Quelle gcj_mlc.c Sprache: C

/*
* Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
* Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose,  provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
*/

#include "private/gc_pmark.h"  /* includes gc_priv.h */

#ifdef GC_GCJ_SUPPORT

/*
* This is an allocator interface tuned for gcj (the GNU static
* java compiler).
*
* Each allocated object has a pointer in its first word to a vtable,
* which for our purposes is simply a structure describing the type of
* the object.
* This descriptor structure contains a GC marking descriptor at offset
* MARK_DESCR_OFFSET.
*
* It is hoped that this interface may also be useful for other systems,
* possibly with some tuning of the constants.  But the immediate goal
* is to get better gcj performance.
*
* We assume:
*  1) Counting on explicit initialization of this interface is OK;
*  2) FASTLOCK is not a significant win.
*/

#include "gc_gcj.h"
#include "private/dbg_mlc.h"

int GC_gcj_kind = 0;    /* Object kind for objects with descriptors     */
                        /* in "vtable".                                 */
int GC_gcj_debug_kind = 0;
                        /* The kind of objects that is always marked    */
                        /* with a mark proc call.                       */

STATIC struct GC_ms_entry * GC_gcj_fake_mark_proc(word * addr GC_ATTR_UNUSED,
                        struct GC_ms_entry *mark_stack_ptr,
                        struct GC_ms_entry * mark_stack_limit GC_ATTR_UNUSED,
                        word env GC_ATTR_UNUSED)
{
    ABORT_RET("No client gcj mark proc is specified");
    return mark_stack_ptr;
}

/* Caller does not hold allocation lock. */
GC_API void GC_CALL GC_init_gcj_malloc(int mp_index,
                                       void * /* really GC_mark_proc */mp)
{
#   ifndef GC_IGNORE_GCJ_INFO
      GC_bool ignore_gcj_info;
#   endif
    DCL_LOCK_STATE;

    if (mp == 0)        /* In case GC_DS_PROC is unused.        */
      mp = (void *)(word)GC_gcj_fake_mark_proc;

    GC_init();  /* In case it's not already done.       */
    LOCK();
    if (GC_gcjobjfreelist != NULL) {
      /* Already initialized.   */
      UNLOCK();
      return;
    }
#   ifdef GC_IGNORE_GCJ_INFO
      /* This is useful for debugging on platforms with missing getenv(). */
#     define ignore_gcj_info TRUE
#   else
      ignore_gcj_info = (0 != GETENV("GC_IGNORE_GCJ_INFO"));
#   endif
    if (ignore_gcj_info) {
      GC_COND_LOG_PRINTF("Gcj-style type information is disabled!\n");
    }
    GC_ASSERT(GC_mark_procs[mp_index] == (GC_mark_proc)0); /* unused */
    GC_mark_procs[mp_index] = (GC_mark_proc)(word)mp;
    if ((unsigned)mp_index >= GC_n_mark_procs)
        ABORT("GC_init_gcj_malloc: bad index");
    /* Set up object kind gcj-style indirect descriptor. */
    GC_gcjobjfreelist = (ptr_t *)GC_new_free_list_inner();
    if (ignore_gcj_info) {
        /* Use a simple length-based descriptor, thus forcing a fully   */
        /* conservative scan.                                           */
        GC_gcj_kind = GC_new_kind_inner((void **)GC_gcjobjfreelist,
                                        /* 0 | */ GC_DS_LENGTH,
                                        TRUE, TRUE);
        GC_gcj_debug_kind = GC_gcj_kind;
    } else {
        GC_gcj_kind = GC_new_kind_inner(
                        (void **)GC_gcjobjfreelist,
                        (((word)(-(signed_word)MARK_DESCR_OFFSET
                                 - GC_INDIR_PER_OBJ_BIAS))
                         | GC_DS_PER_OBJECT),
                        FALSE, TRUE);
        /* Set up object kind for objects that require mark proc call.  */
        GC_gcj_debug_kind = GC_new_kind_inner(GC_new_free_list_inner(),
                                GC_MAKE_PROC(mp_index,
                                             1 /* allocated with debug info */),
                                FALSE, TRUE);
    }
    UNLOCK();
#   undef ignore_gcj_info
}

#define GENERAL_MALLOC_INNER(lb,k) \
    GC_clear_stack(GC_generic_malloc_inner(lb, k))

#define GENERAL_MALLOC_INNER_IOP(lb,k) \
    GC_clear_stack(GC_generic_malloc_inner_ignore_off_page(lb, k))

/* We need a mechanism to release the lock and invoke finalizers.       */
/* We don't really have an opportunity to do this on a rarely executed  */
/* path on which the lock is not held.  Thus we check at a              */
/* rarely executed point at which it is safe to release the lock.       */
/* We do this even where we could just call GC_INVOKE_FINALIZERS,       */
/* since it's probably cheaper and certainly more uniform.              */
/* TODO: Consider doing the same elsewhere? */
static void maybe_finalize(void)
{
   static word last_finalized_no = 0;
   DCL_LOCK_STATE;

   if (GC_gc_no == last_finalized_no ||
       !EXPECT(GC_is_initialized, TRUE)) return;
   UNLOCK();
   GC_INVOKE_FINALIZERS();
   LOCK();
   last_finalized_no = GC_gc_no;
}

