[PATCH] D41121: [sanitizer] Introduce a vDSO aware timing function

[Aleksey Shlyapnikov via Phabricator via llvm-commits]

alekseyshl added inline comments.


================
Comment at: lib/sanitizer_common/sanitizer_linux_libcdep.cc:747
+  return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
+}
+
----------------
Now it seems that it would be easier to parse if we separate implementations completely:


  #if SANITIZER_LINUX && !SANITIZER_GO

  ...all the defs...

  u64 MonotonicNanoTime() {
    timespec ts;
    if (CanUseVDSO()) {
      if (&real_clock_gettime)
        real_clock_gettime(CLOCK_MONOTONIC, &ts);
      else
        clock_gettime(CLOCK_MONOTONIC, &ts);
    } else {
      internal_clock_gettime(CLOCK_MONOTONIC, &ts);
    }
    return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
  }

  #else // !(SANITIZER_LINUX && !SANITIZER_GO)

  u64 MonotonicNanoTime() {
    timespec ts;
    internal_clock_gettime(CLOCK_MONOTONIC, &ts);
    return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
  }

  #endif // SANITIZER_LINUX && !SANITIZER_GO



Also can do 

  u64 MonotonicNanoTime() {
    timespec ts;
    MonotonicNanoTimeImpl(&ts)
    return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
  }

and define inlined MonotonicNanoTimeImpls for each case, but that is up to you.


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D41121