profiling option from C++

3 files changed, 75 insertions, 1 deletions

diff --git a/src/library.js b/src/library.js
index faa86c68..4d230bcc 100644
--- a/src/library.js
+++ b/src/library.js
@@ -5417,6 +5417,36 @@ LibraryManager.library = {
   EMSCRIPTEN_COMMENT__inline: function(param) {
     param = stripCorrections(param);
     return '// ' + Variables.globals[param].value.text.replace('\\00', '') + '   ';
+  },
+
+  $Profiling: {
+    max_: 0,
+    times: null,
+    invalid: 0,
+    dump: function() {
+      if (Profiling.invalid) {
+        print('Invalid # of calls to Profiling begin and end!');
+        return;
+      }
+      print('Profiling data:')
+      for (var i = 0; i < Profiling.max_; i++) {
+        print('Block ' + i + ': ' + Profiling.times[i]);
+      }
+    }
+  },
+  EMSCRIPTEN_PROFILE_INIT__deps: ['$Profiling'],
+  EMSCRIPTEN_PROFILE_INIT: function(max_) {
+    Profiling.max_ = max_;
+    Profiling.times = new Array(max_);
+    for (var i = 0; i < max_; i++) Profiling.times[i] = 0;
+  },
+  EMSCRIPTEN_PROFILE_BEGIN__inline: function(id) {
+    return 'Profiling.times[' + id + '] -= Date.now();'
+         + 'Profiling.invalid++;'
+  },
+  EMSCRIPTEN_PROFILE_END__inline: function(id) {
+    return 'Profiling.times[' + id + '] += Date.now();'
+         + 'Profiling.invalid--;'
   }
 };
 
diff --git a/system/include/emscripten.h b/system/include/emscripten.h
index 4d321b2c..0ce31e9f 100644
--- a/system/include/emscripten.h
+++ b/system/include/emscripten.h
@@ -23,6 +23,19 @@ extern void emscripten_run_script(const char *script);
  */
 extern void EMSCRIPTEN_COMMENT(const char *text);
 
+/*
+ * Profiling tools.
+ * INIT must be called first, with the maximum identifier that
+ * will be used. BEGIN will add some code that marks
+ * the beginning of a section of code whose run time you
+ * want to measure. END will finish such a section. Note: If you
+ * call begin but not end, you will get invalid data!
+ * The profiling data will be written out if you call Profile.dump().
+ */
+extern void EMSCRIPTEN_PROFILE_INIT(int max);
+extern void EMSCRIPTEN_PROFILE_BEGIN(int id);
+extern void EMSCRIPTEN_PROFILE_END(int id);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/tests/runner.py b/tests/runner.py
index 3fd63574..fe2f0f85 100644
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -3381,6 +3381,38 @@ if 'benchmark' not in str(sys.argv):
       self.do_run(src, '*hello slim world*', build_ll_hook=hook)
 
     def test_profiling(self):
+      src = '''
+          #include <emscripten.h>
+          #include <unistd.h>
+
+          int main()
+          {
+            EMSCRIPTEN_PROFILE_INIT(3);
+            EMSCRIPTEN_PROFILE_BEGIN(0);
+            usleep(10 * 1000);
+            EMSCRIPTEN_PROFILE_END(0);
+            EMSCRIPTEN_PROFILE_BEGIN(1);
+            usleep(50 * 1000);
+            EMSCRIPTEN_PROFILE_END(1);
+            EMSCRIPTEN_PROFILE_BEGIN(2);
+            usleep(250 * 1000);
+            EMSCRIPTEN_PROFILE_END(2);
+            return 0;
+          }
+        '''
+
+      def post1(filename):
+        src = open(filename, 'a')
+        src.write('''
+          Profiling.dump();
+        ''')
+        src.close()
+
+      self.do_run(src, '''Profiling data:
+Block 0: ''', post_build=post1)
+
+      # Part 2: old JS version
+
       Settings.PROFILE = 1
       Settings.INVOKE_RUN = 0
 
@@ -3427,7 +3459,6 @@ if 'benchmark' not in str(sys.argv):
         ''')
         src.close()
 
-      # Using build_ll_hook forces a recompile, which leads to DFE being done even without opts
       self.do_run(src, ': __Z6inner1i (5000)\n*ok*', post_build=post)
 
     ### Integration tests