/* Allocate an object, clear it, and store the pointer to the   */
/* type structure (vtable in gcj).                              */
/* This adds a byte at the end of the object if GC_malloc would.*/
#ifdef THREAD_LOCAL_ALLOC
  GC_INNER void * GC_core_gcj_malloc(size_t lb,
                                     void * ptr_to_struct_containing_descr)
#else
  GC_API GC_ATTR_MALLOC void * GC_CALL GC_gcj_malloc(size_t lb,
                                      void * ptr_to_struct_containing_descr)
#endif
{
    ptr_t op;
    DCL_LOCK_STATE;

    GC_DBG_COLLECT_AT_MALLOC(lb);
    if(SMALL_OBJ(lb)) {
        word lg;

        LOCK();
        lg = GC_size_map[lb];
        op = GC_gcjobjfreelist[lg];
        if(EXPECT(0 == op, FALSE)) {
            maybe_finalize();
            op = (ptr_t)GENERAL_MALLOC_INNER((word)lb, GC_gcj_kind);
            if (0 == op) {
                GC_oom_func oom_fn = GC_oom_fn;
                UNLOCK();
                return((*oom_fn)(lb));
            }
        } else {
            GC_gcjobjfreelist[lg] = (ptr_t)obj_link(op);
            GC_bytes_allocd += GRANULES_TO_BYTES((word)lg);
        }
        GC_ASSERT(((void **)op)[1] == 0);
    } else {
        LOCK();
        maybe_finalize();
        op = (ptr_t)GENERAL_MALLOC_INNER((word)lb, GC_gcj_kind);
        if (0 == op) {
            GC_oom_func oom_fn = GC_oom_fn;
            UNLOCK();
            return((*oom_fn)(lb));
        }
    }
    *(void **)op = ptr_to_struct_containing_descr;
    UNLOCK();
    GC_dirty(op);
    REACHABLE_AFTER_DIRTY(ptr_to_struct_containing_descr);
    return (void *)op;
}

/* Similar to GC_gcj_malloc, but add debug info.  This is allocated     */
/* with GC_gcj_debug_kind.                                              */
GC_API GC_ATTR_MALLOC void * GC_CALL GC_debug_gcj_malloc(size_t lb,
                void * ptr_to_struct_containing_descr, GC_EXTRA_PARAMS)
{
    void * result;
    DCL_LOCK_STATE;

    /* We're careful to avoid extra calls, which could          */
    /* confuse the backtrace.                                   */
    LOCK();
    maybe_finalize();
    result = GC_generic_malloc_inner(SIZET_SAT_ADD(lb, DEBUG_BYTES),
                                     GC_gcj_debug_kind);
    if (result == 0) {
        GC_oom_func oom_fn = GC_oom_fn;
        UNLOCK();
        GC_err_printf("GC_debug_gcj_malloc(%lu, %p) returning NULL (%s:%d)\n",
                (unsigned long)lb, ptr_to_struct_containing_descr, s, i);
        return((*oom_fn)(lb));
    }
    *((void **)((ptr_t)result + sizeof(oh))) = ptr_to_struct_containing_descr;
    if (!GC_debugging_started) {
        GC_start_debugging_inner();
    }
    ADD_CALL_CHAIN(result, ra);
    result = GC_store_debug_info_inner(result, (word)lb, s, i);
    UNLOCK();
    GC_dirty(result);
    REACHABLE_AFTER_DIRTY(ptr_to_struct_containing_descr);
    return result;
}

/* There is no THREAD_LOCAL_ALLOC for GC_gcj_malloc_ignore_off_page().  */
GC_API GC_ATTR_MALLOC void * GC_CALL GC_gcj_malloc_ignore_off_page(size_t lb,
                                     void * ptr_to_struct_containing_descr)
{
    ptr_t op;
    DCL_LOCK_STATE;

    GC_DBG_COLLECT_AT_MALLOC(lb);
    if(SMALL_OBJ(lb)) {
        word lg;

        LOCK();
        lg = GC_size_map[lb];
        op = GC_gcjobjfreelist[lg];
        if (EXPECT(0 == op, FALSE)) {
            maybe_finalize();
            op = (ptr_t)GENERAL_MALLOC_INNER_IOP(lb, GC_gcj_kind);
            if (0 == op) {
                GC_oom_func oom_fn = GC_oom_fn;
                UNLOCK();
                return((*oom_fn)(lb));
            }
        } else {
            GC_gcjobjfreelist[lg] = (ptr_t)obj_link(op);
            GC_bytes_allocd += GRANULES_TO_BYTES((word)lg);
        }
    } else {
        LOCK();
        maybe_finalize();
        op = (ptr_t)GENERAL_MALLOC_INNER_IOP(lb, GC_gcj_kind);
        if (0 == op) {
            GC_oom_func oom_fn = GC_oom_fn;
            UNLOCK();
            return((*oom_fn)(lb));
        }
    }
    *(void **)op = ptr_to_struct_containing_descr;
    UNLOCK();
    GC_dirty(op);
    REACHABLE_AFTER_DIRTY(ptr_to_struct_containing_descr);
    return (void *)op;
}

#endif  /* GC_GCJ_SUPPORT */

quality94%

¤ Dauer der Verarbeitung: 0.8 Sekunden ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.