do not use fileno calls in forked child
This fixes an issue that causes QProcess::start to silently fail on OS X 10.9. Apparently, fileno(stdout) locks the handle on OS X 10.9. It may happen that the parent process fflush()s stdout while the child has just been forked. The stdout lock of the parent is never released in the child and fileno(stdout) therefore locks forever. According to the fork documentation on opengroup.org one may only call async-signal-safe functions between fork and exec in the child. The fileno() function does not appear in the list of async-signal-safe functions. Also, fileno(stdout) and friends can be easily replaced by the standard constants STDOUT_FILENO etc. Done-with: Fawzi Mohamed <fawzi.mohamed@digia.com> Task-number: QTBUG-37306 Change-Id: I2b1f5f47cc48a1ad020fb0493a955d2bc27aeb47 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This commit is contained in:
parent
8302d8b5aa
commit
b2216bbe06
@ -880,18 +880,18 @@ void QProcessPrivate::execChild(const char *workingDir, char **path, char **argv
|
||||
|
||||
// copy the stdin socket if asked to (without closing on exec)
|
||||
if (inputChannelMode != QProcess::ForwardedInputChannel)
|
||||
qt_safe_dup2(stdinChannel.pipe[0], fileno(stdin), 0);
|
||||
qt_safe_dup2(stdinChannel.pipe[0], STDIN_FILENO, 0);
|
||||
|
||||
// copy the stdout and stderr if asked to
|
||||
if (processChannelMode != QProcess::ForwardedChannels) {
|
||||
if (processChannelMode != QProcess::ForwardedOutputChannel)
|
||||
qt_safe_dup2(stdoutChannel.pipe[1], fileno(stdout), 0);
|
||||
qt_safe_dup2(stdoutChannel.pipe[1], STDOUT_FILENO, 0);
|
||||
|
||||
// merge stdout and stderr if asked to
|
||||
if (processChannelMode == QProcess::MergedChannels) {
|
||||
qt_safe_dup2(fileno(stdout), fileno(stderr), 0);
|
||||
qt_safe_dup2(STDOUT_FILENO, STDERR_FILENO, 0);
|
||||
} else if (processChannelMode != QProcess::ForwardedErrorChannel) {
|
||||
qt_safe_dup2(stderrChannel.pipe[1], fileno(stderr), 0);
|
||||
qt_safe_dup2(stderrChannel.pipe[1], STDERR_FILENO, 0);
|
||||
}
|
||||
}
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user