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-rw-r--r--util/async.lua37
1 files changed, 29 insertions, 8 deletions
diff --git a/util/async.lua b/util/async.lua
index a07226de..4deb4295 100644
--- a/util/async.lua
+++ b/util/async.lua
@@ -9,6 +9,31 @@ local function checkthread()
return thread;
end
+local function runner_from_thread(thread)
+ local level = 0;
+ -- Find the 'level' of the top-most function (0 == current level, 1 == caller, ...)
+ while debug.getinfo(thread, level, "") do level = level + 1; end
+ local name, runner = debug.getlocal(thread, level-1, 1);
+ if name ~= "self" or type(runner) ~= "table" or runner.thread ~= thread then
+ return nil;
+ end
+ return runner;
+end
+
+local function call_watcher(runner, watcher_name, ...)
+ local watcher = runner.watchers[watcher_name];
+ if not watcher then
+ return false;
+ end
+ runner:log("debug", "Calling '%s' watcher", watcher_name);
+ local ok, err = pcall(watcher, runner, ...); -- COMPAT: Switch to xpcall after Lua 5.1
+ if not ok then
+ runner:log("error", "Error in '%s' watcher: %s", watcher_name, err);
+ return nil, err;
+ end
+ return true;
+end
+
local function runner_continue(thread)
-- ASSUMPTION: runner is in 'waiting' state (but we don't have the runner to know for sure)
if coroutine.status(thread) ~= "suspended" then -- This should suffice
@@ -20,16 +45,12 @@ local function runner_continue(thread)
local err = state;
-- Running the coroutine failed, which means we have to find the runner manually,
-- in order to inform the error handler
- local level = 0;
- -- Find the 'level' of the top-most function (0 == current level, 1 == caller, ...)
- while debug.getinfo(thread, level, "") do level = level + 1; end
- ok, runner = debug.getlocal(thread, level-1, 1);
- if ok ~= "self" or runner.thread ~= thread then
- log("warn", "unexpected async state: unable to locate runner during error handling, got %s", ok);
+ runner = runner_from_thread(thread);
+ if not runner then
+ log("warn", "unexpected async state: unable to locate runner during error handling");
return false;
end
- local error_handler = runner.watchers.error;
- if error_handler then error_handler(runner, debug.traceback(thread, err)); end
+ call_watcher(runner, "error", debug.traceback(thread, err));
runner.state, runner.thread = "ready", nil;
return runner:run();
elseif state == "ready" then