gecko-dev/tools/profiler/GeckoProfiler.h

164 lines
6.8 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* *************** SPS Sampler Information ****************
*
* SPS is an always on profiler that takes fast and low overheads samples
* of the program execution using only userspace functionity for portability.
* The goal of this module is to provide performance data in a generic
* cross platform way without requiring custom tools or kernel support.
*
* Non goals: Support features that are platform specific or replace
* platform specific profilers.
*
* Samples are collected to form a timeline with optional timeline event (markers)
* used for filtering.
*
* SPS collects samples in a platform independant way by using a speudo stack abstraction
* of the real program stack by using 'sample stack frames'. When a sample is collected
* all active sample stack frames and the program counter are recorded.
*/
/* *************** SPS Sampler File Format ****************
*
* Simple new line seperated tag format:
* S -> BOF tags EOF
* tags -> tag tags
* tag -> CHAR - STRING
*
* Tags:
* 's' - Sample tag followed by the first stack frame followed by 0 or more 'c' tags.
* 'c' - Continue Sample tag gives remaining tag element. If a 'c' tag is seen without
* a preceding 's' tag it should be ignored. This is to support the behavior
* of circular buffers.
* If the 'stackwalk' feature is enabled this tag will have the format
* 'l-<library name>@<hex address>' and will expect an external tool to translate
* the tag into something readable through a symbolication processing step.
* 'm' - Timeline marker. Zero or more may appear before a 's' tag.
* 'l' - Information about the program counter library and address. Post processing
* can include function and source line. If built with leaf data enabled
* this tag will describe the last 'c' tag.
* 'r' - Responsiveness tag following an 's' tag. Gives an indication on how well the
* application is responding to the event loop. Lower is better.
* 't' - Elapse time since recording started.
*
*/
#ifndef SAMPLER_H
#define SAMPLER_H
#include "jsfriendapi.h"
#include "mozilla/NullPtr.h"
#include "mozilla/TimeStamp.h"
#ifndef MOZ_ENABLE_PROFILER_SPS
// Insert a RAII in this scope to active a pseudo label. Any samples collected
// in this scope will contain this annotation. For dynamic strings use
// PROFILER_LABEL_PRINTF. Arguments must be string literals.
#define PROFILER_LABEL(name_space, info) do {} while (0)
// Format a dynamic string as a pseudo label. These labels will a considerable
// storage size in the circular buffer compared to regular labels. This function
// can be used to annotate custom information such as URL for the resource being
// decoded or the size of the paint.
#define PROFILER_LABEL_PRINTF(name_space, info, format, ...) do {} while (0)
// Insert a marker in the profile timeline. This is useful to delimit something
// important happening such as the first paint. Unlike profiler_label that are
// only recorded if a sample is collected while it is active, marker will always
// be collected.
#define PROFILER_MARKER(info) do {} while (0)
// Main thread specilization to avoid TLS lookup for performance critical use.
#define PROFILER_MAIN_THREAD_LABEL(name_space, info) do {} while (0)
#define PROFILER_MAIN_THREAD_LABEL_PRINTF(name_space, info, format, ...) do {} while (0)
// Initilize the profiler TLS, signal handlers on linux. If MOZ_PROFILER_STARTUP
// is set the profiler will be started. This call must happen before any other
// sampler calls. Particularly sampler_label/sampler_marker.
static inline void profiler_init(void* stackTop) {};
// Clean up the profiler module, stopping it if required. This function may
// also save a shutdown profile if requested. No profiler calls should happen
// after this point and all pseudo labels should have been popped.
static inline void profiler_shutdown() {};
// Start the profiler with the selected options. The samples will be
// recorded in a circular buffer.
// "aProfileEntries" is an abstract size indication of how big
// the profile's circular buffer should be. Multiply by 4
// words to get the cost.
// "aInterval" the sampling interval. The profiler will do its
// best to sample at this interval. The profiler visualization
// should represent the actual sampling accuracy.
static inline void profiler_start(int aProfileEntries, int aInterval,
const char** aFeatures, uint32_t aFeatureCount) {}
// Stop the profiler and discard the profile. Call 'profiler_save' before this
// to retrieve the profile.
static inline void profiler_stop() {}
static inline bool profiler_is_active() { return false; }
// Internal-only. Used by the event tracer.
static inline void profiler_responsiveness(const mozilla::TimeStamp& aTime) {}
// Internal-only. Used by the event tracer.
static inline double* profiler_get_responsiveness() { return nullptr; }
// Internal-only.
static inline void profiler_set_frame_number(int frameNumber) {}
// Get the profile encoded as a JSON string.
static inline char* profiler_get_profile() { return nullptr; }
// Get the profile encoded as a JSON object.
static inline JSObject* profiler_get_profile_jsobject(JSContext* aCx) { return nullptr; }
// Get the features supported by the profiler that are accepted by profiler_init.
// Returns a null terminated char* array.
static inline char** profiler_get_features() { return nullptr; }
// Print the current location to the console. This functill will do it best effort
// to show the profiler's combined js/c++ if the profiler is running. Note that
// printing the location require symbolicating which is very slow.
static inline void profiler_print_location() {}
// Discard the profile, throw away the profile and notify 'profiler-locked'.
// This function is to be used when entering private browsing to prevent
// the profiler from collecting sensitive data.
static inline void profiler_lock() {}
// Re-enable the profiler and notify 'profiler-unlocked'.
static inline void profiler_unlock() {}
static inline void profiler_register_thread(const char* name, void* stackTop) {}
static inline void profiler_unregister_thread() {}
// Call by the JSRuntime's operation callback. This is used to enable
// profiling on auxilerary threads.
static inline void profiler_js_operation_callback() {}
static inline double profiler_time() { return 0; }
#else
#include "GeckoProfilerImpl.h"
#endif
class GeckoProfilerInitRAII {
public:
GeckoProfilerInitRAII(void* stackTop) {
profiler_init(stackTop);
}
~GeckoProfilerInitRAII() {
profiler_shutdown();
}
};
#endif // ifndef SAMPLER_H