Rollback #1185 fix

As far as I can tell, the hack I was using in rts/Linker.c won't work
on OS X.  Back to the drawing board.

rolling back:

Tue Nov  3 16:05:47 GMT 2009  Simon Marlow <marlowsd@gmail.com>
  * Fix #1185 (RTS part, also needs corresponding change to libraries/base)
  GHC.Conc.ensureIOManagerIsRunning now creates an IO manager thread if
  one does not exist or has died/exited.
  
  Unfortunately this exposed a problem caused by the fact that we have
  two base packages, and hence two IO managers, in GHCi: see NOTE
  [io-manager-ghci] in rts/Linker.c.  The workaround can go away if/when
  we switch to a dynamically linked GHCi.
  

    M ./rts/Linker.c -6 +47
    M ./rts/Schedule.c +4
    M ./rts/package.conf.in +16
    M ./rts/posix/Signals.c -1 +7
    M ./rts/posix/Signals.h +2

Wed Nov  4 10:11:03 GMT 2009  Simon Marlow <marlowsd@gmail.com>
  * hopefully fix validate breakage on OS X and Windows

    M ./rts/Linker.c -1 +1

Wed Nov  4 16:27:40 GMT 2009  Simon Marlow <marlowsd@gmail.com>
  * fix build failure on Windows

    M ./rts/Linker.c -1 +1

5 files changed, 7 insertions, 76 deletions

diff --git a/rts/Linker.c b/rts/Linker.c
index a7ceb66c4c..a2b69f93dd 100644
--- a/rts/Linker.c
+++ b/rts/Linker.c
@@ -957,37 +957,6 @@ typedef struct _RtsSymbolVal {
 #define RTS_LIBGCC_SYMBOLS
 #endif
 
-/* NOTE [io-manager-ghci]
-
-   When GHCi loads the base package, it gets another copy of the CAFs
-   in GHC.Conc that record the IO manager's ThreadId, and the blocking
-   queues, so we get another IO manager.  This is bad enough, but what
-   is worse is that GHCi by default reverts all CAFs on every :load,
-   so we'll get *another* IO manager thread (and an associated pipe)
-   every time the user does :load.  Miraculously, this actually
-   manages to just about work in GHC 6.10 and earlier, but broke when
-   I tried to fix #1185 (restarting the IO manager after a fork()).
-
-   To work around it and ensure that we only have a single IO manager,
-   we map the CAFs in the dynamically-loaded GHC.Conc to the
-   statically-linked GHC.Conc.  This is an ugly hack, but it's the
-   least ugly hack that I could think of (SDM 3/11/2009)
-*/
-
-#define RTS_GHC_CONC_SYMBOLS \
-      SymI_NeedsProto(base_GHCziConc_pendingDelays_closure) \
-      SymI_NeedsProto(base_GHCziConc_ioManagerThread_closure)
-
-#ifdef mingw32_HOST_OS
-#define RTS_GHC_CONC_OS_SYMBOLS /* empty */
-#else
-#define RTS_GHC_CONC_OS_SYMBOLS \
-      SymI_NeedsProto(base_GHCziConc_pendingEvents_closure) \
-      SymI_NeedsProto(base_GHCziConc_prodding_closure) \
-      SymI_NeedsProto(base_GHCziConc_sync_closure) \
-      SymI_NeedsProto(base_GHCziConc_stick_closure)
-#endif
-
 #if defined(darwin_HOST_OS) && defined(powerpc_HOST_ARCH)
       // Symbols that don't have a leading underscore
       // on Mac OS X. They have to receive special treatment,
@@ -1016,8 +985,6 @@ RTS_CYGWIN_ONLY_SYMBOLS
 RTS_DARWIN_ONLY_SYMBOLS
 RTS_LIBGCC_SYMBOLS
 RTS_LIBFFI_SYMBOLS
-RTS_GHC_CONC_SYMBOLS
-RTS_GHC_CONC_OS_SYMBOLS
 #undef SymI_NeedsProto
 #undef SymI_HasProto
 #undef SymI_HasProto_redirect
@@ -1053,8 +1020,6 @@ static RtsSymbolVal rtsSyms[] = {
       RTS_DARWIN_ONLY_SYMBOLS
       RTS_LIBGCC_SYMBOLS
       RTS_LIBFFI_SYMBOLS
-      RTS_GHC_CONC_SYMBOLS
-      RTS_GHC_CONC_OS_SYMBOLS
 #if defined(darwin_HOST_OS) && defined(i386_HOST_ARCH)
       // dyld stub code contains references to this,
       // but it should never be called because we treat
@@ -1076,18 +1041,12 @@ static void ghciInsertStrHashTable ( char* obj_name,
                                      void *data
 				   )
 {
-#define GHC_CONC MAYBE_LEADING_UNDERSCORE_STR("base_GHCziConc")
-
-    if (lookupHashTable(table, (StgWord)key) == NULL)
-    {
+   if (lookupHashTable(table, (StgWord)key) == NULL)
+   {
       insertStrHashTable(table, (StgWord)key, data);
       return;
-    }
-    if (strncmp(key, GHC_CONC, strlen(GHC_CONC)) == 0) {
-        /* see NOTE [io-manager-ghci] */
-        return;
-    }
-    debugBelch(
+   }
+   debugBelch(
       "\n\n"
       "GHCi runtime linker: fatal error: I found a duplicate definition for symbol\n"
       "   %s\n"
@@ -1102,8 +1061,8 @@ static void ghciInsertStrHashTable ( char* obj_name,
       "\n",
       (char*)key,
       obj_name
-    );
-    exit(1);
+   );
+   exit(1);
 }
 /* -----------------------------------------------------------------------------
  * initialize the object linker
diff --git a/rts/Schedule.c b/rts/Schedule.c
index 998d8465a7..539e006fa6 100644
--- a/rts/Schedule.c
+++ b/rts/Schedule.c
@@ -1683,10 +1683,6 @@ forkProcess(HsStablePtr *entry
         initTimer();
         startTimer();
 
