qprocess_unix.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

//#define QPROCESS_DEBUG
#include "qdebug.h"

#ifndef QT_NO_PROCESS

#if defined QPROCESS_DEBUG
#include "qstring.h"
#include <ctype.h>

/*
    Returns a human readable representation of the first \a len
    characters in \a data.
*/
static QByteArray qt_prettyDebug(const char *data, int len, int maxSize)
{
    if (!data) return "(null)";
    QByteArray out;
    for (int i = 0; i < len; ++i) {
        char c = data[i];
        if (isprint(c)) {
            out += c;
        } else switch (c) {
        case '\n': out += "\\n"; break;
        case '\r': out += "\\r"; break;
        case '\t': out += "\\t"; break;
        default:
            QString tmp;
            tmp.sprintf("\\%o", c);
            out += tmp.toLatin1();
        }
    }

    if (len < maxSize)
        out += "...";

    return out;
}
#endif

#include "qplatformdefs.h"

#include "qprocess.h"
#include "qprocess_p.h"

#ifdef Q_OS_MAC
#include <private/qcore_mac_p.h>
#endif

#include <qabstracteventdispatcher.h>
#include <private/qcoreapplication_p.h>
#include <qdatetime.h>
#include <qfile.h>
#include <qfileinfo.h>
#include <qlist.h>
#include <qmap.h>
#include <qmutex.h>
#include <qsemaphore.h>
#include <qsocketnotifier.h>
#include <qthread.h>

#include <errno.h>
#include <stdlib.h>

static int qt_qprocess_deadChild_pipe[2];
static void (*qt_sa_old_sigchld_handler)(int) = 0;
static void qt_sa_sigchld_handler(int signum)
{
    ::write(qt_qprocess_deadChild_pipe[1], "", 1);
#if defined (QPROCESS_DEBUG)
    fprintf(stderr, "*** SIGCHLD\n");
#endif

    if (qt_sa_old_sigchld_handler && qt_sa_old_sigchld_handler != SIG_IGN)
        qt_sa_old_sigchld_handler(signum);
}

struct QProcessInfo {
    QProcess *process;
    int deathPipe;
    int exitResult;
    pid_t pid;
    int serialNumber;
};

class QProcessManager : public QThread
{
    Q_OBJECT
public:
    QProcessManager();
    ~QProcessManager();

    void run();
    void catchDeadChildren();
    void add(pid_t pid, QProcess *process);
    void remove(QProcess *process);
    void lock();
    void unlock();

private:
    QMutex mutex;
    QMap<int, QProcessInfo *> children;
};

Q_GLOBAL_STATIC(QProcessManager, processManager)

QProcessManager::QProcessManager()
{
#if defined (QPROCESS_DEBUG)
    qDebug() << "QProcessManager::QProcessManager()";
#endif
    // initialize the dead child pipe and make it non-blocking. in the
    // extremely unlikely event that the pipe fills up, we do not under any
    // circumstances want to block.
    ::pipe(qt_qprocess_deadChild_pipe);
    ::fcntl(qt_qprocess_deadChild_pipe[0], F_SETFD, FD_CLOEXEC);
    ::fcntl(qt_qprocess_deadChild_pipe[1], F_SETFD, FD_CLOEXEC);
    ::fcntl(qt_qprocess_deadChild_pipe[0], F_SETFL,
	    ::fcntl(qt_qprocess_deadChild_pipe[0], F_GETFL) | O_NONBLOCK);
    ::fcntl(qt_qprocess_deadChild_pipe[1], F_SETFL,
	    ::fcntl(qt_qprocess_deadChild_pipe[1], F_GETFL) | O_NONBLOCK);

    // set up the SIGCHLD handler, which writes a single byte to the dead
    // child pipe every time a child dies.
    struct sigaction oldAction;
    struct sigaction action;
    memset(&action, 0, sizeof(action));
    action.sa_handler = qt_sa_sigchld_handler;
    action.sa_flags = SA_NOCLDSTOP;
    ::sigaction(SIGCHLD, &action, &oldAction);
    if (oldAction.sa_handler != qt_sa_sigchld_handler)
	qt_sa_old_sigchld_handler = oldAction.sa_handler;
}

