7199092: NMT: NMT needs to deal overlapped virtual memory ranges
Summary: Enhanced virtual memory tracking to track committed regions as well as reserved regions, so NMT now can generate virtual memory map.
Reviewed-by: acorn, coleenp
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
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* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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#ifndef SHARE_VM_SERVICES_MEM_SNAPSHOT_HPP
#define SHARE_VM_SERVICES_MEM_SNAPSHOT_HPP
#include "memory/allocation.hpp"
#include "runtime/mutex.hpp"
#include "runtime/mutexLocker.hpp"
#include "services/memBaseline.hpp"
#include "services/memPtrArray.hpp"
// Snapshot pointer array iterator
// The pointer array contains malloc-ed pointers
class MemPointerIterator : public MemPointerArrayIteratorImpl {
public:
MemPointerIterator(MemPointerArray* arr):
MemPointerArrayIteratorImpl(arr) {
assert(arr != NULL, "null array");
}
#ifdef ASSERT
virtual bool is_dup_pointer(const MemPointer* ptr1,
const MemPointer* ptr2) const {
MemPointerRecord* p1 = (MemPointerRecord*)ptr1;
MemPointerRecord* p2 = (MemPointerRecord*)ptr2;
if (p1->addr() != p2->addr()) return false;
if ((p1->flags() & MemPointerRecord::tag_masks) !=
(p2->flags() & MemPointerRecord::tag_masks)) {
return false;
}
// we do see multiple commit/uncommit on the same memory, it is ok
return (p1->flags() & MemPointerRecord::tag_masks) == MemPointerRecord::tag_alloc ||
(p1->flags() & MemPointerRecord::tag_masks) == MemPointerRecord::tag_release;
}
virtual bool insert(MemPointer* ptr) {
if (_pos > 0) {
MemPointer* p1 = (MemPointer*)ptr;
MemPointer* p2 = (MemPointer*)_array->at(_pos - 1);
assert(!is_dup_pointer(p1, p2),
err_msg("duplicated pointer, flag = [%x]", (unsigned int)((MemPointerRecord*)p1)->flags()));
}
if (_pos < _array->length() -1) {
MemPointer* p1 = (MemPointer*)ptr;
MemPointer* p2 = (MemPointer*)_array->at(_pos + 1);
assert(!is_dup_pointer(p1, p2),
err_msg("duplicated pointer, flag = [%x]", (unsigned int)((MemPointerRecord*)p1)->flags()));
}
return _array->insert_at(ptr, _pos);
}
virtual bool insert_after(MemPointer* ptr) {
if (_pos > 0) {
MemPointer* p1 = (MemPointer*)ptr;
MemPointer* p2 = (MemPointer*)_array->at(_pos - 1);
assert(!is_dup_pointer(p1, p2),
err_msg("duplicated pointer, flag = [%x]", (unsigned int)((MemPointerRecord*)p1)->flags()));
}
if (_pos < _array->length() - 1) {
MemPointer* p1 = (MemPointer*)ptr;
MemPointer* p2 = (MemPointer*)_array->at(_pos + 1);
assert(!is_dup_pointer(p1, p2),
err_msg("duplicated pointer, flag = [%x]", (unsigned int)((MemPointerRecord*)p1)->flags()));
}
if (_array->insert_at(ptr, _pos + 1)) {
_pos ++;
return true;
}
return false;
}
#endif
virtual MemPointer* locate(address addr) {
MemPointer* cur = current();
while (cur != NULL && cur->addr() < addr) {
cur = next();
}
return cur;
}
};
class VMMemPointerIterator : public MemPointerIterator {
public:
VMMemPointerIterator(MemPointerArray* arr):
MemPointerIterator(arr) {
}
// 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;
}
// following methods update virtual memory in the context
// of 'current' position, which is properly positioned by
// callers via locate method.
