Deprecate the pause-related APIs of QFuture* classes

Deprecated the pause-related APIs of QFuture* classes and
added alternatives having "suspend" in the name instead.

With 2f15927f01ceef0aca490746302a5ea57ea9441c new
isSuspended()/suspended() APIs have been added to QFuture* classes for
checking if pause/suspension is still in progress or it already took
effect. To keep the naming more consistent, renamed:

 - setPaused() -> setSuspended()
 - pause() -> suspend()
 - togglePaused() -> toggleSuspended()
 - QFutureWatcher::paused() -> QFutureWatcher::suspending()

Note that QFuture*::isPaused() now corresponds to (isSuspending() ||
isSuspended()).

[ChangeLog][Deprecation Notice] Deprecated pause-related APIs of
QFuture and QFutureWatcher. Added alternatives having "suspend" in
the name instead.

Change-Id: Ibeb75017a118401d64d18b72fb95d78e28c4661c
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

2 files changed, 13 insertions, 8 deletions

diff --git a/src/concurrent/qtconcurrentthreadengine.cpp b/src/concurrent/qtconcurrentthreadengine.cpp
index 7ea606f60b..2c6e052621 100644
--- a/src/concurrent/qtconcurrentthreadengine.cpp
+++ b/src/concurrent/qtconcurrentthreadengine.cpp
@@ -219,9 +219,9 @@ void ThreadEngineBase::acquireBarrierSemaphore()
     barrier.acquire();
 }
 
-void ThreadEngineBase::reportIfPausedDone() const
+void ThreadEngineBase::reportIfSuspensionDone() const
 {
-    if (futureInterface && futureInterface->isPaused())
+    if (futureInterface && futureInterface->isSuspending())
         futureInterface->reportSuspended();
 }
 
@@ -313,11 +313,11 @@ void ThreadEngineBase::run() // implements QRunnable.
             if (threadThrottleExit()) {
                 return;
             } else {
-                // If the last worker thread is throttled and the state is paused,
-                // it means that pause has been requested, and it is already
+                // If the last worker thread is throttled and the state is "suspending",
+                // it means that suspension has been requested, and it is already
                 // in effect (because all previous threads have already exited).
                 // Report the "Suspended" state.
-                reportIfPausedDone();
+                reportIfSuspensionDone();
             }
         }
 
diff --git a/src/concurrent/qtconcurrentthreadengine.h b/src/concurrent/qtconcurrentthreadengine.h
index 4e7e8d0b81..82bff5fb3a 100644
--- a/src/concurrent/qtconcurrentthreadengine.h
+++ b/src/concurrent/qtconcurrentthreadengine.h
@@ -99,14 +99,19 @@ public:
     void setProgressValue(int progress);
     void setProgressRange(int minimum, int maximum);
     void acquireBarrierSemaphore();
-    void reportIfPausedDone() const;
+    void reportIfSuspensionDone() const;
 
 protected: // The user overrides these:
     virtual void start() {}
     virtual void finish() {}
     virtual ThreadFunctionResult threadFunction() { return ThreadFinished; }
-    virtual bool shouldStartThread() { return futureInterface ? !futureInterface->isPaused() : true; }
-    virtual bool shouldThrottleThread() { return futureInterface ? futureInterface->isPaused() : false; }
+    virtual bool shouldStartThread() { return !shouldThrottleThread(); }
+    virtual bool shouldThrottleThread()
+    {
+        return futureInterface ? (futureInterface->isSuspending() || futureInterface->isSuspended())
+                               : false;
+    }
+
 private:
     bool startThreadInternal();
     void startThreads();