The Tor Browser / file comparison
comparison: security/sandbox/chromium/base/debug/profiler.h
security/sandbox/chromium/base/debug/profiler.h
- branch
- TOR_BUG_3246
- changeset 6
- 8bccb770b82d
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| -1:000000000000 | 0:f5a6fbddd718 |
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| 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 | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #ifndef BASE_DEBUG_PROFILER_H | |
| 6 #define BASE_DEBUG_PROFILER_H | |
| 7 | |
| 8 #include <string> | |
| 9 | |
| 10 #include "base/base_export.h" | |
| 11 #include "base/basictypes.h" | |
| 12 | |
| 13 // The Profiler functions allow usage of the underlying sampling based | |
| 14 // profiler. If the application has not been built with the necessary | |
| 15 // flags (-DENABLE_PROFILING and not -DNO_TCMALLOC) then these functions | |
| 16 // are noops. | |
| 17 namespace base { | |
| 18 namespace debug { | |
| 19 | |
| 20 // Start profiling with the supplied name. | |
| 21 // {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 BASE_EXPORT void StartProfiling(const std::string& name); | |
| 24 | |
| 25 // Stop profiling and write out data. | |
| 26 BASE_EXPORT void StopProfiling(); | |
| 27 | |
| 28 // Force data to be written to file. | |
| 29 BASE_EXPORT void FlushProfiling(); | |
| 30 | |
| 31 // Returns true if process is being profiled. | |
| 32 BASE_EXPORT bool BeingProfiled(); | |
| 33 | |
| 34 // Reset profiling after a fork, which disables timers. | |
| 35 BASE_EXPORT void RestartProfilingAfterFork(); | |
| 36 | |
| 37 // Returns true iff this executable is instrumented with the Syzygy profiler. | |
| 38 BASE_EXPORT bool IsBinaryInstrumented(); | |
| 39 | |
| 40 // There's a class of profilers that use "return address swizzling" to get a | |
| 41 // hook on function exits. This class of profilers uses some form of entry hook, | |
| 42 // like e.g. binary instrumentation, or a compiler flag, that calls a hook each | |
| 43 // time a function is invoked. The hook then switches the return address on the | |
| 44 // stack for the address of an exit hook function, and pushes the original | |
| 45 // return address to a shadow stack of some type. When in due course the CPU | |
| 46 // executes a return to the exit hook, the exit hook will do whatever work it | |
| 47 // does on function exit, then arrange to return to the original return address. | |
| 48 // This class of profiler does not play well with programs that look at the | |
| 49 // return address, as does e.g. V8. V8 uses the return address to certain | |
| 50 // runtime functions to find the JIT code that called it, and from there finds | |
| 51 // the V8 data structures associated to the JS function involved. | |
| 52 // A return address resolution function is used to fix this. It allows such | |
| 53 // programs to resolve a location on stack where a return address originally | |
| 54 // resided, to the shadow stack location where the profiler stashed it. | |
| 55 typedef uintptr_t (*ReturnAddressLocationResolver)( | |
| 56 uintptr_t return_addr_location); | |
| 57 | |
| 58 // This type declaration must match V8's FunctionEntryHook. | |
| 59 typedef void (*DynamicFunctionEntryHook)(uintptr_t function, | |
| 60 uintptr_t return_addr_location); | |
| 61 | |
| 62 // The functions below here are to support profiling V8-generated code. | |
| 63 // V8 has provisions for generating a call to an entry hook for newly generated | |
| 64 // JIT code, and it can push symbol information on code generation and advise | |
| 65 // when the garbage collector moves code. The functions declarations below here | |
| 66 // make glue between V8's facilities and a profiler. | |
| 67 | |
| 68 // This type declaration must match V8's FunctionEntryHook. | |
| 69 typedef void (*DynamicFunctionEntryHook)(uintptr_t function, | |
| 70 uintptr_t return_addr_location); | |
| 71 | |
| 72 typedef void (*AddDynamicSymbol)(const void* address, | |
| 73 size_t length, | |
| 74 const char* name, | |
| 75 size_t name_len); | |
| 76 typedef void (*MoveDynamicSymbol)(const void* address, const void* new_address); | |
| 77 | |
| 78 | |
| 79 // If this binary is instrumented and the instrumentation supplies a function | |
| 80 // for each of those purposes, find and return the function in question. | |
| 81 // Otherwise returns NULL. | |
| 82 BASE_EXPORT ReturnAddressLocationResolver GetProfilerReturnAddrResolutionFunc(); | |
| 83 BASE_EXPORT DynamicFunctionEntryHook GetProfilerDynamicFunctionEntryHookFunc(); | |
| 84 BASE_EXPORT AddDynamicSymbol GetProfilerAddDynamicSymbolFunc(); | |
| 85 BASE_EXPORT MoveDynamicSymbol GetProfilerMoveDynamicSymbolFunc(); | |
| 86 | |
| 87 } // namespace debug | |
| 88 } // namespace base | |
| 89 | |
| 90 #endif // BASE_DEBUG_DEBUGGER_H |