QProcessManager::~QProcessManager()
{
    // notify the thread that we're shutting down.
    ::write(qt_qprocess_deadChild_pipe[1], "@", 1);
    ::close(qt_qprocess_deadChild_pipe[1]);
    wait();

    // on certain unixes, closing the reading end of the pipe will cause
    // select in run() to block forever, rather than return with EBADF.
    ::close(qt_qprocess_deadChild_pipe[0]);

    qt_qprocess_deadChild_pipe[0] = -1;
    qt_qprocess_deadChild_pipe[1] = -1;

    qDeleteAll(children.values());
    children.clear();
}

void QProcessManager::run()
{
    forever {
        fd_set readset;
        FD_ZERO(&readset);
        FD_SET(qt_qprocess_deadChild_pipe[0], &readset);

#if defined (QPROCESS_DEBUG)
        qDebug() << "QProcessManager::run() waiting for children to die";
#endif

        // block forever, or until activity is detected on the dead child
        // pipe. the only other peers are the SIGCHLD signal handler, and the
        // QProcessManager destructor.
        int nselect = select(qt_qprocess_deadChild_pipe[0] + 1, &readset, 0, 0, 0);
        if (nselect < 0) {
            if (errno == EINTR)
                continue;
            break;
        }

        // empty only one byte from the pipe, even though several SIGCHLD
        // signals may have been delivered in the meantime, to avoid race
        // conditions.
        char c;
        if (::read(qt_qprocess_deadChild_pipe[0], &c, 1) < 0 || c == '@')
            break;

        // catch any and all children that we can.
        catchDeadChildren();
    }
}

void QProcessManager::catchDeadChildren()
{
    QMutexLocker locker(&mutex);

    // try to catch all children whose pid we have registered, and whose
    // deathPipe is still valid (i.e, we have not already notified it).
    QMap<int, QProcessInfo *>::Iterator it = children.begin();
    while (it != children.end()) {
        // notify all children that they may have died. they need to run
        // waitpid() in their own thread.
        QProcessInfo *info = it.value();
        ::write(info->deathPipe, "", 1);

#if defined (QPROCESS_DEBUG)
        qDebug() << "QProcessManager::run() sending death notice to" << info->process;
#endif
        ++it;
    }
}

static QBasicAtomic idCounter = Q_ATOMIC_INIT(1);
static int qt_qprocess_nextId()
{
    register int id;
    for (;;) {
        id = idCounter;
        if (idCounter.testAndSet(id, id + 1))
            break;
    }
    return id;
}

void QProcessManager::add(pid_t pid, QProcess *process)
{
#if defined (QPROCESS_DEBUG)
    qDebug() << "QProcessManager::add() adding pid" << pid << "process" << process;
#endif

    // insert a new info structure for this process
    QProcessInfo *info = new QProcessInfo;
    info->process = process;
    info->deathPipe = process->d_func()->deathPipe[1];
    info->exitResult = 0;
    info->pid = pid;

    int serial = qt_qprocess_nextId();
    process->d_func()->serial = serial;
    children.insert(serial, info);
}

void QProcessManager::remove(QProcess *process)
{
    QMutexLocker locker(&mutex);

    int serial = process->d_func()->serial;
    QProcessInfo *info = children.value(serial);
    if (!info)
        return;

#if defined (QPROCESS_DEBUG)
    qDebug() << "QProcessManager::remove() removing pid" << info->pid << "process" << info->process;
#endif
    
    children.remove(serial);
    delete info;
}

void QProcessManager::lock()
{
    mutex.lock();
}

void QProcessManager::unlock()
{
    mutex.unlock();
}

static void qt_create_pipe(int *pipe)
{
    if (pipe[0] != -1)
        ::close(pipe[0]);
    if (pipe[1] != -1)
        ::close(pipe[1]);
#ifdef Q_OS_IRIX
    if (::socketpair(AF_UNIX, SOCK_STREAM, 0, pipe) == -1) {
        qWarning("QProcessPrivate::createPipe(%p) failed: %s",
                 pipe, qPrintable(qt_error_string(errno)));
    }
#else
    if (::pipe(pipe) != 0) {
        qWarning("QProcessPrivate::createPipe(%p) failed: %s",
                 pipe, qPrintable(qt_error_string(errno)));
    }
#endif
}

