Page History

...

• Awaitility -- await for some state to change
• CountDownLatch -- coordinate between VMs and/or threads
• Mockito Spy and Verify
  • Verify with timeout can be used instead of Awaitility
• Wrap anything with spy or use it to implement a callback such as CacheListener
• Verify is used to validate number of invocations with optional timeout
• All timeouts should use GeodeAwaitility.getTimeout()
• Possible exceptions to the rule
• Busy waiting in loops (Awaitility is usually a better option than custom looping)
• Slow receiver/listener type testing (there’s probably a better way to do it)

Examples: SleepDistributedTest, MultiThreadedIntegrationTest

It’s not polite to eat all the exceptions...

...

• Use ExecutorServiceRule or DistributedExcutorServiceRule
• Provides debugging support for hangs
• Cleans up threads on tear down
• Test task code should be interruptible
• Use Future or CompletableFuture for submitted runnable/callable
• Always invoke get() on any Future or CompletableFuture

Examples: AsyncErrorHandlingTest, ExecutorSyncHangIntegrationTest, ExecutorLockHangIntegrationTest, ExecutorErrorHandlingDistributedTest

Handling exceptions in callbacks

• Avoid catching exception and setting some test state to check later
• Use ErrorCollector in unit and integration tests
• Use SharedErrorCollector in distributed tests

Examples: AsyncErrorHandlingIntegrationTest, AsyncErrorHandlingDistributedTest

AsyncInvocation usage

• Timeout now gets a remote stack trace to use as the cause and dumps stack traces for that JVM’s threads
• Always use await() or get()
• Both check and throw any remote exceptions
• Both use GeodeAwaitility Timeout and will throw TimeoutException if it’s exceeded
• Use await() for Void types and get() when expecting a non-null value

Examples: AsyncInvocationDistributedTest, AsyncInvocationHangDistributedTest

Know your DUnit Rules

• DistributedRule -- simply launches DUnit and greps for suspect strings after each test method
• DistributedExecutorServiceRule -- provides an ExecutorService for all VMs
• DistributedRestoreSystemProperties -- restores system properties in all VMs
• SharedCountersRule -- shares counters across all VMs
• SharedErrorCollector -- shares one JUnit ErrorCollector across all VMs

...