qprocess_unix.cpp

奇趣公司比较新的qt/emd版本

/****************************************************************************
**
** Copyright (C) 1992-2007 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://trolltech.com/products/qt/licenses/licensing/opensource/
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at [e-mail].
**
** In addition, as a special exception, Trolltech gives you certain
** additional rights. These rights are described in the Trolltech GPL
** Exception version 1.0, which can be found at
** http://www.trolltech.com/products/qt/gplexception/ and in the file
** GPL_EXCEPTION.txt in this package.
**
** In addition, as a special exception, Trolltech, as the sole copyright
** holder for Qt Designer, grants users of the Qt/Eclipse Integration
** plug-in the right for the Qt/Eclipse Integration to link to
** functionality provided by Qt Designer and its related libraries.
**
** Trolltech reserves all rights not expressly granted herein.
**
** 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 <private/qcoreapplication_p.h>
#include <private/qthread_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>
#include <string.h>

#ifdef Q_OS_INTEGRITY
static inline char *strdup(const char *data)
{
    return qstrdup(data);
}
#endif

static qint64 qt_native_read(int fd, char *data, qint64 maxlen)
{
    qint64 ret = 0;
    do {
        ret = ::read(fd, data, maxlen);
    } while (ret == -1 && errno == EINTR);
    return ret;
}

static qint64 qt_native_write(int fd, const char *data, qint64 len)
{
    qint64 ret = 0;
    do {
        ret = ::write(fd, data, len);
    } while (ret == -1 && errno == EINTR);
    return ret;
}

static void qt_native_close(int fd)
{
    int ret;
    do {
        ret = ::close(fd);
    } while (ret == -1 && errno == EINTR);
}

static void qt_native_sigaction(int signum, const struct sigaction *act,
                                struct sigaction *oldact)
{
    int ret;
    do {
        ret = ::sigaction(signum, act, oldact);
    } while (ret == -1 && errno == EINTR);
}

static void qt_native_dup2(int oldfd, int newfd)
{
    int ret;
    do {
        ret = ::dup2(oldfd, newfd);
    } while (ret == -1 && errno == EINTR);
}

static void qt_native_chdir(const char *path)
{
    int ret;
    do {
        ret = ::chdir(path);
    } while (ret == -1 && errno == EINTR);
}

static void qt_native_execve(const char *filename, char *const argv[],
                              char *const envp[])
{
    int ret;
    do {
        ret = ::execve(filename, argv, envp);
    } while (ret == -1 && errno == EINTR);
}

static void qt_native_execv(const char *path, char *const argv[])
{
    int ret;
    do {
        ret = ::execv(path, argv);
    } while (ret == -1 && errno == EINTR);
}

static void qt_native_execvp(const char *file, char *const argv[])
{
    int ret;
    do {
        ret = ::execvp(file, argv);
    } while (ret == -1 && errno == EINTR);
}

static int qt_qprocess_deadChild_pipe[2];
static void (*qt_sa_old_sigchld_handler)(int) = 0;
static void qt_sa_sigchld_handler(int signum)
{
    qt_native_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;
    qt_native_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.
    qt_native_write(qt_qprocess_deadChild_pipe[1], "@", 1);
    qt_native_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.
    qt_native_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 (qt_native_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();
        qt_native_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);

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 = idCounter.fetchAndAdd(1);
    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)
        qt_native_close(pipe[0]);
    if (pipe[1] != -1)
        qt_native_close(pipe[1]);
#ifdef Q_OS_IRIX
    if (::socketpair(AF_UNIX, SOCK_STREAM, 0, pipe) == -1) {
        qWarning("QProcessPrivate::createPipe: Cannot create pipe %p: %s",
                 pipe, qPrintable(qt_error_string(errno)));
    }
#else
    if (::pipe(pipe) != 0) {
        qWarning("QProcessPrivate::createPipe: Cannot create pipe %p: %s",
                 pipe, qPrintable(qt_error_string(errno)));
    }
#endif
    ::fcntl(pipe[0], F_SETFD, FD_CLOEXEC);
    ::fcntl(pipe[1], F_SETFD, FD_CLOEXEC);
}

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

/*
    Create the pipes to a QProcessPrivate::Channel.

    This function must be called in order: stdin, stdout, stderr
*/
bool QProcessPrivate::createChannel(Channel &channel)
{
    Q_Q(QProcess);

    if (&channel == &stderrChannel && processChannelMode == QProcess::MergedChannels) {
        channel.pipe[0] = -1;
        channel.pipe[1] = -1;
        return true;
    }

    if (channel.type == Channel::Normal) {
        // we're piping this channel to our own process
        qt_create_pipe(channel.pipe);

        // create the socket notifiers
        if (threadData->eventDispatcher) {
            if (&channel == &stdinChannel) {
                channel.notifier = new QSocketNotifier(channel.pipe[1],
                                                       QSocketNotifier::Write, q);
                channel.notifier->setEnabled(false);
                QObject::connect(channel.notifier, SIGNAL(activated(int)),
                                 q, SLOT(_q_canWrite()));
            } else {
                channel.notifier = new QSocketNotifier(channel.pipe[0],
                                                       QSocketNotifier::Read, q);
                const char *receiver;
                if (&channel == &stdoutChannel)
                    receiver = SLOT(_q_canReadStandardOutput());
                else
                    receiver = SLOT(_q_canReadStandardError());
                QObject::connect(channel.notifier, SIGNAL(activated(int)),
                                 q, receiver);
            }
        }

        return true;
    } else if (channel.type == Channel::Redirect) {
        // we're redirecting the channel to/from a file