rts/Typeable.c

   1 /* -----------------------------------------------------------------------------
   2  *
   3  * (c) The GHC Team, 1995-2005
   4  *
   5  * Data.Typeable support
   6  *
   7  * ---------------------------------------------------------------------------*/
   8
   9 #include "RtsTypeable.h"
  10 #include "Rts.h"
  11 #include "Storage.h"
  12 #include "Stable.h"
  13
  14 static StgPtr typeableStore = 0;
  15 #ifdef THREADED_RTS
  16 Mutex typeableStoreLock;
  17 #endif
  18
  19
  20 void
  21 initTypeableStore()
  22 {
  23     typeableStore=0;
  24 #ifdef THREADED_RTS
  25     initMutex(&typeableStoreLock);
  26 #endif
  27 }
  28
  29 void
  30 exitTypeableStore()
  31 {
  32 #ifdef THREADED_RTS
  33     closeMutex(&typeableStoreLock);
  34 #endif
  35     if(typeableStore!=0) {
  36         freeStablePtr((StgStablePtr)typeableStore);
  37         typeableStore=0;
  38     }
  39 }
  40
  41 StgPtr
  42 getOrSetTypeableStore(StgPtr ptr)
  43 {
  44     StgPtr ret = typeableStore;
  45     if(ret==0) {
  46 #ifdef THREADED_RTS
  47         ACQUIRE_LOCK(&typeableStoreLock);
  48         ret=typeableStore;
  49         if(ret==0) {
  50 #endif
  51             typeableStore = ret = ptr;
  52 #ifdef THREADED_RTS
  53         }
  54         RELEASE_LOCK(&typeableStoreLock);
  55 #endif
  56     }
  57     return ret;
  58 }