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________
_,.-Y | | Y-._
.-~" || | | | "-.
I" ""=="|" !""! "|"[]""| _____
L__ [] |..------|: _[----I" .-{"-.
I___| ..| l______|l_ [__L]_[I_/r(=}=-P
[L______L_[________]______j~ '-=c_]/=-^
\_I_j.--.\==I|I==_/.--L_]
[_((==)[`-----"](==)j
I--I"~~"""~~"I--I
|[]| |[]|
l__j l__j
|!!| |!!|
|..| |..|
([]) ([])
]--[ ]--[
[_L] [_L] -Row
/|..|\ /|..|\
`=}--{=' `=}--{='
.-^--r-^-. .-^--r-^-.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
__ __
____ _/ /_ ____ _/ /_
/ __ `/ __/______/ __ `/ __/
/ /_/ / /_ /_____/ /_/ / /_
\__,_/\__/ \__,_/\__/
### at-at
Simple ahead-of-time function scheduler. Allows you to schedule the execution of an anonymous function for a point in the future.
### Basic Usage
First pull in the lib:
(use 'overtone.at-at)
`at-at` uses `ScheduledThreadPoolExecutor`s behind the scenes which use a thread pool to run the scheduled tasks. You therefore need create a pool before you can get going:
(def my-pool (mk-pool))
It is possible to pass in extra options `:cpu-count`, `:stop-delayed?` and `:stop-periodic?` to further configure your pool. See `mk-pool`'s docstring for further info.
Next, schedule the function of your dreams. Here we schedule the function to execute in 1000 ms from now (i.e. 1 second):
(at (+ 1000 (now)) #(println "hello from the past!") my-pool)
You may also specify a description for the scheduled task with the optional `:desc` key.
Another way of achieving the same result is to use `after` which takes a delaty time in ms from now:
(after 1000 #(println "hello from the past!") my-pool)
You can also schedule functions to occur periodically. Here we schedule the function to execute every second:
(every 1000 #(println "I am cool!") my-pool)
This returns a shceduled-fn which may easily be stopped `stop`:
(stop *1)
Or more forcefully killed with `kill`.
It's also possible to start a periodic repeating fn with an inital delay:
(every 1000 #(println "I am cool!") my-pool :initial-delay 2000)
Finally, you can also schedule tasks for a fixed delay (vs a rate):
(every 1000 #(println "I am cool!") my-pool :fixed-delay true)
This means that it will wait 1000 ms after the task is completed before
starting the next one.
### Resetting a pool.
When necessary it's possible to stop and reset a given pool:
(stop-and-reset-pool! my-pool)
You may forcefully reset the pool using the `:kill` strategy:
(stop-and-reset-pool! my-pool :strategy :kill)
### Viewing running scheduled tasks.
`at-at` keeps an eye on all the tasks you've scheduled. You can get a set of the current jobs (both scheduled and recurring) using `scheduled-jobs` and you can pretty-print a list of these job using `show-schedule`. The ids shown in the output of `show-schedule` are also accepted in `kill` and `stop`, provided you also specify the associated pool. See the `kill` and `stop` docstrings for more information.
(def tp (mk-pool))
(after 10000 #(println "hello") tp :desc "Hello printer")
(every 5000 #(println "I am still alive!") tp :desc "Alive task")
(show-schedule tp)
[6][RECUR] created: Thu 12:03:35s, period: 5000ms, desc: "Alive task
[5][SCHED] created: Thu 12:03:32s, starts at: Thu 12:03:42s, desc: "Hello printer
### Install
Fetch at-at from github: https://github.com/overtone/at-at or pull from clojars: `[overtone/at-at "X.Y.Z"]`
### History
at-at was extracted from the awesome music making wonder that is Overtone (http://github.com/overtone/overtone)
### Authors
* Sam Aaron
* Jeff Rose
* Michael Neale
(Ascii art borrowed from http://www.sanitarium.net/jokes/getjoke.cgi?132)
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