Currently the Gecko Profiler defines a moderate amount of stuff when
MOZ_GECKO_PROFILER is undefined. It also #includes various headers, including
JS ones. This is making it difficult to separate Gecko's media stack for
inclusion in Servo.
This patch greatly simplifies how things are exposed. The starting point is:
- GeckoProfiler.h can be #included unconditionally;
- everything else from the profiler must be guarded by MOZ_GECKO_PROFILER.
In practice this introduces way too many #ifdefs, so the patch loosens it by
adding no-op macros for a number of the most common operations.
The net result is that #ifdefs and macros are used a bit more, but almost
nothing is exposed in non-MOZ_GECKO_PROFILER builds (including
ProfilerMarkerPayload.h and GeckoProfiler.h), and understanding what is exposed
is much simpler than before.
Note also that in BHR, ThreadStackHelper is now entirely absent in
non-MOZ_GECKO_PROFILER builds.
This patch does the following renamings, which increase consistency.
- GeckoProfilerInitRAII -> AutoProfilerInit
- GeckoProfilerThread{Sleep,Wake}RAII -> AutoProfilerThread{Sleep,Wake}
- GeckoProfilerTracingRAII -> AutoProfilerTracing
- AutoProfilerRegister -> AutoProfilerRegisterThread
- ProfilerStackFrameRAII -> AutoProfilerLabel
- nsJSUtils::mProfilerRAII -> nsJSUtils::mAutoProfilerLabel
Plus a few other minor ones (e.g. local variables).
The patch also add MOZ_GUARD_OBJECT macros to all the profiler RAII classes
that lack them, and does some minor whitespace reformatting.
This change moves us away from NSPR primitives for our primary
synchronization primitives. We're still using PRMonitor for
ReentrantMonitor, however.
The benefits of this change:
* Slightly faster, as we don't have to deal with some of NSPR's overhead;
* Smaller datatypes. On POSIX platforms in particular, PRLock is
enormous. PRCondVar also has some unnecessary overhead.
* Less dynamic memory allocation. Out of necessity, Mutex and CondVar
allocated the NSPR data structures they needed, which lead to
unnecessary checks for failure.
While sizeof(Mutex) and sizeof(CondVar) may get bigger, since they're
embedding structures now, the total memory usage should be less.
* Less NSPR usage. This shouldn't need any explanation.
The new names make it clearer that these actions apply to just one thread.
- profiler_sleep_start() --> profiler_thread_sleep()
- profiler_sleep_end() --> profiler_thread_wake()
- profiler_is_sleeping() --> profiler_thread_is_sleeping()
- GeckoProfilerSleepRAII --> GeckoProfilerThreadSleepRAII
- GeckoProfilerWakeRAII --> GeckoProfilerThreadWakeRAII
