X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/64d029f155e0894e3e89af43823c35ed2091e13d..ad653fa23069c5d9378247084f03c9a718c3ad62:/src/unix/utilsunx.cpp diff --git a/src/unix/utilsunx.cpp b/src/unix/utilsunx.cpp index 6126c0a2e5..d757498cc3 100644 --- a/src/unix/utilsunx.cpp +++ b/src/unix/utilsunx.cpp @@ -4,6 +4,7 @@ // Author: Vadim Zeitlin // Id: $Id$ // Copyright: (c) 1998 Robert Roebling, Vadim Zeitlin +// (c) 2013 Rob Bresalier, Vadim Zeitlin // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// @@ -37,6 +38,7 @@ #include "wx/apptrait.h" #include "wx/process.h" +#include "wx/scopedptr.h" #include "wx/thread.h" #include "wx/cmdline.h" @@ -48,9 +50,9 @@ #include "wx/unix/execute.h" #include "wx/unix/private.h" -#ifdef wxHAS_GENERIC_PROCESS_CALLBACK -#include "wx/private/fdiodispatcher.h" -#endif +#include "wx/evtloop.h" +#include "wx/mstream.h" +#include "wx/private/fdioeventloopsourcehandler.h" #include #include // waitpid() @@ -59,35 +61,15 @@ # include #endif -#define HAS_PIPE_INPUT_STREAM (wxUSE_STREAMS && wxUSE_FILE) - -#if HAS_PIPE_INPUT_STREAM +#define HAS_PIPE_STREAMS (wxUSE_STREAMS && wxUSE_FILE) -// define this to let wxexec.cpp know that we know what we're doing -#define _WX_USED_BY_WXEXECUTE_ -#include "../common/execcmn.cpp" +#if HAS_PIPE_STREAMS -#endif // HAS_PIPE_INPUT_STREAM +#include "wx/private/pipestream.h" +#include "wx/private/streamtempinput.h" +#include "wx/unix/private/executeiohandler.h" -#if defined(__MWERKS__) && defined(__MACH__) - #ifndef WXWIN_OS_DESCRIPTION - #define WXWIN_OS_DESCRIPTION "MacOS X" - #endif - #ifndef HAVE_NANOSLEEP - #define HAVE_NANOSLEEP - #endif - #ifndef HAVE_UNAME - #define HAVE_UNAME - #endif - - // our configure test believes we can use sigaction() if the function is - // available but Metrowekrs with MSL run-time does have the function but - // doesn't have sigaction struct so finally we can't use it... - #ifdef __MSL__ - #undef wxUSE_ON_FATAL_EXCEPTION - #define wxUSE_ON_FATAL_EXCEPTION 0 - #endif -#endif +#endif // HAS_PIPE_STREAMS // not only the statfs syscall is called differently depending on platform, but // one of its incarnations, statvfs(), takes different arguments under @@ -137,7 +119,6 @@ #include #include #include -#include // for O_WRONLY and friends #include // nanosleep() and/or usleep() #include // isspace() #include // needed for FD_SETSIZE @@ -152,6 +133,10 @@ #include // for SAGET and MINFO structures #endif +#ifdef HAVE_SETPRIORITY + #include // for setpriority() +#endif + // ---------------------------------------------------------------------------- // conditional compilation // ---------------------------------------------------------------------------- @@ -297,7 +282,7 @@ 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 +322,46 @@ 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 @@ -442,27 +466,100 @@ private: bool wxMacLaunch(char **argv); #endif -long wxExecute(const wxString& command, int flags, wxProcess *process) +long wxExecute(const wxString& command, int flags, wxProcess *process, + const wxExecuteEnv *env) { ArgsArray argv(wxCmdLineParser::ConvertStringToArgs(command, wxCMD_LINE_SPLIT_UNIX)); - return wxExecute(argv, flags, process); + return wxExecute(argv, flags, process, env); } #if wxUSE_UNICODE -long wxExecute(wchar_t **wargv, int flags, wxProcess *process) +long wxExecute(wchar_t **wargv, int flags, wxProcess *process, + const wxExecuteEnv *env) { ArgsArray argv(wargv); - return wxExecute(argv, flags, process); + return wxExecute(argv, flags, process, env); } #endif // wxUSE_UNICODE +namespace +{ + +// Helper function of wxExecute(): wait for the process termination without +// dispatching any events. +// +// This is used in wxEXEC_NOEVENTS case. +int BlockUntilChildExit(wxExecuteData& execData) +{ + wxCHECK_MSG( wxTheApp, -1, + wxS("Can't block until child exit without wxTheApp") ); + + // Even if we don't want to dispatch events, we still need to handle + // child IO notifications and process termination concurrently, i.e. + // we can't simply block waiting for the child to terminate as we would + // dead lock if it writes more than the pipe buffer size (typically + // 4KB) bytes of output -- it would