Fix VibratorCallbackSchedulerTest flakiness

Add test timeout to wait for scheduler to trigger callbacks before
failing.

Also update scheduled callback durations to reduce flakiness.

Bug: 293623689
Test: atest VibratorCallbackSchedulerTest
Change-Id: I49a9cae3f1622a4902ae9e56b37892060eba5c91
diff --git a/services/vibratorservice/test/VibratorCallbackSchedulerTest.cpp b/services/vibratorservice/test/VibratorCallbackSchedulerTest.cpp
index 4c0910a..106ab9e 100644
--- a/services/vibratorservice/test/VibratorCallbackSchedulerTest.cpp
+++ b/services/vibratorservice/test/VibratorCallbackSchedulerTest.cpp
@@ -38,6 +38,9 @@
 
 // -------------------------------------------------------------------------------------------------
 
+// Delay allowed for the scheduler to process callbacks during this test.
+static const auto TEST_TIMEOUT = 50ms;
+
 class VibratorCallbackSchedulerTest : public Test {
 public:
     void SetUp() override {
@@ -67,46 +70,51 @@
         return std::vector<int32_t>(mExpiredCallbacks);
     }
 
-    bool waitForCallbacks(uint32_t callbackCount, milliseconds timeout) {
-        time_point<steady_clock> expiration = steady_clock::now() + timeout;
+    int32_t waitForCallbacks(int32_t callbackCount, milliseconds timeout) {
+        time_point<steady_clock> expiration = steady_clock::now() + timeout + TEST_TIMEOUT;
+        int32_t expiredCallbackCount = 0;
         while (steady_clock::now() < expiration) {
             std::lock_guard<std::mutex> lock(mMutex);
-            if (callbackCount <= mExpiredCallbacks.size()) {
-                return true;
+            expiredCallbackCount = mExpiredCallbacks.size();
+            if (callbackCount <= expiredCallbackCount) {
+                return expiredCallbackCount;
             }
             mCondition.wait_until(mMutex, expiration);
         }
-        return false;
+        return expiredCallbackCount;
     }
 };
 
 // -------------------------------------------------------------------------------------------------
 
 TEST_F(VibratorCallbackSchedulerTest, TestScheduleRunsOnlyAfterDelay) {
-    mScheduler->schedule(createCallback(1), 15ms);
+    time_point<steady_clock> startTime = steady_clock::now();
+    mScheduler->schedule(createCallback(1), 50ms);
 
-    // Not triggered before delay.
-    ASSERT_FALSE(waitForCallbacks(1, 10ms));
-    ASSERT_TRUE(getExpiredCallbacks().empty());
+    ASSERT_EQ(1, waitForCallbacks(1, 50ms));
+    time_point<steady_clock> callbackTime = steady_clock::now();
 
-    ASSERT_TRUE(waitForCallbacks(1, 10ms));
+    // Callback happened at least 50ms after the beginning of the test.
+    ASSERT_TRUE(startTime + 50ms <= callbackTime);
     ASSERT_THAT(getExpiredCallbacks(), ElementsAre(1));
 }
 
 TEST_F(VibratorCallbackSchedulerTest, TestScheduleMultipleCallbacksRunsInDelayOrder) {
-    mScheduler->schedule(createCallback(1), 10ms);
-    mScheduler->schedule(createCallback(2), 5ms);
-    mScheduler->schedule(createCallback(3), 1ms);
+    // Schedule first callbacks long enough that all 3 will be scheduled together and run in order.
+    mScheduler->schedule(createCallback(1), 50ms);
+    mScheduler->schedule(createCallback(2), 40ms);
+    mScheduler->schedule(createCallback(3), 10ms);
 
-    ASSERT_TRUE(waitForCallbacks(3, 15ms));
+    ASSERT_EQ(3, waitForCallbacks(3, 50ms));
     ASSERT_THAT(getExpiredCallbacks(), ElementsAre(3, 2, 1));
 }
 
 TEST_F(VibratorCallbackSchedulerTest, TestDestructorDropsPendingCallbacksAndKillsThread) {
-    mScheduler->schedule(createCallback(1), 5ms);
+    // Schedule callback long enough that scheduler will be destroyed while it's still scheduled.
+    mScheduler->schedule(createCallback(1), 50ms);
     mScheduler.reset(nullptr);
 
-    // Should time out waiting for callback to run.
-    ASSERT_FALSE(waitForCallbacks(1, 10ms));
+    // Should timeout waiting for callback to run.
+    ASSERT_EQ(0, waitForCallbacks(1, 50ms));
     ASSERT_TRUE(getExpiredCallbacks().empty());
 }