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 <stdio.h>
  17 #include <stdlib.h>
  18
  19 #include "sbcl.h"
  20 #include "runtime.h"
  21 #include "globals.h"
  22 #include "dynbind.h"
  23 #include "thread.h"
  24 #include "pseudo-atomic.h"
  25 #include "genesis/symbol.h"
  26 #include "genesis/binding.h"
  27 #include "genesis/thread.h"
  28 #include "genesis/static-symbols.h"
  29
  30 #if defined(BINDING_STACK_POINTER)
  31 #define GetBSP() ((struct binding *)SymbolValue(BINDING_STACK_POINTER,thread))
  32 #define SetBSP(value) SetSymbolValue(BINDING_STACK_POINTER, (lispobj)(value),thread)
  33 #else
  34 #define GetBSP() ((struct binding *)current_binding_stack_pointer)
  35 #define SetBSP(value) (current_binding_stack_pointer=(lispobj *)(value))
  36 #endif
  37
  38 void bind_variable(lispobj symbol, lispobj value, void *th)
  39 {
  40     struct binding *binding;
  41     struct thread *thread=(struct thread *)th;
  42     binding = GetBSP();
  43     SetBSP(binding+1);
  44 #ifdef LISP_FEATURE_SB_THREAD
  45     {
  46         struct symbol *sym=(struct symbol *)native_pointer(symbol);
  47         if(!sym->tls_index) {
  48             lispobj *tls_index_lock=
  49                 &((struct symbol *)native_pointer(TLS_INDEX_LOCK))->value;
  50             FSHOW_SIGNAL((stderr, "entering dynbind tls alloc\n"));
  51             set_pseudo_atomic_atomic(th);
  52             get_spinlock(tls_index_lock,(long)th);
  53             if(!sym->tls_index) {
  54                 sym->tls_index=SymbolValue(FREE_TLS_INDEX,0);
  55                 SetSymbolValue(FREE_TLS_INDEX,
  56                                make_fixnum(fixnum_value(sym->tls_index)+1),0);
  57                 if(fixnum_value(sym->tls_index)>=TLS_SIZE) {
  58                     lose("Thread local storage exhausted.");
  59                 }
  60             }
  61             release_spinlock(tls_index_lock);
  62             FSHOW_SIGNAL((stderr, "exiting dynbind tls alloc\n"));
  63             clear_pseudo_atomic_atomic(th);
  64             if (get_pseudo_atomic_interrupted(th))
  65                 do_pending_interrupt();
  66         }
  67     }
  68 #endif
  69     binding->value = SymbolTlValue(symbol, thread);
  70     binding->symbol = symbol;
  71     SetTlSymbolValue(symbol, value, thread);
  72 }
  73
  74 void
  75 unbind(void *th)
  76 {
  77     struct thread *thread=(struct thread *)th;
  78     struct binding *binding;
  79     lispobj symbol;
  80
  81     binding = GetBSP() - 1;
  82
  83     symbol = binding->symbol;
  84
  85     SetTlSymbolValue(symbol, binding->value,thread);
  86
  87     binding->symbol = 0;
  88     binding->value = 0;
  89
  90     SetBSP(binding);
  91 }
  92
  93 void
  94 unbind_to_here(lispobj *bsp,void *th)
  95 {
  96     struct thread *thread=(struct thread *)th;
  97     struct binding *target = (struct binding *)bsp;
  98     struct binding *binding = GetBSP();
  99     lispobj symbol;
 100
 101     while (target < binding) {
 102         binding--;
 103
 104         symbol = binding->symbol;
 105         if (symbol) {
 106             if (symbol != UNBOUND_MARKER_WIDETAG) {
 107                 SetTlSymbolValue(symbol, binding->value,thread);
 108             }
 109             binding->symbol = 0;
 110             binding->value = 0;
 111         }
 112     }
 113     SetBSP(binding);
 114 }