Try to debug Windows infinite loops in nanobench.
NOTREECHECKS=true
BUG=skia:
Review URL: https://codereview.chromium.org/396753004
diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index 8f3d4aa..4453707 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -50,6 +50,8 @@
DEFINE_string(outResultsFile, "", "If given, write results here as JSON.");
DEFINE_bool(resetGpuContext, true, "Reset the GrContext before running each bench.");
+DEFINE_int32(maxCalibrationAttempts, 3,
+ "Try up to this many times to guess loops for a bench, or skip the bench.");
static SkString humanize(double ms) {
@@ -93,9 +95,14 @@
static int cpu_bench(const double overhead, Benchmark* bench, SkCanvas* canvas, double* samples) {
// First figure out approximately how many loops of bench it takes to make overhead negligible.
double bench_plus_overhead;
+ int round = 0;
do {
bench_plus_overhead = time(1, bench, canvas, NULL);
- } while (bench_plus_overhead < overhead); // Shouldn't normally happen.
+ if (++round == FLAGS_maxCalibrationAttempts) {
+ // At some point we have to just give up.
+ return 0;
+ }
+ } while (bench_plus_overhead < overhead);
// Later we'll just start and stop the timer once but loop N times.
// We'll pick N to make timer overhead negligible:
@@ -306,6 +313,7 @@
bench->preDraw();
for (int j = 0; j < targets.count(); j++) {
SkCanvas* canvas = targets[j]->surface.get() ? targets[j]->surface->getCanvas() : NULL;
+ const char* config = targets[j]->config;
const int loops =
#if SK_SUPPORT_GPU
@@ -315,10 +323,13 @@
#endif
cpu_bench( overhead, bench.get(), canvas, samples.get());
+ if (loops == 0) {
+ SkDebugf("Unable to time %s\t%s (overhead %s)\n",
+ bench->getName(), config, humanize(overhead).c_str());
+ continue;
+ }
+
Stats stats(samples.get(), FLAGS_samples);
-
- const char* config = targets[j]->config;
-
log.config(config);
log.timer("min_ms", stats.min);
log.timer("median_ms", stats.median);