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1002 lines
32 KiB
1002 lines
32 KiB
// Copyright 2010 the V8 project authors. All rights reserved. |
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// Use of this source code is governed by a BSD-style license that can be |
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// found in the LICENSE file. |
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#ifndef V8_V8_PROFILER_H_ |
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#define V8_V8_PROFILER_H_ |
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#include <unordered_set> |
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#include <vector> |
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#include "v8.h" // NOLINT(build/include) |
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/** |
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* Profiler support for the V8 JavaScript engine. |
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*/ |
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namespace v8 { |
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class HeapGraphNode; |
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struct HeapStatsUpdate; |
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typedef uint32_t SnapshotObjectId; |
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struct CpuProfileDeoptFrame { |
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int script_id; |
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size_t position; |
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}; |
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} // namespace v8 |
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#ifdef V8_OS_WIN |
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template class V8_EXPORT std::vector<v8::CpuProfileDeoptFrame>; |
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#endif |
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namespace v8 { |
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struct V8_EXPORT CpuProfileDeoptInfo { |
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/** A pointer to a static string owned by v8. */ |
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const char* deopt_reason; |
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std::vector<CpuProfileDeoptFrame> stack; |
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}; |
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} // namespace v8 |
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#ifdef V8_OS_WIN |
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template class V8_EXPORT std::vector<v8::CpuProfileDeoptInfo>; |
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#endif |
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namespace v8 { |
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// TickSample captures the information collected for each sample. |
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struct TickSample { |
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// Internal profiling (with --prof + tools/$OS-tick-processor) wants to |
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// include the runtime function we're calling. Externally exposed tick |
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// samples don't care. |
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enum RecordCEntryFrame { kIncludeCEntryFrame, kSkipCEntryFrame }; |
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TickSample() |
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: state(OTHER), |
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pc(nullptr), |
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external_callback_entry(nullptr), |
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frames_count(0), |
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has_external_callback(false), |
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update_stats(true) {} |
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/** |
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* Initialize a tick sample from the isolate. |
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* \param isolate The isolate. |
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* \param state Execution state. |
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* \param record_c_entry_frame Include or skip the runtime function. |
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* \param update_stats Whether update the sample to the aggregated stats. |
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* \param use_simulator_reg_state When set to true and V8 is running under a |
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* simulator, the method will use the simulator |
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* register state rather than the one provided |
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* with |state| argument. Otherwise the method |
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* will use provided register |state| as is. |
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*/ |
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void Init(Isolate* isolate, const v8::RegisterState& state, |
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RecordCEntryFrame record_c_entry_frame, bool update_stats, |
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bool use_simulator_reg_state = true); |
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/** |
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* Get a call stack sample from the isolate. |
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* \param isolate The isolate. |
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* \param state Register state. |
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* \param record_c_entry_frame Include or skip the runtime function. |
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* \param frames Caller allocated buffer to store stack frames. |
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* \param frames_limit Maximum number of frames to capture. The buffer must |
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* be large enough to hold the number of frames. |
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* \param sample_info The sample info is filled up by the function |
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* provides number of actual captured stack frames and |
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* the current VM state. |
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* \param use_simulator_reg_state When set to true and V8 is running under a |
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* simulator, the method will use the simulator |
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* register state rather than the one provided |
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* with |state| argument. Otherwise the method |
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* will use provided register |state| as is. |
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* \note GetStackSample is thread and signal safe and should only be called |
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* when the JS thread is paused or interrupted. |
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* Otherwise the behavior is undefined. |
