Add POSIX IPC support to QSystemSemaphore and QSharedMemory

This patch is a forward-port from 4.8 branch
(d869e1ad4b0007757e97046609de2097cd9e9c5d).

Change-Id: I6ae36a5417d1176fbecf775668f6033b1cb22a94
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 8 insertions, 142 deletions

diff --git a/src/corelib/kernel/qsystemsemaphore_unix.cpp b/src/corelib/kernel/qsystemsemaphore_unix.cpp
index 3d0cc76804..e8b3f14375 100644
--- a/src/corelib/kernel/qsystemsemaphore_unix.cpp
+++ b/src/corelib/kernel/qsystemsemaphore_unix.cpp
@@ -35,30 +35,29 @@
 #include "qsystemsemaphore_p.h"
 
 #include <qdebug.h>
-#include <qfile.h>
 #include <qcoreapplication.h>
 
 #ifndef QT_NO_SYSTEMSEMAPHORE
 
 #include <sys/types.h>
 #include <sys/ipc.h>
+#ifndef QT_POSIX_IPC
 #include <sys/sem.h>
+#endif
 #include <fcntl.h>
 #include <errno.h>
 
 #include "private/qcore_unix_p.h"
 
-// OpenBSD 4.2 doesn't define EIDRM, see BUGS section:
-// http://www.openbsd.org/cgi-bin/man.cgi?query=semop&manpath=OpenBSD+4.2
-#if defined(Q_OS_OPENBSD) && !defined(EIDRM)
-#define EIDRM EINVAL
-#endif
-
 QT_BEGIN_NAMESPACE
 
 QSystemSemaphorePrivate::QSystemSemaphorePrivate() :
-        semaphore(-1), createdFile(false),
-        createdSemaphore(false), unix_key(-1), error(QSystemSemaphore::NoError)
+#ifndef QT_POSIX_IPC
+    unix_key(-1), semaphore(-1), createdFile(false),
+#else
+    semaphore(SEM_FAILED),
+#endif // QT_POSIX_IPC
+    createdSemaphore(false), error(QSystemSemaphore::NoError)
 {
 }
 
@@ -93,139 +92,6 @@ void QSystemSemaphorePrivate::setErrorString(const QString &function)
     }
 }
 
-/*!
-    \internal
-
-    Setup unix_key
- */
-key_t QSystemSemaphorePrivate::handle(QSystemSemaphore::AccessMode mode)
-{
-    if (key.isEmpty()){
-        errorString = QCoreApplication::tr("%1: key is empty", "QSystemSemaphore").arg(QLatin1String("QSystemSemaphore::handle:"));
-        error = QSystemSemaphore::KeyError;
-        return -1;
-    }
-
-    // ftok requires that an actual file exists somewhere
-    if (-1 != unix_key)
-        return unix_key;
-
-    // Create the file needed for ftok
-    int built = QSharedMemoryPrivate::createUnixKeyFile(fileName);
-    if (-1 == built) {
-        errorString = QCoreApplication::tr("%1: unable to make key", "QSystemSemaphore").arg(QLatin1String("QSystemSemaphore::handle:"));
-        error = QSystemSemaphore::KeyError;
-        return -1;
-    }
-    createdFile = (1 == built);
-
-    // Get the unix key for the created file
-    unix_key = ftok(QFile::encodeName(fileName).constData(), 'Q');
-    if (-1 == unix_key) {
-        errorString = QCoreApplication::tr("%1: ftok failed", "QSystemSemaphore").arg(QLatin1String("QSystemSemaphore::handle:"));
-        error = QSystemSemaphore::KeyError;
-        return -1;
-    }
-
-    // Get semaphore
-    semaphore = semget(unix_key, 1, 0600 | IPC_CREAT | IPC_EXCL);
-    if (-1 == semaphore) {
-        if (errno == EEXIST)
-            semaphore = semget(unix_key, 1, 0600 | IPC_CREAT);
-        if (-1 == semaphore) {
-            setErrorString(QLatin1String("QSystemSemaphore::handle"));
-            cleanHandle();
-            return -1;
-        }
-    } else {
-        createdSemaphore = true;
-        // Force cleanup of file, it is possible that it can be left over from a crash
-        createdFile = true;
-    }
-
-    if (mode == QSystemSemaphore::Create) {
-        createdSemaphore = true;
-        createdFile = true;
-    }
-
-    // Created semaphore so initialize its value.
-    if (createdSemaphore && initialValue >= 0) {
-        qt_semun init_op;
-        init_op.val = initialValue;
-        if (-1 == semctl(semaphore, 0, SETVAL, init_op)) {
-            setErrorString(QLatin1String("QSystemSemaphore::handle"));
-            cleanHandle();
-            return -1;
-        }
-    }
-
-    return unix_key;
-}
-
-/*!
-    \internal
-
-    Cleanup the unix_key
- */
-void QSystemSemaphorePrivate::cleanHandle()
-{
-    unix_key = -1;
-
-    // remove the file if we made it
-    if (createdFile) {
-        QFile::remove(fileName);
-        createdFile = false;
-    }
-
-    if (createdSemaphore) {
-        if (-1 != semaphore) {
-            if (-1 == semctl(semaphore, 0, IPC_RMID, 0)) {
-                setErrorString(QLatin1String("QSystemSemaphore::cleanHandle"));
-#if defined QSYSTEMSEMAPHORE_DEBUG
-                qDebug() << QLatin1String("QSystemSemaphore::cleanHandle semctl failed.");
-#endif
-            }
-            semaphore = -1;
-        }
-        createdSemaphore = false;
-    }
-}
-
-/*!
-    \internal
- */
-bool QSystemSemaphorePrivate::modifySemaphore(int count)
-{
-    if (-1 == handle())
-        return false;
-
-    struct sembuf operation;
-    operation.sem_num = 0;
-    operation.sem_op = count;
-    operation.sem_flg = SEM_UNDO;
-
-    int res;
-    EINTR_LOOP(res, semop(semaphore, &operation, 1));
-    if (-1 == res) {
-        // If the semaphore was removed be nice and create it and then modifySemaphore again
-        if (errno == EINVAL || errno == EIDRM) {
-            semaphore = -1;
-            cleanHandle();
-            handle();
-            return modifySemaphore(count);
-        }
-        setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore"));
-#if defined QSYSTEMSEMAPHORE_DEBUG
-        qDebug() << QLatin1String("QSystemSemaphore::modify failed") << count << semctl(semaphore, 0, GETVAL) << errno << EIDRM << EINVAL;
-#endif
-        return false;
-    }
-
-    clearError();
-    return true;
-}
-
-
 QT_END_NAMESPACE
 
 #endif // QT_NO_SYSTEMSEMAPHORE