Generate renewal and expiry events

The android timer class was not generating timer events correctly. This caused
renewal and expiration events not to be sent. A strong pointer to the
timer thread was not held and this caused the android util timer
thread to exit after firing once. This is now addressed.

Bug: 8736545

Merge of https://widevine-internal-review.googlesource.com/#/c/5353/
from the Widevine CDM repository.

Change-Id: I2d904e55d4d10eacc1a51f1c6b5c1a267c92c8d8

libwvdrmengine/cdm/core/include/timer.h

@@ -34,7 +34,7 @@ class Timer {
   Timer();
   ~Timer();
 
-  void Start(TimerHandler *handler, uint32_t time_in_secs);
+  bool Start(TimerHandler *handler, uint32_t time_in_secs);
   void Stop();
   bool IsRunning();
 

libwvdrmengine/cdm/core/src/cdm_engine.cpp

@@ -101,6 +101,8 @@ CdmResponseType CdmEngine::CloseSession(const CdmSessionId& session_id) {
   }
 
   sessions_.erase(session_id);
+  if (sessions_.size() == 0)
+    DisablePolicyTimer();
   iter->second->DestroySession();
   delete iter->second;
   return NO_ERROR;

libwvdrmengine/cdm/core/test/timer_unittest.cpp

@@ -0,0 +1,54 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+
+#include "gtest/gtest.h"
+#include "timer.h"
+
+namespace wvcdm {
+
+class TestTimerHandler : public TimerHandler {
+ public:
+  TestTimerHandler() : timer_events_(0) {};
+  virtual ~TestTimerHandler() {};
+
+  virtual void OnTimerEvent() {
+    timer_events_++;
+  }
+
+  uint32_t GetTimerEvents() { return timer_events_; }
+  void ResetTimerEvents() { timer_events_ = 0; }
+
+ private:
+  uint32_t timer_events_;
+};
+
+TEST(TimerTest, ParametersCheck) {
+  Timer timer;
+  EXPECT_FALSE(timer.Start(NULL, 10));
+
+  TestTimerHandler handler;
+  EXPECT_FALSE(timer.Start(&handler, 0));
+}
+
+TEST(TimerTest, TimerCheck) {
+  TestTimerHandler handler;
+  Timer timer;
+  uint32_t duration = 10;
+
+  EXPECT_EQ(static_cast<uint32_t>(0), handler.GetTimerEvents());
+  EXPECT_FALSE(timer.IsRunning());
+
+  EXPECT_TRUE(timer.Start(&handler, 1));
+  EXPECT_TRUE(timer.IsRunning());
+  sleep(duration);
+
+  EXPECT_TRUE(duration-1 <= handler.GetTimerEvents());
+  EXPECT_TRUE(handler.GetTimerEvents() <= duration+1);
+  timer.Stop();
+  EXPECT_FALSE(timer.IsRunning());
+  sleep(duration);
+
+  EXPECT_TRUE(duration-1 <= handler.GetTimerEvents());
+  EXPECT_TRUE(handler.GetTimerEvents() <= duration+1);
+}
+
+}