X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/164db92c14e9f1a7343259826da3653aeec945db..cbbb1f548962b30c43849e29fd64eceb4d8720e8:/src/unix/utilsunx.cpp diff --git a/src/unix/utilsunx.cpp b/src/unix/utilsunx.cpp index fa2eb47287..ec550fcf24 100644 --- a/src/unix/utilsunx.cpp +++ b/src/unix/utilsunx.cpp @@ -59,15 +59,15 @@ # include #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 @@ -297,7 +297,7 @@ bool wxShutdown(int flags) // wxStream classes to support IO redirection in wxExecute // ---------------------------------------------------------------------------- -#if HAS_PIPE_INPUT_STREAM +#if HAS_PIPE_STREAMS bool wxPipeInputStream::CanRead() const { @@ -337,7 +337,46 @@ 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 @@ -559,12 +598,6 @@ long wxExecute(char **argv, int flags, wxProcess *process, } #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() ) { @@ -580,6 +613,39 @@ long wxExecute(char **argv, int flags, wxProcess *process, 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 ) { @@ -643,7 +709,7 @@ long wxExecute(char **argv, int flags, wxProcess *process, // 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, @@ -651,8 +717,24 @@ long wxExecute(char **argv, int flags, wxProcess *process, 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); @@ -671,7 +753,7 @@ long wxExecute(char **argv, int flags, wxProcess *process, execData.fdOut = fdOut; execData.fdErr = fdErr; } -#endif // HAS_PIPE_INPUT_STREAM +#endif // HAS_PIPE_STREAMS if ( pipeIn.IsOk() ) { @@ -1283,7 +1365,7 @@ int wxAppTraits::AddProcessCallback(wxEndProcessData *data, int fd) bool wxAppTraits::CheckForRedirectedIO(wxExecuteData& execData) { -#if HAS_PIPE_INPUT_STREAM +#if HAS_PIPE_STREAMS bool hasIO = false; if ( execData.bufOut && execData.bufOut->Update() ) @@ -1293,9 +1375,11 @@ bool wxAppTraits::CheckForRedirectedIO(wxExecuteData& execData) 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() @@ -1345,7 +1429,7 @@ private: 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 @@ -1374,7 +1458,7 @@ private: 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) @@ -1455,7 +1539,7 @@ int wxAppTraits::WaitForChild(wxExecuteData& execData) } //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() ) { @@ -1479,7 +1563,7 @@ int wxAppTraits::WaitForChild(wxExecuteData& execData) } } //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); }