rts/Typeable.c

   1 /* -----------------------------------------------------------------------------
   2  *
   3  * (c) The GHC Team, 1995-2005
   4  *
   5  * Data.Typeable support
   6  *
   7  * ---------------------------------------------------------------------------*/
   8
   9 #include "Rts.h"
  10 #include "RtsTypeable.h"
  11
  12 static StgPtr typeableStore = 0;
  13 #ifdef THREADED_RTS
  14 Mutex typeableStoreLock;
  15 #endif
  16
  17
  18 void
  19 initTypeableStore()
  20 {
  21     typeableStore=0;
  22 #ifdef THREADED_RTS
  23     initMutex(&typeableStoreLock);
  24 #endif
  25 }
  26
  27 void
  28 exitTypeableStore()
  29 {
  30 #ifdef THREADED_RTS
  31     closeMutex(&typeableStoreLock);
  32 #endif
  33     if(typeableStore!=0) {
  34         freeStablePtr((StgStablePtr)typeableStore);
  35         typeableStore=0;
  36     }
  37 }
  38
  39 StgPtr
  40 getOrSetTypeableStore(StgPtr ptr)
  41 {
  42     StgPtr ret = typeableStore;
  43     if(ret==0) {
  44 #ifdef THREADED_RTS
  45         ACQUIRE_LOCK(&typeableStoreLock);
  46         ret=typeableStore;
  47         if(ret==0) {
  48 #endif
  49             typeableStore = ret = ptr;
  50 #ifdef THREADED_RTS
  51         }
  52         RELEASE_LOCK(&typeableStoreLock);
  53 #endif
  54     }
  55     return ret;
  56 }