src/runtime/alloc.c

   1 /*
   2  * allocation routines for C code.  For allocation done by Lisp look
   3  * instead at src/compiler/target/alloc.lisp and .../macros.lisp
   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 <string.h>
  19
  20 #include "sbcl.h"
  21 #include "runtime.h"
  22 #include "os.h"
  23 #include "alloc.h"
  24 #include "globals.h"
  25 #include "gc.h"
  26 #include "thread.h"
  27 #include "genesis/vector.h"
  28 #include "genesis/cons.h"
  29 #include "genesis/bignum.h"
  30 #include "genesis/sap.h"
  31
  32 #define ALIGNED_SIZE(n) (n+LOWTAG_MASK) & ~LOWTAG_MASK
  33
  34 #if defined LISP_FEATURE_GENCGC
  35 extern lispobj *alloc(int bytes);
  36 lispobj *
  37 pa_alloc(int bytes)
  38 {
  39     lispobj *result=0;
  40     struct thread *th=arch_os_get_current_thread();
  41     /* FIXME: OOAO violation: see arch_pseudo_* */
  42     SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(0),th);
  43     SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(1),th);
  44     result=alloc(bytes);
  45     SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0),th);
  46     if (fixnum_value(SymbolValue(PSEUDO_ATOMIC_INTERRUPTED,th)))
  47         /* even if we gc at this point, the new allocation will be
  48          * protected from being moved, because result is on the c stack
  49          * and points to it */
  50         do_pending_interrupt();
  51     return result;
  52 }
  53
  54 #else
  55
  56 #define GET_FREE_POINTER() dynamic_space_free_pointer
  57 #define SET_FREE_POINTER(new_value) \
  58     (dynamic_space_free_pointer = (new_value))
  59 #define GET_GC_TRIGGER() current_auto_gc_trigger
  60 #define SET_GC_TRIGGER(new_value) \
  61     clear_auto_gc_trigger(); set_auto_gc_trigger(new_value);
  62
  63 /* FIXME: this is not pseudo atomic at all, but is called only from
  64  * interrupt safe places like interrupt handlers. MG - 2005-08-09 */
  65 static lispobj *
  66 pa_alloc(int bytes)
  67 {
  68     char *result;
  69
  70     /* Round to dual word boundary. */
  71     bytes = (bytes + LOWTAG_MASK) & ~LOWTAG_MASK;
  72
  73     result = (char *)GET_FREE_POINTER();
  74
  75     SET_FREE_POINTER((lispobj *)(result + bytes));
  76
  77     if (GET_GC_TRIGGER() && GET_FREE_POINTER() > GET_GC_TRIGGER()) {
  78         SET_GC_TRIGGER((char *)GET_FREE_POINTER()
  79                        - (char *)current_dynamic_space);
  80     }
  81     return (lispobj *) result;
  82 }
  83 #endif
  84
  85
  86 lispobj *
  87 alloc_unboxed(int type, int words)
  88 {
  89     lispobj *result;
  90
  91     result = pa_alloc(ALIGNED_SIZE((1 + words) * sizeof(lispobj)));
  92     *result = (lispobj) (words << N_WIDETAG_BITS) | type;
  93     return result;
  94 }
  95
  96 static lispobj
  97 alloc_vector(int type, int length, int size)
  98 {
  99     struct vector *result;
 100
 101     result = (struct vector *)
 102       pa_alloc(ALIGNED_SIZE((2 + (length*size + 31) / 32) * sizeof(lispobj)));
 103
 104     result->header = type;
 105     result->length = make_fixnum(length);
 106
 107     return make_lispobj(result,OTHER_POINTER_LOWTAG);
 108 }
 109
 110 lispobj
 111 alloc_cons(lispobj car, lispobj cdr)
 112 {
 113     struct cons *ptr = (struct cons *)pa_alloc(ALIGNED_SIZE(sizeof(struct cons)));
 114
 115     ptr->car = car;
 116     ptr->cdr = cdr;
 117
 118     return make_lispobj(ptr, LIST_POINTER_LOWTAG);
 119 }
 120
 121 lispobj
 122 alloc_number(long n)
 123 {
 124     struct bignum *ptr;
 125
 126     if (-0x20000000 < n && n < 0x20000000)
 127         return make_fixnum(n);
 128     else {
 129         ptr = (struct bignum *)alloc_unboxed(BIGNUM_WIDETAG, 1);
 130
 131         ptr->digits[0] = n;
 132
 133         return make_lispobj(ptr, OTHER_POINTER_LOWTAG);
 134     }
 135 }
 136
 137 lispobj
 138 alloc_base_string(char *str)
 139 {
 140     int len = strlen(str);
 141     lispobj result = alloc_vector(SIMPLE_BASE_STRING_WIDETAG, len+1, 8);
 142     struct vector *vec = (struct vector *)native_pointer(result);
 143
 144     vec->length = make_fixnum(len);
 145     strcpy((char *)vec->data, str);
 146
 147     return result;
 148 }
 149
 150 lispobj
 151 alloc_sap(void *ptr)
 152 {
 153     struct sap *sap;
 154     sap=(struct sap *)
 155         alloc_unboxed((int)SAP_WIDETAG, sizeof(struct sap)/sizeof(lispobj) -1);
 156     sap->pointer = ptr;
 157     return make_lispobj(sap,OTHER_POINTER_LOWTAG);
 158 }