Backed out changeset 217ad633fbf7 (bug 1379146) for failing spidermonkey cgc's js/src/jit-test/tests/debug/inspect-wrapped-promise.js on Linux x64 debug. r=backout on a CLOSED TREE

js/src/vm/HelperThreads.cpp

@@ -1233,7 +1233,9 @@ GlobalHelperThreadState::scheduleCompressionTasks(const AutoLockHelperThreadStat
 
     for (size_t i = 0; i < pending.length(); i++) {
         if (pending[i]->shouldStart()) {
-            worklist.infallibleAppend(Move(pending[i]));
+            // OOMing during appending results in the task not being scheduled
+            // and deleted.
+            Unused << worklist.append(Move(pending[i]));
             remove(pending, &i);
         }
     }
@@ -1953,7 +1955,12 @@ HelperThread::handleCompressionWorkload(AutoLockHelperThreadState& locked)
         task->work();
     }
 
-    HelperThreadState().compressionFinishedList(locked).infallibleAppend(Move(task));
+    {
+        AutoEnterOOMUnsafeRegion oomUnsafe;
+        if (!HelperThreadState().compressionFinishedList(locked).append(Move(task)))
+            oomUnsafe.crash("handleCompressionWorkload");
+    }
+
     currentTask.reset();
 
     // Notify the active thread in case it is waiting for the compression to finish.
@@ -1966,25 +1973,6 @@ js::EnqueueOffThreadCompression(JSContext* cx, UniquePtr<SourceCompressionTask>
     AutoLockHelperThreadState lock;
 
     auto& pending = HelperThreadState().compressionPendingList(lock);
-
-    // Ensure there is enough space in the vectors to move the task from one
-    // state to another without having OOM on the helper threads.
-    size_t transitionSpace = pending.length() + 1;
-    auto& worklist = HelperThreadState().compressionWorklist(lock);
-    if (!worklist.reserve(worklist.length() + transitionSpace)) {
-        if (!cx->helperThread())
-            ReportOutOfMemory(cx);
-        return false;
-    }
-
-    transitionSpace += worklist.length();
-    auto& finished = HelperThreadState().compressionFinishedList(lock);
-    if (!finished.reserve(finished.length() + transitionSpace)) {
-        if (!cx->helperThread())
-            ReportOutOfMemory(cx);
-        return false;
-    }
-
     if (!pending.append(Move(task))) {
         if (!cx->helperThread())
             ReportOutOfMemory(cx);