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Diffstat (limited to 'tests/emscripten_get_now.cpp')
-rw-r--r-- | tests/emscripten_get_now.cpp | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/tests/emscripten_get_now.cpp b/tests/emscripten_get_now.cpp new file mode 100644 index 00000000..17aa7d32 --- /dev/null +++ b/tests/emscripten_get_now.cpp @@ -0,0 +1,46 @@ +#include <stdio.h> +#include "emscripten.h" + +#ifndef REPORT_RESULT +// To be able to run this test outside the browser harness in node.js/spidermonkey: +#define REPORT_RESULT int dummy +#endif + +int result = 0; + +int main() { + // This code tests three things: + // a) Calling emscripten_get_now(), time actually proceeds. + // b) Values returned by emscripten_get_now() are strictly nondecreasing. + // c) emscripten_get_now() is able to return sub-millisecond precision timer values. + bool detected_good_timer_precision = false; + float smallest_delta = 0.f; + for(int x = 0; x < 1000; ++x) { // Have several attempts to find a good small delta, i.e. give time to JS engine to warm up the code and so on. + float t = emscripten_get_now(); + float t2 = emscripten_get_now(); + for(int i = 0; i < 100 && t == t2; ++i) { + t2 = emscripten_get_now(); + } + + if (t2 < t && t2 - t < 1000.f) { // Timer must be monotonous. + printf("Timer is not monotonous!\\n"); + smallest_delta = t2 - t; + break; + } + if (t2 > t && t2 - t < 0.7f) { // Must pass less than a millisecond between two calls. + detected_good_timer_precision = true; + smallest_delta = t2 - t; + break; + } + } + + if (detected_good_timer_precision) { + printf("Timer resolution is good. (%f msecs)\\n", smallest_delta); + result = 1; + } else { + printf("Error: Bad timer precision: Smallest timer delta: %f msecs\\n", smallest_delta); + result = 0; + } + REPORT_RESULT(); + return 0; +} |