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base / trace_event / heap_profiler_allocation_context.h [blame]
// Copyright 2015 The Chromium Authors
// 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_H_
#define BASE_TRACE_EVENT_HEAP_PROFILER_ALLOCATION_CONTEXT_H_
#include <stddef.h>
#include <stdint.h>
#include <functional>
#include "base/base_export.h"
#include "base/memory/raw_ptr.h"
namespace base {
namespace trace_event {
// When heap profiling is enabled, tracing keeps track of the allocation
// context for each allocation intercepted. It is generated by the
// |AllocationContextTracker| which keeps stacks of context in TLS.
// The tracker is initialized lazily.
// The backtrace in the allocation context is a snapshot of the native call
// stack.
// Represents a stack frame. Used in Backtrace class below.
//
// Conceptually stack frame is identified by its value, and type is used
// mostly to properly format the value. Value is expected to be a valid
// pointer from process' address space.
struct BASE_EXPORT StackFrame {
enum class Type {
kThreadName, // const char* thread name
kProgramCounter, // as returned by stack tracing (e.g. by StackTrace)
};
static StackFrame FromThreadName(const char* name) {
return {Type::kThreadName, name};
}
static StackFrame FromProgramCounter(const void* pc) {
return {Type::kProgramCounter, pc};
}
Type type;
raw_ptr<const void> value;
};
bool BASE_EXPORT operator < (const StackFrame& lhs, const StackFrame& rhs);
bool BASE_EXPORT operator == (const StackFrame& lhs, const StackFrame& rhs);
bool BASE_EXPORT operator != (const StackFrame& lhs, const StackFrame& rhs);
struct BASE_EXPORT Backtrace {
Backtrace();
// If the stack is higher than what can be stored here, the top frames
// (the ones further from main()) are stored. Depth of 12 is enough for most
// pseudo traces (see above), but not for native traces, where we need more.
enum { kMaxFrameCount = 48 };
StackFrame frames[kMaxFrameCount];
size_t frame_count = 0;
};
bool BASE_EXPORT operator==(const Backtrace& lhs, const Backtrace& rhs);
bool BASE_EXPORT operator!=(const Backtrace& lhs, const Backtrace& rhs);
// The |AllocationContext| is context metadata that is kept for every allocation
// when heap profiling is enabled. To simplify memory management for book-
// keeping, this struct has a fixed size.
struct BASE_EXPORT AllocationContext {
AllocationContext();
AllocationContext(const Backtrace& backtrace, const char* type_name);
Backtrace backtrace;
// Type name of the type stored in the allocated memory. A null pointer
// indicates "unknown type". Grouping is done by comparing pointers, not by
// deep string comparison. In a component build, where a type name can have a
// string literal in several dynamic libraries, this may distort grouping.
const char* type_name;
};
bool BASE_EXPORT operator==(const AllocationContext& lhs,
const AllocationContext& rhs);
bool BASE_EXPORT operator!=(const AllocationContext& lhs,
const AllocationContext& rhs);
// Struct to store the size and count of the allocations.
struct AllocationMetrics {
size_t size;
size_t count;
};
} // namespace trace_event
} // namespace base
namespace std {
template <>
struct BASE_EXPORT hash<base::trace_event::StackFrame> {
size_t operator()(const base::trace_event::StackFrame& frame) const;
};
template <>
struct BASE_EXPORT hash<base::trace_event::Backtrace> {
size_t operator()(const base::trace_event::Backtrace& backtrace) const;
};
template <>
struct BASE_EXPORT hash<base::trace_event::AllocationContext> {
size_t operator()(const base::trace_event::AllocationContext& context) const;
};
} // namespace std
#endif // BASE_TRACE_EVENT_HEAP_PROFILER_ALLOCATION_CONTEXT_H_