Optimize: Use a plain non-recursive QMutex in the QResourceManager.

The overhead of a read/write lock should not be required for such
small critical sections. It will also allow us to cleanup the
code a bit more. Already, the code changes lead to a small improvement

before:
RESULT : tst_QResourcesManager::benchmarkAllocateSmallResources():
     46,552,767 instructions per iteration (total: 46,552,767, iterations: 1)
RESULT : tst_QResourcesManager::benchmarkAllocateBigResources():
     48,338,703 instructions per iteration (total: 48,338,703, iterations: 1)

after:
RESULT : tst_QResourcesManager::benchmarkAllocateSmallResources():
     44,848,672 instructions per iteration (total: 44,848,672, iterations: 1)
RESULT : tst_QResourcesManager::benchmarkAllocateBigResources():
     46,634,161 instructions per iteration (total: 46,634,161, iterations: 1)

Change-Id: I8ef0aa52be3caf8b4c8691579677f693a054565c
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

3 files changed, 12 insertions, 17 deletions

diff --git a/tests/auto/core/arrayresourcesmanager/dynamicarraypolicy/tst_dynamicarraypolicy.cpp b/tests/auto/core/arrayresourcesmanager/dynamicarraypolicy/tst_dynamicarraypolicy.cpp
index 1b41055b4..90b48ba10 100644
--- a/tests/auto/core/arrayresourcesmanager/dynamicarraypolicy/tst_dynamicarraypolicy.cpp
+++ b/tests/auto/core/arrayresourcesmanager/dynamicarraypolicy/tst_dynamicarraypolicy.cpp
@@ -71,7 +71,7 @@ public:
     tst_ArrayResource() : m_value(0)
     {}
 
-    int m_value;
+    QAtomicInt m_value;
 };
 
 typedef Qt3D::QHandle<tst_ArrayResource> tHandle;
@@ -298,8 +298,7 @@ protected:
             tst_ArrayResource *r = m_manager->getOrCreateResource(i);
             i++;
             QVERIFY(r != Q_NULLPTR);
-            Manager::WriteLocker lock(m_manager);
-            r->m_value++;
+            r->m_value.fetchAndAddOrdered(+1);
         }
         qDebug() << QThread::currentThread() << "Done";
     }
@@ -370,9 +369,8 @@ protected:
         while (i < max) {
             tst_ArrayResource *r = m_manager->getOrCreateResource(i);
             QVERIFY(r != Q_NULLPTR);
-            Manager::WriteLocker lock(m_manager);
-            r->m_value++;
-            if (r->m_value > m_releaseAbove)
+            int oldValue = r->m_value.fetchAndAddOrdered(+1);
+            if (oldValue == m_releaseAbove)
                 m_manager->releaseResource(i);
             i++;
         }
diff --git a/tests/auto/core/arrayresourcesmanager/preallocatedarraypolicy/tst_preallocatedarraypolicy.cpp b/tests/auto/core/arrayresourcesmanager/preallocatedarraypolicy/tst_preallocatedarraypolicy.cpp
index b9c18d95e..ffdccf847 100644
--- a/tests/auto/core/arrayresourcesmanager/preallocatedarraypolicy/tst_preallocatedarraypolicy.cpp
+++ b/tests/auto/core/arrayresourcesmanager/preallocatedarraypolicy/tst_preallocatedarraypolicy.cpp
@@ -71,7 +71,7 @@ public:
     tst_ArrayResource() : m_value(0)
     {}
 
-    int m_value;
+    QAtomicInt m_value;
 };
 
 typedef Qt3D::QHandle<tst_ArrayResource> tHandle;
@@ -298,7 +298,7 @@ protected:
             tst_ArrayResource *r = m_manager->getOrCreateResource(i);
             i++;
             QVERIFY(r != Q_NULLPTR);
-            Manager::WriteLocker lock(m_manager);
+            Manager::Locker lock(m_manager);
             r->m_value++;
         }
         qDebug() << QThread::currentThread() << "Done";
@@ -370,9 +370,8 @@ protected:
         while (i < max) {
             tst_ArrayResource *r = m_manager->getOrCreateResource(i);
             QVERIFY(r != Q_NULLPTR);
-            Manager::WriteLocker lock(m_manager);
-            r->m_value++;
-            if (r->m_value > m_releaseAbove)
+            int oldValue = r->m_value.fetchAndAddOrdered(+1);
+            if (oldValue == m_releaseAbove)
                 m_manager->releaseResource(i);
             i++;
         }
diff --git a/tests/auto/core/listresourcesmanager/tst_listresourcesmanager.cpp b/tests/auto/core/listresourcesmanager/tst_listresourcesmanager.cpp
index b5bee9b88..abf695093 100644
--- a/tests/auto/core/listresourcesmanager/tst_listresourcesmanager.cpp
+++ b/tests/auto/core/listresourcesmanager/tst_listresourcesmanager.cpp
@@ -71,7 +71,7 @@ public:
     tst_ListResource() : m_value(0)
     {}
 
-    int m_value;
+    QAtomicInt m_value;
 };
 
 typedef Qt3D::QHandle<tst_ListResource> tHandle;
@@ -298,8 +298,7 @@ protected:
             tst_ListResource *r = m_manager->getOrCreateResource(i);
             i++;
             QVERIFY(r != Q_NULLPTR);
-            Manager::WriteLocker lock(m_manager);
-            r->m_value++;
+            r->m_value.fetchAndAddOrdered(+1);
         }
         qDebug() << QThread::currentThread() << "Done";
     }
@@ -371,9 +370,8 @@ protected:
         while (i < max) {
             tst_ListResource *r = m_manager->getOrCreateResource(i);
             QVERIFY(r != Q_NULLPTR);
-            Manager::WriteLocker lock(m_manager);
-            r->m_value++;
-            if (r->m_value > m_releaseAbove)
+            int oldValue = r->m_value.fetchAndAddOrdered(+1);
+            if (oldValue == m_releaseAbove)
                 m_manager->releaseResource(i);
             i++;
         }