slave-thread 1.0.3 → 1.1

raw patch · 2 files changed

+34/−2 lines, 2 files

Files

• library/SlaveThread.hs +33/−1
• slave-thread.cabal +1/−1

@@ -37,6 +37,7 @@   forkWithUnmask,   forkFinally,   forkFinallyWithUnmask,+  SlaveThreadCrashed(..)   -- * Notes   -- $note-unmask )@@ -121,7 +122,7 @@         handler e = do           case fromException e of             Just ThreadKilled -> return ()-            _ -> throwTo masterThread e+            _ -> throwTo masterThread (SlaveThreadCrashed slaveThread e)         in do           forM_ @Maybe computationExceptions handler           forM_ slavesDyingExceptions handler@@ -150,6 +151,37 @@   atomically $ do     null <- UnfoldlM.null $ Multimap.unfoldMByKey thread slaveRegistry     unless null retry++-- | A slave thread crashed. This exception is classified as /asynchronous/,+-- meaning it extends from 'SomeAsyncException'.+--+-- In general,+--+-- * /Synchronous/ exceptions such as 'IOException' are thrown by IO actions+--   that are explicitly called by the thread that receives them, and may be+--   caught, inspected, and handled by resuming execution.+-- * /Asynchronous/ exceptions such as 'ThreadKilled' should normally only be+--   caught temporarily in order to run finalizers, then re-thrown.+--+-- 'SlaveThreadCrashed' being asynchronous means it should, by default, cause+-- the entire thread hierarchy to come crashing down, ultimately terminating the+-- program.+--+-- If you want more sophisticated behavior, such as a "supervisor" thread that+-- monitors and restarts worker threads when they fail, you have to program+-- that yourself.+--+-- N.B. Consider using a library like+-- @<https://hackage.haskell.org/package/safe-exceptions safe-exceptions>@ or+-- @<https://hackage.haskell.org/package/unliftio unliftio>@, which carefully+-- distinguish synchronous and asynchronous exceptions, unlike @base@.+data SlaveThreadCrashed+  = SlaveThreadCrashed !ThreadId !SomeException+  deriving (Show)++instance Exception SlaveThreadCrashed where+  toException = asyncExceptionToException+  fromException = asyncExceptionFromException  -- $note-unmask --

@@ -1,5 +1,5 @@ name: slave-thread-version: 1.0.3+version: 1.1 synopsis: A fundamental solution to ghost threads and silent exceptions description:   Vanilla thread management in Haskell is low level and