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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef BASE_DEBUG_PROFILER_H | 5 #ifndef BASE_DEBUG_PROFILER_H |
6 #define BASE_DEBUG_PROFILER_H | 6 #define BASE_DEBUG_PROFILER_H |
7 #pragma once | 7 #pragma once |
8 | 8 |
9 #include <string> | 9 #include <string> |
10 | 10 |
11 #include "base/base_export.h" | 11 #include "base/base_export.h" |
| 12 #include "base/basictypes.h" |
12 | 13 |
13 // The Profiler functions allow usage of the underlying sampling based | 14 // The Profiler functions allow usage of the underlying sampling based |
14 // profiler. If the application has not been built with the necessary | 15 // profiler. If the application has not been built with the necessary |
15 // flags (-DENABLE_PROFILING and not -DNO_TCMALLOC) then these functions | 16 // flags (-DENABLE_PROFILING and not -DNO_TCMALLOC) then these functions |
16 // are noops. | 17 // are noops. |
17 namespace base { | 18 namespace base { |
18 namespace debug { | 19 namespace debug { |
19 | 20 |
20 // Start profiling with the supplied name. | 21 // Start profiling with the supplied name. |
21 // {pid} will be replaced by the process' pid and {count} will be replaced | 22 // {pid} will be replaced by the process' pid and {count} will be replaced |
22 // by the count of the profile run (starts at 1 with each process). | 23 // by the count of the profile run (starts at 1 with each process). |
23 BASE_EXPORT void StartProfiling(const std::string& name); | 24 BASE_EXPORT void StartProfiling(const std::string& name); |
24 | 25 |
25 // Stop profiling and write out data. | 26 // Stop profiling and write out data. |
26 BASE_EXPORT void StopProfiling(); | 27 BASE_EXPORT void StopProfiling(); |
27 | 28 |
28 // Force data to be written to file. | 29 // Force data to be written to file. |
29 BASE_EXPORT void FlushProfiling(); | 30 BASE_EXPORT void FlushProfiling(); |
30 | 31 |
31 // Returns true if process is being profiled. | 32 // Returns true if process is being profiled. |
32 BASE_EXPORT bool BeingProfiled(); | 33 BASE_EXPORT bool BeingProfiled(); |
33 | 34 |
34 // Reset profiling after a fork, which disables timers. | 35 // Reset profiling after a fork, which disables timers. |
35 BASE_EXPORT void RestartProfilingAfterFork(); | 36 BASE_EXPORT void RestartProfilingAfterFork(); |
36 | 37 |
| 38 // Returns true iff this executable is instrumented with the Syzygy profiler. |
| 39 BASE_EXPORT bool IsBinaryInstrumented(); |
| 40 |
| 41 // There's a class of profilers that use "return address swizzling" to get a |
| 42 // hook on function exits. This class of profilers uses some form of entry hook, |
| 43 // like e.g. binary instrumentation, or a compiler flag, that calls a hook each |
| 44 // time a function is invoked. The hook then switches the return address on the |
| 45 // stack for the address of an exit hook function, and pushes the original |
| 46 // return address to a shadow stack of some type. When in due course the CPU |
| 47 // executes a return to the exit hook, the exit hook will do whatever work it |
| 48 // does on function exit, then arrange to return to the original return address. |
| 49 // This class of profiler does not play well with programs that look at the |
| 50 // return address, as does e.g. V8. V8 uses the return address to certain |
| 51 // runtime functions to find the JIT code that called it, and from there finds |
| 52 // the V8 data structures associated to the JS function involved. |
| 53 // A return address resolution function is used to fix this. It allows such |
| 54 // programs to resolve a location on stack where a return address originally |
| 55 // resided, to the shadow stack location where the profiler stashed it. |
| 56 typedef uintptr_t (*ReturnAddressLocationResolver)( |
| 57 uintptr_t return_addr_location); |
| 58 |
| 59 // If this binary is instrumented and the instrumentation supplies a return |
| 60 // address resolution function, finds and returns the address resolution |
| 61 // function. Otherwise returns NULL. |
| 62 BASE_EXPORT ReturnAddressLocationResolver |
| 63 GetProfilerReturnAddrResolutionFunc(); |
| 64 |
37 } // namespace debug | 65 } // namespace debug |
38 } // namespace base | 66 } // namespace base |
39 | 67 |
40 #endif // BASE_DEBUG_DEBUGGER_H | 68 #endif // BASE_DEBUG_DEBUGGER_H |
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