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*/ |
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static bool GetStackSample(Isolate* isolate, v8::RegisterState* state, |
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RecordCEntryFrame record_c_entry_frame, |
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void** frames, size_t frames_limit, |
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v8::SampleInfo* sample_info, |
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bool use_simulator_reg_state = true); |
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StateTag state; // The state of the VM. |
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void* pc; // Instruction pointer. |
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union { |
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void* tos; // Top stack value (*sp). |
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void* external_callback_entry; |
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}; |
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static const unsigned kMaxFramesCountLog2 = 8; |
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static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1; |
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void* stack[kMaxFramesCount]; // Call stack. |
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unsigned frames_count : kMaxFramesCountLog2; // Number of captured frames. |
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bool has_external_callback : 1; |
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bool update_stats : 1; // Whether the sample should update aggregated stats. |
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}; |
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/** |
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* CpuProfileNode represents a node in a call graph. |
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*/ |
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class V8_EXPORT CpuProfileNode { |
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public: |
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struct LineTick { |
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/** The 1-based number of the source line where the function originates. */ |
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int line; |
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/** The count of samples associated with the source line. */ |
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unsigned int hit_count; |
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}; |
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/** Returns function name (empty string for anonymous functions.) */ |
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Local<String> GetFunctionName() const; |
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/** |
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* Returns function name (empty string for anonymous functions.) |
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* The string ownership is *not* passed to the caller. It stays valid until |
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* profile is deleted. The function is thread safe. |
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*/ |
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const char* GetFunctionNameStr() const; |
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/** Returns id of the script where function is located. */ |
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int GetScriptId() const; |
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/** Returns resource name for script from where the function originates. */ |
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Local<String> GetScriptResourceName() const; |
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/** |
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* Returns resource name for script from where the function originates. |
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* The string ownership is *not* passed to the caller. It stays valid until |
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* profile is deleted. The function is thread safe. |
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*/ |
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const char* GetScriptResourceNameStr() const; |
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/** |
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* Returns the number, 1-based, of the line where the function originates. |
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* kNoLineNumberInfo if no line number information is available. |
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*/ |
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int GetLineNumber() const; |
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/** |
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* Returns 1-based number of the column where the function originates. |
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* kNoColumnNumberInfo if no column number information is available. |
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*/ |
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int GetColumnNumber() const; |
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/** |
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* Returns the number of the function's source lines that collect the samples. |
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*/ |
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unsigned int GetHitLineCount() const; |
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/** Returns the set of source lines that collect the samples. |
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* The caller allocates buffer and responsible for releasing it. |
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* True if all available entries are copied, otherwise false. |
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* The function copies nothing if buffer is not large enough. |
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*/ |
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bool GetLineTicks(LineTick* entries, unsigned int length) const; |
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/** Returns bailout reason for the function |
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* if the optimization was disabled for it. |
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*/ |
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const char* GetBailoutReason() const; |
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/** |
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* Returns the count of samples where the function was currently executing. |
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*/ |
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unsigned GetHitCount() const; |
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/** Returns function entry UID. */ |
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V8_DEPRECATE_SOON( |
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"Use GetScriptId, GetLineNumber, and GetColumnNumber instead.", |
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unsigned GetCallUid() const); |
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/** Returns id of the node. The id is unique within the tree */ |
