Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: igloo Type: feature request | Status: patch Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Comment(by AndreasVoellmy): I made a new patch that implements the threadWaitReadSTM and threadWaitWriteSTM functions for Windows with the threaded RTS. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: igloo Type: feature request | Status: patch Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Comment(by AndreasVoellmy): Sorry for all the patches. You can ignore all, but the last. expose- threadWaitSTM-on-master.2.patch which expose-threadWaitSTM-on- master.3.patch fixed. expose-threadWaitSTM-on-master.4.patch is a minor simplification. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: igloo Type: feature request | Status: patch Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Comment(by igloo): I'm a bit confused. Do these functions work on Windows? In Control.Concurrent they just raise an exception on Windows, but it looks like in GHC.Conc.IO they are defined on Windows. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: igloo Type: feature request | Status: patch Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Comment(by AndreasVoellmy): I think the confusion also exists for the threadWaitRead and threadWaitWrite functions. They are defined in GHC.Conc.IO even for Windows, but then they seem to be completely ignored in Control.Concurrent and the functions of the same name there are defined for Windows only in the threaded RTS (or for stdin in non-threaded RTS). -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: Type: feature request | Status: new Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Changes (by simonpj): * status: closed = new * resolution: fixed = -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: igloo Type: feature request | Status: new Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Changes (by simonpj): * owner: = igloo -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: igloo Type: feature request | Status: patch Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Changes (by simonpj): * status: new = patch -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: Type: feature request | Status: closed Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Comment(by AndreasVoellmy): The previous patches did not actually expose the new functions in any public module. The attached patch exports these functions in Control.Concurrent, which is where the threadWaitRead and threadWaitWrite functions are exported. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors ---+ Reporter: AndreasVoellmy| Owner: Type: feature request | Status: closed Priority: normal| Milestone: 7.8.1 Component: libraries/base|Version: 7.4.2 Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Changes (by igloo): * status: patch = closed * resolution: = fixed Comment: Applied, thanks! -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors -+-- Reporter: AndreasVoellmy| Owner: Type: feature request | Status: patch Priority: normal| Milestone: 7.8.1 Component: libraries/base| Version: 7.4.2 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Comment(by AndreasVoellmy): The last patch addresses the previous comment by igloo. I made the threadWaitSTM return an IO action that unregisters interest in the file descriptor. By returning an `IO ()` value we avoid having to export the `FdKey` type and `unregsterFd` functions. I also added some haddock comments to `threadWaitReadSTM` and `threadWaitWriteSTM`. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors -+-- Reporter: AndreasVoellmy| Owner: Type: feature request | Status: patch Priority: normal| Milestone: 7.8.1 Component: libraries/base| Version: 7.4.2 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Changes (by igloo): * milestone: = 7.8.1 Comment: This patch warns that the return values of `registerFd` and `unregisterFd_` are ignored. Is that correct? -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors -+-- Reporter: AndreasVoellmy| Owner: Type: feature request | Status: patch Priority: normal| Milestone: 7.8.1 Component: libraries/base| Version: 7.4.2 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Comment(by AndreasVoellmy): `threadWaitSTM` basically follows the template `threadWait`. `threadWait` also ignores the result of applications of unregisterFd_, so on this point it is no different than the code that is already in that module. Regarding the result of `registerFd`: `threadWait` uses the result of `registerFd` in only one place: it creates an empty `MVar`, registers a callback that fills it and waits on the `MVar` handling any exceptions thrown to the thread (it unregisters the callback on exception); unregistering is the only place the result of `registerFd` is used. `threadWaitSTM` does not block on an `MVar` (or anything else, that is the point of it), so it cannot use the result of `registerFd` in the same way. To accomplish the same thing on an exception (i.e. unregistering the callback) we should probably return the registration key in the result of `threadWaitSTM` so that the user can handle and unregister. This would require also re-exporting the unregistration function in `GHC.Event.Thread`, since it is currently exported from the non-exposed `GHC.Event.Manager` module. On the other hand, I don't really see why unregistering is necessary for correctness. It seems to me like unregistering is an optimization, since it keeps the callback table smaller. If this occurs and the registered file is ever ready, then the callback will fire and be unregistered. If the registered file is never ready, then the file will never be removed from the callback table, but this could happen with a file anyway even when no error occurs. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors -+-- Reporter: AndreasVoellmy| Owner: Type: feature request | Status: patch Priority: normal| Milestone: Component: libraries/base| Version: 7.4.2 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Comment(by tibbe): Looks good to me. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
[GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors --+- Reporter: AndreasVoellmy| Owner: Type: feature request | Status: new Priority: normal| Component: libraries/base Version: 7.4.2 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Testcase: Blockedby:| Blocking: Related:| --+- The GHC.Event.Thread module provides threadWaitRead, threadWaitWrite :: Fd - IO () calls that block until a particular file descriptor is ready for reading or writing. With this API a single thread cannot wait on multiple file descriptors or a file descriptor and some other condition (e.g. an MVar, STM transaction, etc). One could work around this by creating extra producer threads that each monitor one file descriptor and then multiplex messages from those threads onto a single channel (or mvar, etc) and then have a consumer thread that waits on this single multiplexed channel. Unfortunately, this extra indirection imposes a modest performance penalty in the form of longer wait times to service events due to having to switch between multiple threads to handle a single ready file. I propose to provide analogous functions in the STM monad threadWaitReadSTM,threadWaitWriteSTM :: Fd - STM (). These will allow a single thread to wait on multiple files or both files and other conditions. This eliminates the switching between threads to service a request. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7216: Compositional blocking on file descriptors
#7216: Compositional blocking on file descriptors --+- Reporter: AndreasVoellmy| Owner: Type: feature request | Status: patch Priority: normal| Component: libraries/base Version: 7.4.2 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Testcase: Blockedby:| Blocking: Related:| --+- Changes (by AndreasVoellmy): * status: new = patch -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7216#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
