[35/50] couch commit: updated refs/heads/2080-port-cors-to-chttpd to 529339b

[ch...@apache.org]

add couch_util:with_proc/4

BugzId: 2657


Project: http://git-wip-us.apache.org/repos/asf/couchdb-couch/repo
Commit: http://git-wip-us.apache.org/repos/asf/couchdb-couch/commit/d4ae1a44
Tree: http://git-wip-us.apache.org/repos/asf/couchdb-couch/tree/d4ae1a44
Diff: http://git-wip-us.apache.org/repos/asf/couchdb-couch/diff/d4ae1a44

Branch: refs/heads/2080-port-cors-to-chttpd
Commit: d4ae1a44aeb2def6014148b8ab72fe1cc1acce6a
Parents: 42c9047
Author: Russell Branca <ch...@apache.org>
Authored: Mon Apr 20 19:57:20 2015 +0000
Committer: Russell Branca <ch...@apache.org>
Committed: Mon Apr 20 21:03:40 2015 +0000

----------------------------------------------------------------------
 src/couch_util.erl | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
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http://git-wip-us.apache.org/repos/asf/couchdb-couch/blob/d4ae1a44/src/couch_util.erl
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diff --git a/src/couch_util.erl b/src/couch_util.erl
index 7e16866..69fd53f 100644
--- a/src/couch_util.erl
+++ b/src/couch_util.erl
@@ -33,6 +33,7 @@
 -export([integer_to_boolean/1, boolean_to_integer/1]).
 -export([find_in_binary/2]).
 -export([callback_exists/3, validate_callback_exists/3]).
+-export([with_proc/4]).
 
 -include_lib("couch/include/couch_db.hrl").
 
@@ -569,3 +570,20 @@ ensure_loaded(Module) when is_atom(Module) ->
         false
     end;
 ensure_loaded(_Module) -> false.
+
+
+%% This is especially useful in gen_servers when you need to call
+%% a function that does a receive as it would hijack incoming messages.
+with_proc(M, F, A, Timeout) ->
+    {Pid, Ref} = spawn_monitor(fun() ->
+        exit(erlang:apply(M, F, A))
+    end),
+    receive
+        {'DOWN', Ref, process, Pid, Resp} ->
+            {ok, Resp};
+        {'DOWN', Ref, process, Pid, Error} ->
+            {error, Error}
+    after Timeout ->
+        erlang:demonitor(Ref, [flush]),
+        {error, timeout}
+    end.