Fixes TEST crash triggered by webrtc-codereview.appspot.com/268014.

Review URL: http://webrtc-codereview.appspot.com/280005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@980 4adac7df-926f-26a2-2b94-8c16560cd09d

src/system_wrappers/interface/cpu_wrapper.h

@@ -32,6 +32,12 @@ public:
     // Note that the pointer passed as cpu_usage is redirected to a local member
     // of the CPU wrapper.
     // numCores is the number of cores in the cpu_usage array.
+    // Note: on some OSs this class is initialized lazy. This means that it
+    // might not yet be possible to retrieve any CPU metrics. When this happens
+    // the return value will be zero (indicating that there is not a failure),
+    // numCores will be 0 and cpu_usage will be set to NULL (indicating that
+    // no metrics are available yet). Once the initialization is completed,
+    // which can take in the order of seconds, CPU metrics can be retrieved.
     virtual WebRtc_Word32 CpuUsageMultiCore(WebRtc_UWord32& numCores,
                                             WebRtc_UWord32*& cpu_usage) = 0;
 

src/system_wrappers/source/cpu_windows.cc

@@ -35,11 +35,18 @@ WebRtc_Word32 CpuWindows::CpuUsage()
 }
 
 WebRtc_Word32 CpuWindows::CpuUsageMultiCore(WebRtc_UWord32& num_cores,
-                                                  WebRtc_UWord32*& cpu_usage)
+                                            WebRtc_UWord32*& cpu_usage)
 {
+    if (has_terminated_) {
+        num_cores = 0;
+        cpu_usage = NULL;
+        return -1;
+    }
     if (!has_initialized_)
     {
-        return -1;
+        num_cores = 0;
+        cpu_usage = NULL;
+        return 0;
     }
     num_cores = number_of_objects_ - 1;
     cpu_usage = cpu_usage_;
@@ -140,6 +147,7 @@ void CpuWindows::StartPollingCpu()
     if (!cpu_polling_thread->Start(dummy_id))
     {
         initialize_ = false;
+        has_terminated_ = true;
         assert(false);
     }
 }

src/system_wrappers/source/cpu_wrapper_unittest.cc

@@ -12,6 +12,7 @@
 
 #include "gtest/gtest.h"
 #include "system_wrappers/interface/cpu_info.h"
+#include "system_wrappers/interface/event_wrapper.h"
 #include "system_wrappers/interface/trace.h"
 
 using webrtc::CpuInfo;
@@ -28,18 +29,39 @@ TEST(CpuWrapperTest, Usage) {
   Trace::SetLevelFilter(webrtc::kTraceAll);
   printf("Number of cores detected:%u\n", CpuInfo::DetectNumberOfCores());
   CpuWrapper* cpu = CpuWrapper::CreateCpu();
-  WebRtc_UWord32 numCores;
+  ASSERT_TRUE(cpu != NULL);
-  WebRtc_UWord32* cores;
+  webrtc::EventWrapper* sleep_event = webrtc::EventWrapper::Create();
-  for (int i = 0; i < 10; i++) {
+  ASSERT_TRUE(sleep_event != NULL);
-    WebRtc_Word32 total = cpu->CpuUsageMultiCore(numCores, cores);
 
-    printf("\nNumCores:%d\n", numCores);
+  int num_iterations = 0;
-    printf("Total cpu:%d\n", total);
+  WebRtc_UWord32 num_cores = 0;
-
+  WebRtc_UWord32* cores = NULL;
-    for (WebRtc_UWord32 i = 0; i < numCores; i++) {
+  bool cpu_usage_available = cpu->CpuUsageMultiCore(num_cores, cores) != -1;
-      printf("Core:%u CPU:%u \n", i, cores[i]);
+  // Initializing the CPU measurements may take a couple of seconds on Windows.
+  // Since the initialization is lazy we need to wait until it is completed.
+  // Should not take more than 10000 ms.
+  while (cpu_usage_available && (++num_iterations < 10000)) {
+    if (cores != NULL) {
+      ASSERT_GT(num_cores, 0);
+      break;
     }
+    sleep_event->Wait(1);
+    cpu_usage_available = cpu->CpuUsageMultiCore(num_cores, cores) != -1;
   }
+  ASSERT_TRUE(cpu_usage_available);
+
+  const WebRtc_Word32 total = cpu->CpuUsageMultiCore(num_cores, cores);
+  ASSERT_TRUE(cores != NULL);
+  EXPECT_GT(num_cores, 0);
+  EXPECT_GE(total, 0);
+
+  printf("\nNumCores:%d\n", num_cores);
+  printf("Total cpu:%d\n", total);
+  for (WebRtc_UWord32 i = 0; i < num_cores; i++) {
+    printf("Core:%u CPU:%u \n", i, cores[i]);
+    EXPECT_LE(cores[i], total);
+  }
+
   delete cpu;
   Trace::ReturnTrace();
 };