task

Task is an Elixir Task model partial implement in Erlang.

Detailed doc, here.

async and await

In this repo, the way to spawn a task is with task:async/3. Then, a new process will be created, linked and monitored by the caller(that is the task owner). Once the task action finishes, a message will be sent to the caller with the result.

task:await/1 and task:await/2 is used to read the message sent bt the task process. On await, Task will also setup a monitor to verify if the process exited for any abnormal reason(or in case exits are being trapped by the caller).

usage

compile and eunit

$ ./rebar com ; ./rebar eunit -v
==> task (compile)
==> task (eunit)
INFO:  sh info:
	cwd: "/Users/redink/github/task"
	cmd: cp -R src/task.erl test/task_test.erl ".eunit"
INFO:  Skipped src/task.erl
Compiled test/task_test.erl
INFO:  Cover compiling /Users/redink/github/task
======================== EUnit ========================
module 'task_test'
  task_test: task_test_ (async/1)...ok
  task_test: task_test_ (async/2)...[0.010 s] ok
  task_test: task_test_ (async/3)...ok
  task_test: task_test_ (async/4)...ok
  task_test: task_test_ (async_opt/2)...ok
  task_test: task_test_ (async_opt/3)...ok
  task_test: task_test_ (async_opt/4)...ok
  task_test: task_test_ (async_opt/5)...ok
  task_test: task_test_ (await/1 exits on timeout)...ok
  task_test: task_test_ (await/1 exits on normal exit)...ok
  task_test: task_test_ (await/1 exits on task throw)...
=ERROR REPORT==== 13-Jan-2015::17:24:41 ===
** Task <0.84.0> terminating
** Started from <0.57.0>
** When function == #Fun<erlang.throw.1>
**      arguments == [unknown]
** Reason for termination == 
** {{nocatch,unknown},
    [{task,do_apply,2,[{file,"src/task.erl"},{line,154}]},
     {task,async_do,3,[{file,"src/task.erl"},{line,134}]},
     {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,237}]}]}

=ERROR REPORT==== 13-Jan-2015::17:24:41 ===
** Task <0.86.0> terminating
** Started from <0.57.0>
** When function == #Fun<erlang.exit.1>
**      arguments == [unknown]
** Reason for termination == 
** unknown
ok
  task_test: task_test_ (await/1 exits on task exit)...ok
  task_test: task_test_ (await/1 exits on noconnection)...ok
  task_test: task_test_ (safe_await/2 exits on noconnection)...
=ERROR REPORT==== 13-Jan-2015::17:24:41 ===
** Task <0.90.0> terminating
** Started from <0.57.0>
** When function == #Fun<erlang.exit.1>
**      arguments == [unknown]
** Reason for termination == 
** unknown
ok
  task_test: task_test_ (safe_await/2 exits on task exit)...ok
  [done in 0.054 s]
module 'task'
=======================================================
  All 15 tests passed.
Cover analysis: /Users/redink/github/task/.eunit/index.html

start

$ erl -pa ./ebin

e.g.

1> task:async(erlang, self, []).
{<0.34.0>,#Ref<0.0.0.30>}

2> task:await(v(1)).
<0.34.0>

3> task:async(erlang, process_info, [erlang:self()]).
{<0.37.0>,#Ref<0.0.0.39>}

4> task:await(v(3)).
[{current_function,{io,wait_io_mon_reply,2}},
 {initial_call,{erlang,apply,2}},
 {status,waiting},
 {message_queue_len,0},
 {messages,[]},
 {links,[<0.26.0>,<0.37.0>]},
 {dictionary,[]},
 {trap_exit,false},
 {error_handler,error_handler},
 {priority,normal},
 {group_leader,<0.25.0>},
 {total_heap_size,986},
 {heap_size,376},
 {stack_size,29},
 {reductions,2153},
 {garbage_collection,[{min_bin_vheap_size,46422},
                      {min_heap_size,233},
                      {fullsweep_after,65535},
                      {minor_gcs,6}]},
 {suspending,[]}]

remote node call

Now, Task support remote node call, you can use it like:

5> task:async('[email protected]', erlang, self, []).
{<6206.43.0>,#Ref<0.0.0.42>}

6> task:await(v(5)).
<6206.43.0>