[heap] fix invocation of NearHeapLimitCallback

This patch makes sure that NearHeapLimitCallback can invoke
operations that trigger garbage collections. In addition
this adds code to make the tracers aware of NearHeapLimitCallback.

Bug: v8:12777
Change-Id: I959a23a3e0224ba536cb18b14933813e56fc5292
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3575468Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Joyee Cheung <joyee@igalia.com>
Cr-Commit-Position: refs/heads/main@{#79934}

src/heap/heap.cc

@@ -4342,6 +4342,9 @@ void Heap::AutomaticallyRestoreInitialHeapLimit(double threshold_percent) {
 
 bool Heap::InvokeNearHeapLimitCallback() {
   if (near_heap_limit_callbacks_.size() > 0) {
+    AllowGarbageCollection allow_gc;
+    TRACE_GC(tracer(), GCTracer::Scope::HEAP_EXTERNAL_NEAR_HEAP_LIMIT);
+    VMState<EXTERNAL> callback_state(isolate());
     HandleScope scope(isolate());
     v8::NearHeapLimitCallback callback =
         near_heap_limit_callbacks_.back().first;

src/init/heap-symbols.h

@@ -527,6 +527,7 @@
   F(HEAP_EPILOGUE_REDUCE_NEW_SPACE)                  \
   F(HEAP_EPILOGUE_SAFEPOINT)                         \
   F(HEAP_EXTERNAL_EPILOGUE)                          \
+  F(HEAP_EXTERNAL_NEAR_HEAP_LIMIT)                   \
   F(HEAP_EXTERNAL_PROLOGUE)                          \
   F(HEAP_EXTERNAL_WEAK_GLOBAL_HANDLES)               \
   F(HEAP_PROLOGUE)                                   \

test/cctest/heap/test-heap.cc

@@ -1272,6 +1272,62 @@ UNINITIALIZED_TEST(Regress10843) {
   isolate->Dispose();
 }
 
+size_t near_heap_limit_invocation_count = 0;
+size_t InvokeGCNearHeapLimitCallback(void* data, size_t current_heap_limit,
+                                     size_t initial_heap_limit) {
+  near_heap_limit_invocation_count++;
+  if (near_heap_limit_invocation_count > 1) {
+    // We are already in a GC triggered in this callback, raise the limit
+    // to avoid an OOM.
+    return current_heap_limit * 5;
+  }
+
+  DCHECK_EQ(near_heap_limit_invocation_count, 1);
+  // Operations that may cause GC (e.g. taking heap snapshots) in the
+  // near heap limit callback should not hit the AllowGarbageCollection
+  // assertion.
+  static_cast<v8::Isolate*>(data)->GetHeapProfiler()->TakeHeapSnapshot();
+  return current_heap_limit * 5;
+}
+
+UNINITIALIZED_TEST(Regress12777) {
+  v8::Isolate::CreateParams create_params;
+  create_params.constraints.set_max_old_generation_size_in_bytes(10 * i::MB);
+  create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
+  v8::Isolate* isolate = v8::Isolate::New(create_params);
+
+  isolate->AddNearHeapLimitCallback(InvokeGCNearHeapLimitCallback, isolate);
+
+  {
+    v8::Isolate::Scope isolate_scope(isolate);
+
+    Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
+    // Allocate data to trigger the NearHeapLimitCallback.
+    HandleScope scope(i_isolate);
+    int length = 2 * i::MB / i::kTaggedSize;
+    std::vector<Handle<FixedArray>> arrays;
+    for (int i = 0; i < 5; i++) {
+      arrays.push_back(i_isolate->factory()->NewFixedArray(length));
+    }
+    CcTest::CollectAllGarbage(i_isolate);
+    for (int i = 0; i < 5; i++) {
+      arrays.push_back(i_isolate->factory()->NewFixedArray(length));
+    }
+    CcTest::CollectAllGarbage(i_isolate);
+    for (int i = 0; i < 5; i++) {
+      arrays.push_back(i_isolate->factory()->NewFixedArray(length));
+    }
+
+    // The work done above should trigger the heap limit callback at least
+    // twice to prove that the callback can raise the limit in the second
+    // or later calls to avoid an OOM.
+    CHECK_GE(near_heap_limit_invocation_count, 2);
+  }
+
+  isolate->GetHeapProfiler()->DeleteAllHeapSnapshots();
+  isolate->Dispose();
+}
+
 #ifndef V8_LITE_MODE
 
 TEST(TestOptimizeAfterBytecodeFlushingCandidate) {