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 #include "genesis/code.h"
  32
  33 #define ALIGNED_SIZE(n) ((n) + LOWTAG_MASK) & ~LOWTAG_MASK
  34
  35 #ifdef LISP_FEATURE_GENCGC
  36 static lispobj *
  37 pa_alloc(int bytes, int page_type_flag)
  38 {
  39     lispobj *result;
  40     struct thread *th = arch_os_get_current_thread();
  41
  42     /* FIXME: OOAO violation: see arch_pseudo_* */
  43     clear_pseudo_atomic_interrupted(th);
  44     set_pseudo_atomic_atomic(th);
  45     result = general_alloc(bytes, page_type_flag);
  46     clear_pseudo_atomic_atomic(th);
  47
  48     if (get_pseudo_atomic_interrupted(th)) {
  49         /* WARNING KLUDGE FIXME: pa_alloc() is not pseudo-atomic on
  50          * anything but x86[-64]. maybe_defer_handler doesn't defer
  51          * interrupts if foreign_function_call_active
  52          *
  53          * If the C stack is not scavenged during GC, result needs to
  54          * be protected against not being referred to by any roots, so
  55          * we push it onto the lisp control stack, and read it back
  56          * off after any potential GC has finished */
  57 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
  58 #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
  59 #error "!C_STACK_IS_CONTROL_STACK and STACK_GROWS_DOWNWARD_NOT_UPWARD is not supported"
  60 #endif
  61         *current_control_stack_pointer = (lispobj) result;
  62         current_control_stack_pointer += 1;
  63 #endif
  64         do_pending_interrupt();
  65 #ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
  66         current_control_stack_pointer -= 1;
  67         result = (lispobj *) *current_control_stack_pointer;
  68 #endif
  69     }
  70     return result;
  71 }
  72 #else
  73 static lispobj *
  74 pa_alloc(int bytes, int page_type_flag)
  75 {
  76     lispobj *result;
  77
  78     /* FIXME: this is not pseudo atomic at all, but is called only from
  79      * interrupt safe places like interrupt handlers. MG - 2005-08-09 */
  80     result = dynamic_space_free_pointer;
  81
  82     /* Align up to next dual word boundary. */
  83     bytes = ALIGNED_SIZE(bytes);
  84
  85     dynamic_space_free_pointer = (lispobj *)((char *)result + bytes);
  86
  87     if (current_auto_gc_trigger
  88         && dynamic_space_free_pointer > current_auto_gc_trigger) {
  89         clear_auto_gc_trigger();
  90         set_auto_gc_trigger((char *)dynamic_space_free_pointer
  91                             - (char *)current_dynamic_space);
  92     }
  93     return result;
  94 }
  95 #endif
  96
  97 lispobj *
  98 alloc_unboxed(int type, int words)
  99 {
 100     lispobj *result;
 101
 102     result = pa_alloc(ALIGNED_SIZE((1 + words) * sizeof(lispobj)), UNBOXED_PAGE_FLAG);
 103     *result = (lispobj) (words << N_WIDETAG_BITS) | type;
 104     return result;
 105 }
 106
 107 static lispobj
 108 alloc_vector(int type, int length, int size, int page_type_flag)
 109 {
 110     struct vector *result;
 111
 112     result = (struct vector *)
 113         pa_alloc(ALIGNED_SIZE((2 + (length*size + 31) / 32) * sizeof(lispobj)), page_type_flag);
 114
 115     result->header = type;
 116     result->length = make_fixnum(length);
 117
 118     return make_lispobj(result,OTHER_POINTER_LOWTAG);
 119 }
 120
 121 lispobj
 122 alloc_cons(lispobj car, lispobj cdr)
 123 {
 124     struct cons *ptr =
 125         (struct cons *)pa_alloc(ALIGNED_SIZE(sizeof(struct cons)), BOXED_PAGE_FLAG);
 126
 127     ptr->car = car;
 128     ptr->cdr = cdr;
 129
 130     return make_lispobj(ptr, LIST_POINTER_LOWTAG);
 131 }
 132
 133 lispobj
 134 alloc_number(long n)
 135 {
 136     struct bignum *ptr;
 137
 138     if (-0x20000000 < n && n < 0x20000000)
 139         return make_fixnum(n);
 140     else {
 141         ptr = (struct bignum *)alloc_unboxed(BIGNUM_WIDETAG, 1);
 142
 143         ptr->digits[0] = n;
 144
 145         return make_lispobj(ptr, OTHER_POINTER_LOWTAG);
 146     }
 147 }
 148
 149 lispobj
 150 alloc_base_string(char *str)
 151 {
 152     int len = strlen(str);
 153     lispobj result = alloc_vector(SIMPLE_BASE_STRING_WIDETAG, len+1, 8, UNBOXED_PAGE_FLAG);
 154     struct vector *vec = (struct vector *)native_pointer(result);
 155
 156     vec->length = make_fixnum(len);
 157     strcpy((char *)vec->data, str);
 158
 159     return result;
 160 }
 161
 162 lispobj
 163 alloc_sap(void *ptr)
 164 {
 165     struct sap *sap;
 166     sap=(struct sap *)
 167         alloc_unboxed((int)SAP_WIDETAG, sizeof(struct sap)/sizeof(lispobj) -1);
 168     sap->pointer = ptr;
 169     return make_lispobj(sap,OTHER_POINTER_LOWTAG);
 170 }
 171
 172 lispobj
 173 alloc_code_object (unsigned boxed, unsigned unboxed) {
 174     struct code * code;
 175     boxed = make_fixnum(boxed + 1 + 4); /* 4 == trace_table_offset offset in words */
 176     boxed &= ~LOWTAG_MASK;
 177
 178     unboxed += LOWTAG_MASK;
 179     unboxed &= ~LOWTAG_MASK;
 180
 181     code = (struct code *) pa_alloc(ALIGNED_SIZE((boxed + unboxed) * sizeof(lispobj)),
 182                                     CODE_PAGE_FLAG);
 183
 184     boxed = boxed << (N_WIDETAG_BITS - WORD_SHIFT);
 185     code->header = boxed | CODE_HEADER_WIDETAG;
 186     code->code_size = unboxed;
 187     code->entry_points = NIL;
 188     code->debug_info = NIL;
 189     return make_lispobj(code, OTHER_POINTER_LOWTAG);
 190 }