Merge branch 'rabbitmq-server-157' into stable

1 files changed, 29 insertions, 2 deletions

diff --git a/src/rabbit.erl b/src/rabbit.erl
index 24883dc6d4..ee87739337 100644
--- a/src/rabbit.erl
+++ b/src/rabbit.erl
@@ -885,6 +885,33 @@ config_setting() ->
 %% We don't want this in fhc since it references rabbit stuff. And we can't put
 %% this in the bootstep directly.
 start_fhc() ->
-    rabbit_sup:start_restartable_child(
+    ok = rabbit_sup:start_restartable_child(
       file_handle_cache,
-      [fun rabbit_alarm:set_alarm/1, fun rabbit_alarm:clear_alarm/1]).
+      [fun rabbit_alarm:set_alarm/1, fun rabbit_alarm:clear_alarm/1]),
+    ensure_working_fhc().
+
+ensure_working_fhc() ->
+    %% To test the file handle cache, we simply read a file we know it
+    %% exists (Erlang kernel's .app file).
+    %%
+    %% To avoid any pollution of the application process' dictionary by
+    %% file_handle_cache, we spawn a separate process.
+    Parent = self(),
+    TestFun = fun() ->
+        Filename = filename:join(code:lib_dir(kernel, ebin), "kernel.app"),
+        {ok, Fd} = file_handle_cache:open(Filename, [raw, binary, read], []),
+        {ok, _} = file_handle_cache:read(Fd, 1),
+        ok = file_handle_cache:close(Fd),
+        Parent ! fhc_ok
+    end,
+    TestPid = spawn_link(TestFun),
+    %% Because we are waiting for the test fun, abuse the
+    %% 'mnesia_table_loading_timeout' parameter to find a sane timeout
+    %% value.
+    Timeout = rabbit_table:wait_timeout(),
+    receive
+        fhc_ok                       -> ok;
+        {'EXIT', TestPid, Exception} -> throw({ensure_working_fhc, Exception})
+    after Timeout ->
+            throw({ensure_working_fhc, {timeout, TestPid}})
+    end.