#13497: GHC does not use select()/poll() correctly on non-Linux platforms -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8684, #12912 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nh2): Reading the aforementioned [https://github.com/ghc/ghc/commit/0b79d5cd4687dacf7efd430df7fba9d9a5a5ce32 #diff-dce00d71def2bd086622a775b0723323R71 commit] in detail, it seems that the code currently doesn't do what the code may not follow the intents expressed in the comments: {{{ + * The timer interrupt transitions ACTIVITY_YES into + * ACTIVITY_MAYBE_NO, waits for RtsFlags.GcFlags.idleGCDelayTime, + * and then: + * - if idle GC is no, set ACTIVITY_INACTIVE and wakeUpRts() + * - if idle GC is off, set ACTIVITY_DONE_GC and stopTimer() }}} [https://github.com/ghc/ghc/blob/380b25ea4754c2aea683538ffdb179f8946219a0/rts... Code:] {{{ if (RtsFlags.GcFlags.doIdleGC) { recent_activity = ACTIVITY_INACTIVE; #ifdef THREADED_RTS ... }}} It depends on what `if idle GC is no` (read: `on`) means. In many places I have read that idle GC can really only be "on" in the threaded RTS. In that case, the code does not implement the comment, as it sets `ACTIVITY_INACTIVE` even when we're not in the threaded RTS. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13497#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler