Update gen_event:stop to be synchronous

This function now uses proc_lib:stop, which guarantees that the
process is terminated before the function return.

3 files changed, 36 insertions, 16 deletions

diff --git a/lib/stdlib/doc/src/gen_event.xml b/lib/stdlib/doc/src/gen_event.xml
index b9dfff833e..5c96d6e576 100644
--- a/lib/stdlib/doc/src/gen_event.xml
+++ b/lib/stdlib/doc/src/gen_event.xml
@@ -4,7 +4,7 @@
 <erlref>
   <header>
     <copyright>
-      <year>1996</year><year>2013</year>
+      <year>1996</year><year>2014</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -44,6 +44,7 @@
     <pre>
 gen_event module                   Callback module
 ----------------                   ---------------
+gen_event:start
 gen_event:start_link       ----->  -
 
 gen_event:add_handler
@@ -177,7 +178,7 @@ gen_event:stop             ----->  Module:terminate/2
       <name>add_handler(EventMgrRef, Handler, Args) -> Result</name>
       <fsummary>Add an event handler to a generic event manager.</fsummary>
       <type>
-        <v>EventMgr = Name | {Name,Node} | {global,GlobalName}
+        <v>EventMgrRef = Name | {Name,Node} | {global,GlobalName}
 	| {via,Module,ViaName} | pid()</v>
         <v>&nbsp;Name = Node = atom()</v>
         <v>&nbsp;GlobalName = ViaName = term()</v>
@@ -223,7 +224,7 @@ gen_event:stop             ----->  Module:terminate/2
       <name>add_sup_handler(EventMgrRef, Handler, Args) -> Result</name>
       <fsummary>Add a supervised event handler to a generic event manager.</fsummary>
       <type>
-        <v>EventMgr = Name | {Name,Node} | {global,GlobalName}
+        <v>EventMgrRef = Name | {Name,Node} | {global,GlobalName}
 	| {via,Module,ViaName} | pid()</v>
         <v>&nbsp;Name = Node = atom()</v>
         <v>&nbsp;GlobalName = ViaName = term()</v>
@@ -456,19 +457,37 @@ gen_event:stop             ----->  Module:terminate/2
     </func>
     <func>
       <name>stop(EventMgrRef) -> ok</name>
+      <name>stop(EventMgrRef, Reason, Timeout) -> ok</name>
       <fsummary>Terminate a generic event manager.</fsummary>
       <type>
         <v>EventMgrRef = Name | {Name,Node} | {global,GlobalName}
 	| {via,Module,ViaName} | pid()</v>
         <v>Name = Node = atom()</v>
         <v>GlobalName = ViaName = term()</v>
+        <v>Reason = term()</v>
+        <v>Timeout = int()>0 | infinity</v>
       </type>
       <desc>
-        <p>Terminates the event manager <c>EventMgrRef</c>. Before
-          terminating, the event manager will call
-          <c>Module:terminate(stop,...)</c> for each installed event
-          handler.</p>
-        <p>See <c>add_handler/3</c> for a description of the argument.</p>
+        <p>Orders the event manager <c>EventMgrRef</c> to exit with
+          the given <c>Reason</c> and waits for it to
+          terminate. Before terminating, the gen_event will call
+          <seealso marker="#Module:terminate/2">Module:terminate(stop,...)</seealso>
+	  for each installed event handler.</p>
+	<p>The function returns <c>ok</c> if the event manager terminates
+	  with the expected reason. Any other reason than <c>normal</c>,
+          <c>shutdown</c>, or <c>{shutdown,Term}</c> will cause an
+          error report to be issued using
+          <seealso marker="kernel:error_logger#format/2">error_logger:format/2</seealso>.
+	  The default <c>Reason</c> is <c>normal</c>.</p>
+	<p><c>Timeout</c> is an integer greater than zero which
+          specifies how many milliseconds to wait for the event manager to
+          terminate, or the atom <c>infinity</c> to wait
+          indefinitely. The default value is <c>infinity</c>. If the
+          event manager has not terminated within the specified time, a
+          <c>timeout</c> exception is raised.</p>
+	<p>If the process does not exist, a <c>noproc</c> exception
+	  is raised.</p>
+        <p>See <c>add_handler/3</c> for a description of <c>EventMgrRef</c>.</p>
       </desc>
     </func>
   </funcs>
diff --git a/lib/stdlib/src/gen_event.erl b/lib/stdlib/src/gen_event.erl
index bb0ff46268..934b112f6f 100644
--- a/lib/stdlib/src/gen_event.erl
+++ b/lib/stdlib/src/gen_event.erl
@@ -31,8 +31,8 @@
 %%% Modified by Martin - uses proc_lib, sys and gen!
 
 
--export([start/0, start/1, start_link/0, start_link/1, stop/1, notify/2, 
-	 sync_notify/2,
+-export([start/0, start/1, start_link/0, start_link/1, stop/1, stop/3,
+	 notify/2, sync_notify/2,
 	 add_handler/3, add_sup_handler/3, delete_handler/3, swap_handler/3,
 	 swap_sup_handler/3, which_handlers/1, call/3, call/4, wake_hib/4]).
 
@@ -193,7 +193,11 @@ swap_sup_handler(M, {H1, A1}, {H2, A2}) ->
 which_handlers(M) -> rpc(M, which_handlers).
 
 -spec stop(emgr_ref()) -> 'ok'.
-stop(M) -> rpc(M, stop).
+stop(M) ->
+    gen:stop(M).
+
+stop(M, Reason, Timeout) ->
+    gen:stop(M, Reason, Timeout).
 
 rpc(M, Cmd) -> 
     {ok, Reply} = gen:call(M, self(), Cmd, infinity),
@@ -292,9 +296,6 @@ handle_msg(Msg, Parent, ServerName, MSL, Debug) ->
 						Args2, MSL, Sup, ServerName),
 	    ?reply(Reply),
 	    loop(Parent, ServerName, MSL1, Debug, Hib);
-	{From, Tag, stop} ->
-	    catch terminate_server(normal, Parent, MSL, ServerName),
-	    ?reply(ok);
 	{From, Tag, which_handlers} ->
 	    ?reply(the_handlers(MSL)),
 	    loop(Parent, ServerName, MSL, Debug, false);
diff --git a/lib/stdlib/test/gen_event_SUITE.erl b/lib/stdlib/test/gen_event_SUITE.erl
index 60a1ba8c60..576a5adfce 100644
--- a/lib/stdlib/test/gen_event_SUITE.erl
+++ b/lib/stdlib/test/gen_event_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -106,7 +106,7 @@ start(Config) when is_list(Config) ->
     ?line {error, {already_started, _}} =
 	gen_event:start({global, my_dummy_name}),
 
-    exit(Pid6, shutdown),
+    ok = gen_event:stop({global, my_dummy_name}, shutdown, 10000),
     receive
 	{'EXIT', Pid6, shutdown} -> ok
     after 10000 ->