Merge pull request #1311 from juj/emscripten_get_now

emscripten_get_now enabled for SpiderMonkey, optimization and test.

3 files changed, 54 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;
+}
diff --git a/tests/test_browser.py b/tests/test_browser.py
index 32b29966..a0c4dceb 100644
--- a/tests/test_browser.py
+++ b/tests/test_browser.py
@@ -794,6 +794,9 @@ If manually bisecting:
   def test_glut_touchevents(self):
     self.btest('glut_touchevents.c', '1')
 
+  def test_emscripten_get_now(self):
+    self.btest('emscripten_get_now.cpp', '1')
+
   def test_file_db(self):
     secret = str(time.time())
     open('moar.txt', 'w').write(secret)
diff --git a/tests/test_core.py b/tests/test_core.py
index 51face6a..491db66c 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -3734,6 +3734,11 @@ def process(filename):
       Settings.EXPORT_ALL = 1
       self.do_run(src, 'hello world!\n*100*\n*fivesix*\nmann\n', post_build=check)
 
+  def test_emscripten_get_now(self):
+      if self.run_name == 'o2':
+        self.emcc_args += ['--closure', '1'] # Use closure here for some additional coverage
+      self.do_run(open(path_from_root('tests', 'emscripten_get_now.cpp')).read(), 'Timer resolution is good.')
+
   def test_inlinejs(self):
       if Settings.ASM_JS: return self.skip('asm does not support random code, TODO: something that works in asm')
       src = r'''