docs/examples/tests/heartbeat/gilsleep.ipynb

{
 "metadata": {
  "name": "gilsleep"
 }, 
 "nbformat": 2, 
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "markdown", 
     "source": [
      "Holding the GIL for too long could disrupt the heartbeat due to non-copying sends.", 
      "", 
      "The following cell repeatedly calls a function that holds the GIL for five seconds.", 
      "", 
      "The heartbeat will fail after a few iterations prior to fixing Issue [#1260](https://github.com/ipython/ipython/issues/1260)."
     ]
    }, 
    {
     "cell_type": "code", 
     "collapsed": false, 
     "input": [
      "import sys", 
      "import time", 
      "", 
      "from cython import inline", 
      "", 
      "def gilsleep(t):", 
      "    \"\"\"gil-holding sleep with cython.inline\"\"\"", 
      "    code = '\\n'.join([", 
      "        'from posix cimport unistd',", 
      "        'unistd.sleep(t)',", 
      "    ])", 
      "    while True:", 
      "        inline(code, quiet=True, t=t)", 
      "        print time.time()", 
      "        sys.stdout.flush() # this is important", 
      "", 
      "gilsleep(5)"
     ], 
     "language": "python", 
     "outputs": [], 
     "prompt_number": 1
    }, 
    {
     "cell_type": "code", 
     "collapsed": true, 
     "input": [], 
     "language": "python", 
     "outputs": [], 
     "prompt_number": " "
    }
   ]
  }
 ]
}