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unsigned GetNodeId() const; |
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/** Returns child nodes count of the node. */ |
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int GetChildrenCount() const; |
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/** Retrieves a child node by index. */ |
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const CpuProfileNode* GetChild(int index) const; |
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/** Retrieves deopt infos for the node. */ |
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const std::vector<CpuProfileDeoptInfo>& GetDeoptInfos() const; |
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static const int kNoLineNumberInfo = Message::kNoLineNumberInfo; |
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static const int kNoColumnNumberInfo = Message::kNoColumnInfo; |
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}; |
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/** |
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* CpuProfile contains a CPU profile in a form of top-down call tree |
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* (from main() down to functions that do all the work). |
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*/ |
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class V8_EXPORT CpuProfile { |
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public: |
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/** Returns CPU profile title. */ |
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Local<String> GetTitle() const; |
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/** Returns the root node of the top down call tree. */ |
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const CpuProfileNode* GetTopDownRoot() const; |
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/** |
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* Returns number of samples recorded. The samples are not recorded unless |
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* |record_samples| parameter of CpuProfiler::StartCpuProfiling is true. |
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*/ |
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int GetSamplesCount() const; |
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/** |
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* Returns profile node corresponding to the top frame the sample at |
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* the given index. |
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*/ |
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const CpuProfileNode* GetSample(int index) const; |
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/** |
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* Returns the timestamp of the sample. The timestamp is the number of |
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* microseconds since some unspecified starting point. |
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* The point is equal to the starting point used by GetStartTime. |
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*/ |
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int64_t GetSampleTimestamp(int index) const; |
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/** |
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* Returns time when the profile recording was started (in microseconds) |
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* since some unspecified starting point. |
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*/ |
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int64_t GetStartTime() const; |
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/** |
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* Returns time when the profile recording was stopped (in microseconds) |
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* since some unspecified starting point. |
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* The point is equal to the starting point used by GetStartTime. |
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*/ |
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int64_t GetEndTime() const; |
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/** |
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* Deletes the profile and removes it from CpuProfiler's list. |
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* All pointers to nodes previously returned become invalid. |
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*/ |
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void Delete(); |
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}; |
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enum CpuProfilingMode { |
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// In the resulting CpuProfile tree, intermediate nodes in a stack trace |
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// (from the root to a leaf) will have line numbers that point to the start |
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// line of the function, rather than the line of the callsite of the child. |
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kLeafNodeLineNumbers, |
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// In the resulting CpuProfile tree, nodes are separated based on the line |
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// number of their callsite in their parent. |
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kCallerLineNumbers, |
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}; |
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/** |
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* Interface for controlling CPU profiling. Instance of the |
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* profiler can be created using v8::CpuProfiler::New method. |
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*/ |
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class V8_EXPORT CpuProfiler { |
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public: |
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/** |
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* Creates a new CPU profiler for the |isolate|. The isolate must be |
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* initialized. The profiler object must be disposed after use by calling |
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* |Dispose| method. |
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*/ |
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static CpuProfiler* New(Isolate* isolate); |
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/** |
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* Synchronously collect current stack sample in all profilers attached to |
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* the |isolate|. The call does not affect number of ticks recorded for |
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* the current top node. |
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*/ |
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static void CollectSample(Isolate* isolate); |
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/** |
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* Disposes the CPU profiler object. |
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*/ |
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void Dispose(); |
