Annotation of OpenXM_contrib2/asir2000/gc/include/private/gc_pmark.h, Revision 1.1
1.1 ! noro 1: /*
! 2: * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
! 3: * Copyright (c) 2001 by Hewlett-Packard Company. All rights reserved.
! 4: *
! 5: * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
! 6: * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
! 7: *
! 8: * Permission is hereby granted to use or copy this program
! 9: * for any purpose, provided the above notices are retained on all copies.
! 10: * Permission to modify the code and to distribute modified code is granted,
! 11: * provided the above notices are retained, and a notice that the code was
! 12: * modified is included with the above copyright notice.
! 13: *
! 14: */
! 15:
! 16: /* Private declarations of GC marker data structures and macros */
! 17:
! 18: /*
! 19: * Declarations of mark stack. Needed by marker and client supplied mark
! 20: * routines. Transitively include gc_priv.h.
! 21: * (Note that gc_priv.h should not be included before this, since this
! 22: * includes dbg_mlc.h, which wants to include gc_priv.h AFTER defining
! 23: * I_HIDE_POINTERS.)
! 24: */
! 25: #ifndef GC_PMARK_H
! 26: # define GC_PMARK_H
! 27:
! 28: # ifdef KEEP_BACK_PTRS
! 29: # include "dbg_mlc.h"
! 30: # endif
! 31: # ifndef GC_MARK_H
! 32: # include "../gc_mark.h"
! 33: # endif
! 34: # ifndef GC_PRIVATE_H
! 35: # include "gc_priv.h"
! 36: # endif
! 37:
! 38: /* The real declarations of the following is in gc_priv.h, so that */
! 39: /* we can avoid scanning the following table. */
! 40: /*
! 41: extern mark_proc GC_mark_procs[MAX_MARK_PROCS];
! 42: */
! 43:
! 44: /*
! 45: * Mark descriptor stuff that should remain private for now, mostly
! 46: * because it's hard to export WORDSZ without including gcconfig.h.
! 47: */
! 48: # define BITMAP_BITS (WORDSZ - GC_DS_TAG_BITS)
! 49: # define PROC(descr) \
! 50: (GC_mark_procs[((descr) >> GC_DS_TAG_BITS) & (GC_MAX_MARK_PROCS-1)])
! 51: # define ENV(descr) \
! 52: ((descr) >> (GC_DS_TAG_BITS + GC_LOG_MAX_MARK_PROCS))
! 53: # define MAX_ENV \
! 54: (((word)1 << (WORDSZ - GC_DS_TAG_BITS - GC_LOG_MAX_MARK_PROCS)) - 1)
! 55:
! 56:
! 57: extern word GC_n_mark_procs;
! 58:
! 59: /* Number of mark stack entries to discard on overflow. */
! 60: #define GC_MARK_STACK_DISCARDS (INITIAL_MARK_STACK_SIZE/8)
! 61:
! 62: typedef struct GC_ms_entry {
! 63: GC_word * mse_start; /* First word of object */
! 64: GC_word mse_descr; /* Descriptor; low order two bits are tags, */
! 65: /* identifying the upper 30 bits as one of the */
! 66: /* following: */
! 67: } mse;
! 68:
! 69: extern word GC_mark_stack_size;
! 70:
! 71: extern mse * GC_mark_stack_limit;
! 72:
! 73: #ifdef PARALLEL_MARK
! 74: extern mse * VOLATILE GC_mark_stack_top;
! 75: #else
! 76: extern mse * GC_mark_stack_top;
! 77: #endif
! 78:
! 79: extern mse * GC_mark_stack;
! 80:
! 81: #ifdef PARALLEL_MARK
! 82: /*
! 83: * Allow multiple threads to participate in the marking process.
! 84: * This works roughly as follows:
! 85: * The main mark stack never shrinks, but it can grow.
! 86: *
! 87: * The initiating threads holds the GC lock, and sets GC_help_wanted.
! 88: *
! 89: * Other threads:
! 90: * 1) update helper_count (while holding mark_lock.)
! 91: * 2) allocate a local mark stack
! 92: * repeatedly:
! 93: * 3) Steal a global mark stack entry by atomically replacing
! 94: * its descriptor with 0.
! 95: * 4) Copy it to the local stack.
! 96: * 5) Mark on the local stack until it is empty, or
! 97: * it may be profitable to copy it back.
! 98: * 6) If necessary, copy local stack to global one,
! 99: * holding mark lock.
! 100: * 7) Stop when the global mark stack is empty.
! 101: * 8) decrement helper_count (holding mark_lock).
! 102: *
! 103: * This is an experiment to see if we can do something along the lines
! 104: * of the University of Tokyo SGC in a less intrusive, though probably
! 105: * also less performant, way.
! 106: */
! 107: void GC_do_parallel_mark();
! 108: /* inititate parallel marking. */
! 109:
! 110: extern GC_bool GC_help_wanted; /* Protected by mark lock */
! 111: extern unsigned GC_helper_count; /* Number of running helpers. */
! 112: /* Protected by mark lock */
! 113: extern unsigned GC_active_count; /* Number of active helpers. */
! 114: /* Protected by mark lock */
! 115: /* May increase and decrease */
! 116: /* within each mark cycle. But */
! 117: /* once it returns to 0, it */
! 118: /* stays zero for the cycle. */
! 119: /* GC_mark_stack_top is also protected by mark lock. */
! 120: extern mse * VOLATILE GC_first_nonempty;
! 121: /* Lowest entry on mark stack */
! 122: /* that may be nonempty. */
! 123: /* Updated only by initiating */
! 124: /* thread. */
! 125: /*
! 126: * GC_notify_all_marker() is used when GC_help_wanted is first set,
! 127: * when the last helper becomes inactive,
! 128: * when something is added to the global mark stack, and just after
! 129: * GC_mark_no is incremented.
! 130: * This could be split into multiple CVs (and probably should be to
! 131: * scale to really large numbers of processors.)
! 132: */
! 133: #endif /* PARALLEL_MARK */
! 134:
! 135: ptr_t GC_find_start();
! 136:
! 137: mse * GC_signal_mark_stack_overflow();
! 138:
! 139: # ifdef GATHERSTATS
! 140: # define ADD_TO_ATOMIC(sz) GC_atomic_in_use += (sz)
! 141: # define ADD_TO_COMPOSITE(sz) GC_composite_in_use += (sz)
! 142: # else
! 143: # define ADD_TO_ATOMIC(sz)
! 144: # define ADD_TO_COMPOSITE(sz)
! 145: # endif
! 146:
! 147: /* Push the object obj with corresponding heap block header hhdr onto */
! 148: /* the mark stack. */
! 149: # define PUSH_OBJ(obj, hhdr, mark_stack_top, mark_stack_limit) \
! 150: { \
! 151: register word _descr = (hhdr) -> hb_descr; \
! 152: \
! 153: if (_descr == 0) { \
! 154: ADD_TO_ATOMIC((hhdr) -> hb_sz); \
! 155: } else { \
! 156: ADD_TO_COMPOSITE((hhdr) -> hb_sz); \
! 157: mark_stack_top++; \
! 158: if (mark_stack_top >= mark_stack_limit) { \
! 159: mark_stack_top = GC_signal_mark_stack_overflow(mark_stack_top); \
! 160: } \
! 161: mark_stack_top -> mse_start = (obj); \
! 162: mark_stack_top -> mse_descr = _descr; \
! 163: } \
! 164: }
! 165:
! 166: #ifdef PRINT_BLACK_LIST
! 167: # define GC_FIND_START(current, hhdr, source) \
! 168: GC_find_start(current, hhdr, source)
! 169: #else
! 170: # define GC_FIND_START(current, hhdr, source) \
! 171: GC_find_start(current, hhdr)
! 172: #endif
! 173:
! 174: /* Push the contents of current onto the mark stack if it is a valid */
! 175: /* ptr to a currently unmarked object. Mark it. */
! 176: /* If we assumed a standard-conforming compiler, we could probably */
! 177: /* generate the exit_label transparently. */
! 178: # define PUSH_CONTENTS(current, mark_stack_top, mark_stack_limit, \
! 179: source, exit_label) \
! 180: { \
! 181: hdr * my_hhdr; \
! 182: ptr_t my_current = current; \
! 183: \
! 184: GET_HDR(my_current, my_hhdr); \
! 185: if (IS_FORWARDING_ADDR_OR_NIL(my_hhdr)) { \
! 186: my_current = GC_FIND_START(my_current, my_hhdr, (word)source); \
! 187: if (my_current == 0) goto exit_label; \
! 188: my_hhdr = GC_find_header(my_current); \
! 189: } \
! 190: PUSH_CONTENTS_HDR(my_current, mark_stack_top, mark_stack_limit, \
! 191: source, exit_label, my_hhdr); \
! 192: exit_label: ; \
! 193: }
! 194:
! 195: /* As above, but use header cache for header lookup. */
! 196: # define HC_PUSH_CONTENTS(current, mark_stack_top, mark_stack_limit, \
! 197: source, exit_label) \
! 198: { \
! 199: hdr * my_hhdr; \
! 200: ptr_t my_current = current; \
! 201: \
! 202: HC_GET_HDR(my_current, my_hhdr, source); \
! 203: PUSH_CONTENTS_HDR(my_current, mark_stack_top, mark_stack_limit, \
! 204: source, exit_label, my_hhdr); \
! 205: exit_label: ; \
! 206: }
! 207:
! 208: /* As above, but deal with two pointers in interleaved fashion. */
! 209: # define HC_PUSH_CONTENTS2(current1, current2, mark_stack_top, \
! 210: mark_stack_limit, \
! 211: source1, source2, exit_label1, exit_label2) \
! 212: { \
! 213: hdr * hhdr1; \
! 214: ptr_t my_current1 = current1; \
! 215: hdr * hhdr2; \
! 216: ptr_t my_current2 = current2; \
! 217: \
! 218: HC_GET_HDR2(my_current1, hhdr1, source1, my_current2, hhdr2, source2); \
! 219: PUSH_CONTENTS_HDR(my_current1, mark_stack_top, mark_stack_limit, \
! 220: source1, exit_label1, hhdr1); \
! 221: exit_label1: ; \
! 222: if (0 != hhdr2) { \
! 223: PUSH_CONTENTS_HDR(my_current2, mark_stack_top, mark_stack_limit, \
! 224: source2, exit_label2, hhdr2); \
! 225: } \
! 226: exit_label2: ; \
! 227: }
! 228:
! 229: /* Set mark bit, exit if it was already set. */
! 230:
! 231: # ifdef USE_MARK_BYTES
! 232: /* Unlike the mark bit case, there is a race here, and we may set */
! 233: /* the bit twice in the concurrent case. This can result in the */
! 234: /* object being pushed twice. But that's only a performance issue. */
! 235: # define SET_MARK_BIT_EXIT_IF_SET(hhdr,displ,exit_label) \
! 236: { \
! 237: register VOLATILE char * mark_byte_addr = \
! 238: hhdr -> hb_marks + ((displ) >> 1); \
! 239: register char mark_byte = *mark_byte_addr; \
! 240: \
! 241: if (mark_byte) goto exit_label; \
! 242: *mark_byte_addr = 1; \
! 243: }
! 244: # else
! 245: # define SET_MARK_BIT_EXIT_IF_SET(hhdr,displ,exit_label) \
! 246: { \
! 247: register word * mark_word_addr = hhdr -> hb_marks + divWORDSZ(displ); \
! 248: register word mark_word = *mark_word_addr; \
! 249: \
! 250: OR_WORD_EXIT_IF_SET(mark_word_addr, (word)1 << modWORDSZ(displ), \
! 251: exit_label); \
! 252: }
! 253: # endif /* USE_MARK_BYTES */
! 254:
! 255: /* If the mark bit corresponding to current is not set, set it, and */
! 256: /* push the contents of the object on the mark stack. Since we */
! 257: /* already have the header, we only look at the low order bits of */
! 258: /* current. (The value of current doesn't matter if hhdr = */
! 259: /* GC_invalid_header.) */
! 260: # define PUSH_CONTENTS_HDR(current, mark_stack_top, mark_stack_limit, \
! 261: source, exit_label, hhdr) \
! 262: { \
! 263: int displ; /* Displacement in block; first bytes, then words */ \
! 264: int map_entry; \
! 265: \
! 266: displ = HBLKDISPL(current); \
! 267: map_entry = MAP_ENTRY((hhdr -> hb_map), displ); \
! 268: displ = BYTES_TO_WORDS(displ); \
! 269: if (map_entry > CPP_MAX_OFFSET) { \
! 270: if (map_entry == OFFSET_TOO_BIG) { \
! 271: map_entry = displ % (hhdr -> hb_sz); \
! 272: displ -= map_entry; \
! 273: if (displ + (hhdr -> hb_sz) > BYTES_TO_WORDS(HBLKSIZE)) { \
! 274: GC_ADD_TO_BLACK_LIST_NORMAL((word)current, source); \
! 275: goto exit_label; \
! 276: } \
! 277: } else { \
! 278: GC_ADD_TO_BLACK_LIST_NORMAL((word)current, source); goto exit_label; \
! 279: } \
! 280: } else { \
! 281: displ -= map_entry; \
! 282: } \
! 283: GC_ASSERT(displ >= 0 && displ < MARK_BITS_PER_HBLK); \
! 284: SET_MARK_BIT_EXIT_IF_SET(hhdr, displ, exit_label); \
! 285: GC_STORE_BACK_PTR((ptr_t)source, (ptr_t)HBLKPTR(current) \
! 286: + WORDS_TO_BYTES(displ)); \
! 287: PUSH_OBJ(((word *)(HBLKPTR(current)) + displ), hhdr, \
! 288: mark_stack_top, mark_stack_limit) \
! 289: }
! 290:
! 291: #if defined(PRINT_BLACK_LIST) || defined(KEEP_BACK_PTRS)
! 292: # define PUSH_ONE_CHECKED_STACK(p, source) \
! 293: GC_mark_and_push_stack(p, (ptr_t)(source))
! 294: #else
! 295: # define PUSH_ONE_CHECKED_STACK(p, source) \
! 296: GC_mark_and_push_stack(p)
! 297: #endif
! 298:
! 299: /*
! 300: * Push a single value onto mark stack. Mark from the object pointed to by p.
! 301: * P is considered valid even if it is an interior pointer.
! 302: * Previously marked objects are not pushed. Hence we make progress even
! 303: * if the mark stack overflows.
! 304: */
! 305: # define GC_PUSH_ONE_STACK(p, source) \
! 306: if ((ptr_t)(p) >= (ptr_t)GC_least_plausible_heap_addr \
! 307: && (ptr_t)(p) < (ptr_t)GC_greatest_plausible_heap_addr) { \
! 308: PUSH_ONE_CHECKED_STACK(p, source); \
! 309: }
! 310:
! 311: /*
! 312: * As above, but interior pointer recognition as for
! 313: * normal for heap pointers.
! 314: */
! 315: # define GC_PUSH_ONE_HEAP(p,source) \
! 316: if ((ptr_t)(p) >= (ptr_t)GC_least_plausible_heap_addr \
! 317: && (ptr_t)(p) < (ptr_t)GC_greatest_plausible_heap_addr) { \
! 318: GC_mark_stack_top = GC_mark_and_push( \
! 319: (GC_PTR)(p), GC_mark_stack_top, \
! 320: GC_mark_stack_limit, (GC_PTR *)(source)); \
! 321: }
! 322:
! 323: /* Mark starting at mark stack entry top (incl.) down to */
! 324: /* mark stack entry bottom (incl.). Stop after performing */
! 325: /* about one page worth of work. Return the new mark stack */
! 326: /* top entry. */
! 327: mse * GC_mark_from GC_PROTO((mse * top, mse * bottom, mse *limit));
! 328:
! 329: #define MARK_FROM_MARK_STACK() \
! 330: GC_mark_stack_top = GC_mark_from(GC_mark_stack_top, \
! 331: GC_mark_stack, \
! 332: GC_mark_stack + GC_mark_stack_size);
! 333:
! 334: /*
! 335: * Mark from one finalizable object using the specified
! 336: * mark proc. May not mark the object pointed to by
! 337: * real_ptr. That is the job of the caller, if appropriate
! 338: */
! 339: # define GC_MARK_FO(real_ptr, mark_proc) \
! 340: { \
! 341: (*(mark_proc))(real_ptr); \
! 342: while (!GC_mark_stack_empty()) MARK_FROM_MARK_STACK(); \
! 343: if (GC_mark_state != MS_NONE) { \
! 344: GC_set_mark_bit(real_ptr); \
! 345: while (!GC_mark_some((ptr_t)0)); \
! 346: } \
! 347: }
! 348:
! 349: extern GC_bool GC_mark_stack_too_small;
! 350: /* We need a larger mark stack. May be */
! 351: /* set by client supplied mark routines.*/
! 352:
! 353: typedef int mark_state_t; /* Current state of marking, as follows:*/
! 354: /* Used to remember where we are during */
! 355: /* concurrent marking. */
! 356:
! 357: /* We say something is dirty if it was */
! 358: /* written since the last time we */
! 359: /* retrieved dirty bits. We say it's */
! 360: /* grungy if it was marked dirty in the */
! 361: /* last set of bits we retrieved. */
! 362:
! 363: /* Invariant I: all roots and marked */
! 364: /* objects p are either dirty, or point */
! 365: /* to objects q that are either marked */
! 366: /* or a pointer to q appears in a range */
! 367: /* on the mark stack. */
! 368:
! 369: # define MS_NONE 0 /* No marking in progress. I holds. */
! 370: /* Mark stack is empty. */
! 371:
! 372: # define MS_PUSH_RESCUERS 1 /* Rescuing objects are currently */
! 373: /* being pushed. I holds, except */
! 374: /* that grungy roots may point to */
! 375: /* unmarked objects, as may marked */
! 376: /* grungy objects above scan_ptr. */
! 377:
! 378: # define MS_PUSH_UNCOLLECTABLE 2
! 379: /* I holds, except that marked */
! 380: /* uncollectable objects above scan_ptr */
! 381: /* may point to unmarked objects. */
! 382: /* Roots may point to unmarked objects */
! 383:
! 384: # define MS_ROOTS_PUSHED 3 /* I holds, mark stack may be nonempty */
! 385:
! 386: # define MS_PARTIALLY_INVALID 4 /* I may not hold, e.g. because of M.S. */
! 387: /* overflow. However marked heap */
! 388: /* objects below scan_ptr point to */
! 389: /* marked or stacked objects. */
! 390:
! 391: # define MS_INVALID 5 /* I may not hold. */
! 392:
! 393: extern mark_state_t GC_mark_state;
! 394:
! 395: #endif /* GC_PMARK_H */
! 396:
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