src/runtime/dynbind.c

   1 /*
   2  * support for dynamic binding from C
   3  */
   4
   5 /*
   6  * This software is part of the SBCL system. See the README file for
   7  * more information.
   8  *
   9  * This software is derived from the CMU CL system, which was
  10  * written at Carnegie Mellon University and released into the
  11  * public domain. The software is in the public domain and is
  12  * provided with absolutely no warranty. See the COPYING and CREDITS
  13  * files for more information.
  14  */
  15
  16 #include "sbcl.h"
  17 #include "runtime.h"
  18 #include "globals.h"
  19 #include "dynbind.h"
  20 #include "thread.h"
  21 #include "genesis/symbol.h"
  22 #include "genesis/binding.h"
  23 #include "genesis/thread.h"
  24 #include "genesis/static-symbols.h"
  25
  26 #if defined(BINDING_STACK_POINTER)
  27 #define GetBSP() ((struct binding *)SymbolValue(BINDING_STACK_POINTER,thread))
  28 #define SetBSP(value) SetSymbolValue(BINDING_STACK_POINTER, (lispobj)(value),thread)
  29 #else
  30 #define GetBSP() ((struct binding *)current_binding_stack_pointer)
  31 #define SetBSP(value) (current_binding_stack_pointer=(lispobj *)(value))
  32 #endif
  33
  34 void bind_variable(lispobj symbol, lispobj value, void *th)
  35 {
  36     struct binding *binding;
  37     struct thread *thread=(struct thread *)th;
  38     binding = GetBSP();
  39     SetBSP(binding+1);
  40 #ifdef LISP_FEATURE_SB_THREAD
  41     {
  42         struct symbol *sym=(struct symbol *)native_pointer(symbol);
  43         if(!sym->tls_index) {
  44             lispobj *tls_index_lock=
  45                 &((struct symbol *)native_pointer(TLS_INDEX_LOCK))->value;
  46             SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(0),th);
  47             SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(1),th);
  48             get_spinlock(tls_index_lock,(long)th);
  49             if(!sym->tls_index) {
  50                 sym->tls_index=SymbolValue(FREE_TLS_INDEX,0);
  51                 SetSymbolValue(FREE_TLS_INDEX,
  52                                make_fixnum(fixnum_value(sym->tls_index)+1),0);
  53             }
  54             release_spinlock(tls_index_lock);
  55             SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0),th);
  56             if (fixnum_value(SymbolValue(PSEUDO_ATOMIC_INTERRUPTED,th)))
  57                 do_pending_interrupt();
  58         }
  59     }
  60 #endif
  61     binding->value = SymbolTlValue(symbol, thread);
  62     binding->symbol = symbol;
  63     SetTlSymbolValue(symbol, value, thread);
  64 }
  65
  66 void
  67 unbind(void *th)
  68 {
  69     struct thread *thread=(struct thread *)th;
  70     struct binding *binding;
  71     lispobj symbol;
  72
  73     binding = GetBSP() - 1;
  74
  75     symbol = binding->symbol;
  76
  77     SetTlSymbolValue(symbol, binding->value,thread);
  78
  79     binding->symbol = 0;
  80
  81     SetBSP(binding);
  82 }
  83
  84 void
  85 unbind_to_here(lispobj *bsp,void *th)
  86 {
  87     struct thread *thread=(struct thread *)th;
  88     struct binding *target = (struct binding *)bsp;
  89     struct binding *binding = GetBSP();
  90     lispobj symbol;
  91
  92     while (target < binding) {
  93         binding--;
  94
  95         symbol = binding->symbol;
  96         if (symbol) {
  97             SetTlSymbolValue(symbol, binding->value,thread);
  98             binding->symbol = 0;
  99         }
 100     }
 101     SetBSP(binding);
 102 }