diff options
| author | Thiago Macieira <thiago.macieira@intel.com> | 2023-03-18 15:05:17 -0700 |
|---|---|---|
| committer | Thiago Macieira <thiago.macieira@intel.com> | 2023-06-09 17:32:33 -0700 |
| commit | 90bc0ad41f9937f9cba801b3166635f6f55e0678 (patch) | |
| tree | f76814f7e266ac68f719f0320f1f5a9e0ae14491 /src/corelib/io/qprocess.cpp | |
| parent | abd2ffc1497e6d13a607362f7f4362e2a6d00448 (diff) | |
QProcess/Unix: add failChildProcessModifier()
QProcess detects other types of failures from inside the modifier as
successful starts, because the childStartedPipe gets closed without an
error condition getting written. The new method allows a reporting as a
proper failure-to-start.
Added tests for both cases.
[ChangeLog][QtCore][QProcess] Added failChildProcessModifier().
Change-Id: Icfe44ecf285a480fafe4fffd174da2b10306d3c2
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'src/corelib/io/qprocess.cpp')
| -rw-r--r-- | src/corelib/io/qprocess.cpp | 48 |
1 files changed, 45 insertions, 3 deletions
diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp index a7107507329..ab7219a6cdb 100644 --- a/src/corelib/io/qprocess.cpp +++ b/src/corelib/io/qprocess.cpp @@ -1646,8 +1646,10 @@ std::function<void(void)> QProcess::childProcessModifier() const \snippet code/src_corelib_io_qprocess.cpp 4 - If the modifier function needs to exit the process, remember to use - \c{_exit()}, not \c{exit()}. + If the modifier function experiences a failure condition, it can use + failChildProcessModifier() to report the situation to the QProcess caller. + Alternatively, it may use other methods of stopping the process, like + \c{_exit()}, or \c{abort()}. Certain properties of the child process, such as closing all extraneous file descriptors or disconnecting from the controlling TTY, can be more @@ -1674,7 +1676,7 @@ std::function<void(void)> QProcess::childProcessModifier() const only make use of low-level system calls, such as \c{read()}, \c{write()}, \c{setsid()}, \c{nice()}, and similar. - \sa childProcessModifier(), setUnixProcessParameters() + \sa childProcessModifier(), failChildProcessModifier(), setUnixProcessParameters() */ void QProcess::setChildProcessModifier(const std::function<void(void)> &modifier) { @@ -1685,6 +1687,46 @@ void QProcess::setChildProcessModifier(const std::function<void(void)> &modifier } /*! + \fn void QProcess::failChildProcessModifier(const char *description, int error) noexcept + \since 6.7 + + This functions can be used inside the modifier set with + setChildProcessModifier() to indicate an error condition was encountered. + When the modifier calls these functions, QProcess will emit errorOccurred() + with code QProcess::FailedToStart in the parent process. The \a description + can be used to include some information in errorString() to help diagnose + the problem, usually the name of the call that failed, similar to the C + Library function \c{perror()}. Additionally, the \a error parameter can be + an \c{<errno.h>} error code whose text form will also be included. + + For example, a child modifier could prepare an extra file descriptor for + the child process this way: + + \code + process.setChildProcessModifier([fd, &process]() { + if (dup2(fd, TargetFileDescriptor) < 0) + process.failChildProcessModifier(errno, "aux comm channel"); + }); + process.start(); + \endcode + + Where \c{fd} is a file descriptor currently open in the parent process. If + the \c{dup2()} system call resulted in an \c EBADF condition, the process + errorString() could be "Child process modifier reported error: aux comm + channel: Bad file descriptor". + + This function does not return to the caller. Using it anywhere except in + the child modifier and with the correct QProcess object is undefined + behavior. + + \note The implementation imposes a length limit to the \a description + parameter to about 500 characters. This does not include the text from the + \a error code. + + \sa setChildProcessModifier(), setUnixProcessParameters() +*/ + +/*! \since 6.6 Returns the \l UnixProcessParameters object describing extra flags and settings that will be applied to the child process on Unix systems. The |