[Gtk2hs-commit] (main branch): use `runCommand` instead `forkProcess` for spawn process safely

[Andy S. <And...@co...>]

Sat Mar 13 01:44:07 EST 2010  laz...@gm...
  * use `runCommand` instead `forkProcess` for spawn process safely
  Ignore-this: 67cdbdcc06120cf98dde089405157655

    hunk ./demo/embbeded/Embedded.hs 1
    --- Use GtkSocket and GtkPlug for cross-process embedded.
    +-- |Use GtkSocket and GtkPlug for cross-process embedded.
    hunk ./demo/embbeded/Embedded.hs 5
    +--
    +-- Note:
    +--
    +-- Don't use `forkProcess` in gtk2hs!
    +-- Because `forkProcess` haven't any protect when spawn process, [_$_]
    +-- so you will got two processes *race condition*, when those two
    +-- process access same resource will crash your program.
    +-- Solution is use `runProcess` or `runCommand` instead, [_$_]
    +-- Because those functions add MVar to make sure two processes won't
    +-- get *race condition* problem.
    +--
    hunk ./demo/embbeded/Embedded.hs 19
    -import System.Posix.Process
    +import System.Process
    hunk ./demo/embbeded/Embedded.hs 74
    -               forkProcess (executeFile path False [show $ fromNativeWindowId id] Nothing)
    +               runCommand $ path ++ " " ++ (show $ fromNativeWindowId id) -- don't use `forkProcess` !