// locate an exiting record that contains specified address, or
// the record, where the record with specified address, should
// be inserted
virtual MemPointer* locate(address addr) {
VMMemRegion* cur = (VMMemRegion*)current();
VMMemRegion* next_p;
while (cur != NULL) {
if (cur->base() > addr) {
return cur;
} else {
// find nearest existing range that has base address <= addr
next_p = (VMMemRegion*)peek_next();
if (next_p != NULL && next_p->base() <= addr) {
cur = (VMMemRegion*)next();
continue;
}
}
if (cur->is_reserve_record() &&
cur->base() <= addr &&
(cur->base() + cur->size() > addr)) {
return cur;
} else if (cur->is_commit_record() &&
cur->base() <= addr &&
(cur->base() + cur->committed_size() > addr)) {
return cur;
}
cur = (VMMemRegion*)next();
}
return NULL;
}
bool VMMemPointerIterator::insert_reserved_region(MemPointerRecord* rec) {
// skip all 'commit' records associated with previous reserved region
VMMemRegion* p = (VMMemRegion*)next();
while (p != NULL && p->is_committed_region() &&
p->base() + p->size() < rec->addr()) {
p = (VMMemRegion*)next();
}
return insert_record(rec);
}
// locate an existing reserved memory region that contains specified address,
// or the reserved region just above this address, where the incoming
// reserved region should be inserted.
virtual MemPointer* locate(address addr) {
reset();
VMMemRegion* reg = (VMMemRegion*)current();
while (reg != NULL) {
if (reg->is_reserved_region()) {
if (reg->contains_address(addr) || addr < reg->base()) {
return reg;
}
}
reg = (VMMemRegion*)next();
}
return NULL;
}
bool VMMemPointerIterator::remove_released_region(MemPointerRecord* rec) {
assert(rec->is_deallocation_record(), "Sanity check");
VMMemRegion* cur = (VMMemRegion*)current();
assert(cur->is_reserved_region() && cur->contains_region(rec),
"Sanity check");
if (rec->is_same_region(cur)) {
// In snapshot, the virtual memory records are sorted in following orders:
// 1. virtual memory's base address
// 2. virtual memory reservation record, followed by commit records within this reservation.
// The commit records are also in base address order.
// When a reserved region is released, we want to remove the reservation record and all
// commit records following it.
#ifdef ASSERT
address low_addr = cur->addr();
address high_addr = low_addr + cur->size();
#endif
// remove virtual memory reservation record
remove();
// remove committed regions within above reservation
VMMemRegion* next_region = (VMMemRegion*)current();
while (next_region != NULL && next_region->is_committed_region()) {
assert(next_region->addr() >= low_addr &&
next_region->addr() + next_region->size() <= high_addr,
"Range check");
remove();
next_region = (VMMemRegion*)current();
}
} else if (rec->addr() == cur->addr() ||
rec->addr() + rec->size() == cur->addr() + cur->size()) {
// released region is at either end of this region
cur->exclude_region(rec->addr(), rec->size());
assert(check_reserved_region(), "Integrity check");
} else { // split the reserved region and release the middle
address high_addr = cur->addr() + cur->size();
size_t sz = high_addr - rec->addr();
cur->exclude_region(rec->addr(), sz);
sz = high_addr - rec->addr() - rec->size();
if (MemTracker::track_callsite()) {
MemPointerRecordEx tmp(rec->addr() + rec->size(), cur->flags(), sz,
((VMMemRegionEx*)cur)->pc());
bool ret = insert_reserved_region(&tmp);
assert(!ret || check_reserved_region(), "Integrity check");
return ret;
} else {
MemPointerRecord tmp(rec->addr() + rec->size(), cur->flags(), sz);
bool ret = insert_reserved_region(&tmp);
assert(!ret || check_reserved_region(), "Integrity check");
return ret;
}
}
return true;
}
bool VMMemPointerIterator::remove_uncommitted_region(MemPointerRecord* rec) {
assert(rec->is_uncommit_record(), "sanity check");
VMMemRegion* cur;
cur = (VMMemRegion*)current();
assert(cur->is_reserved_region() && cur->contains_region(rec),
"Sanity check");
// thread's native stack is always marked as "committed", ignore
// the "commit" operation for creating stack guard pages
if (FLAGS_TO_MEMORY_TYPE(cur->flags()) == mtThreadStack &&
FLAGS_TO_MEMORY_TYPE(rec->flags()) != mtThreadStack) {
return true;
}
cur = (VMMemRegion*)next();
while (cur != NULL && cur->is_committed_region()) {
// region already uncommitted, must be due to duplicated record
if (cur->addr() >= rec->addr() + rec->size()) {
break;
} else if (cur->contains_region(rec)) {
// uncommit whole region
if (cur->is_same_region(rec)) {
remove();
break;
} else if (rec->addr() == cur->addr() ||
rec->addr() + rec->size() == cur->addr() + cur->size()) {
// uncommitted from either end of current memory region.
cur->exclude_region(rec->addr(), rec->size());
break;
} else { // split the committed region and release the middle
address high_addr = cur->addr() + cur->size();
size_t sz = high_addr - rec->addr();
cur->exclude_region(rec->addr(), sz);
sz = high_addr - (rec->addr() + rec->size());
if (MemTracker::track_callsite()) {
MemPointerRecordEx tmp(rec->addr() + rec->size(), cur->flags(), sz,
((VMMemRegionEx*)cur)->pc());
return insert_record_after(&tmp);
} else {
MemPointerRecord tmp(rec->addr() + rec->size(), cur->flags(), sz);
return insert_record_after(&tmp);
}
}
}
cur = (VMMemRegion*)next();
}
// we may not find committed record due to duplicated records
return true;
}
bool VMMemPointerIterator::remove_released_region(MemPointerRecord* rec) {
assert(rec->is_deallocation_record(), "Sanity check");
VMMemRegion* cur = (VMMemRegion*)current();
assert(cur->is_reserved_region() && cur->contains_region(rec),
"Sanity check");
if (rec->is_same_region(cur)) {
// release whole reserved region
#ifdef ASSERT
VMMemRegion* next_region = (VMMemRegion*)peek_next();
// should not have any committed memory in this reserved region
assert(next_region == NULL || !next_region->is_committed_region(), "Sanity check");
#endif
remove();
} else if (rec->addr() == cur->addr() ||
rec->addr() + rec->size() == cur->addr() + cur->size()) {
// released region is at either end of this region
cur->exclude_region(rec->addr(), rec->size());
assert(check_reserved_region(), "Integrity check");
} else { // split the reserved region and release the middle
address high_addr = cur->addr() + cur->size();
size_t sz = high_addr - rec->addr();
cur->exclude_region(rec->addr(), sz);
sz = high_addr - rec->addr() - rec->size();
if (MemTracker::track_callsite()) {
MemPointerRecordEx tmp(rec->addr() + rec->size(), cur->flags(), sz,
((VMMemRegionEx*)cur)->pc());
bool ret = insert_reserved_region(&tmp);
assert(!ret || check_reserved_region(), "Integrity check");
return ret;
} else {
MemPointerRecord tmp(rec->addr() + rec->size(), cur->flags(), sz);
bool ret = insert_reserved_region(&tmp);
assert(!ret || check_reserved_region(), "Integrity check");
return ret;
}
}
return true;
}