then block waiting for us to read + // the data while we'd block waiting for it to terminate. + // + // So while we don't use the full blown event loop, we still do use a + // dispatcher with which we register just the 3 FDs we're interested + // in: the child stdout and stderr and the pipe written to by the + // signal handler so that we could react to the child process + // termination too. + + // Notice that we must create a new dispatcher object here instead of + // reusing the global wxFDIODispatcher::Get() because we want to + // monitor only the events on the FDs explicitly registered with this + // one and not all the other ones that could be registered with the + // global dispatcher (think about the case of nested wxExecute() calls). + wxSelectDispatcher dispatcher; + + // Do register all the FDs we want to monitor here: first, the one used to + // handle the signals asynchronously. + wxScopedPtr + signalHandler(wxTheApp->RegisterSignalWakeUpPipe(dispatcher)); + +#if wxUSE_STREAMS + // And then the two for the child output and error streams if necessary. + wxScopedPtr + stdoutHandler, + stderrHandler; + if ( execData.IsRedirected() ) + { + stdoutHandler.reset(new wxExecuteFDIOHandler + ( + dispatcher, + execData.fdOut, + execData.bufOut + )); + stderrHandler.reset(new wxExecuteFDIOHandler + ( + dispatcher, + execData.fdErr, + execData.bufErr + )); + } +#endif // wxUSE_STREAMS + + // And dispatch until the PID is reset from wxExecuteData::OnExit(). + while ( execData.pid ) + { + dispatcher.Dispatch(); + } + + return execData.exitcode; +} + +} // anonymous namespace + // wxExecute: the real worker function -long wxExecute(char **argv, int flags, wxProcess *process) +long wxExecute(char **argv, int flags, wxProcess *process, + const wxExecuteEnv *env) { // for the sync execution, we return -1 to indicate failure, but for async // case we return 0 which is never a valid PID @@ -494,21 +591,14 @@ long wxExecute(char **argv, int flags, wxProcess *process) } #endif // __DARWIN__ - // this struct contains all information which we use for housekeeping - wxExecuteData execData; + wxScopedPtr execDataPtr(new wxExecuteData); + wxExecuteData& execData = *execDataPtr; + execData.flags = flags; execData.process = process; - // create pipes - if ( !execData.pipeEndProcDetect.Create() ) - { - wxLogError( _("Failed to execute '%s'\n"), *argv ); - - return ERROR_RETURN_CODE; - } - - // pipes for inter process communication + // create pipes for inter process communication wxPipe pipeIn, // stdin pipeOut, // stdout pipeErr; // stderr @@ -523,6 +613,21 @@ long wxExecute(char **argv, int flags, wxProcess *process) } } + // priority: we need to map wxWidgets priority which is in the range 0..100 + // to Unix nice value which is in the range -20..19. As there is an odd + // number of elements in our range and an even number in the Unix one, we + // have to do it in this rather ugly way to guarantee that: + // 1. wxPRIORITY_{MIN,DEFAULT,MAX} map to -20, 0 and 19 respectively. + // 2. The mapping is monotonously increasing. + // 3. The mapping is onto the target range. + int prio = process ? process->GetPriority() : 0; + if ( prio <= 50 ) + prio = (2*prio)/5 - 20; + else if ( prio < 55 ) + prio = 1; + else + prio = (2*prio)/5 - 21; + // fork the process // // NB: do *not* use vfork() here, it completely breaks this code for some @@ -556,11 +661,12 @@ 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(); +#if defined(HAVE_SETPRIORITY) + if ( prio && setpriority(PRIO_PROCESS, 0, prio) != 0 ) + { + wxLogSysError(_("Failed to set process priority")); + } +#endif // HAVE_SETPRIORITY // redirect stdin, stdout and stderr if ( pipeIn.IsOk() ) @@ -577,6 +683,65 @@ 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. + + // 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 ) + { + close(fd); + } + } + + + // Process additional options if we have any + if ( env ) + { + // Change working directory if it is specified + if ( !env->cwd.empty() ) + wxSetWorkingDirectory(env->cwd); + + // Change environment if needed. + // + // NB: We can't use execve() currently because we allow using + // non full paths to wxExecute(), i.e. we want to search for + // the program in PATH. However it just might be simpler/better + // to do the search manually and use execve() envp parameter to + // set up the environment of the child process explicitly + // instead of doing what we do below. + if ( !env->env.empty() ) + { + wxEnvVariableHashMap oldenv; + wxGetEnvMap(&oldenv); + + // Remove unwanted variables + wxEnvVariableHashMap::const_iterator it; + for ( it = oldenv.begin(); it != oldenv.end(); ++it ) + { + if ( env->env.find(it->first) == env->env.end() ) + wxUnsetEnv(it->first); + } + + // And add the new ones (possibly replacing the old values) + for ( it = env->env.begin(); it != env->env.end(); ++it ) + wxSetEnv(it->first, it->second); + } + } + execvp(*argv, argv); fprintf(stderr, "execvp("); @@ -599,23 +764,32 @@ long wxExecute(char **argv, int flags, wxProcess *process) } else // we're in parent { - // save it for WaitForChild() use - execData.pid = pid; - if (execData.process) - execData.process->SetPid(pid); // and also in the wxProcess + execData.OnStart(pid); // prepare for IO redirection -#if HAS_PIPE_INPUT_STREAM - // the input buffer bufOut is connected to stdout, this is why it is - // called bufOut and not bufIn - wxStreamTempInputBuffer bufOut, - bufErr; +#if HAS_PIPE_STREAMS 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); @@ -625,16 +799,16 @@ long wxExecute(char **argv, int flags, wxProcess *process) process->SetPipeStreams(outStream, inStream, errStream); - bufOut.Init(outStream); - bufErr.Init(errStream); - - execData.bufOut = &bufOut; - execData.bufErr = &bufErr; + if ( flags & wxEXEC_SYNC ) + { + execData.bufOut.Init(outStream); + execData.bufErr.Init(errStream); - execData.fdOut = fdOut; - execData.fdErr = fdErr; + execData.fdOut = fdOut; + execData.fdErr = fdErr; + } } -#endif // HAS_PIPE_INPUT_STREAM +#endif // HAS_PIPE_STREAMS if ( pipeIn.IsOk() ) { @@ -643,14 +817,32 @@ long wxExecute(char **argv, int flags, wxProcess *process) pipeErr.Close(); } - // we want this function to work even if there is no wxApp so ensure - // that we have a valid traits pointer - wxConsoleAppTraits traitsConsole; - wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL; - if ( !traits ) - traits = &traitsConsole; + // For the asynchronous case we don't have to do anything else, just + // let the process run. + if ( !(flags & wxEXEC_SYNC) ) + { + // Ensure that the housekeeping data is kept alive, it will be + // destroyed only when the child terminates. + execDataPtr.release(); + + return execData.pid; + } + + + // If we don't need to dispatch any events, things are relatively + // simple and we don't need to delegate to wxAppTraits. + if ( flags & wxEXEC_NOEVENTS ) + { + return BlockUntilChildExit(execData); + } + - return traits->WaitForChild(execData); + // If we do need to dispatch events, enter a local event loop waiting + // until the child exits. As the exact kind of event loop depends on + // the sort of application we're in (console or GUI), we delegate this + // to wxAppTraits which virtualizes all the differences between the + // console and the GUI programs. + return wxApp::GetValidTraits().WaitForChild(execData); } #if !defined(__VMS) && !defined(__INTEL_COMPILER) @@ -719,11 +911,16 @@ wxString wxGetUserHome( const wxString &user ) // the trailing newline static wxString wxGetCommandOutput(const wxString &cmd) { - FILE *f = popen(cmd.ToAscii(), "r"); + // Suppress stderr from the shell to avoid outputting errors if the command + // doesn't exist. + FILE *f = popen((cmd + " 2>/dev/null").ToAscii(), "r"); if ( !f ) { - wxLogSysError(wxT("Executing \"%s\" failed"), cmd.c_str()); - return wxEmptyString; + // Notice that this doesn't happen simply if the command doesn't exist, + // but only in case of some really catastrophic failure inside popen() + // so we should really notify the user about this as this is not normal. + wxLogSysError(wxT("Executing \"%s\" failed"), cmd); + return wxString(); } wxString s; @@ -893,7 +1090,7 @@ wxLinuxDistributionInfo wxGetLinuxDistributionInfo() #endif // these functions are in src/osx/utilsexc_base.cpp for wxMac -#ifndef __WXMAC__ +#ifndef __DARWIN__ wxOperatingSystemId wxGetOsVersion(int *verMaj, int *verMin) { @@ -929,7 +1126,7 @@ wxString wxGetOsDescription() return wxGetCommandOutput(wxT("uname -s -r -m")); } -#endif // !