// Copyright 2015 The Chromium 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 BASE_PROFILER_STACK_SAMPLER_H_ #define BASE_PROFILER_STACK_SAMPLER_H_ #include #include #include "base/base_export.h" #include "base/callback.h" #include "base/profiler/sampling_profiler_thread_token.h" #include "base/threading/platform_thread.h" namespace base { class Unwinder; class ModuleCache; class ProfileBuilder; class StackBuffer; class StackSamplerTestDelegate; // StackSampler is an implementation detail of StackSamplingProfiler. It // abstracts the native implementation required to record a set of stack frames // for a given thread. class BASE_EXPORT StackSampler { public: // Factory for generating a set of Unwinders for use by the profiler. using UnwindersFactory = OnceCallback>()>; StackSampler(const StackSampler&) = delete; StackSampler& operator=(const StackSampler&) = delete; virtual ~StackSampler(); // Creates a stack sampler that records samples for thread with // |thread_token|. Unwinders in |unwinders| must be stored in increasing // priority to guide unwind attempts. Only the unwinder with the lowest // priority is allowed to return with UnwindResult::kCompleted. Returns null // if this platform does not support stack sampling. static std::unique_ptr Create( SamplingProfilerThreadToken thread_token, ModuleCache* module_cache, UnwindersFactory core_unwinders_factory, RepeatingClosure record_sample_callback, StackSamplerTestDelegate* test_delegate); // Gets the required size of the stack buffer. static size_t GetStackBufferSize(); // Creates an instance of the a stack buffer that can be used for calls to // any StackSampler object. static std::unique_ptr CreateStackBuffer(); // The following functions are all called on the SamplingThread (not the // thread being sampled). // Performs post-construction initialization on the SamplingThread. virtual void Initialize() {} // Adds an auxiliary unwinder to handle additional, non-native-code unwind // scenarios. Unwinders must be inserted in increasing priority, following // |unwinders| provided in Create(), to guide unwind attempts. virtual void AddAuxUnwinder(std::unique_ptr unwinder) = 0; // Records a set of frames and returns them. virtual void RecordStackFrames(StackBuffer* stackbuffer, ProfileBuilder* profile_builder, PlatformThreadId thread_id) = 0; protected: StackSampler(); }; // StackSamplerTestDelegate provides seams for test code to execute during stack // collection. class BASE_EXPORT StackSamplerTestDelegate { public: StackSamplerTestDelegate(const StackSamplerTestDelegate&) = delete; StackSamplerTestDelegate& operator=(const StackSamplerTestDelegate&) = delete; virtual ~StackSamplerTestDelegate(); // Called after copying the stack and resuming the target thread, but prior to // walking the stack. Invoked on the SamplingThread. virtual void OnPreStackWalk() = 0; protected: StackSamplerTestDelegate(); }; } // namespace base #endif // BASE_PROFILER_STACK_SAMPLER_H_