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{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Background Jobs"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"We start by loading the `backgroundjobs` library and defining a few trivial functions to illustrate things with."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import print_function\n",
"from IPython.lib import backgroundjobs as bg\n",
"\n",
"import sys\n",
"import time\n",
"\n",
"def sleepfunc(interval=2, *a, **kw):\n",
" args = dict(interval=interval,\n",
" args=a,\n",
" kwargs=kw)\n",
" time.sleep(interval)\n",
" return args\n",
"\n",
"def diefunc(interval=2, *a, **kw):\n",
" time.sleep(interval)\n",
" raise Exception(\"Dead job with interval %s\" % interval)\n",
"\n",
"def printfunc(interval=1, reps=5):\n",
" for n in range(reps):\n",
" time.sleep(interval)\n",
" print('In the background...', n)\n",
" sys.stdout.flush()\n",
" print('All done!')\n",
" sys.stdout.flush()"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 1
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"Now, we can create a job manager (called simply `jobs`) and use it to submit new jobs.\n",
"
\n",
"Run the cell below and wait a few seconds for the whole thing to finish, until you see the \"All done!\" printout."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"jobs = bg.BackgroundJobManager()\n",
"\n",
"# Start a few jobs, the first one will have ID # 0\n",
"jobs.new(sleepfunc, 4)\n",
"jobs.new(sleepfunc, kw={'reps':2})\n",
"jobs.new('printfunc(1,3)')\n",
"\n",
"# This makes a couple of jobs which will die. Let's keep a reference to\n",
"# them for easier traceback reporting later\n",
"diejob1 = jobs.new(diefunc, 1)\n",
"diejob2 = jobs.new(diefunc, 2)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Starting job # 0 in a separate thread.\n",
"Starting job # 2 in a separate thread.\n",
"Starting job # 3 in a separate thread.\n",
"Starting job # 4 in a separate thread.\n",
"Starting job # 5 in a separate thread.\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"You can check the status of your jobs at any time:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"jobs.status()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"In the background... 0\n",
"Running jobs:"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n",
"0 : \n",
"2 : \n",
"3 : printfunc(1,3)\n",
"5 : \n",
"\n",
"Dead jobs:\n",
"4 : \n",
"\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"For any completed job, you can get its result easily:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"jobs[0].result\n",
"j0 = jobs[0]\n",
"j0.join?"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 4
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"You can get the traceback of any dead job. Run the line\n",
"below again interactively until it prints a traceback (check the status\n",
"of the job):\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"print \"Status of diejob1:\", diejob1.status\n",
"diejob1.traceback() # jobs.traceback(4) would also work here, with the job number"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"In the background... 1\n",
"In the background... 2\n",
"All done!\n"
]
},
{
"ename": "SyntaxError",
"evalue": "invalid syntax (, line 1)",
"output_type": "pyerr",
"traceback": [
"\u001b[0;36m File \u001b[0;32m\"\"\u001b[0;36m, line \u001b[0;32m1\u001b[0m\n\u001b[0;31m print \"Status of diejob1:\", diejob1.status\u001b[0m\n\u001b[0m ^\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m invalid syntax\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"This will print all tracebacks for all dead jobs:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"jobs.traceback()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Traceback for: >\n",
"\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n",
"\u001b[0;31mException\u001b[0m Traceback (most recent call last)\n",
"\u001b[0;32m/Users/bgranger/Documents/Computing/IPython/code/ipython/IPython/lib/backgroundjobs.pyc\u001b[0m in \u001b[0;36mcall\u001b[0;34m(self)\u001b[0m\n",
"\u001b[1;32m 489\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[1;32m 490\u001b[0m \u001b[0;32mdef\u001b[0m \u001b[0mcall\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[0;32m--> 491\u001b[0;31m \u001b[0;32mreturn\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mfunc\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m*\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0margs\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[0m\n",
"\u001b[0;32m\u001b[0m in \u001b[0;36mdiefunc\u001b[0;34m(interval, *a, **kw)\u001b[0m\n",
"\u001b[1;32m 14\u001b[0m \u001b[0;32mdef\u001b[0m \u001b[0mdiefunc\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0minterval\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;36m2\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m*\u001b[0m\u001b[0ma\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkw\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[1;32m 15\u001b[0m \u001b[0mtime\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0msleep\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0minterval\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[0;32m---> 16\u001b[0;31m \u001b[0;32mraise\u001b[0m \u001b[0mException\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Dead job with interval %s\"\u001b[0m \u001b[0;34m%\u001b[0m \u001b[0minterval\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[0m\u001b[1;32m 17\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[1;32m 18\u001b[0m \u001b[0;32mdef\u001b[0m \u001b[0mprintfunc\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0minterval\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mreps\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;36m5\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\n",
"\u001b[0;31mException\u001b[0m: Dead job with interval 1\n",
"\n",
"Traceback for: >\n",
"\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n",
"\u001b[0;31mException\u001b[0m Traceback (most recent call last)\n",
"\u001b[0;32m/Users/bgranger/Documents/Computing/IPython/code/ipython/IPython/lib/backgroundjobs.pyc\u001b[0m in \u001b[0;36mcall\u001b[0;34m(self)\u001b[0m\n",
"\u001b[1;32m 489\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[1;32m 490\u001b[0m \u001b[0;32mdef\u001b[0m \u001b[0mcall\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[0;32m--> 491\u001b[0;31m \u001b[0;32mreturn\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mfunc\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m*\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0margs\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[0m\n",
"\u001b[0;32m\u001b[0m in \u001b[0;36mdiefunc\u001b[0;34m(interval, *a, **kw)\u001b[0m\n",
"\u001b[1;32m 14\u001b[0m \u001b[0;32mdef\u001b[0m \u001b[0mdiefunc\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0minterval\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;36m2\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m*\u001b[0m\u001b[0ma\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkw\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[1;32m 15\u001b[0m \u001b[0mtime\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0msleep\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0minterval\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[0;32m---> 16\u001b[0;31m \u001b[0;32mraise\u001b[0m \u001b[0mException\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Dead job with interval %s\"\u001b[0m \u001b[0;34m%\u001b[0m \u001b[0minterval\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[0m\u001b[1;32m 17\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
"\u001b[1;32m 18\u001b[0m \u001b[0;32mdef\u001b[0m \u001b[0mprintfunc\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0minterval\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mreps\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;36m5\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
"\n",
"\u001b[0;31mException\u001b[0m: Dead job with interval 2\n",
"\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"The job manager can be flushed of all completed jobs at any time:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"jobs.flush()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Flushing 3 Completed jobs.\n",
"Flushing 2 Dead jobs.\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"After that, the status is simply empty:"
]
},
{
"cell_type": "code",
"collapsed": true,
"input": [
"jobs.status()"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 8
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"It's easy to wait on a job:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"j = jobs.new(sleepfunc, 2)\n",
"print(\"Will wait for j now...\")\n",
"sys.stdout.flush()\n",
"j.join()\n",
"print(\"Result from j:\")\n",
"j.result"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Starting job # 0 in a separate thread.\n",
"Will wait for j now...\n"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Result from j:\n"
]
},
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 9,
"text": [
"{'args': (), 'interval': 2, 'kwargs': {}}"
]
}
],
"prompt_number": 9
}
],
"metadata": {}
}
]
}