[vm/metrics] Ensure the metrics exposed by VM also include on-the-fly metrics

The lower-case "value()" metrics getter can only be used to obtain
metrics which are explicitly set by the VM.

The metrics we expose also include ones which are computed on-the-fly.
Those have to be accessed via "Value()".

Change-Id: I283c3c7c660d47c383b880b4bff6357a4dba9c01
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/123252
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>

runtime/vm/dart_api_impl.cc

@@ -1060,7 +1060,7 @@ DART_EXPORT bool Dart_IsVMFlagSet(const char* flag_name) {
 #if !defined(PRODUCT)
 #define VM_METRIC_API(type, variable, name, unit)                              \
   DART_EXPORT int64_t Dart_VM##variable##Metric() {                            \
-    return vm_metric_##variable.value();                                       \
+    return vm_metric_##variable.Value();                                       \
   }
 VM_METRIC_LIST(VM_METRIC_API);
 #undef VM_METRIC_API
@@ -1071,7 +1071,7 @@ VM_METRIC_LIST(VM_METRIC_API);
       FATAL1("%s expects argument 'isolate' to be non-null.", CURRENT_FUNC);   \
     }                                                                          \
     Isolate* iso = reinterpret_cast<Isolate*>(isolate);                        \
-    return iso->Get##variable##Metric()->value();                              \
+    return iso->Get##variable##Metric()->Value();                              \
   }
 ISOLATE_METRIC_LIST(ISOLATE_METRIC_API);
 #undef ISOLATE_METRIC_API

runtime/vm/metrics.h

@@ -88,7 +88,6 @@ class Metric {
 
   static Metric* vm_head() { return vm_list_head_; }
 
- protected:
   // Override to get a callback when value is serialized to JSON.
   // Use this for metrics that produce their value on demand.
   virtual int64_t Value() const { return value(); }
@@ -131,52 +130,52 @@ class MinMetric : public Metric {
 };
 
 class MetricHeapOldUsed : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricHeapOldCapacity : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricHeapOldExternal : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricHeapNewUsed : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricHeapNewCapacity : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricHeapNewExternal : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricIsolateCount : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricCurrentRSS : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricPeakRSS : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 
 class MetricHeapUsed : public Metric {
- protected:
+ public:
   virtual int64_t Value() const;
 };
 

runtime/vm/metrics_test.cc

@@ -4,6 +4,9 @@
 
 #include "platform/assert.h"
 
+#include "include/dart_api.h"
+#include "include/dart_tools_api.h"
+
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
 #include "vm/globals.h"
@@ -73,6 +76,42 @@ VM_UNIT_TEST_CASE(Metric_OnDemand) {
   Dart_ShutdownIsolate();
 }
 
+ISOLATE_UNIT_TEST_CASE(Metric_EmbedderAPI) {
+  {
+    TransitionVMToNative transition(Thread::Current());
+
+    const char* kScript = "void main() {}";
+    Dart_Handle api_lib = TestCase::LoadTestScript(
+        kScript, /*resolver=*/nullptr, RESOLVED_USER_TEST_URI);
+    EXPECT_VALID(api_lib);
+  }
+
+  // Ensure we've done new/old GCs to ensure max metrics are initialized.
+  String::New("<land-in-new-space>", Heap::kNew);
+  Isolate::Current()->heap()->new_space()->Scavenge();
+  Isolate::Current()->heap()->CollectAllGarbage(Heap::kLowMemory);
+
+  // Ensure we've something live in new space.
+  String::New("<land-in-new-space2>", Heap::kNew);
+
+  {
+    TransitionVMToNative transition(Thread::Current());
+
+    Dart_Isolate isolate = Dart_CurrentIsolate();
+    EXPECT(Dart_VMIsolateCountMetric() > 0);
+    EXPECT(Dart_IsolateHeapOldUsedMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapOldUsedMaxMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapOldCapacityMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapOldCapacityMaxMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapNewUsedMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapNewUsedMaxMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapNewCapacityMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapNewCapacityMaxMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapGlobalUsedMetric(isolate) > 0);
+    EXPECT(Dart_IsolateHeapGlobalUsedMaxMetric(isolate) > 0);
+  }
+}
+
 #endif  // !PRODUCT
 
 }  // namespace dart