chore(healthcheck) increase verbosity for locked function failures

lib/resty/healthcheck.lua

@@ -51,6 +51,9 @@ local new_tab
 local nkeys
 local is_array
 
+
+local TESTING = _G.__TESTING_HEALTHCHECKER or false
+
 do
  local ok
 
@@ -96,7 +99,6 @@ local EMPTY = setmetatable({},{
  end
  })
 
-
 --- timer constants
 -- evaluate active checks every 0.1s
 local CHECK_INTERVAL = 0.1
@@ -216,6 +218,10 @@ local function key_for(key_prefix, ip, port, hostname)
  return string.format("%s:%s:%s%s", key_prefix, ip, port, hostname and ":" .. hostname or "")
 end
 
+
+-- resty.lock timeout when yieldable
+local LOCK_TIMEOUT = 5
+
 local run_locked
 do
  -- resty_lock is restricted to this scope in order to keep sensitive
@@ -235,25 +241,31 @@ do
  timer = true,
  }
 
- local function run_in_timer(premature, fn, ...)
+ local function run_in_timer(premature, self, key, fn, ...)
  if premature then
  return
  end
 
- return fn(...)
+ local ok, err = run_locked(self, key, fn, ...)
+ if not ok then
+ self:log(ERR, "locked function for key '", key, "' failed in timer: ", err)
+ end
  end
 
- local function schedule(fn, ...)
- return ngx.timer.at(0, run_in_timer, fn, ...)
- end
+ local function schedule(self, key, fn, ...)
+ local ok, err = ngx.timer.at(0, run_in_timer, self, key, fn, ...)
+ if not ok then
+ return nil, "failed scheduling locked function for key '" .. key ..
+ "', " .. err
+ end
 
- -- timeout when yieldable
- local timeout = 5
+  return "scheduled"
+ end
 
  -- resty.lock consumes these options immediately, so this table can be reused
  local opts = {
- exptime = 10, -- timeout after which lock is released anyway
- timeout = timeout, -- max wait time to acquire lock
+ exptime = 10,  -- timeout after which lock is released anyway
+ timeout = LOCK_TIMEOUT, -- max wait time to acquire lock
  }
 
  ---
@@ -291,7 +303,7 @@ do
  local yield = yieldable[get_phase()]
 
  if yield then
- opts.timeout = timeout
+ opts.timeout = LOCK_TIMEOUT
  else
  -- if yielding is not possible in the current phase, use a zero timeout
  -- so that resty.lock will return `nil, "timeout"` immediately instead of
@@ -310,12 +322,7 @@ do
 
  if not elapsed and err == "timeout" and not yield then
  -- yielding is not possible in the current phase, so retry in a timer
- local ok, terr = schedule(run_locked, self, key, fn, ...)
- if not ok then
- return nil, terr
- end
-
- return "scheduled"
+ return schedule(self, key, fn, ...)
 
  elseif not elapsed then
  return nil, "failed acquiring lock for '" .. key .. "', " .. err
@@ -330,7 +337,7 @@ do
  end
 
  if not pok then
- return nil, perr
+ return nil, "locked function threw an exception: " .. tostring(perr)
  end
 
  return perr, res
@@ -1700,4 +1707,12 @@ function _M.new(opts)
 end
 
 
+if TESTING then
+ checker._run_locked = run_locked
+ checker._set_lock_timeout = function(t)
+ LOCK_TIMEOUT = t
+ end
+end
+
+
 return _M