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Sun HotSpot VM 1.4.2 $B$+$i$O0J2<$N$h$&$J;XDj$,2DG=$G$"$k!#(B

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---

3. Mostly-concurrent Mark & Sweep

HotSpot VM 1.4.x $B$,:NMQ$7$?%3%s%+%l%s%H(B GC $B$O(B Mostly-concurrent Mark & Sweep $B$G$"$k!#(B

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1. $B%^!<%/(B $B%U%'!<%:(B (Mark phase)

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2. $B%9%$!<%W(B $B%U%'!<%:(B (Sweep phase)

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$B%i%$%H%P%j%"(B (write barrier)

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object2 $B$,(B null $B$G$J$$>l9g$O!"$I$s$J%*%V%8%'%/%H$G$b%A%'%C%/$r9T$&!#(B

void method( Class1 object, Class2 object2 ){
  object1.field = object2;
}

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$B$?$@

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#define CARD_SIZE  512
#define DIRTY_MASK ((unsigned char)-1)

/* $B%+!<%I%F!<%V%k(B */
unsigned char card_marking_table[CARD_SIZE];

void write_barrier(Object* object) {
  int offset = ((intptr_t)object) / CARD_SIZE;
  card_marking_table = DIRTY_MASK;
}

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