src/runtime/dynbind.c

   1 /*
   2  * support for dynamic binding from C
   3  * See the "Chapter 9: Specials" of the SBCL Internals Manual.
   4  */
   5
   6 /*
   7  * This software is part of the SBCL system. See the README file for
   8  * more information.
   9  *
  10  * This software is derived from the CMU CL system, which was
  11  * written at Carnegie Mellon University and released into the
  12  * public domain. The software is in the public domain and is
  13  * provided with absolutely no warranty. See the COPYING and CREDITS
  14  * files for more information.
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19
  20 #include "sbcl.h"
  21 #include "runtime.h"
  22 #include "globals.h"
  23 #include "dynbind.h"
  24 #include "thread.h"
  25 #include "pseudo-atomic.h"
  26 #include "genesis/symbol.h"
  27 #include "genesis/binding.h"
  28 #include "genesis/static-symbols.h"
  29
  30 void bind_variable(lispobj symbol, lispobj value, void *th)
  31 {
  32     struct binding *binding;
  33     struct thread *thread=(struct thread *)th;
  34     binding = (struct binding *)get_binding_stack_pointer(thread);
  35     set_binding_stack_pointer(thread,binding+1);
  36 #ifdef LISP_FEATURE_SB_THREAD
  37     {
  38         struct symbol *sym=(struct symbol *)native_pointer(symbol);
  39         if(!sym->tls_index) {
  40             lispobj *tls_index_lock=
  41                 &((struct symbol *)native_pointer(TLS_INDEX_LOCK))->value;
  42             FSHOW_SIGNAL((stderr, "entering dynbind tls alloc\n"));
  43             set_pseudo_atomic_atomic(thread);
  44             get_spinlock(tls_index_lock,(uword_t)th);
  45             if(!sym->tls_index) {
  46                 sym->tls_index=SymbolValue(FREE_TLS_INDEX,0);
  47                 SetSymbolValue(FREE_TLS_INDEX, sym->tls_index+N_WORD_BYTES, 0);
  48                 if((sym->tls_index)>=(TLS_SIZE << WORD_SHIFT)) {
  49                     lose("Thread local storage exhausted.");
  50                 }
  51             }
  52             release_spinlock(tls_index_lock);
  53             FSHOW_SIGNAL((stderr, "exiting dynbind tls alloc\n"));
  54             clear_pseudo_atomic_atomic(thread);
  55             if (get_pseudo_atomic_interrupted(thread))
  56                 do_pending_interrupt();
  57         }
  58         binding->symbol = sym->tls_index;
  59         binding->value = SymbolTlValue(symbol, thread);
  60     }
  61 #else
  62     binding->symbol = symbol;
  63     binding->value = SymbolTlValue(symbol, thread);
  64 #endif
  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 = ((struct binding *)get_binding_stack_pointer(thread)) - 1;
  76
  77     /* On sb-thread, it's actually a tls-index */
  78     symbol = binding->symbol;
  79
  80 #ifdef LISP_FEATURE_SB_THREAD
  81
  82     ((union per_thread_data *)thread)->dynamic_values[(symbol) >> WORD_SHIFT]
  83         = binding->value;
  84 #else
  85     SetSymbolValue(symbol, binding->value, thread);
  86 #endif
  87
  88     binding->symbol = 0;
  89     binding->value = 0;
  90
  91     set_binding_stack_pointer(thread,binding);
  92 }
  93
  94 void
  95 unbind_to_here(lispobj *bsp,void *th)
  96 {
  97     struct thread *thread=(struct thread *)th;
  98     struct binding *target = (struct binding *)bsp;
  99     struct binding *binding = (struct binding *)get_binding_stack_pointer(thread);
 100     lispobj symbol;
 101
 102     while (target < binding) {
 103         binding--;
 104
 105         symbol = binding->symbol;
 106         if (symbol) {
 107             if (symbol != UNBOUND_MARKER_WIDETAG) {
 108 #ifdef LISP_FEATURE_SB_THREAD
 109                 ((union per_thread_data *)thread)->dynamic_values[(symbol) >> WORD_SHIFT]
 110                     = binding->value;
 111 #else
 112                 SetSymbolValue(symbol, binding->value, thread);
 113 #endif
 114             }
 115             binding->symbol = 0;
 116             binding->value = 0;
 117         }
 118     }
 119     set_binding_stack_pointer(thread,binding);
 120 }