bool ReservedMemoryRegion::remove_uncommitted_region(address addr, size_t sz) {
// uncommit stack guard pages
if (flag() == mtThreadStack && !same_region(addr, sz)) {
return true;
}
assert(addr != NULL, "Invalid address");
assert(sz > 0, "Invalid size");
if (all_committed()) {
assert(_committed_regions.is_empty(), "Sanity check");
assert(contain_region(addr, sz), "Reserved region does not contain this region");
set_all_committed(false);
VirtualMemorySummary::record_uncommitted_memory(sz, flag());
if (same_region(addr, sz)) {
return true;
} else {
CommittedMemoryRegion rgn(base(), size(), *call_stack());
if (rgn.base() == addr || rgn.end() == (addr + sz)) {
rgn.exclude_region(addr, sz);
return add_committed_region(rgn);
} else {
// split this region
// top of the whole region
address top =rgn.end();
// use this region for lower part
size_t exclude_size = rgn.end() - addr;
rgn.exclude_region(addr, exclude_size);
if (add_committed_region(rgn)) {
// higher part
address high_base = addr + sz;
size_t high_size = top - high_base;
CommittedMemoryRegion high_rgn(high_base, high_size, NativeCallStack::EMPTY_STACK);
return add_committed_region(high_rgn);
} else {
return false;
}
}
}
} else {
// we have to walk whole list to remove the committed regions in
// specified range
LinkedListNode<CommittedMemoryRegion>* head =
_committed_regions.head();
LinkedListNode<CommittedMemoryRegion>* prev = NULL;
VirtualMemoryRegion uncommitted_rgn(addr, sz);
while (head != NULL && !uncommitted_rgn.is_empty()) {
CommittedMemoryRegion* crgn = head->data();
// this committed region overlaps to region to uncommit
if (crgn->overlap_region(uncommitted_rgn.base(), uncommitted_rgn.size())) {
if (crgn->same_region(uncommitted_rgn.base(), uncommitted_rgn.size())) {
// find matched region, remove the node will do
VirtualMemorySummary::record_uncommitted_memory(uncommitted_rgn.size(), flag());
_committed_regions.remove_after(prev);
return true;
} else if (crgn->contain_region(uncommitted_rgn.base(), uncommitted_rgn.size())) {
// this committed region contains whole uncommitted region
VirtualMemorySummary::record_uncommitted_memory(uncommitted_rgn.size(), flag());
return remove_uncommitted_region(head, uncommitted_rgn.base(), uncommitted_rgn.size());
} else if (uncommitted_rgn.contain_region(crgn->base(), crgn->size())) {
// this committed region has been uncommitted
size_t exclude_size = crgn->end() - uncommitted_rgn.base();
uncommitted_rgn.exclude_region(uncommitted_rgn.base(), exclude_size);
VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());
LinkedListNode<CommittedMemoryRegion>* tmp = head;
head = head->next();
_committed_regions.remove_after(prev);
continue;
} else if (crgn->contain_address(uncommitted_rgn.base())) {
size_t toUncommitted = crgn->end() - uncommitted_rgn.base();
crgn->exclude_region(uncommitted_rgn.base(), toUncommitted);
uncommitted_rgn.exclude_region(uncommitted_rgn.base(), toUncommitted);
VirtualMemorySummary::record_uncommitted_memory(toUncommitted, flag());
} else if (uncommitted_rgn.contain_address(crgn->base())) {
size_t toUncommitted = uncommitted_rgn.end() - crgn->base();
crgn->exclude_region(crgn->base(), toUncommitted);
uncommitted_rgn.exclude_region(uncommitted_rgn.end() - toUncommitted,
toUncommitted);
VirtualMemorySummary::record_uncommitted_memory(toUncommitted, flag());
}
}
prev = head;
head = head->next();
}
}
return true;
}
bool ReservedMemoryRegion::remove_uncommitted_region(address addr, size_t sz) {
// uncommit stack guard pages
if (flag() == mtThreadStack && !same_region(addr, sz)) {
return true;
}
assert(addr != NULL, "Invalid address");
assert(sz > 0, "Invalid size");
if (all_committed()) {
assert(_committed_regions.is_empty(), "Sanity check");
assert(contain_region(addr, sz), "Reserved region does not contain this region");
set_all_committed(false);
VirtualMemorySummary::record_uncommitted_memory(sz, flag());
if (same_region(addr, sz)) {
return true;
} else {
CommittedMemoryRegion rgn(base(), size(), *call_stack());
if (rgn.base() == addr || rgn.end() == (addr + sz)) {
rgn.exclude_region(addr, sz);
return add_committed_region(rgn);
} else {
// split this region
// top of the whole region
address top =rgn.end();
// use this region for lower part
size_t exclude_size = rgn.end() - addr;
rgn.exclude_region(addr, exclude_size);
if (add_committed_region(rgn)) {
// higher part
address high_base = addr + sz;
size_t high_size = top - high_base;
CommittedMemoryRegion high_rgn(high_base, high_size, NativeCallStack::EMPTY_STACK);
return add_committed_region(high_rgn);
} else {
return false;
}
}
}
} else {
CommittedMemoryRegion del_rgn(addr, sz, *call_stack());
address end = addr + sz;
LinkedListNode<CommittedMemoryRegion>* head = _committed_regions.head();
LinkedListNode<CommittedMemoryRegion>* prev = NULL;
CommittedMemoryRegion* crgn;
while (head != NULL) {
crgn = head->data();
if (crgn->same_region(addr, sz)) {
VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());
_committed_regions.remove_after(prev);
return true;
}
// del_rgn contains crgn
if (del_rgn.contain_region(crgn->base(), crgn->size())) {
VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());
head = head->next();
_committed_regions.remove_after(prev);
continue; // don't update head or prev
}
// Found addr in the current crgn. There are 2 subcases:
if (crgn->contain_address(addr)) {
// (1) Found addr+size in current crgn as well. (del_rgn is contained in crgn)
if (crgn->contain_address(end - 1)) {
VirtualMemorySummary::record_uncommitted_memory(sz, flag());
return remove_uncommitted_region(head, addr, sz); // done!
} else {
// (2) Did not find del_rgn's end in crgn.
size_t size = crgn->end() - del_rgn.base();
crgn->exclude_region(addr, size);
VirtualMemorySummary::record_uncommitted_memory(size, flag());
}
} else if (crgn->contain_address(end - 1)) {
// Found del_rgn's end, but not its base addr.
size_t size = del_rgn.end() - crgn->base();
crgn->exclude_region(crgn->base(), size);
VirtualMemorySummary::record_uncommitted_memory(size, flag());
return true; // should be done if the list is sorted properly!
}
prev = head;
head = head->next();
}
}
return true;
}