| // 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_TRACE_EVENT_HEAP_PROFILER_ALLOCATION_CONTEXT_TRACKER_H_ |
| #define BASE_TRACE_EVENT_HEAP_PROFILER_ALLOCATION_CONTEXT_TRACKER_H_ |
| |
| #include <vector> |
| |
| #include "base/atomicops.h" |
| #include "base/base_export.h" |
| #include "base/logging.h" |
| #include "base/macros.h" |
| #include "base/trace_event/heap_profiler_allocation_context.h" |
| |
| namespace base { |
| namespace trace_event { |
| |
| // The allocation context tracker keeps track of thread-local context for heap |
| // profiling. It includes a pseudo stack of trace events. On every allocation |
| // the tracker provides a snapshot of its context in the form of an |
| // |AllocationContext| that is to be stored together with the allocation |
| // details. |
| class BASE_EXPORT AllocationContextTracker { |
| public: |
| // Globally enables capturing allocation context. |
| // TODO(ruuda): Should this be replaced by |EnableCapturing| in the future? |
| // Or at least have something that guards agains enable -> disable -> enable? |
| static void SetCaptureEnabled(bool enabled); |
| |
| // Returns whether capturing allocation context is enabled globally. |
| inline static bool capture_enabled() { |
| // A little lag after heap profiling is enabled or disabled is fine, it is |
| // more important that the check is as cheap as possible when capturing is |
| // not enabled, so do not issue a memory barrier in the fast path. |
| if (subtle::NoBarrier_Load(&capture_enabled_) == 0) |
| return false; |
| |
| // In the slow path, an acquire load is required to pair with the release |
| // store in |SetCaptureEnabled|. This is to ensure that the TLS slot for |
| // the thread-local allocation context tracker has been initialized if |
| // |capture_enabled| returns true. |
| return subtle::Acquire_Load(&capture_enabled_) != 0; |
| } |
| |
| // Pushes a frame onto the thread-local pseudo stack. |
| static void PushPseudoStackFrame(StackFrame frame); |
| |
| // Pops a frame from the thread-local pseudo stack. |
| static void PopPseudoStackFrame(StackFrame frame); |
| |
| // Returns a snapshot of the current thread-local context. |
| static AllocationContext GetContextSnapshot(); |
| |
| ~AllocationContextTracker(); |
| |
| private: |
| AllocationContextTracker(); |
| |
| static AllocationContextTracker* GetThreadLocalTracker(); |
| |
| static subtle::Atomic32 capture_enabled_; |
| |
| // The pseudo stack where frames are |TRACE_EVENT| names. |
| std::vector<StackFrame> pseudo_stack_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AllocationContextTracker); |
| }; |
| |
| } // namespace trace_event |
| } // namespace base |
| |
| #endif // BASE_TRACE_EVENT_HEAP_PROFILER_ALLOCATION_CONTEXT_TRACKER_H_ |