Support narrowing a cpu profile to a given time window

runtime/vm/profiler_test.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/assert.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
 #include "vm/globals.h"
 #include "vm/profiler.h"
@@ skipping 131 matching lines @@
 static RawClass* GetClass(const Library& lib, const char* name) {
   const Class& cls = Class::Handle(
       lib.LookupClassAllowPrivate(String::Handle(Symbols::New(name))));
   EXPECT(!cls.IsNull());  // No ambiguity error expected.
   return cls.raw();
 }
 
 
 class AllocationFilter : public SampleFilter {
  public:
-  explicit AllocationFilter(Isolate* isolate, intptr_t cid)
-      : SampleFilter(isolate),
+  AllocationFilter(Isolate* isolate,
+                   intptr_t cid,
+                   int64_t time_origin_micros = -1,
+                   int64_t time_extent_micros = -1)
+      : SampleFilter(isolate,
+                     time_origin_micros,
+                     time_extent_micros),
         cid_(cid),
         enable_vm_ticks_(false) {
   }
 
   bool FilterSample(Sample* sample) {
     if (!enable_vm_ticks_ &&
         (sample->vm_tag() == VMTag::kVMTagId)) {
       // We don't want to see embedder ticks in the test.
       return false;
     }
@@ skipping 25 matching lines @@
       "}\n"
       "main() {\n"
       "  return B.boo();\n"
       "}\n";
 
   Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
   EXPECT_VALID(lib);
   Library& root_library = Library::Handle();
   root_library ^= Api::UnwrapHandle(lib);
 
+  const int64_t before_allocations_micros = Dart_TimelineGetMicros();
   const Class& class_a = Class::Handle(GetClass(root_library, "A"));
   EXPECT(!class_a.IsNull());
   class_a.SetTraceAllocation(true);
 
   Dart_Handle result = Dart_Invoke(lib, NewString("main"), 0, NULL);
   EXPECT_VALID(result);
 
-
+  const int64_t after_allocations_micros = Dart_TimelineGetMicros();
+  const int64_t allocation_extent_micros =
+      after_allocations_micros - before_allocations_micros;
   {
     Thread* thread = Thread::Current();
     Isolate* isolate = thread->isolate();
     StackZone zone(thread);
     HANDLESCOPE(thread);
     Profile profile(isolate);
-    AllocationFilter filter(isolate, class_a.id());
+    // Filter for the class in the time range.
+    AllocationFilter filter(isolate,
+                            class_a.id(),
+                            before_allocations_micros,
+                            allocation_extent_micros);
     profile.Build(thread, &filter, Profile::kNoTags);
     // We should have 1 allocation sample.
     EXPECT_EQ(1, profile.sample_count());
     ProfileTrieWalker walker(&profile);
 
     // Exclusive code: B.boo -> main.
     walker.Reset(Profile::kExclusiveCode);
     // Move down from the root.
     EXPECT(walker.Down());
     EXPECT_STREQ("B.boo", walker.CurrentName());
@@ skipping 21 matching lines @@
 
     // Inclusive function: main -> B.boo.
     walker.Reset(Profile::kInclusiveFunction);
     // Move down from the root.
     EXPECT(walker.Down());
     EXPECT_STREQ("main", walker.CurrentName());
     EXPECT(walker.Down());
     EXPECT_STREQ("B.boo", walker.CurrentName());
     EXPECT(!walker.Down());
   }
+
+  // Query with a time filter where no allocations occurred.
+  {
+    Thread* thread = Thread::Current();
+    Isolate* isolate = thread->isolate();
+    StackZone zone(thread);
+    HANDLESCOPE(thread);
+    Profile profile(isolate);
+    AllocationFilter filter(isolate,
+                            class_a.id(),
+                            Dart_TimelineGetMicros(),
+                            16000);
+    profile.Build(thread, &filter, Profile::kNoTags);
+    // We should have no allocation samples because none occured within
+    // the specified time range.
+    EXPECT_EQ(0, profile.sample_count());
+  }
 }
 
 
 TEST_CASE(Profiler_ToggleRecordAllocation) {
   DisableNativeProfileScope dnps;
   const char* kScript =
       "class A {\n"
       "  var a;\n"
       "  var b;\n"
       "}\n"
@@ skipping 1212 matching lines @@
     EXPECT(walker.Down());
     EXPECT_STREQ("go", walker.CurrentName());
     EXPECT(walker.Down());
     EXPECT_STREQ("main", walker.CurrentName());
     EXPECT(!walker.Down());
   }
 }
 
 }  // namespace dart