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/** |
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* Changes default CPU profiler sampling interval to the specified number |
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* of microseconds. Default interval is 1000us. This method must be called |
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* when there are no profiles being recorded. |
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*/ |
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void SetSamplingInterval(int us); |
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/** |
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* Starts collecting CPU profile. Title may be an empty string. It |
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* is allowed to have several profiles being collected at |
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* once. Attempts to start collecting several profiles with the same |
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* title are silently ignored. While collecting a profile, functions |
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* from all security contexts are included in it. The token-based |
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* filtering is only performed when querying for a profile. |
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* |
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* |record_samples| parameter controls whether individual samples should |
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* be recorded in addition to the aggregated tree. |
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*/ |
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void StartProfiling(Local<String> title, CpuProfilingMode mode, |
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bool record_samples = false); |
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/** |
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* The same as StartProfiling above, but the CpuProfilingMode defaults to |
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* kLeafNodeLineNumbers mode, which was the previous default behavior of the |
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* profiler. |
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*/ |
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void StartProfiling(Local<String> title, bool record_samples = false); |
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/** |
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* Stops collecting CPU profile with a given title and returns it. |
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* If the title given is empty, finishes the last profile started. |
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*/ |
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CpuProfile* StopProfiling(Local<String> title); |
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/** |
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* Force collection of a sample. Must be called on the VM thread. |
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* Recording the forced sample does not contribute to the aggregated |
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* profile statistics. |
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*/ |
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V8_DEPRECATED("Use static CollectSample(Isolate*) instead.", |
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void CollectSample()); |
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/** |
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* Tells the profiler whether the embedder is idle. |
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*/ |
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V8_DEPRECATED("Use Isolate::SetIdle(bool) instead.", |
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void SetIdle(bool is_idle)); |
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/** |
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* Generate more detailed source positions to code objects. This results in |
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* better results when mapping profiling samples to script source. |
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*/ |
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static void UseDetailedSourcePositionsForProfiling(Isolate* isolate); |
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private: |
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CpuProfiler(); |
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~CpuProfiler(); |
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CpuProfiler(const CpuProfiler&); |
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CpuProfiler& operator=(const CpuProfiler&); |
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}; |
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/** |
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* HeapSnapshotEdge represents a directed connection between heap |
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* graph nodes: from retainers to retained nodes. |
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*/ |
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class V8_EXPORT HeapGraphEdge { |
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public: |
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enum Type { |
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kContextVariable = 0, // A variable from a function context. |
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kElement = 1, // An element of an array. |
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kProperty = 2, // A named object property. |
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kInternal = 3, // A link that can't be accessed from JS, |
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// thus, its name isn't a real property name |
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// (e.g. parts of a ConsString). |
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kHidden = 4, // A link that is needed for proper sizes |
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// calculation, but may be hidden from user. |
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kShortcut = 5, // A link that must not be followed during |
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// sizes calculation. |
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kWeak = 6 // A weak reference (ignored by the GC). |
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}; |
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/** Returns edge type (see HeapGraphEdge::Type). */ |
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Type GetType() const; |
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/** |
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* Returns edge name. This can be a variable name, an element index, or |
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* a property name. |
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*/ |
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Local<Value> GetName() const; |
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/** Returns origin node. */ |
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const HeapGraphNode* GetFromNode() const; |
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/** Returns destination node. */ |
