// Author: Vadim Zeitlin
// Id: $Id$
// Copyright: (c) 1998 Robert Roebling, Vadim Zeitlin
+// (c) 2013 Rob Bresalier, Vadim Zeitlin
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#include "wx/apptrait.h"
#include "wx/process.h"
+#include "wx/scopedptr.h"
#include "wx/thread.h"
#include "wx/cmdline.h"
#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 <pwd.h>
#include <sys/wait.h> // waitpid()
# include <sys/select.h>
#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
#include <errno.h>
#include <netdb.h>
#include <signal.h>
-#include <fcntl.h> // for O_WRONLY and friends
#include <time.h> // nanosleep() and/or usleep()
#include <ctype.h> // isspace()
#include <sys/time.h> // needed for FD_SETSIZE
#include <sys/sysinfo.h> // for SAGET and MINFO structures
#endif
+#ifdef HAVE_SETPRIORITY
+ #include <sys/resource.h> // for setpriority()
+#endif
+
// ----------------------------------------------------------------------------
// conditional compilation
// ----------------------------------------------------------------------------
// 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
ArgsArray(wchar_t **wargv)
{
int argc = 0;
- while ( *wargv++ )
+ while ( wargv[argc] )
argc++;
Init(argc);
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<wxFDIOHandler>
+ signalHandler(wxTheApp->RegisterSignalWakeUpPipe(dispatcher));
+
+#if wxUSE_STREAMS
+ // And then the two for the child output and error streams if necessary.
+ wxScopedPtr<wxFDIOHandler>
+ 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
}
#endif // __DARWIN__
-
// this struct contains all information which we use for housekeeping
- wxExecuteData execData;
+ wxScopedPtr<wxExecuteData> 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
}
}
+ // 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
}
#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() )
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(");
}
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);
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() )
{
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;
+ }
+
- return traits->WaitForChild(execData);
+ // 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);
+ }
+
+
+ // 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)
// 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;
const wxString desc = wxGetCommandOutput(wxT("lsb_release --description"));
const wxString rel = wxGetCommandOutput(wxT("lsb_release --release"));
const wxString codename = wxGetCommandOutput(wxT("lsb_release --codename"));
-
+
wxLinuxDistributionInfo ret;
-
+
id.StartsWith("Distributor ID:\t", &ret.Id);
desc.StartsWith("Description:\t", &ret.Description);
rel.StartsWith("Release:\t", &ret.Release);
#endif
// these functions are in src/osx/utilsexc_base.cpp for wxMac
-#ifndef __WXMAC__
+#ifndef __DARWIN__
wxOperatingSystemId wxGetOsVersion(int *verMaj, int *verMin)
{
return wxGetCommandOutput(wxT("uname -s -r -m"));
}
-#endif // !__WXMAC__
+#endif // !__DARWIN__
unsigned long wxGetProcessId()
{
// 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
-{
-public:
- wxReadFDIOHandler(wxFDIODispatcher& disp, int fd) : m_fd(fd)
- {
- if ( fd )
- disp.RegisterFD(fd, this, wxFDIO_INPUT);
- }
-
- 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
+// 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:
- wxEndHandler(wxFDIODispatcher& disp, int fd)
- : wxReadFDIOHandler(disp, 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<wxEventLoopSourceHandler>
+ stdoutHandler,
+ stderrHandler;
+ if ( execData.IsRedirected() )
{
- m_terminated = false;
+ stdoutHandler.reset(new wxExecuteEventLoopSourceHandler
+ (
+ execData.fdOut, execData.bufOut
+ ));
+ stderrHandler.reset(new wxExecuteEventLoopSourceHandler
+ (
+ execData.fdErr, execData.bufErr
+ ));
}
+#endif // wxUSE_STREAMS
- bool Terminated() const { return m_terminated; }
-
- virtual void OnReadWaiting() { m_terminated = true; }
+ // 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;
-private:
- bool m_terminated;
+ // And run it.
+ loop.Run();
- 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" );
// 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 )
+ switch ( rc )
{
- // 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
- {
- wxASSERT_MSG( rc == pid, "unexpected waitpid() return value" );
+ case 0:
+ // No error but the child is still running.
+ return false;
- if ( WIFEXITED(status) )
- return WEXITSTATUS(status);
- else if ( WIFSIGNALED(status) )
- return -WTERMSIG(status);
- else
- {
- wxLogError("Child process (PID %d) exited for unknown reason, "
- "status = %d", pid, status);
- }
- }
+ 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
- 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();
}
}
-
projects / wxWidgets.git / blobdiff