Support narrowing a cpu profile to a given time window

runtime/vm/profiler.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/address_sanitizer.h"
 #include "platform/memory_sanitizer.h"
 #include "platform/utils.h"
 
 #include "vm/allocation.h"
 #include "vm/atomic.h"
@@ skipping 278 matching lines @@
 #elif defined(TARGET_ARCH_MIPS)
 bool ReturnAddressLocator::LocateReturnAddress(uword* return_address) {
   ASSERT(return_address != NULL);
   return false;
 }
 #else
 #error ReturnAddressLocator implementation missing for this architecture.
 #endif
 
 
+bool SampleFilter::TimeFilterSample(Sample* sample) {
+  if ((time_origin_micros_ == -1) ||
+      (time_extent_micros_ == -1)) {
+    // No time filter passed in, always pass.
+    return true;
+  }
+  const int64_t timestamp = sample->timestamp();
+  int64_t delta = timestamp - time_origin_micros_;
+  return (delta >= 0) && (delta < time_extent_micros_);
+}
+
+
 ClearProfileVisitor::ClearProfileVisitor(Isolate* isolate)
     : SampleVisitor(isolate) {
 }
 
 
 void ClearProfileVisitor::VisitSample(Sample* sample) {
   sample->Clear();
 }
 
 
@@ skipping 892 matching lines @@
       continue;
     }
     if (sample->timestamp() == 0) {
       // Empty.
       continue;
     }
     if (sample->At(0) == 0) {
       // No frames.
       continue;
     }
+    if (!filter->TimeFilterSample(sample)) {
+      // Did not pass time filter.
+      continue;
+    }
     if (!filter->FilterSample(sample)) {
       // Did not pass filter.
       continue;
     }
     buffer->Add(BuildProcessedSample(sample, buffer->code_lookup_table()));
   }
   return buffer;
 }
 
 
@@ skipping 142 matching lines @@
   }
 }
 
 
 ProcessedSampleBuffer::ProcessedSampleBuffer()
     : code_lookup_table_(new CodeLookupTable(Thread::Current())) {
   ASSERT(code_lookup_table_ != NULL);
 }
 
 }  // namespace dart