void QProcessPrivate::destroyPipe(int *pipe)
{
    if (pipe[1] != -1) {
        ::close(pipe[1]);
        pipe[1] = -1;
    }
    if (pipe[0] != -1) {
        ::close(pipe[0]);
        pipe[0] = -1;
    }
}

void QProcessPrivate::startProcess()
{
    Q_Q(QProcess);

#if defined (QPROCESS_DEBUG)
    qDebug("QProcessPrivate::startProcess()");
#endif

    processManager()->start();

    // Initialize pipes
    qt_create_pipe(childStartedPipe);
    if (QAbstractEventDispatcher::instance(q->thread())) {
        startupSocketNotifier = new QSocketNotifier(childStartedPipe[0],
                                                    QSocketNotifier::Read, q);
        QObject::connect(startupSocketNotifier, SIGNAL(activated(int)),
                         q, SLOT(_q_startupNotification()));
    }

    qt_create_pipe(deathPipe);
    ::fcntl(deathPipe[0], F_SETFD, FD_CLOEXEC);
    ::fcntl(deathPipe[1], F_SETFD, FD_CLOEXEC);
    if (QAbstractEventDispatcher::instance(q->thread())) {
        deathNotifier = new QSocketNotifier(deathPipe[0],
                                            QSocketNotifier::Read, q);
        QObject::connect(deathNotifier, SIGNAL(activated(int)),
                         q, SLOT(_q_processDied()));
    }

    qt_create_pipe(writePipe);
    if (QAbstractEventDispatcher::instance(q->thread())) {
        writeSocketNotifier = new QSocketNotifier(writePipe[1],
                                                  QSocketNotifier::Write, q);
        QObject::connect(writeSocketNotifier, SIGNAL(activated(int)),
                         q, SLOT(_q_canWrite()));
        writeSocketNotifier->setEnabled(false);
    }

    qt_create_pipe(standardReadPipe);
    qt_create_pipe(errorReadPipe);

    if (QAbstractEventDispatcher::instance(q->thread())) {
        standardReadSocketNotifier = new QSocketNotifier(standardReadPipe[0],
                                                         QSocketNotifier::Read,
                                                         q);
        QObject::connect(standardReadSocketNotifier, SIGNAL(activated(int)),
                         q, SLOT(_q_canReadStandardOutput()));

        errorReadSocketNotifier = new QSocketNotifier(errorReadPipe[0],
                                                      QSocketNotifier::Read,
                                                      q);
        QObject::connect(errorReadSocketNotifier, SIGNAL(activated(int)),
                         q, SLOT(_q_canReadStandardError()));
    }

    // Start the process (platform dependent)
    processState = QProcess::Starting;
    emit q->stateChanged(processState);

    QByteArray encodedProg = QFile::encodeName(program);
    processManager()->lock();
    pid_t childPid = fork();
    if (childPid < 0) {
        // Cleanup, report error and return
        processManager()->unlock();
        processState = QProcess::NotRunning;
        emit q->stateChanged(processState);
        processError = QProcess::FailedToStart;
        q->setErrorString(QT_TRANSLATE_NOOP(QProcess, "Resource error (fork failure)"));
        emit q->error(processError);
        cleanup();
        return;
    }

    if (childPid == 0) {
        execChild(encodedProg);
        ::_exit(-1);
    }
    processManager()->add(childPid, q);
    pid = Q_PID(childPid);
    processManager()->unlock();

    // parent
    ::close(childStartedPipe[1]);
    ::close(standardReadPipe[1]);
    ::close(errorReadPipe[1]);
    ::close(writePipe[0]);

    childStartedPipe[1] = -1;
    standardReadPipe[1] = -1;
    errorReadPipe[1] = -1;
    writePipe[0] = -1;