__WXMAC__ +#endif // !__DARWIN__ unsigned long wxGetProcessId() { @@ -1208,139 +1405,67 @@ bool wxHandleFatalExceptions(bool doit) // wxExecute support // ---------------------------------------------------------------------------- -int wxAppTraits::AddProcessCallback(wxEndProcessData *data, int fd) -{ - // define a custom handler processing only the closure of the descriptor - struct wxEndProcessFDIOHandler : public wxFDIOHandler - { - wxEndProcessFDIOHandler(wxEndProcessData *data, int fd) - : m_data(data), m_fd(fd) - { - } - - virtual void OnReadWaiting() - { - wxFDIODispatcher::Get()->UnregisterFD(m_fd); - close(m_fd); - - wxHandleProcessTermination(m_data); - - delete this; - } - - virtual void OnWriteWaiting() { wxFAIL_MSG("unreachable"); } - virtual void OnExceptionWaiting() { wxFAIL_MSG("unreachable"); } - - wxEndProcessData * const m_data; - const int m_fd; - }; - - wxFDIODispatcher::Get()->RegisterFD - ( - fd, - new wxEndProcessFDIOHandler(data, fd), - wxFDIO_INPUT - ); - return fd; // unused, but return something unique for the tag -} - -bool wxAppTraits::CheckForRedirectedIO(wxExecuteData& execData) +int wxAppTraits::WaitForChild(wxExecuteData& execData) { -#if HAS_PIPE_INPUT_STREAM - bool hasIO = false; - - if ( execData.bufOut && execData.bufOut->Update() ) - hasIO = true; - - if ( execData.bufErr && execData.bufErr->Update() ) - hasIO = true; - - return hasIO; -#else // !HAS_PIPE_INPUT_STREAM - return false; -#endif // HAS_PIPE_INPUT_STREAM/!HAS_PIPE_INPUT_STREAM + wxConsoleEventLoop loop; + return RunLoopUntilChildExit(execData, loop); } -// helper classes/functions used by WaitForChild() -namespace -{ - -// convenient base class for IO handlers which are registered for read -// notifications only and which also stores the FD we're reading from +// This function is common code for both console and GUI applications and used +// by wxExecute() to wait for the child exit while dispatching events. // -// the derived classes still have to implement OnReadWaiting() -class wxReadFDIOHandler : public wxFDIOHandler +// Notice that it should not be used for all the other cases, e.g. when we +// don't need to wait for the child (wxEXEC_ASYNC) or when the events must not +// dispatched (wxEXEC_NOEVENTS). +int +wxAppTraits::RunLoopUntilChildExit(wxExecuteData& execData, + wxEventLoopBase& loop) { -public: - wxReadFDIOHandler(wxFDIODispatcher& disp, int fd) : m_fd(fd) + // It is possible that wxExecuteData::OnExit() had already been called + // and reset the PID to 0, in which case we don't need to do anything + // at all. + if ( !execData.pid ) + return execData.exitcode; + +#if wxUSE_STREAMS + // Monitor the child streams if necessary. + wxScopedPtr + stdoutHandler, + stderrHandler; + if ( execData.IsRedirected() ) { - if ( fd ) - disp.RegisterFD(fd, this, wxFDIO_INPUT); + stdoutHandler.reset(new wxExecuteEventLoopSourceHandler + ( + execData.fdOut, execData.bufOut + )); + stderrHandler.reset(new wxExecuteEventLoopSourceHandler + ( + execData.fdErr, execData.bufErr + )); } +#endif // wxUSE_STREAMS - virtual void OnWriteWaiting() { wxFAIL_MSG("unreachable"); } - virtual void OnExceptionWaiting() { wxFAIL_MSG("unreachable"); } - -protected: - const int m_fd; - - wxDECLARE_NO_COPY_CLASS(wxReadFDIOHandler); -}; - -// class for monitoring our end of the process detection pipe, simply sets a -// flag when input on the pipe (which must be due to EOF) is detected -class wxEndHandler : public wxReadFDIOHandler -{ -public: - wxEndHandler(wxFDIODispatcher& disp, int fd) - : wxReadFDIOHandler(disp, fd) - { - m_terminated = false; - } + // Store the event loop in the data associated with the child + // process so that it could exit the loop when the child exits. + execData.syncEventLoop = &loop; - bool Terminated() const { return m_terminated; } + // And run it. + loop.Run(); - virtual void OnReadWaiting() { m_terminated = true; } - -private: - bool m_terminated; - - wxDECLARE_NO_COPY_CLASS(wxEndHandler); -}; + // The exit code will have been set when the child termination was detected. + return execData.exitcode; +} -#if HAS_PIPE_INPUT_STREAM +// ---------------------------------------------------------------------------- +// wxExecuteData +// ---------------------------------------------------------------------------- -// 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 -// invalid -// -// unlike wxEndHandler this class registers itself with the provided dispatcher -class wxRedirectedIOHandler : public wxReadFDIOHandler +namespace { -public: - wxRedirectedIOHandler(wxFDIODispatcher& disp, - int fd, - wxStreamTempInputBuffer *buf) - : wxReadFDIOHandler(disp, fd), - m_buf(buf) - { - } - - virtual void OnReadWaiting() - { - m_buf->Update(); - } - -private: - wxStreamTempInputBuffer * const m_buf; - - wxDECLARE_NO_COPY_CLASS(wxRedirectedIOHandler); -}; -#endif // HAS_PIPE_INPUT_STREAM - -// helper function which calls waitpid() and analyzes the result -int DoWaitForChild(int pid, int flags = 0) +// Helper function that checks whether the child with the given PID has exited +// and fills the provided parameter with its return code if it did. +bool CheckForChildExit(int pid, int* exitcodeOut) { wxASSERT_MSG( pid > 0, "invalid PID" ); @@ -1349,124 +1474,150 @@ int DoWaitForChild(int pid, int flags = 0) // loop while we're getting EINTR for ( ;; ) { - rc = waitpid(pid, &status, flags); + rc = waitpid(pid, &status, WNOHANG); if ( rc != -1 || errno != EINTR ) break; } - if ( rc == 0 ) - { - // This can only happen if the child application closes our dummy pipe - // that is used to monitor its lifetime; in that case, our best bet is - // to pretend the process did terminate, because otherwise wxExecute() - // would hang indefinitely (OnReadWaiting() won't be called again, the - // descriptor is closed now). - wxLogDebug("Child process (PID %d) still alive but pipe closed so " - "generating a close notification", pid); - } - else if ( rc == -1 ) - { - wxLogLastError(wxString::Format("waitpid(%d)", pid)); - } - else // child did terminate + switch ( rc ) { - wxASSERT_MSG( rc == pid, "unexpected waitpid() return value" ); - - // notice that the caller expects the exit code to be signed, e.g. -1 - // instead of 255 so don't assign WEXITSTATUS() to an int - signed char exitcode; - if ( WIFEXITED(status) ) - exitcode = WEXITSTATUS(status); - else if ( WIFSIGNALED(status) ) - exitcode = -WTERMSIG(status); - else - { - wxLogError("Child process (PID %d) exited for unknown reason, " - "status = %d", pid, status); - exitcode = -1; - } + case 0: + // No error but the child is still running. + return false; - return exitcode; - } + case -1: + // Checking child status failed. Invalid PID? + wxLogLastError(wxString::Format("waitpid(%d)", pid)); + return false; - return -1; + default: + // Child did terminate. + wxASSERT_MSG( rc == pid, "unexpected waitpid() return value" ); + + // notice that the caller expects the exit code to be signed, e.g. -1 + // instead of 255 so don't assign WEXITSTATUS() to an int + signed char exitcode; + if ( WIFEXITED(status) ) + exitcode = WEXITSTATUS(status); + else if ( WIFSIGNALED(status) ) + exitcode = -WTERMSIG(status); + else + { + wxLogError("Child process (PID %d) exited for unknown reason, " + "status = %d", pid, status); + exitcode = -1; + } + + if ( exitcodeOut ) + *exitcodeOut = exitcode; + + return true; + } } } // anonymous namespace -int wxAppTraits::WaitForChild(wxExecuteData& execData) +wxExecuteData::ChildProcessesData wxExecuteData::ms_childProcesses; + +/* static */ +void wxExecuteData::OnSomeChildExited(int WXUNUSED(sig)) { - if ( !(execData.flags & wxEXEC_SYNC) ) - { - // asynchronous execution: just launch the process and return, - // endProcData will be destroyed when it terminates (currently we leak - // it if the process doesn't terminate before we do and this should be - // fixed but it's not a real leak so it's not really very high - // priority) - wxEndProcessData *endProcData = new wxEndProcessData; - endProcData->process = execData.process; - endProcData->pid = execData.pid; - endProcData->tag = AddProcessCallback - ( - endProcData, - execData.GetEndProcReadFD() - ); - endProcData->async = true; - - return execData.pid; - } - //else: synchronous execution case + // We know that some child process has terminated, but