Flakiness debugging

DataDog · Dec 20, 2023 · 9dba020 · 9dba020
1 parent 01cb735
commit 9dba020
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Showing 4 changed files with 37 additions and 0 deletions.
diff --git a/ext/ddtrace_profiling_native_extension/heap_recorder.c b/ext/ddtrace_profiling_native_extension/heap_recorder.c
@@ -333,6 +333,24 @@ void heap_recorder_testonly_assert_hash_matches(ddog_prof_Slice_Location locatio
   }
 }
 
+int st_object_records_debug(DDTRACE_UNUSED st_data_t key, st_data_t value, DDTRACE_UNUSED st_data_t extra) {
+  object_record *record = (object_record*) value;
+  VALUE ref;
+  if (!ruby_ref_from_id(LONG2NUM(record->obj_id), &ref)) {
+    return ST_CONTINUE;
+  }
+
+  heap_frame top_frame = record->heap_record->stack->frames[0];
+  VALUE str = rb_sprintf("obj_id=%ld weight=%d location=%s:%d object=%+"PRIsVALUE, record->obj_id, record->object_data.weight, top_frame.filename, (int) top_frame.line, ref);
+  fprintf(stderr, "%s\n", RSTRING_PTR(str));
+  return ST_CONTINUE;
+}
+
+void heap_recorder_testonly_debug(heap_recorder *heap_recorder) {
+  fprintf(stderr, "object records:\n");
+  st_foreach(heap_recorder->object_records, st_object_records_debug, (st_data_t) NULL);
+}
+
 // ==========================
 // Heap Recorder Internal API
 // ==========================

diff --git a/ext/ddtrace_profiling_native_extension/heap_recorder.h b/ext/ddtrace_profiling_native_extension/heap_recorder.h
@@ -106,3 +106,5 @@ bool heap_recorder_for_each_live_object(
 // Assert internal hashing logic is valid for the provided locations and its
 // corresponding internal representations in heap recorder.
 void heap_recorder_testonly_assert_hash_matches(ddog_prof_Slice_Location locations);
+
+void heap_recorder_testonly_debug(heap_recorder *heap_recorder);
diff --git a/ext/ddtrace_profiling_native_extension/stack_recorder.c b/ext/ddtrace_profiling_native_extension/stack_recorder.c
@@ -234,6 +234,7 @@ static VALUE _native_track_object(DDTRACE_UNUSED VALUE _self, VALUE recorder_ins
 static VALUE _native_check_heap_hashes(DDTRACE_UNUSED VALUE _self, VALUE locations);
 static VALUE _native_start_fake_slow_heap_serialization(DDTRACE_UNUSED VALUE _self, VALUE recorder_instance);
 static VALUE _native_end_fake_slow_heap_serialization(DDTRACE_UNUSED VALUE _self, VALUE recorder_instance);
+static VALUE _native_debug_heap_recorder(DDTRACE_UNUSED VALUE _self, VALUE recorder_instance);
 
 
 void stack_recorder_init(VALUE profiling_module) {
@@ -264,6 +265,8 @@ void stack_recorder_init(VALUE profiling_module) {
       _native_start_fake_slow_heap_serialization, 1);
   rb_define_singleton_method(testing_module, "_native_end_fake_slow_heap_serialization",
       _native_end_fake_slow_heap_serialization, 1);
+  rb_define_singleton_method(testing_module, "_native_debug_heap_recorder",
+      _native_debug_heap_recorder, 1);
 
   ok_symbol = ID2SYM(rb_intern_const("ok"));
   error_symbol = ID2SYM(rb_intern_const("error"));
@@ -840,3 +843,14 @@ static VALUE _native_end_fake_slow_heap_serialization(DDTRACE_UNUSED VALUE _self
 
   return Qnil;
 }
+
+// This method exists only to enable testing Datadog::Profiling::StackRecorder behavior using RSpec.
+// It SHOULD NOT be used for other purposes.
+static VALUE _native_debug_heap_recorder(DDTRACE_UNUSED VALUE _self, VALUE recorder_instance) {
+  struct stack_recorder_state *state;
+  TypedData_Get_Struct(recorder_instance, struct stack_recorder_state, &stack_recorder_typed_data, state);
+
+  heap_recorder_testonly_debug(state->heap_recorder);
+
+  return Qnil;
+}
diff --git a/spec/datadog/profiling/stack_recorder_spec.rb b/spec/datadog/profiling/stack_recorder_spec.rb
@@ -403,6 +403,9 @@ def sample_allocation(obj)
           # We sample from 2 distinct locations
           expect(heap_samples.size).to eq(2)
 
+          # FIXME: Remove, this is just for debugging purposes
+          described_class::Testing._native_debug_heap_recorder(stack_recorder)
+
           sum_heap_samples = 0
           heap_samples.each { |s| sum_heap_samples += s.values[:'heap-live-samples'] }
           expect(sum_heap_samples).to eq([a_string, an_array, a_hash].size * sample_rate)