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 "pseudo-atomic.h"
  22 #include "genesis/symbol.h"
  23 #include "genesis/binding.h"
  24 #include "genesis/thread.h"
  25 #include "genesis/static-symbols.h"
  26
  27 #if defined(BINDING_STACK_POINTER)
  28 #define GetBSP() ((struct binding *)SymbolValue(BINDING_STACK_POINTER,thread))
  29 #define SetBSP(value) SetSymbolValue(BINDING_STACK_POINTER, (lispobj)(value),thread)
  30 #else
  31 #define GetBSP() ((struct binding *)current_binding_stack_pointer)
  32 #define SetBSP(value) (current_binding_stack_pointer=(lispobj *)(value))
  33 #endif
  34
  35 void bind_variable(lispobj symbol, lispobj value, void *th)
  36 {
  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             clear_pseudo_atomic_interrupted(th);
  48             set_pseudo_atomic_atomic(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             clear_pseudo_atomic_atomic(th);
  57             if (get_pseudo_atomic_interrupted(th))
  58                 do_pending_interrupt();
  59         }
  60     }
  61 #endif
  62     binding->value = SymbolTlValue(symbol, thread);
  63     binding->symbol = symbol;
  64     SetTlSymbolValue(symbol, value, thread);
  65 }
  66
  67 void
  68 unbind(void *th)
  69 {
  70     struct thread *thread=(struct thread *)th;
  71     struct binding *binding;
  72     lispobj symbol;
  73
  74     binding = GetBSP() - 1;
  75
  76     symbol = binding->symbol;
  77
  78     SetTlSymbolValue(symbol, binding->value,thread);
  79
  80     binding->symbol = 0;
  81
  82     SetBSP(binding);
  83 }
  84
  85 void
  86 unbind_to_here(lispobj *bsp,void *th)
  87 {
  88     struct thread *thread=(struct thread *)th;
  89     struct binding *target = (struct binding *)bsp;
  90     struct binding *binding = GetBSP();
  91     lispobj symbol;
  92
  93     while (target < binding) {
  94         binding--;
  95
  96         symbol = binding->symbol;
  97         if (symbol) {
  98             if (symbol != UNBOUND_MARKER_WIDETAG) {
  99                 SetTlSymbolValue(symbol, binding->value,thread);
 100             }
 101             binding->symbol = 0;
 102         }
 103     }
 104     SetBSP(binding);
 105 }