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const HeapGraphNode* GetToNode() const; |
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}; |
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/** |
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* HeapGraphNode represents a node in a heap graph. |
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*/ |
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class V8_EXPORT HeapGraphNode { |
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public: |
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enum Type { |
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kHidden = 0, // Hidden node, may be filtered when shown to user. |
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kArray = 1, // An array of elements. |
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kString = 2, // A string. |
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kObject = 3, // A JS object (except for arrays and strings). |
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kCode = 4, // Compiled code. |
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kClosure = 5, // Function closure. |
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kRegExp = 6, // RegExp. |
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kHeapNumber = 7, // Number stored in the heap. |
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kNative = 8, // Native object (not from V8 heap). |
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kSynthetic = 9, // Synthetic object, usually used for grouping |
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// snapshot items together. |
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kConsString = 10, // Concatenated string. A pair of pointers to strings. |
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kSlicedString = 11, // Sliced string. A fragment of another string. |
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kSymbol = 12, // A Symbol (ES6). |
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kBigInt = 13 // BigInt. |
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}; |
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/** Returns node type (see HeapGraphNode::Type). */ |
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Type GetType() const; |
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/** |
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* Returns node name. Depending on node's type this can be the name |
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* of the constructor (for objects), the name of the function (for |
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* closures), string value, or an empty string (for compiled code). |
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*/ |
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Local<String> GetName() const; |
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/** |
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* Returns node id. For the same heap object, the id remains the same |
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* across all snapshots. |
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*/ |
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SnapshotObjectId GetId() const; |
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/** Returns node's own size, in bytes. */ |
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size_t GetShallowSize() const; |
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/** Returns child nodes count of the node. */ |
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int GetChildrenCount() const; |
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/** Retrieves a child by index. */ |
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const HeapGraphEdge* GetChild(int index) const; |
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}; |
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/** |
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* An interface for exporting data from V8, using "push" model. |
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*/ |
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class V8_EXPORT OutputStream { // NOLINT |
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public: |
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enum WriteResult { |
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kContinue = 0, |
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kAbort = 1 |
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}; |
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virtual ~OutputStream() = default; |
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/** Notify about the end of stream. */ |
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virtual void EndOfStream() = 0; |
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/** Get preferred output chunk size. Called only once. */ |
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virtual int GetChunkSize() { return 1024; } |
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/** |
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* Writes the next chunk of snapshot data into the stream. Writing |
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* can be stopped by returning kAbort as function result. EndOfStream |
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* will not be called in case writing was aborted. |
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*/ |
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virtual WriteResult WriteAsciiChunk(char* data, int size) = 0; |
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/** |
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* Writes the next chunk of heap stats data into the stream. Writing |
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* can be stopped by returning kAbort as function result. EndOfStream |
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* will not be called in case writing was aborted. |
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*/ |
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virtual WriteResult WriteHeapStatsChunk(HeapStatsUpdate* data, int count) { |
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return kAbort; |
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} |
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}; |
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/** |
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* HeapSnapshots record the state of the JS heap at some moment. |
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*/ |
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class V8_EXPORT HeapSnapshot { |
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public: |
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enum SerializationFormat { |
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kJSON = 0 // See format description near 'Serialize' method. |
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}; |
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/** Returns the root node of the heap graph. */ |
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const HeapGraphNode* GetRoot() const; |
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/** Returns a node by its id. */ |
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const HeapGraphNode* GetNodeById(SnapshotObjectId id) const; |
