Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1 into 4.7-integration

* '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1: (119 commits)
  Bearer management documentation.
  Bearer management changes from Qt Mobility (6fb31d1e).
  Remove extraneous semi-colon.
  Use the default codec with QString::vsprintf()
  Fix build with QT_NO_DOCKWIDGET
  Fix the test of QDirIterator with NoDot and NoDotDot
  Split QDir::NoDotAndDotDot into QDir::NoDot and QDir::NoDotDot
  QFSFileEngine: don't look through NTFS junctions
  After showing modal windows, WM_LBUTTONUP for double click is ignored.
  Possible fix for missing QML properties in the qt.qhp file.
  Use standard theme icons in Linguist where possible
  Use more standard icons from the theme in Assistant
  Use more standard icons for standard actions in Designer
  Drag & drop operations wont end while using Remote Desktop sessions
  _close(fd) closes the associated handle and not the other way around
  Fixed locale mapping on Symbian.
  Revert change 7bf4512659 on Cocoa.
  Extended the high_attributes array, since we have more than 127 widget attributes now.
  Added instructions for MinGW users wanting to build the MySQL driver.
  Designer: Fix broken resource view.
  ...

1 files changed, 62 insertions, 45 deletions

diff --git a/src/corelib/thread/qthread_unix.cpp b/src/corelib/thread/qthread_unix.cpp
index cda35a4..5a50646 100644
--- a/src/corelib/thread/qthread_unix.cpp
+++ b/src/corelib/thread/qthread_unix.cpp
@@ -92,10 +92,17 @@
 # endif
 #endif
 
+#if defined(Q_OS_LINUX) && !defined(SCHED_IDLE)
+// from linux/sched.h
+# define SCHED_IDLE    5
+#endif
+
 QT_BEGIN_NAMESPACE
 
 #ifndef QT_NO_THREAD
 
+enum { ThreadPriorityResetFlag = 0x80000000 };
+
 static pthread_once_t current_thread_data_once = PTHREAD_ONCE_INIT;
 static pthread_key_t current_thread_data_key;
 
@@ -221,6 +228,11 @@ void *QThreadPrivate::start(void *arg)
     QThread *thr = reinterpret_cast<QThread *>(arg);
     QThreadData *data = QThreadData::get2(thr);
 
+    // do we need to reset the thread priority?
+    if (int(thr->d_func()->priority) & ThreadPriorityResetFlag) {
+        thr->setPriority(QThread::Priority(thr->d_func()->priority & ~ThreadPriorityResetFlag));
+    }
+
 #ifdef Q_OS_SYMBIAN
     // Because Symbian Open C does not provide a way to convert between
     // RThread and pthread_t, we must delay initialization of the RThread
@@ -436,6 +448,37 @@ void QThread::usleep(unsigned long usecs)
     thread_sleep(&ti);
 }
 
+// Does some magic and calculate the Unix scheduler priorities
+// sched_policy is IN/OUT: it must be set to a valid policy before calling this function
+// sched_priority is OUT only
+static bool calculateUnixPriority(int priority, int *sched_policy, int *sched_priority)
+{
+#ifdef SCHED_IDLE
+    if (priority == QThread::IdlePriority) {
+        *sched_policy = SCHED_IDLE;
+        *sched_priority = 0;
+        return true;
+    }
+    const int lowestPriority = QThread::LowestPriority;
+#else
+    const int lowestPriority = QThread::IdlePriority;
+#endif
+    const int highestPriority = QThread::TimeCriticalPriority;
+
+    int prio_min = sched_get_priority_min(*sched_policy);
+    int prio_max = sched_get_priority_max(*sched_policy);
+    if (prio_min == -1 || prio_max == -1)
+        return false;
+
+    int prio;
+    // crudely scale our priority enum values to the prio_min/prio_max
+    prio = ((priority - lowestPriority) * (prio_max - prio_min) / highestPriority) + prio_min;
+    prio = qMax(prio_min, qMin(prio_max, prio));
+
+    *sched_priority = prio;
+    return true;
+}
+
 void QThread::start(Priority priority)
 {
     Q_D(QThread);
@@ -472,32 +515,14 @@ void QThread::start(Priority priority)
                 break;
             }
 
-            int prio_min = sched_get_priority_min(sched_policy);
-            int prio_max = sched_get_priority_max(sched_policy);
-            if (prio_min == -1 || prio_max == -1) {
+            int prio;
+            if (!calculateUnixPriority(priority, &sched_policy, &prio)) {
                 // failed to get the scheduling parameters, don't
                 // bother setting the priority
                 qWarning("QThread::start: Cannot determine scheduler priority range");
                 break;
             }
 
-            int prio;
-            switch (priority) {
-            case IdlePriority:
-                prio = prio_min;
-                break;
-
-            case TimeCriticalPriority:
-                prio = prio_max;
-                break;
-
-            default:
-                // crudely scale our priority enum values to the prio_min/prio_max
-                prio = (priority * (prio_max - prio_min) / TimeCriticalPriority) + prio_min;
-                prio = qMax(prio_min, qMin(prio_max, prio));
-                break;
-            }
-
             sched_param sp;
             sp.sched_priority = prio;
 
@@ -505,7 +530,9 @@ void QThread::start(Priority priority)
                 || pthread_attr_setschedpolicy(&attr, sched_policy) != 0
                 || pthread_attr_setschedparam(&attr, &sp) != 0) {
                 // could not set scheduling hints, fallback to inheriting them
+                // we'll try again from inside the thread
                 pthread_attr_setinheritsched(&attr, PTHREAD_INHERIT_SCHED);
+                d->priority = Priority(priority | ThreadPriorityResetFlag);
             }
             break;
         }
@@ -672,38 +699,28 @@ void QThread::setPriority(Priority priority)
         return;
     }
 
-    int prio_min = sched_get_priority_min(sched_policy);
-    int prio_max = sched_get_priority_max(sched_policy);
-    if (prio_min == -1 || prio_max == -1) {
+    int prio;
+    if (!calculateUnixPriority(priority, &sched_policy, &prio)) {
         // failed to get the scheduling parameters, don't
         // bother setting the priority
         qWarning("QThread::setPriority: Cannot determine scheduler priority range");
         return;
     }
 
-    int prio;
-    switch (priority) {
-    case InheritPriority:
-        qWarning("QThread::setPriority: Argument cannot be InheritPriority");
-        return;
-
-    case IdlePriority:
-        prio = prio_min;
-        break;
-
-    case TimeCriticalPriority:
-        prio = prio_max;
-        break;
-
-    default:
-        // crudely scale our priority enum values to the prio_min/prio_max
-        prio = (priority * (prio_max - prio_min) / TimeCriticalPriority) + prio_min;
-        prio = qMax(prio_min, qMin(prio_max, prio));
-        break;
-    }
-
     param.sched_priority = prio;
-    pthread_setschedparam(d->thread_id, sched_policy, &param);
+    int status = pthread_setschedparam(d->thread_id, sched_policy, &param);
+
+# ifdef SCHED_IDLE
+    // were we trying to set to idle priority and failed?
+    if (status == -1 && sched_policy == SCHED_IDLE && errno == EINVAL) {
+        // reset to lowest priority possible
+        pthread_getschedparam(d->thread_id, &sched_policy, &param);
+        param.sched_priority = sched_get_priority_min(sched_policy);
+        pthread_setschedparam(d->thread_id, sched_policy, &param);
+    }
+# else
+    Q_UNUSED(status);
+# endif // SCHED_IDLE
 #endif
 }