we don't know which + // one, so check all of them (notice that more than one could have exited). + // + // An alternative approach would be to call waitpid(-1, &status, WNOHANG) + // (in a loop to take care of the multiple children exiting case) and + // perhaps this would be more efficient. But for now this seems to work. -#if HAS_PIPE_INPUT_STREAM && wxUSE_SOCKETS - wxProcess * const process = execData.process; - if ( process && process->IsRedirected() ) + + // Make a copy of the list before iterating over it to avoid problems due + // to deleting entries from it in the process. + const ChildProcessesData allChildProcesses = ms_childProcesses; + for ( ChildProcessesData::const_iterator it = allChildProcesses.begin(); + it != allChildProcesses.end(); + ++it ) { - // we can't simply block waiting for the child to terminate as we would - // dead lock if it writes more than the pipe buffer size (typically - // 4KB) bytes of output -- it would then block waiting for us to read - // the data while we'd block waiting for it to terminate + const int pid = it->first; + + // Check whether this child exited. + int exitcode; + if ( !CheckForChildExit(pid, &exitcode) ) + continue; + + // And handle its termination if it did. // - // so multiplex here waiting for any input from the child or closure of - // the pipe used to indicate its termination - wxSelectDispatcher disp; + // Notice that this will implicitly remove it from ms_childProcesses. + it->second->OnExit(exitcode); + } +} - wxEndHandler endHandler(disp, execData.GetEndProcReadFD()); +void wxExecuteData::OnStart(int pid_) +{ + wxCHECK_RET( wxTheApp, + wxS("Ensure wxTheApp is set before calling wxExecute()") ); - wxRedirectedIOHandler outHandler(disp, execData.fdOut, execData.bufOut), - errHandler(disp, execData.fdErr, execData.bufErr); + // Setup the signal handler for SIGCHLD to be able to detect the child + // termination. + // + // Notice that SetSignalHandler() is idempotent, so it's fine to call + // it more than once with the same handler. + wxTheApp->SetSignalHandler(SIGCHLD, OnSomeChildExited); - while ( !endHandler.Terminated() ) - { - disp.Dispatch(); - } - } - //else: no IO redirection, just block waiting for the child to exit -#endif // HAS_PIPE_INPUT_STREAM - return DoWaitForChild(execData.pid); + // Remember the child PID to be able to wait for it later. + pid = pid_; + + // Also save it in wxProcess where it will be accessible to the user code. + if ( process ) + process->SetPid(pid); + + // Finally, add this object itself to the list of child processes so that + // we can check for its termination the next time we get SIGCHLD. + ms_childProcesses[pid] = this; } -void wxHandleProcessTermination(wxEndProcessData *data) +void wxExecuteData::OnExit(int exitcode_) { - data->exitcode = DoWaitForChild(data->pid, WNOHANG); + // Remove this process from the hash list of child processes that are + // still open as soon as possible to ensure we don't process it again even + // if another SIGCHLD happens. + if ( !ms_childProcesses.erase(pid) ) + { + wxFAIL_MSG(wxString::Format(wxS("Data for PID %d not in the list?"), pid)); + } - // notify user about termination if required - if ( data->process ) + + exitcode = exitcode_; + +#if wxUSE_STREAMS + if ( IsRedirected() ) { - data->process->OnTerminate(data->pid, data->exitcode); + // Read the remaining data in a blocking way: this is fine because the + // child has already exited and hence all the data must be already + // available in the streams buffers. + bufOut.ReadAll(); + bufErr.ReadAll(); } +#endif // wxUSE_STREAMS - if ( data->async ) + // Notify user about termination if required + if ( !(flags & wxEXEC_SYNC) ) { - // in case of asynchronous execution we don't need this data any more + if ( process ) + process->OnTerminate(pid, exitcode); + + // in case of asynchronous execution we don't need this object any more // after the child terminates - delete data; + delete this; } else // sync execution { // let wxExecute() know that the process has terminated - data->pid = 0; + pid = 0; + + // Stop the event loop for synchronous wxExecute() if we're running one. + if ( syncEventLoop ) + syncEventLoop->ScheduleExit(); } } -