Revert of Create libsampler as V8 sampler library.

src/profiler/sampler.h

Index: src/profiler/sampler.h
diff --git a/src/profiler/sampler.h b/src/profiler/sampler.h
new file mode 100644
index 0000000000000000000000000000000000000000..3d3a6e997ffb3b891a16093c53db74e7c01075ed
--- /dev/null
+++ b/src/profiler/sampler.h
@@ -0,0 +1,108 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_PROFILER_SAMPLER_H_
+#define V8_PROFILER_SAMPLER_H_
+
+#include "include/v8.h"
+
+#include "src/base/atomicops.h"
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace internal {
+
+class Isolate;
+struct TickSample;
+
+// ----------------------------------------------------------------------------
+// Sampler
+//
+// A sampler periodically samples the state of the VM and optionally
+// (if used for profiling) the program counter and stack pointer for
+// the thread that created it.
+
+class Sampler {
+ public:
+  // Initializes the Sampler support. Called once at VM startup.
+  static void SetUp();
+  static void TearDown();
+
+  // Initialize sampler.
+  Sampler(Isolate* isolate, int interval);
+  virtual ~Sampler();
+
+  Isolate* isolate() const { return isolate_; }
+  int interval() const { return interval_; }
+
+  // Performs stack sampling.
+  void SampleStack(const v8::RegisterState& regs);
+
+  // Start and stop sampler.
+  void Start();
+  void Stop();
+
+  // Whether the sampling thread should use this Sampler for CPU profiling?
+  bool IsProfiling() const {
+    return base::NoBarrier_Load(&profiling_) > 0 &&
+        !base::NoBarrier_Load(&has_processing_thread_);
+  }
+  void IncreaseProfilingDepth();
+  void DecreaseProfilingDepth();
+
+  // Whether the sampler is running (that is, consumes resources).
+  bool IsActive() const { return base::NoBarrier_Load(&active_); }
+
+  // CpuProfiler collects samples by calling DoSample directly
+  // without calling Start. To keep it working, we register the sampler
+  // with the CpuProfiler.
+  bool IsRegistered() const { return base::NoBarrier_Load(&registered_); }
+
+  void DoSample();
+  // If true next sample must be initiated on the profiler event processor
+  // thread right after latest sample is processed.
+  void SetHasProcessingThread(bool value) {
+    base::NoBarrier_Store(&has_processing_thread_, value);
+  }
+
+  // Used in tests to make sure that stack sampling is performed.
+  unsigned js_sample_count() const { return js_sample_count_; }
+  unsigned external_sample_count() const { return external_sample_count_; }
+  void StartCountingSamples() {
+    js_sample_count_ = 0;
+    external_sample_count_ = 0;
+    is_counting_samples_ = true;
+  }
+
+  class PlatformData;
+  PlatformData* platform_data() const { return data_; }
+
+ protected:
+  // This method is called for each sampling period with the current
+  // program counter.
+  virtual void Tick(TickSample* sample) = 0;
+
+ private:
+  void SetActive(bool value) { base::NoBarrier_Store(&active_, value); }
+
+  void SetRegistered(bool value) { base::NoBarrier_Store(&registered_, value); }
+
+  Isolate* isolate_;
+  const int interval_;
+  base::Atomic32 profiling_;
+  base::Atomic32 has_processing_thread_;
+  base::Atomic32 active_;
+  base::Atomic32 registered_;
+  PlatformData* data_;  // Platform specific data.
+  // Counts stack samples taken in various VM states.
+  bool is_counting_samples_;
+  unsigned js_sample_count_;
+  unsigned external_sample_count_;
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_PROFILER_SAMPLER_H_