    // make all pipes non-blocking
    ::fcntl(deathPipe[0], F_SETFL, ::fcntl(deathPipe[0], F_GETFL) | O_NONBLOCK);
    ::fcntl(standardReadPipe[0], F_SETFL, ::fcntl(standardReadPipe[0], F_GETFL) | O_NONBLOCK);
    ::fcntl(errorReadPipe[0], F_SETFL, ::fcntl(errorReadPipe[0], F_GETFL) | O_NONBLOCK);
    ::fcntl(writePipe[1], F_SETFL, ::fcntl(writePipe[1], F_GETFL) | O_NONBLOCK);
}

void QProcessPrivate::execChild(const QByteArray &programName)
{
    QByteArray encodedProgramName = programName;
    Q_Q(QProcess);

    // create argument list with right number of elements, and set the
    // final one to 0.
    char **argv = new char *[arguments.count() + 2];
    argv[arguments.count() + 1] = 0;

    // allow invoking of .app bundles on the Mac.
#ifdef Q_OS_MAC
    QFileInfo fileInfo(encodedProgramName);
    if (encodedProgramName.endsWith(".app") && fileInfo.isDir()) {
        QCFType<CFURLRef> url = CFURLCreateWithFileSystemPath(0,
                                                          QCFString(fileInfo.absoluteFilePath()),
                                                          kCFURLPOSIXPathStyle, true);
        QCFType<CFBundleRef> bundle = CFBundleCreate(0, url);
        url = CFBundleCopyExecutableURL(bundle);
        if (url) {
            QCFString str = CFURLCopyFileSystemPath(url, kCFURLPOSIXPathStyle);
            encodedProgramName += "/Contents/MacOS/" + static_cast<QString>(str).toUtf8();
        }
    }
#endif

    // add the program name
    argv[0] = ::strdup(encodedProgramName.constData());

    // add every argument to the list
    for (int i = 0; i < arguments.count(); ++i) {
        QString arg = arguments.at(i);
        argv[i + 1] = ::strdup(arg.toLocal8Bit().constData());
    }

    // on all pipes, close the end that we don't use
    ::close(standardReadPipe[0]);
    ::close(errorReadPipe[0]);
    ::close(writePipe[1]);

    // copy the stdin socket
    ::dup2(writePipe[0], fileno(stdin));
    ::close(writePipe[0]);

    // copy the stdout and stderr if asked to
    if (processChannelMode != QProcess::ForwardedChannels) {
        ::dup2(standardReadPipe[1], fileno(stdout));
        ::dup2(errorReadPipe[1], fileno(stderr));
        ::close(standardReadPipe[1]);
        ::close(errorReadPipe[1]);

        // merge stdout and stderr if asked to
        if (processChannelMode == QProcess::MergedChannels)
            ::dup2(fileno(stdout), fileno(stderr));
    }

    // make sure this fd is closed if execvp() succeeds
    ::close(childStartedPipe[0]);
    ::fcntl(childStartedPipe[1], F_SETFD, FD_CLOEXEC);

    // enter the working directory
    if (!workingDirectory.isEmpty())
        ::chdir(QFile::encodeName(workingDirectory).constData());

    // this is a virtual call, and it base behavior is to do nothing.
    q->setupChildProcess();

    // execute the process
    if (environment.isEmpty()) {
        ::execvp(argv[0], argv);
    } else {
        // if LD_LIBRARY_PATH exists in the current environment, but
        // not in the environment list passed by the programmer, then
        // copy it over.
#if defined(Q_OS_MAC)
        static const char libraryPath[] = "DYLD_LIBRARY_PATH";
#else
        static const char libraryPath[] = "LD_LIBRARY_PATH";
#endif
        QStringList matches = environment.filter(QRegExp("^" + QByteArray(libraryPath) + "="));
        char *envLibraryPath = ::getenv(libraryPath);
        if (matches.isEmpty() && envLibraryPath != 0) {
            QString entry = libraryPath;
            entry += "=";
            entry += envLibraryPath;
            environment << QString(libraryPath) +  "=" + QString(envLibraryPath);
        }

        char **envp = new char *[environment.count() + 1];
        envp[environment.count()] = 0;

        for (int j = 0; j < environment.count(); ++j) {