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/** Returns total nodes count in the snapshot. */ |
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int GetNodesCount() const; |
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/** Returns a node by index. */ |
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const HeapGraphNode* GetNode(int index) const; |
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/** Returns a max seen JS object Id. */ |
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SnapshotObjectId GetMaxSnapshotJSObjectId() const; |
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/** |
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* Deletes the snapshot and removes it from HeapProfiler's list. |
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* All pointers to nodes, edges and paths previously returned become |
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* invalid. |
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*/ |
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void Delete(); |
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/** |
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* Prepare a serialized representation of the snapshot. The result |
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* is written into the stream provided in chunks of specified size. |
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* The total length of the serialized snapshot is unknown in |
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* advance, it can be roughly equal to JS heap size (that means, |
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* it can be really big - tens of megabytes). |
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* |
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* For the JSON format, heap contents are represented as an object |
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* with the following structure: |
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* |
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* { |
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* snapshot: { |
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* title: "...", |
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* uid: nnn, |
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* meta: { meta-info }, |
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* node_count: nnn, |
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* edge_count: nnn |
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* }, |
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* nodes: [nodes array], |
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* edges: [edges array], |
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* strings: [strings array] |
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* } |
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* |
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* Nodes reference strings, other nodes, and edges by their indexes |
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* in corresponding arrays. |
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*/ |
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void Serialize(OutputStream* stream, |
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SerializationFormat format = kJSON) const; |
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}; |
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/** |
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* An interface for reporting progress and controlling long-running |
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* activities. |
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*/ |
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class V8_EXPORT ActivityControl { // NOLINT |
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public: |
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enum ControlOption { |
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kContinue = 0, |
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kAbort = 1 |
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}; |
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virtual ~ActivityControl() = default; |
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/** |
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* Notify about current progress. The activity can be stopped by |
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* returning kAbort as the callback result. |
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*/ |
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virtual ControlOption ReportProgressValue(int done, int total) = 0; |
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}; |
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/** |
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* AllocationProfile is a sampled profile of allocations done by the program. |
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* This is structured as a call-graph. |
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*/ |
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class V8_EXPORT AllocationProfile { |
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public: |
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struct Allocation { |
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/** |
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* Size of the sampled allocation object. |
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*/ |
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size_t size; |
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/** |
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* The number of objects of such size that were sampled. |
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*/ |
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unsigned int count; |
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}; |
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/** |
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* Represents a node in the call-graph. |
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*/ |
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struct Node { |
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/** |
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* Name of the function. May be empty for anonymous functions or if the |
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* script corresponding to this function has been unloaded. |
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*/ |
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Local<String> name; |
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/** |
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* Name of the script containing the function. May be empty if the script |
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* name is not available, or if the script has been unloaded. |
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*/ |
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Local<String> script_name; |
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/** |
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* id of the script where the function is located. May be equal to |
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* v8::UnboundScript::kNoScriptId in cases where the script doesn't exist. |
