#9423: shutdownCapability sometimes loops indefinitely on OSX after hs_exit() -------------------------------------+------------------------------------- Reporter: | Owner: simonmar AndreasVoellmy | Status: new Type: bug | Milestone: Priority: normal | Version: 7.8.2 Component: Runtime | Keywords: System | Architecture: Unknown/Multiple Resolution: | Difficulty: Unknown Operating System: MacOS X | Blocked By: Type of failure: Incorrect | Related Tickets: 9284 result at runtime | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by AndreasVoellmy): The attached program illustrates the problem. Compile like this, where `<your-ghc>` should be a recent (7.8.x) GHC: {{{ <your-ghc> -c Foo.hs <your-ghc> -threaded -no-hs-main FooMain.c Foo.o }}} Then run `a.out`. You should see some printouts and then it should hang (i.e. fail to terminate). You may need to run it a few times t see the behavior. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9423#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#9423: shutdownCapability sometimes loops indefinitely on OSX after hs_exit() -------------------------------------+------------------------------------- Reporter: | Owner: simonmar AndreasVoellmy | Status: new Type: bug | Milestone: Priority: normal | Version: 7.8.2 Component: Runtime | Keywords: System | Architecture: Unknown/Multiple Resolution: | Difficulty: Unknown Operating System: MacOS X | Blocked By: Type of failure: Incorrect | Related Tickets: 9284 result at runtime | Test Case: | Blocking: | Differential Revisions: Phab:D129 | -------------------------------------+------------------------------------- Comment (by Austin Seipp ): In [changeset:"f9f89b7884ccc8ee5047cf4fffdf2b36df6832df/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="f9f89b7884ccc8ee5047cf4fffdf2b36df6832df" rts/base: Fix #9423 Summary: Fix #9423. The problem in #9423 is caused when code invoked by `hs_exit()` waits on all foreign calls to return, but some IO managers are in `safe` foreign calls and do not return. The previous design signaled to the timer manager (via its control pipe) that it should "die" and when the timer manager returned to Haskell-land, the Haskell code in timer manager then signalled to the IO manager threads that they should return from foreign calls and `die`. Unfortunately, in the shutdown sequence the timer manager is unable to return to Haskell-land fast enough and so the code that signals to the IO manager threads (via their control pipes) is never executed and the IO manager threads remain out in the foreign calls. This patch solves this problem by having the RTS signal to all the IO manager threads (via their control pipes; and in addition to signalling to the timer manager thread) that they should shutdown (in `ioManagerDie()` in `rts/Signals.c`. To do this, we arrange for each IO manager thread to register its control pipe with the RTS (in `GHC.Thread.startIOManagerThread`). In addition, `GHC.Thread.startTimerManagerThread` registers its control pipe. These are registered via C functions `setTimerManagerControlFd` (in `rts/Signals.c`) and `setIOManagerControlFd` (in `rts/Capability.c`). The IO manager control pipe file descriptors are stored in a new field of the `Capability_ struct`. Test Plan: See the notes on #9423 to recreate the problem and to verify that it no longer occurs with the fix. Auditors: simonmar Reviewers: simonmar, edsko, ezyang, austin Reviewed By: austin Subscribers: phaskell, simonmar, ezyang, carter, relrod Differential Revision: https://phabricator.haskell.org/D129 GHC Trac Issues: #9423, #9284 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9423#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#9423: shutdownCapability sometimes loops indefinitely on OSX after hs_exit() -------------------------------------+------------------------------------- Reporter: | Owner: simonmar AndreasVoellmy | Status: closed Type: bug | Milestone: 7.10.1 Priority: normal | Version: 7.8.2 Component: Runtime | Keywords: System | Architecture: Unknown/Multiple Resolution: fixed | Difficulty: Unknown Operating System: MacOS X | Blocked By: Type of failure: Incorrect | Related Tickets: 9284 result at runtime | Test Case: | Blocking: | Differential Revisions: Phab:D129 | -------------------------------------+------------------------------------- Comment (by Austin Seipp ): In [changeset:"4748f5936fe72d96edfa17b153dbfd84f2c4c053/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="4748f5936fe72d96edfa17b153dbfd84f2c4c053" Revert "rts/base: Fix #9423" This should fix the Windows fallout, and hopefully this will be fixed once that's sorted out. This reverts commit f9f89b7884ccc8ee5047cf4fffdf2b36df6832df. Signed-off-by: Austin Seipp }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9423#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#9423: shutdownCapability sometimes loops indefinitely on OSX after hs_exit() -------------------------------------+------------------------------------- Reporter: | Owner: AndreasVoellmy | Status: new Type: bug | Milestone: 7.10.1 Priority: normal | Version: 7.8.2 Component: Runtime | Keywords: System | Architecture: Unknown/Multiple Resolution: | Difficulty: Unknown Operating System: MacOS X | Blocked By: Type of failure: Incorrect | Related Tickets: 9284 result at runtime | Test Case: | Blocking: | Differential Revisions: Phab:D129 | -------------------------------------+------------------------------------- Comment (by AndreasVoellmy): Are there ticket numbers for the "Windows fallout" stuff? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9423#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#9423: shutdownCapability sometimes loops indefinitely on OSX after hs_exit() -------------------------------------+------------------------------------- Reporter: | Owner: AndreasVoellmy | Status: closed Type: bug | Milestone: 7.10.1 Priority: normal | Version: 7.8.2 Component: Runtime | Keywords: System | Architecture: Unknown/Multiple Resolution: fixed | Difficulty: Unknown Operating System: MacOS X | Blocked By: Type of failure: Incorrect | Related Tickets: 9284 result at runtime | Test Case: | Blocking: | Differential Revisions: Phab:D129 | -------------------------------------+------------------------------------- Changes (by thoughtpolice): * status: new => closed * resolution: => fixed Comment: OK, this should be fixed For Real this time. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9423#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler