Prioritizing input and compositor tasks in the blink scheduler.

Source/platform/scheduler/SchedulerTest.cpp

Index: Source/platform/scheduler/SchedulerTest.cpp
diff --git a/Source/platform/scheduler/SchedulerTest.cpp b/Source/platform/scheduler/SchedulerTest.cpp
index 0b35485e9232fb0518f3c5ef9e964dca34c5de72..9e2d54846c3ecd775eb71c1bc7f41924bc7ba16b 100644
--- a/Source/platform/scheduler/SchedulerTest.cpp
+++ b/Source/platform/scheduler/SchedulerTest.cpp
@@ -10,9 +10,13 @@
 #include "public/platform/Platform.h"
 #include "public/platform/WebThread.h"
 
+#include <gmock/gmock.h>
 #include <gtest/gtest.h>
+#include <string>
+#include <vector>
 
 using blink::Scheduler;
+using namespace std;
 
 namespace {
 
@@ -131,9 +135,24 @@ public:
         m_platformSupport.runPendingTasks();
     }
 
+    void appendToVector(string value)
+    {
+        m_order.push_back(value);
+    }
+
+    void appendToVectorReentrant(int count)
+    {
+        m_reentrantOrder.push_back(count);
+
+        if (count < 4)
+            m_scheduler->postTask(FROM_HERE, bind(&SchedulerTest::appendToVectorReentrant, this, count + 1));
+    }
+
 protected:
     SchedulerTestingPlatformSupport m_platformSupport;
     Scheduler* m_scheduler;
+    std::vector<string> m_order;
+    std::vector<int> m_reentrantOrder;
 };
 
 void orderedTestTask(int value, int* result)
@@ -173,6 +192,17 @@ TEST_F(SchedulerTest, TestPostMixedTaskTypes)
     EXPECT_EQ(15, result);
 }
 
+TEST_F(SchedulerTest, TestTasksExecutedOnShutdown)
+{
+    int result = 0;
+    m_scheduler->postTask(FROM_HERE, bind(&unorderedTestTask, 1, &result));
+    m_scheduler->postInputTask(FROM_HERE, bind(&unorderedTestTask, 2, &result));
+    m_scheduler->postCompositorTask(FROM_HERE, bind(&unorderedTestTask, 4, &result));
+    m_scheduler->postTask(FROM_HERE, bind(&unorderedTestTask, 8, &result));
+    Scheduler::shutdown();

[Sami, 2014/08/07 15:51:27]

Thanks for adding this test. Can you add a re-entrant one here too since those
are the tricky ones?

[alexclarke, 2014/08/07 16:01:30]

Done.

+    EXPECT_EQ(15, result);
+}
+
 int s_sharedTimerTickCount;
 void sharedTimerFunction()
 {
@@ -209,4 +239,27 @@ TEST_F(SchedulerTest, TestIdleTask)
     EXPECT_EQ(4, result);
 }
 
+TEST_F(SchedulerTest, TestTaskPrioritization)
+{
+    m_scheduler->postTask(FROM_HERE, bind(&SchedulerTest::appendToVector, this, string("L1")));
+    m_scheduler->postTask(FROM_HERE, bind(&SchedulerTest::appendToVector, this, string("L2")));
+    m_scheduler->postInputTask(FROM_HERE, bind(&SchedulerTest::appendToVector, this, string("I1")));
+    m_scheduler->postInputTask(FROM_HERE, bind(&SchedulerTest::appendToVector, this, string("I2")));
+    m_scheduler->postCompositorTask(FROM_HERE, bind(&SchedulerTest::appendToVector, this, string("C1")));
+    m_scheduler->postCompositorTask(FROM_HERE, bind(&SchedulerTest::appendToVector, this, string("C2")));
+
+    runPendingTasks();
+    EXPECT_THAT(m_order, testing::ElementsAre(
+        string("I1"), string("I2"), string("C1"), string("C2"), string("L1"), string("L2")));
+}
+
+TEST_F(SchedulerTest, TestRentrantTask)
+{
+    m_scheduler->postTask(FROM_HERE, bind(&SchedulerTest::appendToVectorReentrant, this, 0));
+    runPendingTasks();
+
+    EXPECT_THAT(m_reentrantOrder, testing::ElementsAre(0, 1, 2, 3, 4));
+}
+
+
 } // namespace