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     lispobj old_tl_value;
  37     struct binding *binding;
  38     struct thread *thread=(struct thread *)th;
  39 #ifdef LISP_FEATURE_SB_THREAD
  40     struct symbol *sym=(struct symbol *)native_pointer(symbol);
  41 #endif
  42     binding = GetBSP();
  43     SetBSP(binding+1);
  44 #ifdef LISP_FEATURE_SB_THREAD
  45     if(!sym->tls_index) {
  46         sym->tls_index=SymbolValue(FREE_TLS_INDEX,0);
  47         SetSymbolValue(FREE_TLS_INDEX,
  48                        make_fixnum(fixnum_value(sym->tls_index)+1),0);
  49     }
  50 #endif
  51     old_tl_value=SymbolTlValue(symbol,thread);
  52     binding->value = old_tl_value;
  53     binding->symbol = symbol;
  54     SetTlSymbolValue(symbol, value,thread);
  55 }
  56
  57 void
  58 unbind(void *th)
  59 {
  60     struct thread *thread=(struct thread *)th;
  61     struct binding *binding;
  62     lispobj symbol;
  63
  64     binding = GetBSP() - 1;
  65
  66     symbol = binding->symbol;
  67
  68     SetTlSymbolValue(symbol, binding->value,thread);
  69
  70     binding->symbol = 0;
  71
  72     SetBSP(binding);
  73 }
  74
  75 void
  76 unbind_to_here(lispobj *bsp,void *th)
  77 {
  78     struct thread *thread=(struct thread *)th;
  79     struct binding *target = (struct binding *)bsp;
  80     struct binding *binding = GetBSP();
  81     lispobj symbol;
  82
  83     while (target < binding) {
  84         binding--;
  85
  86         symbol = binding->symbol;
  87         if (symbol) {
  88             SetTlSymbolValue(symbol, binding->value,thread);
  89             binding->symbol = 0;
  90         }
  91     }
  92     SetBSP(binding);
  93 }