From 7f82eddfaa3b89f734b4d58f1de92db86e5880cf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 19 Oct 2010 13:43:13 +0200 Subject: Fix hang in on_load handlers in embedded mode In embedded mode, all on_load handlers will be called after loading all modules but before starting any servers. Therefore, if an on_load handler calls any function in the code module that calls the code server (such as code:priv_dir/1), there will be a deadlock because the code server has not yet been started. Fix this problem by invoking the on_load handlers after having started most servers in the kernel application. --- lib/kernel/src/kernel.erl | 7 +++++++ .../code_SUITE_data/on_load_app-1.0/src/on_load_embedded.erl | 9 +++++++++ 2 files changed, 16 insertions(+) (limited to 'lib') diff --git a/lib/kernel/src/kernel.erl b/lib/kernel/src/kernel.erl index 92ee7b441a..d3b0f6c712 100644 --- a/lib/kernel/src/kernel.erl +++ b/lib/kernel/src/kernel.erl @@ -143,6 +143,13 @@ init(safe) -> Boot = start_boot_server(), DiskLog = start_disk_log(), Pg2 = start_pg2(), + + %% Run the on_load handlers for all modules that have been + %% loaded so far. Running them at this point means that + %% on_load handlers can safely call kernel processes + %% (and in particular call code:priv_dir/1 or code:lib_dir/1). + init:run_on_load_handlers(), + {ok, {SupFlags, Boot ++ DiskLog ++ Pg2}}. get_code_args() -> diff --git a/lib/kernel/test/code_SUITE_data/on_load_app-1.0/src/on_load_embedded.erl b/lib/kernel/test/code_SUITE_data/on_load_app-1.0/src/on_load_embedded.erl index a39332f81d..b7fdd4d9ae 100644 --- a/lib/kernel/test/code_SUITE_data/on_load_app-1.0/src/on_load_embedded.erl +++ b/lib/kernel/test/code_SUITE_data/on_load_app-1.0/src/on_load_embedded.erl @@ -3,6 +3,15 @@ -on_load(run_me/0). run_me() -> + %% An onload handler typically calls code:priv_dir/1 + %% or code:lib_dir/1, so make sure that it works. + LibDir = code:lib_dir(on_load_app), + PrivDir = code:priv_dir(on_load_app), + LibDir = filename:dirname(PrivDir), + ModPath = code:which(?MODULE), + LibDir = filename:dirname(filename:dirname(ModPath)), + + %% Start a process to remember that the on_load was called. spawn(fun() -> register(everything_is_fine, self()), receive Any -> -- cgit v1.2.3