[GHC] #13554: Allow the user to provide a C function that is called on each thread the RTS creates before running any Haskell code

[GHC]

#13554: Allow the user to provide a C function that is called on each thread the
RTS creates before running any Haskell code
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        Reporter:  dobenour          |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.4.1
       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:                    |  Differential Rev(s):
       Wiki Page:                    |
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Description changed by bgamari:

@@ -19,1 +19,1 @@
- This is a feature requ
+ This is a feature request.

New description:

 Currently, it is very difficult to use the MySQL/MariaDB client library
 with Haskell.  One must use bound threads, which comes at a performance
 penalty.  The reason is that the underlying library requires a certain
 initialization function to be called on each OS thread before any other
 functions are called.

 Similarly, it is difficult to optimally use libcurl with GHC.  The best-
 performing way to use libcurl is to have one multi handle per thread and
 to use `curl_multi_socket_action` to respond to events.  This is currently
 not possible from Haskell, at least not easily.

 (There are other issues with using libcurl from Haskell; most notably
 libcurl’s event support makes heavy use of callbacks, which are slow, to
 tell the application which file descriptors to wait for.  But that is a
 separate issue.)

 Setting milestone to 8.4.1 because I don’t think that this is difficult.

 This is a feature request.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13554#comment:1>
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