| // Copyright 2013 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #ifndef V8_SAMPLER_H_ |
| #define V8_SAMPLER_H_ |
| |
| #include "atomicops.h" |
| #include "frames.h" |
| #include "v8globals.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| class Isolate; |
| |
| // ---------------------------------------------------------------------------- |
| // 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. |
| |
| struct RegisterState { |
| RegisterState() : pc(NULL), sp(NULL), fp(NULL) {} |
| Address pc; // Instruction pointer. |
| Address sp; // Stack pointer. |
| Address fp; // Frame pointer. |
| }; |
| |
| // TickSample captures the information collected for each sample. |
| struct TickSample { |
| TickSample() |
| : state(OTHER), |
| pc(NULL), |
| external_callback(NULL), |
| frames_count(0), |
| has_external_callback(false), |
| top_frame_type(StackFrame::NONE) {} |
| void Init(Isolate* isolate, const RegisterState& state); |
| StateTag state; // The state of the VM. |
| Address pc; // Instruction pointer. |
| union { |
| Address tos; // Top stack value (*sp). |
| Address external_callback; |
| }; |
| static const int kMaxFramesCount = 64; |
| Address stack[kMaxFramesCount]; // Call stack. |
| int frames_count : 8; // Number of captured frames. |
| bool has_external_callback : 1; |
| StackFrame::Type top_frame_type : 4; |
| }; |
| |
| 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 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 NoBarrier_Load(&profiling_) > 0 && |
| !NoBarrier_Load(&has_processing_thread_); |
| } |
| void IncreaseProfilingDepth(); |
| void DecreaseProfilingDepth(); |
| |
| // Whether the sampler is running (that is, consumes resources). |
| bool IsActive() const { return NoBarrier_Load(&active_); } |
| |
| 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) { |
| NoBarrier_Store(&has_processing_thread_, value); |
| } |
| |
| // Used in tests to make sure that stack sampling is performed. |
| unsigned js_and_external_sample_count() const { |
| return js_and_external_sample_count_; |
| } |
| void StartCountingSamples() { |
| is_counting_samples_ = true; |
| js_and_external_sample_count_ = 0; |
| } |
| |
| 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) { NoBarrier_Store(&active_, value); } |
| |
| Isolate* isolate_; |
| const int interval_; |
| Atomic32 profiling_; |
| Atomic32 has_processing_thread_; |
| Atomic32 active_; |
| PlatformData* data_; // Platform specific data. |
| bool is_counting_samples_; |
| // Counts stack samples taken in JS VM state. |
| unsigned js_and_external_sample_count_; |
| DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler); |
| }; |
| |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_SAMPLER_H_ |