env )
{
// prepare for IO redirection
-#if HAS_PIPE_INPUT_STREAM
+#if HAS_PIPE_STREAMS
// the input buffer bufOut is connected to stdout, this is why it is
// called bufOut and not bufIn
wxStreamTempInputBuffer bufOut,
if ( process && process->IsRedirected() )
{
+ // Avoid deadlocks which could result from trying to write to the
+ // child input pipe end while the child itself is writing to its
+ // output end and waiting for us to read from it.
+ if ( !pipeIn.MakeNonBlocking(wxPipe::Write) )
+ {
+ // This message is not terrible useful for the user but what
+ // else can we do? Also, should we fail here or take the risk
+ // to continue and deadlock? Currently we choose the latter but
+ // it might not be the best idea.
+ wxLogSysError(_("Failed to set up non-blocking pipe, "
+ "the program might hang."));
+#if wxUSE_LOG
+ wxLog::FlushActive();
+#endif
+ }
+
wxOutputStream *inStream =
- new wxFileOutputStream(pipeIn.Detach(wxPipe::Write));
+ new wxPipeOutputStream(pipeIn.Detach(wxPipe::Write));
const int fdOut = pipeOut.Detach(wxPipe::Read);
wxPipeInputStream *outStream = new wxPipeInputStream(fdOut);
execData.fdOut = fdOut;
execData.fdErr = fdErr;
}
-#endif // HAS_PIPE_INPUT_STREAM
+#endif // HAS_PIPE_STREAMS
if ( pipeIn.IsOk() )
{
bool wxAppTraits::CheckForRedirectedIO(wxExecuteData& execData)
{
-#if HAS_PIPE_INPUT_STREAM
+#if HAS_PIPE_STREAMS
bool hasIO = false;
if ( execData.bufOut && execData.bufOut->Update() )
hasIO = true;
return hasIO;
-#else // !HAS_PIPE_INPUT_STREAM
+#else // !HAS_PIPE_STREAMS
+ wxUnusedVar(execData);
+
return false;
-#endif // HAS_PIPE_INPUT_STREAM/!HAS_PIPE_INPUT_STREAM
+#endif // HAS_PIPE_STREAMS/!HAS_PIPE_STREAMS
}
// helper classes/functions used by WaitForChild()
wxDECLARE_NO_COPY_CLASS(wxEndHandler);
};
-#if HAS_PIPE_INPUT_STREAM
+#if HAS_PIPE_STREAMS
// class for monitoring our ends of child stdout/err, should be constructed
// with the FD and stream from wxExecuteData and will do nothing if they're
wxDECLARE_NO_COPY_CLASS(wxRedirectedIOHandler);
};
-#endif // HAS_PIPE_INPUT_STREAM
+#endif // HAS_PIPE_STREAMS
// helper function which calls waitpid() and analyzes the result
int DoWaitForChild(int pid, int flags = 0)
}
//else: synchronous execution case
-#if HAS_PIPE_INPUT_STREAM && wxUSE_SOCKETS
+#if HAS_PIPE_STREAMS && wxUSE_SOCKETS
wxProcess * const process = execData.process;
if ( process && process->IsRedirected() )
{
}
}
//else: no IO redirection, just block waiting for the child to exit
-#endif // HAS_PIPE_INPUT_STREAM
+#endif // HAS_PIPE_STREAMS
return DoWaitForChild(execData.pid);
}
projects / wxWidgets.git / blobdiff