53
54 // Register mark stack space start
55 ZMarkStackSpaceStart = _start;
56 }
57
58 bool ZMarkStackSpace::is_initialized() const {
59 return _start != 0;
60 }
61
62 uintptr_t ZMarkStackSpace::alloc_space(size_t size) {
63 uintptr_t top = Atomic::load(&_top);
64
65 for (;;) {
66 const uintptr_t end = Atomic::load(&_end);
67 const uintptr_t new_top = top + size;
68 if (new_top > end) {
69 // Not enough space left
70 return 0;
71 }
72
73 const uintptr_t prev_top = Atomic::cmpxchg(new_top, &_top, top);
74 if (prev_top == top) {
75 // Success
76 return top;
77 }
78
79 // Retry
80 top = prev_top;
81 }
82 }
83
84 uintptr_t ZMarkStackSpace::expand_and_alloc_space(size_t size) {
85 ZLocker<ZLock> locker(&_expand_lock);
86
87 // Retry allocation before expanding
88 uintptr_t addr = alloc_space(size);
89 if (addr != 0) {
90 return addr;
91 }
92
93 // Check expansion limit
94 const size_t expand_size = ZMarkStackSpaceExpandSize;
95 const size_t old_size = _end - _start;
96 const size_t new_size = old_size + expand_size;
97 if (new_size > ZMarkStackSpaceLimit) {
98 // Expansion limit reached. This is a fatal error since we
99 // currently can't recover from running out of mark stack space.
100 fatal("Mark stack space exhausted. Use -XX:ZMarkStackSpaceLimit=<size> to increase the "
101 "maximum number of bytes allocated for mark stacks. Current limit is " SIZE_FORMAT "M.",
102 ZMarkStackSpaceLimit / M);
103 }
104
105 log_debug(gc, marking)("Expanding mark stack space: " SIZE_FORMAT "M->" SIZE_FORMAT "M",
106 old_size / M, new_size / M);
107
108 // Expand
109 os::commit_memory_or_exit((char*)_end, expand_size, false /* executable */, "Mark stack space");
110
111 // Increment top before end to make sure another
112 // thread can't steal out newly expanded space.
113 addr = Atomic::add(size, &_top) - size;
114 Atomic::add(expand_size, &_end);
115
116 return addr;
117 }
118
119 uintptr_t ZMarkStackSpace::alloc(size_t size) {
120 const uintptr_t addr = alloc_space(size);
121 if (addr != 0) {
122 return addr;
123 }
124
125 return expand_and_alloc_space(size);
126 }
127
128 ZMarkStackAllocator::ZMarkStackAllocator() :
129 _freelist(),
130 _space() {
131 guarantee(sizeof(ZMarkStack) == ZMarkStackSize, "Size mismatch");
132 guarantee(sizeof(ZMarkStackMagazine) <= ZMarkStackSize, "Size mismatch");
133
134 // Prime free list to avoid an immediate space
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53
54 // Register mark stack space start
55 ZMarkStackSpaceStart = _start;
56 }
57
58 bool ZMarkStackSpace::is_initialized() const {
59 return _start != 0;
60 }
61
62 uintptr_t ZMarkStackSpace::alloc_space(size_t size) {
63 uintptr_t top = Atomic::load(&_top);
64
65 for (;;) {
66 const uintptr_t end = Atomic::load(&_end);
67 const uintptr_t new_top = top + size;
68 if (new_top > end) {
69 // Not enough space left
70 return 0;
71 }
72
73 const uintptr_t prev_top = Atomic::cmpxchg(&_top, top, new_top);
74 if (prev_top == top) {
75 // Success
76 return top;
77 }
78
79 // Retry
80 top = prev_top;
81 }
82 }
83
84 uintptr_t ZMarkStackSpace::expand_and_alloc_space(size_t size) {
85 ZLocker<ZLock> locker(&_expand_lock);
86
87 // Retry allocation before expanding
88 uintptr_t addr = alloc_space(size);
89 if (addr != 0) {
90 return addr;
91 }
92
93 // Check expansion limit
94 const size_t expand_size = ZMarkStackSpaceExpandSize;
95 const size_t old_size = _end - _start;
96 const size_t new_size = old_size + expand_size;
97 if (new_size > ZMarkStackSpaceLimit) {
98 // Expansion limit reached. This is a fatal error since we
99 // currently can't recover from running out of mark stack space.
100 fatal("Mark stack space exhausted. Use -XX:ZMarkStackSpaceLimit=<size> to increase the "
101 "maximum number of bytes allocated for mark stacks. Current limit is " SIZE_FORMAT "M.",
102 ZMarkStackSpaceLimit / M);
103 }
104
105 log_debug(gc, marking)("Expanding mark stack space: " SIZE_FORMAT "M->" SIZE_FORMAT "M",
106 old_size / M, new_size / M);
107
108 // Expand
109 os::commit_memory_or_exit((char*)_end, expand_size, false /* executable */, "Mark stack space");
110
111 // Increment top before end to make sure another
112 // thread can't steal out newly expanded space.
113 addr = Atomic::add(&_top, size) - size;
114 Atomic::add(&_end, expand_size);
115
116 return addr;
117 }
118
119 uintptr_t ZMarkStackSpace::alloc(size_t size) {
120 const uintptr_t addr = alloc_space(size);
121 if (addr != 0) {
122 return addr;
123 }
124
125 return expand_and_alloc_space(size);
126 }
127
128 ZMarkStackAllocator::ZMarkStackAllocator() :
129 _freelist(),
130 _space() {
131 guarantee(sizeof(ZMarkStack) == ZMarkStackSize, "Size mismatch");
132 guarantee(sizeof(ZMarkStackMagazine) <= ZMarkStackSize, "Size mismatch");
133
134 // Prime free list to avoid an immediate space
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