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     binding = GetBSP();
  40     SetBSP(binding+1);
  41 #ifdef LISP_FEATURE_SB_THREAD
  42     {
  43         struct symbol *sym=(struct symbol *)native_pointer(symbol);
  44         if(!sym->tls_index) {
  45             lispobj *tls_index_lock=
  46                 &((struct symbol *)native_pointer(TLS_INDEX_LOCK))->value;
  47             SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(0),th);
  48             SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(1),th);
  49             get_spinlock(tls_index_lock,(long)th);
  50             if(!sym->tls_index) {
  51                 sym->tls_index=SymbolValue(FREE_TLS_INDEX,0);
  52                 SetSymbolValue(FREE_TLS_INDEX,
  53                                make_fixnum(fixnum_value(sym->tls_index)+1),0);
  54             }
  55             release_spinlock(tls_index_lock);
  56             SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0),th);
  57             if (fixnum_value(SymbolValue(PSEUDO_ATOMIC_INTERRUPTED,th)))
  58                 do_pending_interrupt();
  59         }
  60     }
  61 #endif
  62     old_tl_value=SymbolTlValue(symbol,thread);
  63     binding->value = old_tl_value;
  64     binding->symbol = symbol;
  65     SetTlSymbolValue(symbol, value,thread);
  66 }
  67
  68 void
  69 unbind(void *th)
  70 {
  71     struct thread *thread=(struct thread *)th;
  72     struct binding *binding;
  73     lispobj symbol;
  74
  75     binding = GetBSP() - 1;
  76
  77     symbol = binding->symbol;
  78
  79     SetTlSymbolValue(symbol, binding->value,thread);
  80
  81     binding->symbol = 0;
  82
  83     SetBSP(binding);
  84 }
  85
  86 void
  87 unbind_to_here(lispobj *bsp,void *th)
  88 {
  89     struct thread *thread=(struct thread *)th;
  90     struct binding *target = (struct binding *)bsp;
  91     struct binding *binding = GetBSP();
  92     lispobj symbol;
  93
  94     while (target < binding) {
  95         binding--;
  96
  97         symbol = binding->symbol;
  98         if (symbol) {
  99             SetTlSymbolValue(symbol, binding->value,thread);
 100             binding->symbol = 0;
 101         }
 102     }
 103     SetBSP(binding);
 104 }