getCpuGpuTime to return false when unavailable

This commit addresses crash issue in AUB standalone mode
when queue profiling is enabled on Linux platform.

Change-Id: Ie2d02093d3628efac3a8925890f22afd6a49469d

Author: smilczar

runtime/os_interface/linux/os_time_linux.cpp

@@ -125,6 +125,9 @@ bool OSTimeLinux::getGpuTimeSplitted(uint64_t *timestamp) {
 }
 
 bool OSTimeLinux::getCpuGpuTime(TimeStampData *pGpuCpuTime) {
+    if (nullptr == this->getGpuTime) {
+        return false;
+    }
     if (!(this->*getGpuTime)(&pGpuCpuTime->GPUTimeStamp)) {
         return false;
     }

runtime/os_interface/linux/os_time_linux.h

@@ -38,7 +38,7 @@ class OSTimeLinux : public OSTime {
     bool getCpuGpuTime(TimeStampData *pGpuCpuTime) override;
     typedef bool (OSTimeLinux::*TimestampFunction)(uint64_t *);
     void timestampTypeDetect();
-    TimestampFunction getGpuTime;
+    TimestampFunction getGpuTime = nullptr;
     bool getGpuTime32(uint64_t *timestamp);
     bool getGpuTime36(uint64_t *timestamp);
     bool getGpuTimeSplitted(uint64_t *timestamp);

unit_tests/os_interface/linux/os_time_test.cpp

@@ -148,6 +148,12 @@ TEST_F(DrmTimeTest, GIVENDrmWHENGetCpuGpuTimeTHENPassed) {
     delete pDrm;
 }
 
+TEST_F(DrmTimeTest, givenGetCpuGpuTimeWhenItIsUnavailableThenReturnFalse) {
+    TimeStampData CPUGPUTime = {0, 0};
+    auto error = osTime->getCpuGpuTime(&CPUGPUTime);
+    EXPECT_FALSE(error);
+}
+
 TEST_F(DrmTimeTest, GetCpuGpuTimeFails) {
     TimeStampData CPUGPUTime01 = {0, 0};
     auto pDrm = new DrmMockFail();