#10017: signal handlers are invoked multiple times when the threaded rts is used -------------------------------------+------------------------------------- Reporter: redneb | Owner: Type: bug | AndreasVoellmy Priority: highest | Status: new Component: Runtime System | Milestone: 7.10.1 Resolution: | Version: 7.10.1-rc1 Operating System: Linux | Keywords: Type of failure: Incorrect result | Architecture: at runtime | Unknown/Multiple Blocked By: | Test Case: Related Tickets: #9423 | Blocking: | Differential Revisions: Phab:D641 -------------------------------------+------------------------------------- Comment (by AndreasVoellmy): In the threaded RTS, a signal is delivered from the RTS to Haskell user code by writing to file that one of the IO managers watches (via an instance of GHC.Event.Control.Control). When the IO manager receives the signal, it calls GHC.Conc.Signal.runHandlers to invoke Haskell signal handler. In the move from a single IO manager to one IO manager per capability, the behavior was (wrongly) extended so that a signal is delivered to every event manager (see Trac #9423), each of which invoke Haskell signal handlers, leading to multiple invocations of Haskell signal handlers for a single signal. This change fixes this problem by having the RTS (in generic_handler()) notify only the Control instance used by the TimerManager, rather than all the per-capability IO managers. This has no impact on #9423; i.e. the fix here does not re-introduce the issue identified in #9423. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10017#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler