--- /dev/null
+/*
+ * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
+ * Copyright (c) 2001 by Hewlett-Packard Company. All rights reserved.
+ *
+ * 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.
+ *
+ */
+
+/* Private declarations of GC marker data structures and macros */
+
+/*
+ * Declarations of mark stack. Needed by marker and client supplied mark
+ * routines. Transitively include gc_priv.h.
+ */
+#ifndef GC_PMARK_H
+#define GC_PMARK_H
+
+#ifdef HAVE_CONFIG_H
+# include "private/config.h"
+#endif
+
+#ifndef GC_BUILD
+# define GC_BUILD
+#endif
+
+#if defined(KEEP_BACK_PTRS) || defined(PRINT_BLACK_LIST)
+# include "dbg_mlc.h"
+#endif
+
+#ifndef GC_MARK_H
+# include "../gc_mark.h"
+#endif
+
+#ifndef GC_PRIVATE_H
+# include "gc_priv.h"
+#endif
+
+/* The real declarations of the following is in gc_priv.h, so that */
+/* we can avoid scanning the following table. */
+/*
+mark_proc GC_mark_procs[MAX_MARK_PROCS];
+*/
+
+#ifndef MARK_DESCR_OFFSET
+# define MARK_DESCR_OFFSET sizeof(word)
+#endif
+
+/*
+ * Mark descriptor stuff that should remain private for now, mostly
+ * because it's hard to export WORDSZ without including gcconfig.h.
+ */
+#define BITMAP_BITS (WORDSZ - GC_DS_TAG_BITS)
+#define PROC(descr) \
+ (GC_mark_procs[((descr) >> GC_DS_TAG_BITS) & (GC_MAX_MARK_PROCS-1)])
+#define ENV(descr) \
+ ((descr) >> (GC_DS_TAG_BITS + GC_LOG_MAX_MARK_PROCS))
+#define MAX_ENV \
+ (((word)1 << (WORDSZ - GC_DS_TAG_BITS - GC_LOG_MAX_MARK_PROCS)) - 1)
+
+GC_EXTERN unsigned GC_n_mark_procs;
+
+/* Number of mark stack entries to discard on overflow. */
+#define GC_MARK_STACK_DISCARDS (INITIAL_MARK_STACK_SIZE/8)
+
+typedef struct GC_ms_entry {
+ ptr_t mse_start; /* First word of object, word aligned. */
+ GC_word mse_descr; /* Descriptor; low order two bits are tags, */
+ /* as described in gc_mark.h. */
+} mse;
+
+GC_EXTERN size_t GC_mark_stack_size;
+
+GC_EXTERN mse * GC_mark_stack_limit;
+
+#ifdef PARALLEL_MARK
+ GC_EXTERN mse * volatile GC_mark_stack_top;
+#else
+ GC_EXTERN mse * GC_mark_stack_top;
+#endif
+
+GC_EXTERN mse * GC_mark_stack;
+
+#ifdef PARALLEL_MARK
+ /*
+ * Allow multiple threads to participate in the marking process.
+ * This works roughly as follows:
+ * The main mark stack never shrinks, but it can grow.
+ *
+ * The initiating threads holds the GC lock, and sets GC_help_wanted.
+ *
+ * Other threads:
+ * 1) update helper_count (while holding mark_lock.)
+ * 2) allocate a local mark stack
+ * repeatedly:
+ * 3) Steal a global mark stack entry by atomically replacing
+ * its descriptor with 0.
+ * 4) Copy it to the local stack.
+ * 5) Mark on the local stack until it is empty, or
+ * it may be profitable to copy it back.
+ * 6) If necessary, copy local stack to global one,
+ * holding mark lock.
+ * 7) Stop when the global mark stack is empty.
+ * 8) decrement helper_count (holding mark_lock).
+ *
+ * This is an experiment to see if we can do something along the lines
+ * of the University of Tokyo SGC in a less intrusive, though probably
+ * also less performant, way.
+ */
+
+ /* GC_mark_stack_top is protected by mark lock. */
+
+ /*
+ * GC_notify_all_marker() is used when GC_help_wanted is first set,
+ * when the last helper becomes inactive,
+ * when something is added to the global mark stack, and just after
+ * GC_mark_no is incremented.
+ * This could be split into multiple CVs (and probably should be to
+ * scale to really large numbers of processors.)
+ */
+#endif /* PARALLEL_MARK */
+
+GC_INNER mse * GC_signal_mark_stack_overflow(mse *msp);
+
+/* Push the object obj with corresponding heap block header hhdr onto */
+/* the mark stack. */
+#define PUSH_OBJ(obj, hhdr, mark_stack_top, mark_stack_limit) \
+{ \
+ register word _descr = (hhdr) -> hb_descr; \
+ GC_ASSERT(!HBLK_IS_FREE(hhdr)); \
+ if (_descr != 0) { \
+ mark_stack_top++; \
+ if (mark_stack_top >= mark_stack_limit) { \
+ mark_stack_top = GC_signal_mark_stack_overflow(mark_stack_top); \
+ } \
+ mark_stack_top -> mse_start = (obj); \
+ mark_stack_top -> mse_descr = _descr; \
+ } \
+}
+
+/* Push the contents of current onto the mark stack if it is a valid */
+/* ptr to a currently unmarked object. Mark it. */
+/* If we assumed a standard-conforming compiler, we could probably */
+/* generate the exit_label transparently. */
+#define PUSH_CONTENTS(current, mark_stack_top, mark_stack_limit, \
+ source, exit_label) \
+{ \
+ hdr * my_hhdr; \
+ HC_GET_HDR(current, my_hhdr, source, exit_label); \
+ PUSH_CONTENTS_HDR(current, mark_stack_top, mark_stack_limit, \
+ source, exit_label, my_hhdr, TRUE); \
+exit_label: ; \
+}
+
+/* Set mark bit, exit if it was already set. */
+#ifdef USE_MARK_BYTES
+ /* There is a race here, and we may set */
+ /* the bit twice in the concurrent case. This can result in the */
+ /* object being pushed twice. But that's only a performance issue. */
+# define SET_MARK_BIT_EXIT_IF_SET(hhdr,bit_no,exit_label) \
+ { \
+ char * mark_byte_addr = (char *)hhdr -> hb_marks + (bit_no); \
+ if (*mark_byte_addr) goto exit_label; \
+ *mark_byte_addr = 1; \
+ }
+#else
+# ifdef PARALLEL_MARK
+ /* This is used only if we explicitly set USE_MARK_BITS. */
+ /* The following may fail to exit even if the bit was already set. */
+ /* For our uses, that's benign: */
+# define OR_WORD_EXIT_IF_SET(addr, bits, exit_label) \
+ { \
+ if (!(*(addr) & (bits))) { \
+ AO_or((AO_t *)(addr), (bits)); \
+ } else { \
+ goto exit_label; \
+ } \
+ }
+# else
+# define OR_WORD_EXIT_IF_SET(addr, bits, exit_label) \
+ { \
+ word old = *(addr); \
+ word my_bits = (bits); \
+ if (old & my_bits) goto exit_label; \
+ *(addr) = (old | my_bits); \
+ }
+# endif /* !PARALLEL_MARK */
+# define SET_MARK_BIT_EXIT_IF_SET(hhdr,bit_no,exit_label) \
+ { \
+ word * mark_word_addr = hhdr -> hb_marks + divWORDSZ(bit_no); \
+ OR_WORD_EXIT_IF_SET(mark_word_addr, (word)1 << modWORDSZ(bit_no), \
+ exit_label); \
+ }
+#endif /* !USE_MARK_BYTES */
+
+#ifdef PARALLEL_MARK
+# define INCR_MARKS(hhdr) \
+ AO_store(&hhdr->hb_n_marks, AO_load(&hhdr->hb_n_marks) + 1)
+#else
+# define INCR_MARKS(hhdr) (void)(++hhdr->hb_n_marks)
+#endif
+
+#ifdef ENABLE_TRACE
+# define TRACE(source, cmd) \
+ if (GC_trace_addr != 0 && (ptr_t)(source) == GC_trace_addr) cmd
+# define TRACE_TARGET(target, cmd) \
+ if (GC_trace_addr != 0 && (target) == *(ptr_t *)GC_trace_addr) cmd
+#else
+# define TRACE(source, cmd)
+# define TRACE_TARGET(source, cmd)
+#endif
+
+#if defined(I386) && defined(__GNUC__)
+# define LONG_MULT(hprod, lprod, x, y) { \
+ __asm__ __volatile__("mull %2" : "=a"(lprod), "=d"(hprod) \
+ : "g"(y), "0"(x)); \
+ }
+#else
+# define LONG_MULT(hprod, lprod, x, y) { \
+ unsigned long long prod = (unsigned long long)(x) \
+ * (unsigned long long)(y); \
+ hprod = prod >> 32; \
+ lprod = (unsigned32)prod; \
+ }
+#endif /* !I386 */
+
+/* If the mark bit corresponding to current is not set, set it, and */
+/* push the contents of the object on the mark stack. Current points */
+/* to the beginning of the object. We rely on the fact that the */
+/* preceding header calculation will succeed for a pointer past the */
+/* first page of an object, only if it is in fact a valid pointer */
+/* to the object. Thus we can omit the otherwise necessary tests */
+/* here. Note in particular that the "displ" value is the displacement */
+/* from the beginning of the heap block, which may itself be in the */
+/* interior of a large object. */
+#ifdef MARK_BIT_PER_GRANULE
+# define PUSH_CONTENTS_HDR(current, mark_stack_top, mark_stack_limit, \
+ source, exit_label, hhdr, do_offset_check) \
+{ \
+ size_t displ = HBLKDISPL(current); /* Displacement in block; in bytes. */\
+ /* displ is always within range. If current doesn't point to */ \
+ /* first block, then we are in the all_interior_pointers case, and */ \
+ /* it is safe to use any displacement value. */ \
+ size_t gran_displ = BYTES_TO_GRANULES(displ); \
+ size_t gran_offset = hhdr -> hb_map[gran_displ]; \
+ size_t byte_offset = displ & (GRANULE_BYTES - 1); \
+ ptr_t base = current; \
+ /* The following always fails for large block references. */ \
+ if (EXPECT((gran_offset | byte_offset) != 0, FALSE)) { \
+ if (hhdr -> hb_large_block) { \
+ /* gran_offset is bogus. */ \
+ size_t obj_displ; \
+ base = (ptr_t)(hhdr -> hb_block); \
+ obj_displ = (ptr_t)(current) - base; \
+ if (obj_displ != displ) { \
+ GC_ASSERT(obj_displ < hhdr -> hb_sz); \
+ /* Must be in all_interior_pointer case, not first block */ \
+ /* already did validity check on cache miss. */ \
+ } else { \
+ if (do_offset_check && !GC_valid_offsets[obj_displ]) { \
+ GC_ADD_TO_BLACK_LIST_NORMAL(current, source); \
+ goto exit_label; \
+ } \
+ } \
+ gran_displ = 0; \
+ GC_ASSERT(hhdr -> hb_sz > HBLKSIZE || \
+ hhdr -> hb_block == HBLKPTR(current)); \
+ GC_ASSERT((ptr_t)(hhdr -> hb_block) <= (ptr_t) current); \
+ } else { \
+ size_t obj_displ = GRANULES_TO_BYTES(gran_offset) \
+ + byte_offset; \
+ if (do_offset_check && !GC_valid_offsets[obj_displ]) { \
+ GC_ADD_TO_BLACK_LIST_NORMAL(current, source); \
+ goto exit_label; \
+ } \
+ gran_displ -= gran_offset; \
+ base -= obj_displ; \
+ } \
+ } \
+ GC_ASSERT(hhdr == GC_find_header(base)); \
+ GC_ASSERT(gran_displ % BYTES_TO_GRANULES(hhdr -> hb_sz) == 0); \
+ TRACE(source, GC_log_printf("GC:%u: passed validity tests\n", \
+ (unsigned)GC_gc_no)); \
+ SET_MARK_BIT_EXIT_IF_SET(hhdr, gran_displ, exit_label); \
+ TRACE(source, GC_log_printf("GC:%u: previously unmarked\n", \
+ (unsigned)GC_gc_no)); \
+ TRACE_TARGET(base, \
+ GC_log_printf("GC:%u: marking %p from %p instead\n", \
+ (unsigned)GC_gc_no, base, source)); \
+ INCR_MARKS(hhdr); \
+ GC_STORE_BACK_PTR((ptr_t)source, base); \
+ PUSH_OBJ(base, hhdr, mark_stack_top, mark_stack_limit); \
+}
+#endif /* MARK_BIT_PER_GRANULE */
+
+#ifdef MARK_BIT_PER_OBJ
+# define PUSH_CONTENTS_HDR(current, mark_stack_top, mark_stack_limit, \
+ source, exit_label, hhdr, do_offset_check) \
+{ \
+ size_t displ = HBLKDISPL(current); /* Displacement in block; in bytes. */\
+ unsigned32 low_prod, high_prod; \
+ unsigned32 inv_sz = hhdr -> hb_inv_sz; \
+ ptr_t base = current; \
+ LONG_MULT(high_prod, low_prod, displ, inv_sz); \
+ /* product is > and within sz_in_bytes of displ * sz_in_bytes * 2**32 */ \
+ if (EXPECT(low_prod >> 16 != 0, FALSE)) { \
+ FIXME: fails if offset is a multiple of HBLKSIZE which becomes 0 \
+ if (inv_sz == LARGE_INV_SZ) { \
+ size_t obj_displ; \
+ base = (ptr_t)(hhdr -> hb_block); \
+ obj_displ = (ptr_t)(current) - base; \
+ if (obj_displ != displ) { \
+ GC_ASSERT(obj_displ < hhdr -> hb_sz); \
+ /* Must be in all_interior_pointer case, not first block */ \
+ /* already did validity check on cache miss. */ \
+ } else { \
+ if (do_offset_check && !GC_valid_offsets[obj_displ]) { \
+ GC_ADD_TO_BLACK_LIST_NORMAL(current, source); \
+ goto exit_label; \
+ } \
+ } \
+ GC_ASSERT(hhdr -> hb_sz > HBLKSIZE || \
+ hhdr -> hb_block == HBLKPTR(current)); \
+ GC_ASSERT((ptr_t)(hhdr -> hb_block) < (ptr_t) current); \
+ } else { \
+ /* Accurate enough if HBLKSIZE <= 2**15. */ \
+ GC_STATIC_ASSERT(HBLKSIZE <= (1 << 15)); \
+ size_t obj_displ = (((low_prod >> 16) + 1) * (hhdr->hb_sz)) >> 16; \
+ if (do_offset_check && !GC_valid_offsets[obj_displ]) { \
+ GC_ADD_TO_BLACK_LIST_NORMAL(current, source); \
+ goto exit_label; \
+ } \
+ base -= obj_displ; \
+ } \
+ } \
+ /* May get here for pointer to start of block not at */ \
+ /* beginning of object. If so, it's valid, and we're fine. */ \
+ GC_ASSERT(high_prod >= 0 && high_prod <= HBLK_OBJS(hhdr -> hb_sz)); \
+ TRACE(source, GC_log_printf("GC:%u: passed validity tests\n", \
+ (unsigned)GC_gc_no)); \
+ SET_MARK_BIT_EXIT_IF_SET(hhdr, high_prod, exit_label); \
+ TRACE(source, GC_log_printf("GC:%u: previously unmarked\n", \
+ (unsigned)GC_gc_no)); \
+ TRACE_TARGET(base, \
+ GC_log_printf("GC:%u: marking %p from %p instead\n", \
+ (unsigned)GC_gc_no, base, source)); \
+ INCR_MARKS(hhdr); \
+ GC_STORE_BACK_PTR((ptr_t)source, base); \
+ PUSH_OBJ(base, hhdr, mark_stack_top, mark_stack_limit); \
+}
+#endif /* MARK_BIT_PER_OBJ */
+
+#if defined(PRINT_BLACK_LIST) || defined(KEEP_BACK_PTRS)
+# define PUSH_ONE_CHECKED_STACK(p, source) \
+ GC_mark_and_push_stack((ptr_t)(p), (ptr_t)(source))
+#else
+# define PUSH_ONE_CHECKED_STACK(p, source) \
+ GC_mark_and_push_stack((ptr_t)(p))
+#endif
+
+/*
+ * Push a single value onto mark stack. Mark from the object pointed to by p.
+ * Invoke FIXUP_POINTER(p) before any further processing.
+ * P is considered valid even if it is an interior pointer.
+ * Previously marked objects are not pushed. Hence we make progress even
+ * if the mark stack overflows.
