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comparison: js/src/perf/jsperf.h
js/src/perf/jsperf.h
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| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ | |
| 2 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 3 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 5 | |
| 6 #ifndef perf_jsperf_h | |
| 7 #define perf_jsperf_h | |
| 8 | |
| 9 #include "jstypes.h" | |
| 10 | |
| 11 #include "js/TypeDecls.h" | |
| 12 #include "js/Utility.h" | |
| 13 | |
| 14 namespace JS { | |
| 15 | |
| 16 /* | |
| 17 * JS::PerfMeasurement is a generic way to access detailed performance | |
| 18 * measurement APIs provided by your operating system. The details of | |
| 19 * exactly how this works and what can be measured are highly | |
| 20 * system-specific, but this interface is (one hopes) implementable | |
| 21 * on top of all of them. | |
| 22 * | |
| 23 * To use this API, create a PerfMeasurement object, passing its | |
| 24 * constructor a bitmask indicating which events you are interested | |
| 25 * in. Thereafter, Start() zeroes all counters and starts timing; | |
| 26 * Stop() stops timing again; and the counters for the events you | |
| 27 * requested are available as data values after calling Stop(). The | |
| 28 * object may be reused for many measurements. | |
| 29 */ | |
| 30 class JS_FRIEND_API(PerfMeasurement) | |
| 31 { | |
| 32 protected: | |
| 33 // Implementation-specific data, if any. | |
| 34 void* impl; | |
| 35 | |
| 36 public: | |
| 37 /* | |
| 38 * Events that may be measured. Taken directly from the list of | |
| 39 * "generalized hardware performance event types" in the Linux | |
| 40 * perf_event API, plus some of the "software events". | |
| 41 */ | |
| 42 enum EventMask { | |
| 43 CPU_CYCLES = 0x00000001, | |
| 44 INSTRUCTIONS = 0x00000002, | |
| 45 CACHE_REFERENCES = 0x00000004, | |
| 46 CACHE_MISSES = 0x00000008, | |
| 47 BRANCH_INSTRUCTIONS = 0x00000010, | |
| 48 BRANCH_MISSES = 0x00000020, | |
| 49 BUS_CYCLES = 0x00000040, | |
| 50 PAGE_FAULTS = 0x00000080, | |
| 51 MAJOR_PAGE_FAULTS = 0x00000100, | |
| 52 CONTEXT_SWITCHES = 0x00000200, | |
| 53 CPU_MIGRATIONS = 0x00000400, | |
| 54 | |
| 55 ALL = 0x000007ff, | |
| 56 NUM_MEASURABLE_EVENTS = 11 | |
| 57 }; | |
| 58 | |
| 59 /* | |
| 60 * Bitmask of events that will be measured when this object is | |
| 61 * active (between Start() and Stop()). This may differ from the | |
| 62 * bitmask passed to the constructor if the platform does not | |
| 63 * support measuring all of the requested events. | |
| 64 */ | |
| 65 const EventMask eventsMeasured; | |
| 66 | |
| 67 /* | |
| 68 * Counters for each measurable event. | |
| 69 * Immediately after one of these objects is created, all of the | |
| 70 * counters for enabled events will be zero, and all of the | |
| 71 * counters for disabled events will be uint64_t(-1). | |
| 72 */ | |
| 73 uint64_t cpu_cycles; | |
| 74 uint64_t instructions; | |
| 75 uint64_t cache_references; | |
| 76 uint64_t cache_misses; | |
| 77 uint64_t branch_instructions; | |
| 78 uint64_t branch_misses; | |
| 79 uint64_t bus_cycles; | |
| 80 uint64_t page_faults; | |
| 81 uint64_t major_page_faults; | |
| 82 uint64_t context_switches; | |
| 83 uint64_t cpu_migrations; | |
| 84 | |
| 85 /* | |
| 86 * Prepare to measure the indicated set of events. If not all of | |
| 87 * the requested events can be measured on the current platform, | |
| 88 * then the eventsMeasured bitmask will only include the subset of | |
| 89 * |toMeasure| corresponding to the events that can be measured. | |
| 90 */ | |
| 91 PerfMeasurement(EventMask toMeasure); | |
| 92 | |
| 93 /* Done with this set of measurements, tear down OS-level state. */ | |
| 94 ~PerfMeasurement(); | |
| 95 | |
| 96 /* Start a measurement cycle. */ | |
| 97 void start(); | |
| 98 | |
| 99 /* | |
| 100 * End a measurement cycle, and for each enabled counter, add the | |
| 101 * number of measured events of that type to the appropriate | |
| 102 * visible variable. | |
| 103 */ | |
| 104 void stop(); | |
| 105 | |
| 106 /* Reset all enabled counters to zero. */ | |
| 107 void reset(); | |
| 108 | |
| 109 /* | |
| 110 * True if this platform supports measuring _something_, i.e. it's | |
| 111 * not using the stub implementation. | |
| 112 */ | |
| 113 static bool canMeasureSomething(); | |
| 114 }; | |
| 115 | |
| 116 /* Inject a Javascript wrapper around the above C++ class into the | |
| 117 * Javascript object passed as an argument (this will normally be a | |
| 118 * global object). The JS-visible API is identical to the C++ API. | |
| 119 */ | |
| 120 extern JS_FRIEND_API(JSObject*) | |
| 121 RegisterPerfMeasurement(JSContext *cx, JS::HandleObject global); | |
| 122 | |
| 123 /* | |
| 124 * Given a Value which contains an instance of the aforementioned | |
| 125 * wrapper class, extract the C++ object. Returns nullptr if the | |
| 126 * Value is not an instance of the wrapper. | |
| 127 */ | |
| 128 extern JS_FRIEND_API(PerfMeasurement*) | |
| 129 ExtractPerfMeasurement(Value wrapper); | |
| 130 | |
| 131 } // namespace JS | |
| 132 | |
| 133 #endif /* perf_jsperf_h */ |
