[pypy-svn] r59906 - pypy/build/benchmem

[xoraxax at codespeak.net]

Author: xoraxax
Date: Thu Nov 13 21:56:02 2008
New Revision: 59906

Modified:
   pypy/build/benchmem/runbench.py
Log:
Only run the actual function when run argument is used, generate less samples by employing busy looping/waiting.

Modified: pypy/build/benchmem/runbench.py
==============================================================================
--- pypy/build/benchmem/runbench.py	(original)
+++ pypy/build/benchmem/runbench.py	Thu Nov 13 21:56:02 2008
@@ -299,19 +299,34 @@
                 """, self.getbenchsource(), """
 
             def init():
-                %s %s
+                if len(sys.argv) > 1 and sys.argv[1] == 'run':
+                    %s %s
                 sys.stdin.close()
 
         """ %(name, arglist))
         p = self.tmpdir.join("generatedbenchmark.py")
         p.write(source)
         return runner_file
-    
+
     def interact_with_child(self, rec, stdin, stdout):
         while not stdin.closed:
             try:
-                self.write_internal_header({"TS": str(time.time())})
+                ts = time.time()
+                self.write_internal_header({"TS": str(ts)})
                 rec.snapshot()
+
+                # if we yielded to the scheduler via sleep(), the process
+                # under test would advance more than while we are running in
+                # our sampling code. instead of that, we do busy waiting here
+                # because some systems
+                # this program is used on only provide 20 hz sampling rate
+                # when doing no sleep at all.
+                # also we do not adjust the waiting time to the wall clock
+                # because this would give very different results based on
+                # the system speed. a better solution would be cpu timers
+                # or ptrace etc.
+                for _ in xrange(2**13):
+                    pass
             except py.error.ENOENT:
                 break
         rec.stream.flush()