+ */
+
+#if NEED_FIXUP_POINTER
+ /* Try both the raw version and the fixed up one. */
+# define GC_PUSH_ONE_STACK(p, source) \
+ if ((ptr_t)(p) >= (ptr_t)GC_least_plausible_heap_addr \
+ && (ptr_t)(p) < (ptr_t)GC_greatest_plausible_heap_addr) { \
+ PUSH_ONE_CHECKED_STACK(p, source); \
+ } \
+ FIXUP_POINTER(p); \
+ if ((ptr_t)(p) >= (ptr_t)GC_least_plausible_heap_addr \
+ && (ptr_t)(p) < (ptr_t)GC_greatest_plausible_heap_addr) { \
+ PUSH_ONE_CHECKED_STACK(p, source); \
+ }
+#else /* !NEED_FIXUP_POINTER */
+# define GC_PUSH_ONE_STACK(p, source) \
+ if ((ptr_t)(p) >= (ptr_t)GC_least_plausible_heap_addr \
+ && (ptr_t)(p) < (ptr_t)GC_greatest_plausible_heap_addr) { \
+ PUSH_ONE_CHECKED_STACK(p, source); \
+ }
+#endif
+
+
+/*
+ * As above, but interior pointer recognition as for
+ * normal heap pointers.
+ */
+#define GC_PUSH_ONE_HEAP(p,source) \
+ FIXUP_POINTER(p); \
+ if ((ptr_t)(p) >= (ptr_t)GC_least_plausible_heap_addr \
+ && (ptr_t)(p) < (ptr_t)GC_greatest_plausible_heap_addr) { \
+ GC_mark_stack_top = GC_mark_and_push( \
+ (void *)(p), GC_mark_stack_top, \
+ GC_mark_stack_limit, (void * *)(source)); \
+ }
+
+/* Mark starting at mark stack entry top (incl.) down to */
+/* mark stack entry bottom (incl.). Stop after performing */
+/* about one page worth of work. Return the new mark stack */
+/* top entry. */
+GC_INNER mse * GC_mark_from(mse * top, mse * bottom, mse *limit);
+
+#define MARK_FROM_MARK_STACK() \
+ GC_mark_stack_top = GC_mark_from(GC_mark_stack_top, \
+ GC_mark_stack, \
+ GC_mark_stack + GC_mark_stack_size);
+
+/*
+ * Mark from one finalizable object using the specified
+ * mark proc. May not mark the object pointed to by
+ * real_ptr. That is the job of the caller, if appropriate.
+ * Note that this is called with the mutator running, but
+ * with us holding the allocation lock. This is safe only if the
+ * mutator needs the allocation lock to reveal hidden pointers.
+ * FIXME: Why do we need the GC_mark_state test below?
+ */
+#define GC_MARK_FO(real_ptr, mark_proc) \
+{ \
+ (*(mark_proc))(real_ptr); \
+ while (!GC_mark_stack_empty()) MARK_FROM_MARK_STACK(); \
+ if (GC_mark_state != MS_NONE) { \
+ GC_set_mark_bit(real_ptr); \
+ while (!GC_mark_some((ptr_t)0)) {} \
+ } \
+}
+
+GC_EXTERN GC_bool GC_mark_stack_too_small;
+ /* We need a larger mark stack. May be */
+ /* set by client supplied mark routines.*/
+
+typedef int mark_state_t; /* Current state of marking, as follows:*/
+ /* Used to remember where we are during */
+ /* concurrent marking. */
+
+ /* We say something is dirty if it was */
+ /* written since the last time we */
+ /* retrieved dirty bits. We say it's */
+ /* grungy if it was marked dirty in the */
+ /* last set of bits we retrieved. */
+
+ /* Invariant I: all roots and marked */
+ /* objects p are either dirty, or point */
+ /* to objects q that are either marked */
+ /* or a pointer to q appears in a range */
+ /* on the mark stack. */
+
+#define MS_NONE 0 /* No marking in progress. I holds. */
+ /* Mark stack is empty. */
+
+#define MS_PUSH_RESCUERS 1 /* Rescuing objects are currently */
+ /* being pushed. I holds, except */
+ /* that grungy roots may point to */
+ /* unmarked objects, as may marked */
+ /* grungy objects above scan_ptr. */
+
+#define MS_PUSH_UNCOLLECTABLE 2 /* I holds, except that marked */
+ /* uncollectable objects above scan_ptr */
+ /* may point to unmarked objects. */
+ /* Roots may point to unmarked objects */
+
+#define MS_ROOTS_PUSHED 3 /* I holds, mark stack may be nonempty */
+
+#define MS_PARTIALLY_INVALID 4 /* I may not hold, e.g. because of M.S. */
+ /* overflow. However marked heap */
+ /* objects below scan_ptr point to */
+ /* marked or stacked objects. */
+
+#define MS_INVALID 5 /* I may not hold. */
+
+GC_EXTERN mark_state_t GC_mark_state;
+
+#endif /* GC_PMARK_H */
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