Change ThreadCPUUsage to call ProcessCPUUsage if __rtems__ is defined.
RTEMS real time OS doesn't support CLOCK_THREAD_CPUTIME_ID. See
https://github.com/RTEMS/rtems/blob/master/cpukit/posix/src/clockgettime.c#L58-L59
Prior to this change, ThreadCPUUsage would fail when running on RTEMS with:
ERROR: clock_gettime(CLOCK_THREAD_CPUTIME_ID, ...) failed
* Implement cycleclock::Now for PNaCl
* Make cycleclock::Now compatible with NaCl/ARM
* Support Emscripten (Asm.js, WebAssembly)
* Rearrange #ifs from to handle specific cases first
* DoNotOptimize without inline asm for Emscripten & PNaCl
* Refactor benchmark.cc into benchmark_register.cc and benchmark_run.cc
The benchmark.cc file is getting really big and it contains a bunch of
unrelated components. This patch separates the files into two separate
parts. The "runtime" parts and the "registration" parts.
This patch also removes the PIMPL used by Benchmark. Previously we couldn't
have STL types in the interface but now we can. Therefore there is no reason
to keep BenchmarkImp.
* add missing include
* rework windows timers again
* Guard timespec on older Windows versions
* Remove old thread safety annotation workarounds
* Change to using per-thread timers
* fix bad assertions
* fix copy paste error on windows
* Fix thread safety annotations
* Make null-log thread safe
* remove remaining globals
* use chrono for walltime since it is thread safe
* consolidate timer functions
* Add missing ctime include
* Rename to be consistent with Google style
* Format patch using clang-format
* cleanup -Wthread-safety configuration
* Don't trust _POSIX_FEATURE macros because OS X lies.
* Fix OS X thread timings
* attempt to fix mingw build
* Attempt to make mingw work again
* Revert old mingw workaround
* improve diagnostics
* Drastically improve OS X measurements
* Use average real time instead of max