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*/ |
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int script_id; |
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/** |
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* Start position of the function in the script. |
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*/ |
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int start_position; |
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/** |
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* 1-indexed line number where the function starts. May be |
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* kNoLineNumberInfo if no line number information is available. |
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*/ |
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int line_number; |
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|
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/** |
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* 1-indexed column number where the function starts. May be |
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* kNoColumnNumberInfo if no line number information is available. |
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*/ |
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int column_number; |
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|
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/** |
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* Unique id of the node. |
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*/ |
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uint32_t node_id; |
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/** |
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* List of callees called from this node for which we have sampled |
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* allocations. The lifetime of the children is scoped to the containing |
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* AllocationProfile. |
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*/ |
|
std::vector<Node*> children; |
|
|
|
/** |
|
* List of self allocations done by this node in the call-graph. |
|
*/ |
|
std::vector<Allocation> allocations; |
|
}; |
|
|
|
/** |
|
* Represent a single sample recorded for an allocation. |
|
*/ |
|
struct Sample { |
|
/** |
|
* id of the node in the profile tree. |
|
*/ |
|
uint32_t node_id; |
|
|
|
/** |
|
* Size of the sampled allocation object. |
|
*/ |
|
size_t size; |
|
|
|
/** |
|
* The number of objects of such size that were sampled. |
|
*/ |
|
unsigned int count; |
|
|
|
/** |
|
* Unique time-ordered id of the allocation sample. Can be used to track |
|
* what samples were added or removed between two snapshots. |
|
*/ |
|
uint64_t sample_id; |
|
}; |
|
|
|
/** |
|
* Returns the root node of the call-graph. The root node corresponds to an |
|
* empty JS call-stack. The lifetime of the returned Node* is scoped to the |
|
* containing AllocationProfile. |
|
*/ |
|
virtual Node* GetRootNode() = 0; |
|
virtual const std::vector<Sample>& GetSamples() = 0; |
|
|
|
virtual ~AllocationProfile() = default; |
|
|
|
static const int kNoLineNumberInfo = Message::kNoLineNumberInfo; |
|
static const int kNoColumnNumberInfo = Message::kNoColumnInfo; |
|
}; |
|
|
|
/** |
|
* An object graph consisting of embedder objects and V8 objects. |
|
* Edges of the graph are strong references between the objects. |
|
* The embedder can build this graph during heap snapshot generation |
|
* to include the embedder objects in the heap snapshot. |
|
* Usage: |
|
* 1) Define derived class of EmbedderGraph::Node for embedder objects. |
|
* 2) Set the build embedder graph callback on the heap profiler using |
|
* HeapProfiler::AddBuildEmbedderGraphCallback. |
|
* 3) In the callback use graph->AddEdge(node1, node2) to add an edge from |
|
* node1 to node2. |
|
* 4) To represent references from/to V8 object, construct V8 nodes using |
|
* graph->V8Node(value). |
|
*/ |
|
class V8_EXPORT EmbedderGraph { |
|
public: |
|
class Node { |
|
public: |
|
Node() = default; |
|
virtual ~Node() = default; |
|
virtual const char* Name() = 0; |
|
virtual size_t SizeInBytes() = 0; |
|
/** |
|
* The corresponding V8 wrapper node if not null. |
|
* During heap snapshot generation the embedder node and the V8 wrapper |
|
* node will be merged into one node to simplify retaining paths. |
|
*/ |
|
virtual Node* WrapperNode() { return nullptr; } |
|
virtual bool IsRootNode() { return false; } |
|
/** Must return true for non-V8 nodes. */ |
|
virtual bool IsEmbedderNode() { return true; } |
|
/** |
|
* Optional name prefix. It is used in Chrome for tagging detached nodes. |
|
*/ |
|
virtual const char* NamePrefix() { return nullptr; } |
|
|
|
private: |
|
Node(const Node&) = delete; |
|
Node& operator=(const Node&) = delete; |
|
}; |
|
|
|
/** |
|
* Returns a node corresponding to the given V8 value. Ownership is not |
|
* transferred. The result pointer is valid while the graph is alive. |
|
*/ |
|
virtual Node* V8Node(const v8::Local<v8::Value>& value) = 0; |
|
|
|
/** |
|
* Adds the given node to the graph and takes ownership of the node. |
|
* Returns a raw pointer to the node that is valid while the graph is alive. |
|
*/ |
|
virtual Node* AddNode(std::unique_ptr<Node> node) = 0; |
|
|
|
/** |
|
* Adds an edge that represents a strong reference from the given |
|
* node |from| to the given node |to|. The nodes must be added to the graph |
|
* before calling this function. |
|
* |
|
* If name is nullptr, the edge will have auto-increment indexes, otherwise |
|
* it will be named accordingly. |
|
*/ |
|
virtual void AddEdge(Node* from, Node* to, const char* name = nullptr) = 0; |
|
|
|
virtual ~EmbedderGraph() = default; |
|
}; |
|
|
|
/** |
|
* Interface for controlling heap profiling. Instance of the |
|
* profiler can be retrieved using v8::Isolate::GetHeapProfiler. |
|
*/ |
|
class V8_EXPORT HeapProfiler { |
|
public: |
|
enum SamplingFlags { |
|
kSamplingNoFlags = 0, |
|
kSamplingForceGC = 1 << 0, |
|
}; |
|
|
|
/** |
|
* Callback function invoked during heap snapshot generation to retrieve |
|
* the embedder object graph. The callback should use graph->AddEdge(..) to |
|
* add references between the objects. |
|
* The callback must not trigger garbage collection in V8. |
|
*/ |
|
typedef void (*BuildEmbedderGraphCallback)(v8::Isolate* isolate, |
|
v8::EmbedderGraph* graph, |
|
void* data); |
|
|
|
/** Returns the number of snapshots taken. */ |
|
int GetSnapshotCount(); |
|
|
|
/** Returns a snapshot by index. */ |
|
const HeapSnapshot* GetHeapSnapshot(int index); |
|
|
|
/** |
|
* Returns SnapshotObjectId for a heap object referenced by |value| if |
|
* it has been seen by the heap profiler, kUnknownObjectId otherwise. |
|
*/ |
|
SnapshotObjectId GetObjectId(Local<Value> value); |
|
|
|
/** |
|
* Returns heap object with given SnapshotObjectId if the object is alive, |
|
* otherwise empty handle is returned. |
|
*/ |
|
Local<Value> FindObjectById(SnapshotObjectId id); |
|
|
|
/** |
|
* Clears internal map from SnapshotObjectId to heap object. The new objects |
|
* will not be added into it unless a heap snapshot is taken or heap object |
|
* tracking is kicked off. |
|
*/ |
|
void ClearObjectIds(); |
|
|
|
/** |
|
* A constant for invalid SnapshotObjectId. GetSnapshotObjectId will return |
|
* it in case heap profiler cannot find id for the object passed as |
|
