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 #ifdef LISP_FEATURE_GENCGC
  35 extern lispobj *alloc(long bytes);
  36 #endif
  37
  38 static lispobj *
  39 pa_alloc(int bytes)
  40 {
  41     lispobj *result;
  42 #ifdef LISP_FEATURE_GENCGC
  43     struct thread *th = arch_os_get_current_thread();
  44
  45     /* FIXME: OOAO violation: see arch_pseudo_* */
  46     clear_pseudo_atomic_interrupted(th);
  47     set_pseudo_atomic_atomic(th);
  48     result = alloc(bytes);
  49     clear_pseudo_atomic_atomic(th);
  50
  51     if (get_pseudo_atomic_interrupted(th)) {
  52         /* WARNING KLUDGE FIXME: pa_alloc() is not pseudo-atomic on
  53          * anything but x86[-64]. maybe_defer_handler doesn't defer
  54          * interrupts if foreign_function_call_active
  55          *
  56          * If the C stack is not scavenged during GC, result needs to
  57          * be protected against not being referred to by any roots, so
  58          * we push it onto the lisp control stack, and read it back
  59          * off after any potential GC has finished */
  60 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
  61 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
  62 #error "!C_STACK_IS_CONTROL_STACK and STACK_GROWS_DOWNWARD_NOT_UPWARD is not supported"
  63 #endif
  64         *current_control_stack_pointer = (lispobj) result;
  65         current_control_stack_pointer += 1;
  66 #endif
  67         do_pending_interrupt();
  68 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
  69         current_control_stack_pointer -= 1;
  70         result = (lispobj *) *current_control_stack_pointer;
  71 #endif
  72     }
  73 #else
  74     /* FIXME: this is not pseudo atomic at all, but is called only from
  75      * interrupt safe places like interrupt handlers. MG - 2005-08-09 */
  76     result = dynamic_space_free_pointer;
  77
  78     /* Align up to next dual word boundary. */
  79     bytes = ALIGNED_SIZE(bytes);
  80
  81     dynamic_space_free_pointer = (lispobj *)((char *)result + bytes);
  82
  83     if (current_auto_gc_trigger
  84         && dynamic_space_free_pointer > current_auto_gc_trigger) {
  85         clear_auto_gc_trigger();
  86         set_auto_gc_trigger((char *)dynamic_space_free_pointer
  87                             - (char *)current_dynamic_space);
  88     }
  89 #endif
  90     return result;
  91 }
  92
  93
  94 lispobj *
  95 alloc_unboxed(int type, int words)
  96 {
  97     lispobj *result;
  98
  99     result = pa_alloc(ALIGNED_SIZE((1 + words) * sizeof(lispobj)));
 100     *result = (lispobj) (words << N_WIDETAG_BITS) | type;
 101     return result;
 102 }
 103
 104 static lispobj
 105 alloc_vector(int type, int length, int size)
 106 {
 107     struct vector *result;
 108
 109     result = (struct vector *)
 110       pa_alloc(ALIGNED_SIZE((2 + (length*size + 31) / 32) * sizeof(lispobj)));
 111
 112     result->header = type;
 113     result->length = make_fixnum(length);
 114
 115     return make_lispobj(result,OTHER_POINTER_LOWTAG);
 116 }
 117
 118 lispobj
 119 alloc_cons(lispobj car, lispobj cdr)
 120 {
 121     struct cons *ptr =
 122         (struct cons *)pa_alloc(ALIGNED_SIZE(sizeof(struct cons)));
 123
 124     ptr->car = car;
 125     ptr->cdr = cdr;
 126
 127     return make_lispobj(ptr, LIST_POINTER_LOWTAG);
 128 }
 129
 130 lispobj
 131 alloc_number(long n)
 132 {
 133     struct bignum *ptr;
 134
 135     if (-0x20000000 < n && n < 0x20000000)
 136         return make_fixnum(n);
 137     else {
 138         ptr = (struct bignum *)alloc_unboxed(BIGNUM_WIDETAG, 1);
 139
 140         ptr->digits[0] = n;
 141
 142         return make_lispobj(ptr, OTHER_POINTER_LOWTAG);
 143     }
 144 }
 145
 146 lispobj
 147 alloc_base_string(char *str)
 148 {
 149     int len = strlen(str);
 150     lispobj result = alloc_vector(SIMPLE_BASE_STRING_WIDETAG, len+1, 8);
 151     struct vector *vec = (struct vector *)native_pointer(result);
 152
 153     vec->length = make_fixnum(len);
 154     strcpy((char *)vec->data, str);
 155
 156     return result;
 157 }
 158
 159 lispobj
 160 alloc_sap(void *ptr)
 161 {
 162     struct sap *sap;
 163     sap=(struct sap *)
 164         alloc_unboxed((int)SAP_WIDETAG, sizeof(struct sap)/sizeof(lispobj) -1);
 165     sap->pointer = ptr;
 166     return make_lispobj(sap,OTHER_POINTER_LOWTAG);
 167 }