-#if defined(THREADED_RTS)
-        cap = ioManagerStartCap(cap);
-#endif
-
 	cap = rts_evalStableIO(cap, entry, NULL);  // run the action
 	rts_checkSchedStatus("forkProcess",cap);
 	
diff --git a/rts/package.conf.in b/rts/package.conf.in
index 131f1e389b..087a7e9d66 100644
--- a/rts/package.conf.in
+++ b/rts/package.conf.in
@@ -99,14 +99,6 @@ ld-options:
 	 , "-u", "_base_GHCziConc_ensureIOManagerIsRunning_closure"
 	 , "-u", "_base_GHCziConc_runSparks_closure"
 	 , "-u", "_base_GHCziConc_runHandlers_closure"
-         , "-u", "_base_GHCziConc_pendingDelays_closure"
-         , "-u", "_base_GHCziConc_pendingEvents_closure"
-         , "-u", "_base_GHCziConc_ioManagerThread_closure"
-#if !defined(mingw32_HOST_OS)
-         , "-u", "_base_GHCziConc_prodding_closure"
-         , "-u", "_base_GHCziConc_sync_closure"
-         , "-u", "_base_GHCziConc_stick_closure"
-#endif
 #else
            "-u", "ghczmprim_GHCziTypes_Izh_static_info"
          , "-u", "ghczmprim_GHCziTypes_Czh_static_info"
@@ -145,14 +137,6 @@ ld-options:
 	 , "-u", "base_GHCziConc_ensureIOManagerIsRunning_closure"
 	 , "-u", "base_GHCziConc_runSparks_closure"
 	 , "-u", "base_GHCziConc_runHandlers_closure"
-         , "-u", "base_GHCziConc_pendingDelays_closure"
-         , "-u", "base_GHCziConc_pendingEvents_closure"
-         , "-u", "base_GHCziConc_ioManagerThread_closure"
-#if !defined(mingw32_HOST_OS)
-         , "-u", "base_GHCziConc_prodding_closure"
-         , "-u", "base_GHCziConc_sync_closure"
-         , "-u", "base_GHCziConc_stick_closure"
-#endif
 #endif
 
 /*  Pick up static libraries in preference over dynamic if in earlier search
diff --git a/rts/posix/Signals.c b/rts/posix/Signals.c
index aa7877452b..660065734b 100644
--- a/rts/posix/Signals.c
+++ b/rts/posix/Signals.c
@@ -124,12 +124,6 @@ ioManagerDie (void)
     }
 }
 
-Capability *
-ioManagerStartCap (Capability *cap)
-{
-    return rts_evalIO(cap,&base_GHCziConc_ensureIOManagerIsRunning_closure,NULL);
-}
-
 void
 ioManagerStart (void)
 {
@@ -137,7 +131,7 @@ ioManagerStart (void)
     Capability *cap;
     if (io_manager_pipe < 0) {
 	cap = rts_lock();
-	cap = ioManagerStartCap(cap);
+	cap = rts_evalIO(cap,&base_GHCziConc_ensureIOManagerIsRunning_closure,NULL);
 	rts_unlock(cap);
     }
 }
diff --git a/rts/posix/Signals.h b/rts/posix/Signals.h
index b80f711b17..4d0a5a5fc7 100644
--- a/rts/posix/Signals.h
+++ b/rts/posix/Signals.h
@@ -24,8 +24,6 @@ extern siginfo_t *next_pending_handler;
 void startSignalHandlers(Capability *cap);
 #endif
 
-Capability *ioManagerStartCap (Capability *cap);
-
 extern StgInt *signal_handlers;
 
 END_RTS_PRIVATE