Reinvocation only occurs locally if more than a minute of execution time remains (#188)

* Changing re-invocation calculation to reschedule after a minute elapses

* Factor in 60 second guarantee of execution time

* Account for negative callback time

Author: John Tompkins

src/main/java/com/amazonaws/cloudformation/LambdaWrapper.java

@@ -81,6 +81,7 @@
 public abstract class LambdaWrapper<ResourceT, CallbackT> implements RequestStreamHandler {
 
     private static final List<Action> MUTATING_ACTIONS = Arrays.asList(Action.CREATE, Action.DELETE, Action.UPDATE);
+    private static final int INVOCATION_TIMEOUT_MS = 60000;
 
     protected final Serializer serializer;
     protected LoggerProxy loggerProxy;
@@ -557,8 +558,10 @@ private boolean scheduleReinvocation(final HandlerRequest<ResourceT, CallbackT>
         // has enough runtime (with 20% buffer), we can reschedule from a thread wait
         // otherwise we re-invoke through CloudWatchEvents which have a granularity of
         // minutes
-        if ((handlerResponse.getCallbackDelaySeconds() < 60)
-            && (context.getRemainingTimeInMillis() / 1000d) > handlerResponse.getCallbackDelaySeconds() * 1.2) {
+        // This also guarantees a maximum of a minute of execution time per local
+        // reinvocation
+        if ((handlerResponse.getCallbackDelaySeconds() < 60) && context
+            .getRemainingTimeInMillis() > Math.abs(handlerResponse.getCallbackDelaySeconds()) * 1200 + INVOCATION_TIMEOUT_MS) {
             log(String.format("Scheduling re-invoke locally after %s seconds, with Context {%s}",
                 handlerResponse.getCallbackDelaySeconds(), reinvocationContext.toString()));
             sleepUninterruptibly(handlerResponse.getCallbackDelaySeconds(), TimeUnit.SECONDS);
@@ -567,7 +570,7 @@ private boolean scheduleReinvocation(final HandlerRequest<ResourceT, CallbackT>
 
         log(String.format("Scheduling re-invoke with Context {%s}", reinvocationContext.toString()));
         try {
-            int callbackDelayMinutes = handlerResponse.getCallbackDelaySeconds() / 60;
+            int callbackDelayMinutes = Math.abs(handlerResponse.getCallbackDelaySeconds() / 60);
             this.scheduler.rescheduleAfterMinutes(context.getInvokedFunctionArn(), callbackDelayMinutes, request);
         } catch (final Throwable e) {
             this.log(String.format("Failed to schedule re-invoke, caused by %s", e.toString()));

src/main/java/com/amazonaws/cloudformation/proxy/ProgressEvent.java

@@ -57,8 +57,7 @@ public class ProgressEvent<ResourceT, CallbackT> {
 
     /**
      * A callback will be scheduled with an initial delay of no less than the number
-     * of seconds specified in the progress event. Set this value to <= 0 to
-     * indicate no callback should be made.
+     * of seconds specified in the progress event.
      */
     private int callbackDelaySeconds;
 

src/test/java/com/amazonaws/cloudformation/LambdaWrapperTest.java

@@ -846,7 +846,6 @@ public void invokeHandler_withDefaultInjection_returnsInProgress() throws IOExce
         try (final InputStream in = loadRequestStream("create.request.json");
             final OutputStream out = new ByteArrayOutputStream()) {
             final Context context = getLambdaContext();
-
             wrapper.handleRequest(in, out, context);
 
             // verify output response
@@ -1008,7 +1007,8 @@ public void invokeHandler_localReinvokeWithSufficientRemainingTime() throws IOEx
             final OutputStream out = new ByteArrayOutputStream()) {
 
             final Context context = getLambdaContext();
-            when(context.getRemainingTimeInMillis()).thenReturn(60000); // ~1 minute
+            // give enough time to invoke again locally
+            when(context.getRemainingTimeInMillis()).thenReturn(75000);
 
             wrapper.handleRequest(in, out, context);
 
@@ -1100,8 +1100,9 @@ public void invokeHandler_localReinvokeWithSufficientRemainingTimeForFirstIterat
             final OutputStream out = new ByteArrayOutputStream()) {
 
             final Context context = getLambdaContext();
-            when(context.getRemainingTimeInMillis()).thenReturn(60000, // 60 seconds
-                6000); // 6 seconds is <= 1.2 * 5 seconds requested, causes CWE reinvoke
+            // first remaining time allows for a local reinvocation, whereas the latter will
+            // force the second invocation to be via CWE
+            when(context.getRemainingTimeInMillis()).thenReturn(70000, 5000);
 
             wrapper.handleRequest(in, out, context);