* parameter. HeapSnapshot::GetNodeById will always return NULL for such id. |
|
*/ |
|
static const SnapshotObjectId kUnknownObjectId = 0; |
|
|
|
/** |
|
* Callback interface for retrieving user friendly names of global objects. |
|
*/ |
|
class ObjectNameResolver { |
|
public: |
|
/** |
|
* Returns name to be used in the heap snapshot for given node. Returned |
|
* string must stay alive until snapshot collection is completed. |
|
*/ |
|
virtual const char* GetName(Local<Object> object) = 0; |
|
|
|
protected: |
|
virtual ~ObjectNameResolver() = default; |
|
}; |
|
|
|
/** |
|
* Takes a heap snapshot and returns it. |
|
*/ |
|
const HeapSnapshot* TakeHeapSnapshot( |
|
ActivityControl* control = nullptr, |
|
ObjectNameResolver* global_object_name_resolver = nullptr); |
|
|
|
/** |
|
* Starts tracking of heap objects population statistics. After calling |
|
* this method, all heap objects relocations done by the garbage collector |
|
* are being registered. |
|
* |
|
* |track_allocations| parameter controls whether stack trace of each |
|
* allocation in the heap will be recorded and reported as part of |
|
* HeapSnapshot. |
|
*/ |
|
void StartTrackingHeapObjects(bool track_allocations = false); |
|
|
|
/** |
|
* Adds a new time interval entry to the aggregated statistics array. The |
|
* time interval entry contains information on the current heap objects |
|
* population size. The method also updates aggregated statistics and |
|
* reports updates for all previous time intervals via the OutputStream |
|
* object. Updates on each time interval are provided as a stream of the |
|
* HeapStatsUpdate structure instances. |
|
* If |timestamp_us| is supplied, timestamp of the new entry will be written |
|
* into it. The return value of the function is the last seen heap object Id. |
|
* |
|
* StartTrackingHeapObjects must be called before the first call to this |
|
* method. |
|
*/ |
|
SnapshotObjectId GetHeapStats(OutputStream* stream, |
|
int64_t* timestamp_us = nullptr); |
|
|
|
/** |
|
* Stops tracking of heap objects population statistics, cleans up all |
|
* collected data. StartHeapObjectsTracking must be called again prior to |
|
* calling GetHeapStats next time. |
|
*/ |
|
void StopTrackingHeapObjects(); |
|
|
|
/** |
|
* Starts gathering a sampling heap profile. A sampling heap profile is |
|
* similar to tcmalloc's heap profiler and Go's mprof. It samples object |
|
* allocations and builds an online 'sampling' heap profile. At any point in |
|
* time, this profile is expected to be a representative sample of objects |
|
* currently live in the system. Each sampled allocation includes the stack |
|
* trace at the time of allocation, which makes this really useful for memory |
|
* leak detection. |
|
* |
|
* This mechanism is intended to be cheap enough that it can be used in |
|
* production with minimal performance overhead. |
|
* |
|
* Allocations are sampled using a randomized Poisson process. On average, one |
|
* allocation will be sampled every |sample_interval| bytes allocated. The |
|
* |stack_depth| parameter controls the maximum number of stack frames to be |
|
* captured on each allocation. |
|
* |
|
* NOTE: This is a proof-of-concept at this point. Right now we only sample |
|
* newspace allocations. Support for paged space allocation (e.g. pre-tenured |
|
* objects, large objects, code objects, etc.) and native allocations |
|
* doesn't exist yet, but is anticipated in the future. |
|
* |
|
* Objects allocated before the sampling is started will not be included in |
|
* the profile. |
|
* |
|
* Returns false if a sampling heap profiler is already running. |
|
*/ |
|
bool StartSamplingHeapProfiler(uint64_t sample_interval = 512 * 1024, |
|
int stack_depth = 16, |
|
SamplingFlags flags = kSamplingNoFlags); |
|
|
|
/** |
|
* Stops the sampling heap profile and discards the current profile. |
|
*/ |
|
void StopSamplingHeapProfiler(); |
|
|
|
/** |
|
* Returns the sampled profile of allocations allocated (and still live) since |
|
* StartSamplingHeapProfiler was called. The ownership of the pointer is |
|
* transferred to the caller. Returns nullptr if sampling heap profiler is not |
|
* active. |
|
*/ |
|
AllocationProfile* GetAllocationProfile(); |
|
|
|
/** |
|
* Deletes all snapshots taken. All previously returned pointers to |
|
* snapshots and their contents become invalid after this call. |
|
*/ |
|
void DeleteAllHeapSnapshots(); |
|
|
|
void AddBuildEmbedderGraphCallback(BuildEmbedderGraphCallback callback, |
|
void* data); |
|
void RemoveBuildEmbedderGraphCallback(BuildEmbedderGraphCallback callback, |
|
void* data); |
|
|
|
/** |
|
* Default value of persistent handle class ID. Must not be used to |
|
* define a class. Can be used to reset a class of a persistent |
|
* handle. |
|
*/ |
|
static const uint16_t kPersistentHandleNoClassId = 0; |
|
|
|
private: |
|
HeapProfiler(); |
|
~HeapProfiler(); |
|
HeapProfiler(const HeapProfiler&); |
|
HeapProfiler& operator=(const HeapProfiler&); |
|
}; |
|
|
|
/** |
|
* A struct for exporting HeapStats data from V8, using "push" model. |
|
* See HeapProfiler::GetHeapStats. |
|
*/ |
|
struct HeapStatsUpdate { |
|
HeapStatsUpdate(uint32_t index, uint32_t count, uint32_t size) |
|
: index(index), count(count), size(size) { } |
|
uint32_t index; // Index of the time interval that was changed. |
|
uint32_t count; // New value of count field for the interval with this index. |
|
uint32_t size; // New value of size field for the interval with this index. |
|
}; |
|
|
|
#define CODE_EVENTS_LIST(V) \ |
|
V(Builtin) \ |
|
V(Callback) \ |
|
V(Eval) \ |
|
V(Function) \ |
|
V(InterpretedFunction) \ |
|
V(Handler) \ |
|
V(BytecodeHandler) \ |
|
V(LazyCompile) \ |
|
V(RegExp) \ |
|
V(Script) \ |
|
V(Stub) |
|
|
|
/** |
|
* Note that this enum may be extended in the future. Please include a default |
|
* case if this enum is used in a switch statement. |
|
*/ |
|
enum CodeEventType { |
|
kUnknownType = 0 |
|
#define V(Name) , k##Name##Type |
|
CODE_EVENTS_LIST(V) |
|
#undef V |
|
}; |
|
|
|
/** |
|
* Representation of a code creation event |
|
*/ |
|
class V8_EXPORT CodeEvent { |
|
public: |
|
uintptr_t GetCodeStartAddress(); |
|
size_t GetCodeSize(); |
|
Local<String> GetFunctionName(); |
|
Local<String> GetScriptName(); |
|
int GetScriptLine(); |
|
int GetScriptColumn(); |
|
/** |
|
* NOTE (mmarchini): We can't allocate objects in the heap when we collect |
|
* existing code, and both the code type and the comment are not stored in the |
|
* heap, so we return those as const char*. |
|
*/ |
|
CodeEventType GetCodeType(); |
|
const char* GetComment(); |
|
|
|
static const char* GetCodeEventTypeName(CodeEventType code_event_type); |
|
}; |
|
|
|
/** |
|
* Interface to listen to code creation events. |
|
*/ |
|
class V8_EXPORT CodeEventHandler { |
|
public: |
|
/** |
|
* Creates a new listener for the |isolate|. The isolate must be initialized. |
|
* The listener object must be disposed after use by calling |Dispose| method. |
|
* Multiple listeners can be created for the same isolate. |
|
*/ |
|
explicit CodeEventHandler(Isolate* isolate); |
|
virtual ~CodeEventHandler(); |
|
|
|
virtual void Handle(CodeEvent* code_event) = 0; |
|
|
|
void Enable(); |
|
void Disable(); |
|
|
|
private: |
|
CodeEventHandler(); |
|
CodeEventHandler(const CodeEventHandler&); |
|
CodeEventHandler& operator=(const CodeEventHandler&); |
|
void* internal_listener_; |
|
}; |
|
|
|
} // namespace v8 |
|
|
|
|
|
#endif // V8_V8_PROFILER_H_
|
|
|