X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/09d68ec1c35deb4fe3bd5b3ad61d7adcbd260bb3..3a922bb4bd8dbcb04e31e324648c2912e167e0cd:/src/unix/utilsunx.cpp diff --git a/src/unix/utilsunx.cpp b/src/unix/utilsunx.cpp index 9118bcb7b1..b246d08f7a 100644 --- a/src/unix/utilsunx.cpp +++ b/src/unix/utilsunx.cpp @@ -298,19 +298,30 @@ void wxHandleProcessTermination(wxEndProcessData *proc_data) } while ( rc == -1 && errno == EINTR ); - - if( rc == -1 || ! (WIFEXITED(status) || WIFSIGNALED(status)) ) + if (rc == -1) + { + // JACS: this could happen if the process was terminated and waitpid called, + // so commenting out for now. + //wxLogSysError(_("Waiting for subprocess termination failed (return code = -1)")); + } + else if (! (WIFEXITED(status))) { - // wxLogSysError(_("Waiting for subprocess termination failed")); + wxLogSysError(_("Waiting for subprocess termination failed (WIFEXITED returned zero)")); + + /* AFAIK, this can only happen if something went wrong within + wxGTK, i.e. due to a race condition or some serious bug. + After having fixed the order of statements in + GTK_EndProcessDetector(). (KB) + */ + } + else if (WIFSIGNALED(status)) + { + wxLogSysError(_("Waiting for subprocess termination failed (signal not caught)")); + /* AFAIK, this can only happen if something went wrong within wxGTK, i.e. due to a race condition or some serious bug. After having fixed the order of statements in GTK_EndProcessDetector(). (KB) - - JACS adds -- I have other code that kills a process recursively - and calls waitpid; so this function then generates an error. - I've commented out the wxLogSysError and the 'else' so that - termination is always done properly. */ } // else @@ -440,6 +451,106 @@ size_t wxProcessFileOutputStream::OnSysWrite(const void *buffer, size_t bufsize) return ret; } +// ---------------------------------------------------------------------------- +// wxStreamTempBuffer +// ---------------------------------------------------------------------------- + +/* + Extract of a mail to wx-users to give the context of the problem we are + trying to solve here: + + MC> If I run the command: + MC> find . -name "*.h" -exec grep linux {} \; + MC> in the exec sample synchronously from the 'Capture command output' + MC> menu, wxExecute never returns. I have to xkill it. Has anyone + MC> else encountered this? + + Yes, I can reproduce it too. + + I even think I understand why it happens: before launching the external + command we set up a pipe with a valid file descriptor on the reading side + when the output is redirected. So the subprocess happily writes to it ... + until the pipe buffer (which is usually quite big on Unix, I think the + default is 4Mb) is full. Then the writing process stops and waits until we + read some data from the pipe to be able to continue writing to it but we + never do it because we wait until it terminates to start reading and so we + have a classical deadlock. + + Here is the fix: we now read the output as soon as it appears into a temp + buffer (wxStreamTempBuffer object) and later just stuff it back into the + stream when the process terminates. See supporting code in wxExecute() + itself as well. +*/ + +class wxStreamTempBuffer +{ +public: + wxStreamTempBuffer(); + + // call to associate a stream with this buffer, otherwise nothing happens + // at all + void Init(wxInputStream *stream); + + // check for input on our stream and cache it in our buffer if any + void Update(); + + ~wxStreamTempBuffer(); + +private: + // the stream we're buffering, if NULL we don't do anything at all + wxInputStream *m_stream; + + // the buffer of size m_size (NULL if m_size == 0) + void *m_buffer; + + // the size of the buffer + size_t m_size; +}; + +wxStreamTempBuffer::wxStreamTempBuffer() +{ + m_stream = NULL; + m_buffer = NULL; + m_size = 0; +} + +void wxStreamTempBuffer::Init(wxInputStream *stream) +{ + m_stream = stream; +} + +void wxStreamTempBuffer::Update() +{ + if ( m_stream && !m_stream->Eof() ) + { + // realloc in blocks of 1Kb - surely not the best strategy but which + // one is? + static const size_t incSize = 1024; + + void *buf = realloc(m_buffer, m_size + incSize); + if ( !buf ) + { + // don't read any more, we don't have enough memory to do it + m_stream = NULL; + } + else // got memory for the buffer + { + m_buffer = buf; + m_stream->Read((char *)m_buffer + m_size, incSize); + m_size += incSize; + } + } +} + +wxStreamTempBuffer::~wxStreamTempBuffer() +{ + if ( m_buffer ) + { + m_stream->Ungetch(m_buffer, m_size); + free(m_buffer); + } +} + #endif // wxUSE_STREAMS long wxExecute(wxChar **argv, @@ -595,21 +706,35 @@ long wxExecute(wxChar **argv, // there is no return after successful exec() _exit(-1); + + // some compilers complain about missing return - of course, they + // should know that exit() doesn't return but what else can we do if + // they don't? +#if defined(__VMS) || defined(__INTEL_COMPILER) + return 0; +#endif } else // we're in parent { ARGS_CLEANUP; // pipe initialization: construction of the wxStreams +#if wxUSE_STREAMS + wxStreamTempBuffer bufIn, bufErr; +#endif // wxUSE_STREAMS + if ( process && process->IsRedirected() ) { #if wxUSE_STREAMS - // These two streams are relative to this process. + // in/out for subprocess correspond to our out/in wxOutputStream *outStream = new wxProcessFileOutputStream(pipeIn[1]); wxInputStream *inStream = new wxProcessFileInputStream(pipeOut[0]); wxInputStream *errStream = new wxProcessFileInputStream(pipeErr[0]); process->SetPipeStreams(inStream, outStream, errStream); + + bufIn.Init(inStream); + bufErr.Init(inStream); #endif // wxUSE_STREAMS close(pipeIn[0]); // close reading side @@ -635,9 +760,19 @@ long wxExecute(wxChar **argv, wxBusyCursor bc; wxWindowDisabler wd; - // it will be set to 0 from GTK_EndProcessDetector - while (data->pid != 0) + // data->pid will be set to 0 from GTK_EndProcessDetector when the + // process terminates + while ( data->pid != 0 ) + { +#if wxUSE_STREAMS + bufIn.Update(); + bufErr.Update(); +#endif // wxUSE_STREAMS + + // give GTK+ a chance to call GTK_EndProcessDetector here and + // also repaint the GUI wxYield(); + } int exitcode = data->exitcode; @@ -670,13 +805,6 @@ long wxExecute(wxChar **argv, return exitcode; #endif // wxUSE_GUI } -#ifdef __VMS - // VMS does not recognise exit as a return and complains about - // a missing return - // I think VMS is wrong in this - // JJ - return 0; -#endif } #undef ERROR_RETURN_CODE