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Diffstat (limited to 'apps/rexi/src/rexi_monitor.erl')
-rw-r--r-- | apps/rexi/src/rexi_monitor.erl | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/apps/rexi/src/rexi_monitor.erl b/apps/rexi/src/rexi_monitor.erl new file mode 100644 index 00000000..bbff22b3 --- /dev/null +++ b/apps/rexi/src/rexi_monitor.erl @@ -0,0 +1,40 @@ +-module(rexi_monitor). +-export([start/1, stop/1]). + +-include_lib("eunit/include/eunit.hrl"). + +%% @doc spawn_links a process which monitors the supplied list of items and +%% returns the process ID. If a monitored process exits, the caller will +%% receive a {rexi_DOWN, MonitoringPid, DeadPid, Reason} message. +-spec start([pid() | atom() | {atom(),node()}]) -> pid(). +start(Procs) -> + Parent = self(), + spawn_link(fun() -> + [erlang:monitor(process, P) || P <- Procs], + wait_monitors(Parent) + end). + +%% @doc Cleanly shut down the monitoring process and flush all rexi_DOWN +%% messages from our mailbox. +-spec stop(pid()) -> ok. +stop(MonitoringPid) -> + MonitoringPid ! {self(), shutdown}, + flush_down_messages(). + +%% internal functions %% + +wait_monitors(Parent) -> + receive + {'DOWN', _, process, Pid, Reason} -> + Parent ! {rexi_DOWN, self(), Pid, Reason}, + wait_monitors(Parent); + {Parent, shutdown} -> + ok + end. + +flush_down_messages() -> + receive {rexi_DOWN, _, _, _} -> + flush_down_messages() + after 0 -> + ok + end. |