Use glib thread initialization functions when glib main loop is in use

This resolves Bug 1484

configure

@@ -734,9 +734,6 @@ while [ "$#" -gt 0 ]; do
     glibmainloop)
 	if [ "$VAL" = "yes" ] || [ "$VAL" = "no" ]; then
 	    CFG_GLIBMAINLOOP="$VAL"
-	    if [ "$VAL" = "yes" ]; then
-		echo "WARNING: glib main loop support is ***incomplete*** and will cause problems with threaded applications and/or those using non-standard event loops!"
-	    fi
 	else
 	    UNKNOWN_OPT=yes
 	fi
@@ -2644,13 +2641,11 @@ if [ "$CFG_GLIBMAINLOOP" = "no" ]; then
 elif [ "$CFG_GLIBMAINLOOP" = "yes" ]; then
     QMAKE_CONFIG="$QMAKE_CONFIG glibmainloop"
 
-    GLIB_CFLAGS="`pkg-config --cflags glib-2.0`"
+    GLIB_CFLAGS="`pkg-config --cflags glib-2.0` `pkg-config --cflags gthread-2.0`"
     QMAKE_VARS="$QMAKE_VARS \"QMAKE_CFLAGS_GLIB=$GLIB_CFLAGS\""
 
-    GLIB_LINKFLAG="`pkg-config --libs glib-2.0`"
+    GLIB_LINKFLAG="`pkg-config --libs glib-2.0` `pkg-config --libs gthread-2.0`"
     QMAKE_VARS="$QMAKE_VARS \"QMAKE_LIBS_GLIB=$GLIB_LINKFLAG\""
-    
-
 fi
 if [ "$CFG_GIF" = "no" ]; then
     QMAKE_CONFIG="$QMAKE_CONFIG no-gif"

src/kernel/qeventloop.cpp

@@ -223,8 +223,9 @@ int QEventLoop::enterLoop()
     d->shortcut = FALSE;
 
     d->looplevel++;
-    while ( ! d->exitloop )
+    while ( ! d->exitloop ) {
 	processEvents( AllEvents | WaitForMore );
+    }
     d->looplevel--;
 
     // restore the exitloop state, but if quitnow is TRUE, we need to keep

src/kernel/qeventloop_x11_glib.cpp

@@ -54,6 +54,7 @@
 #include <errno.h>
 
 #include <glib.h>
+#include <sys/syscall.h>
 
 // #define DEBUG_QT_GLIBMAINLOOP 1
 
@@ -245,7 +246,6 @@ void QEventLoop::init()
 #ifdef DEBUG_QT_GLIBMAINLOOP
 	printf("inside init(2)\n");
 #endif
-	
 }
 
 void QEventLoop::cleanup()
@@ -266,9 +266,8 @@ void QEventLoop::cleanup()
 
 bool QEventLoop::processEvents( ProcessEventsFlags flags )
 {
-
 #ifdef DEBUG_QT_GLIBMAINLOOP
-	printf("inside processEvents(1) looplevel=%d\n", d->looplevel );
+	printf("inside processEvents(1) looplevel=%d eventloop=%p d->ctx=%p this=%p\n", d->looplevel, QApplication::eventLoop(), d->ctx, this ); fflush(stdout);
 #endif
 
 	ProcessEventsFlags save_flags;
@@ -282,7 +281,7 @@ bool QEventLoop::processEvents( ProcessEventsFlags flags )
 	d->pev_flags = save_flags;
 
 #ifdef DEBUG_QT_GLIBMAINLOOP
-	printf("inside processEvents(2) looplevel=%d rval=%d\n", d->looplevel, rval );
+	printf("inside processEvents(2) looplevel=%d eventloop=%p d->ctx=%p this=%p rval=%d\n", d->looplevel, QApplication::eventLoop(), d->ctx, this, rval ); fflush(stdout);
 #endif
 
 	return rval; // were events processed?

src/kernel/qthread_unix.cpp

@@ -51,10 +51,12 @@ typedef pthread_mutex_t Q_MUTEX_T;
 #include <errno.h>
 #include <sched.h>
 
+#if defined(QT_USE_GLIBMAINLOOP)
+#include <glib.h>
+#endif // QT_USE_GLIBMAINLOOP
 
 static QMutexPool *qt_thread_mutexpool = 0;
 
-
 #if defined(Q_C_CALLBACKS)
 extern "C" {
 #endif
@@ -121,6 +123,11 @@ void *QThreadInstance::start( void *_arg )
 {
     void **arg = (void **) _arg;
 
+#if defined(QT_USE_GLIBMAINLOOP)
+    // This is the first time we have access to the native pthread ID of this newly created thread
+    ((QThreadInstance*)arg[1])->thread_id = pthread_self();
+#endif // QT_USE_GLIBMAINLOOP
+
     setCurrentThread( (QThread *) arg[0] );
 
     pthread_cleanup_push( QThreadInstance::finish, arg[1] );
@@ -390,6 +397,20 @@ void QThread::start(Priority priority)
 
     d->args[0] = this;
     d->args[1] = d;
+#if defined(QT_USE_GLIBMAINLOOP)
+    // Legacy glib versions require this threading system initialization call
+    g_thread_init(NULL);
+
+    GThread* glib_thread_handle = g_thread_create((GThreadFunc)QThreadInstance::start, d->args, false, NULL);
+    if (glib_thread_handle) {
+	ret = 0;
+    }
+    else {
+	ret = -1;
+    }
+    // The correct thread_id is set in QThreadInstance::start using the value of d->args[1]
+    d->thread_id = NULL;
+#else // QT_USE_GLIBMAINLOOP
     ret = pthread_create( &d->thread_id, &attr, (QtThreadCallback)QThreadInstance::start, d->args );
 #if defined (Q_OS_HPUX)
     if (ret == EPERM) {
@@ -398,6 +419,7 @@ void QThread::start(Priority priority)
     }
 #endif
     pthread_attr_destroy( &attr );
+#endif // QT_USE_GLIBMAINLOOP
 
     if ( ret ) {
 #ifdef QT_CHECK_STATE
@@ -444,8 +466,9 @@ bool QThread::wait( unsigned long time )
 	return FALSE;
     }
 
-    if ( d->finished || ! d->running )
+    if ( d->finished || ! d->running ) {
 	return TRUE;
+    }
 
     int ret;
     if (time != ULONG_MAX) {
@@ -458,12 +481,15 @@ bool QThread::wait( unsigned long time )
 	ti.tv_nsec %= 1000000000;
 
 	ret = pthread_cond_timedwait(&d->thread_done, &locker.mutex()->d->handle, &ti);
-    } else
+    }
+    else {
 	ret = pthread_cond_wait(&d->thread_done, &locker.mutex()->d->handle);
+    }
 
 #ifdef QT_CHECK_RANGE
-    if (ret && ret != ETIMEDOUT)
+    if (ret && ret != ETIMEDOUT) {
 	qWarning("Wait condition wait failure: %s",strerror(ret));
+    }
 #endif
 
     return (ret == 0);