bool add_reserved_region(MemPointerRecord* rec);
bool add_committed_region(MemPointerRecord* rec);
bool remove_uncommitted_region(MemPointerRecord* rec);
bool remove_released_region(MemPointerRecord* rec);
// split a reserved region to create a new memory region with specified base and size
bool split_reserved_region(VMMemRegion* rgn, address new_rgn_addr, size_t new_rgn_size);
private:
bool insert_record(MemPointerRecord* rec);
bool insert_record_after(MemPointerRecord* rec);
bool insert_reserved_region(MemPointerRecord* rec);
// reset current position
inline void reset() { _pos = 0; }
#ifdef ASSERT
virtual bool is_dup_pointer(const MemPointer* ptr1,
const MemPointer* ptr2) const {
VMMemRegion* p1 = (VMMemRegion*)ptr1;
VMMemRegion* p2 = (VMMemRegion*)ptr2;
if (p1->addr() != p2->addr()) return false;
if ((p1->flags() & MemPointerRecord::tag_masks) !=
(p2->flags() & MemPointerRecord::tag_masks)) {
return false;
}
// we do see multiple commit/uncommit on the same memory, it is ok
return (p1->flags() & MemPointerRecord::tag_masks) == MemPointerRecord::tag_alloc ||
(p1->flags() & MemPointerRecord::tag_masks) == MemPointerRecord::tag_release;
}
#endif
};
class MallocRecordIterator : public MemPointerArrayIterator {
protected:
MemPointerArrayIteratorImpl _itr;
public:
MallocRecordIterator(MemPointerArray* arr) : _itr(arr) {
}
virtual MemPointer* current() const {
MemPointerRecord* cur = (MemPointerRecord*)_itr.current();
assert(cur == NULL || !cur->is_vm_pointer(), "seek error");
MemPointerRecord* next = (MemPointerRecord*)_itr.peek_next();
if (next == NULL || next->addr() != cur->addr()) {
return cur;
} else {
assert(!cur->is_vm_pointer(), "Sanity check");
assert(cur->is_allocation_record() && next->is_deallocation_record(),
"sorting order");
assert(cur->seq() != next->seq(), "Sanity check");
return cur->seq() > next->seq() ? cur : next;
}
}
virtual MemPointer* next() {
MemPointerRecord* cur = (MemPointerRecord*)_itr.current();
assert(cur == NULL || !cur->is_vm_pointer(), "Sanity check");
MemPointerRecord* next = (MemPointerRecord*)_itr.next();
if (next == NULL) {
return NULL;
}
if (cur->addr() == next->addr()) {
next = (MemPointerRecord*)_itr.next();
}
return current();
}
MemPointer* peek_next() const { ShouldNotReachHere(); return NULL; }
MemPointer* peek_prev() const { ShouldNotReachHere(); return NULL; }
void remove() { ShouldNotReachHere(); }
bool insert(MemPointer* ptr) { ShouldNotReachHere(); return false; }
bool insert_after(MemPointer* ptr) { ShouldNotReachHere(); return false; }
};
// collapse duplicated records. Eliminating duplicated records here, is much
// cheaper than during promotion phase. However, it does have limitation - it
// can only eliminate duplicated records within the generation, there are
// still chances seeing duplicated records during promotion.
// We want to use the record with higher sequence number, because it has
// more accurate callsite pc.
class VMRecordIterator : public MallocRecordIterator {
public:
VMRecordIterator(MemPointerArray* arr) : MallocRecordIterator(arr) {
MemPointerRecord* cur = (MemPointerRecord*)_itr.current();
MemPointerRecord* next = (MemPointerRecord*)_itr.peek_next();
while (next != NULL) {
assert(cur != NULL, "Sanity check");
assert(((SeqMemPointerRecord*)next)->seq() > ((SeqMemPointerRecord*)cur)->seq(),
"pre-sort order");
if (is_duplicated_record(cur, next)) {
_itr.next();
next = (MemPointerRecord*)_itr.peek_next();
} else {
break;
}
}
}
virtual MemPointer* current() const {
return _itr.current();
}
// get next record, but skip the duplicated records
virtual MemPointer* next() {
MemPointerRecord* cur = (MemPointerRecord*)_itr.next();
MemPointerRecord* next = (MemPointerRecord*)_itr.peek_next();
while (next != NULL) {
assert(cur != NULL, "Sanity check");
assert(((SeqMemPointerRecord*)next)->seq() > ((SeqMemPointerRecord*)cur)->seq(),
"pre-sort order");
if (is_duplicated_record(cur, next)) {
_itr.next();
cur = next;
next = (MemPointerRecord*)_itr.peek_next();
} else {
break;
}
}
return cur;
}
private:
bool is_duplicated_record(MemPointerRecord* p1, MemPointerRecord* p2) const {
bool ret = (p1->addr() == p2->addr() && p1->size() == p2->size() && p1->flags() == p2->flags());
assert(!(ret && FLAGS_TO_MEMORY_TYPE(p1->flags()) == mtThreadStack), "dup on stack record");
return ret;
}
};
class StagingArea : public _ValueObj {
private:
MemPointerArray* _malloc_data;
MemPointerArray* _vm_data;
public:
StagingArea() : _malloc_data(NULL), _vm_data(NULL) {
init();
}
~StagingArea() {
if (_malloc_data != NULL) delete _malloc_data;
if (_vm_data != NULL) delete _vm_data;
}
MallocRecordIterator malloc_record_walker() {
return MallocRecordIterator(malloc_data());
}
VMRecordIterator virtual_memory_record_walker();
bool init();
void clear() {
assert(_malloc_data != NULL && _vm_data != NULL, "Just check");
_malloc_data->shrink();
_malloc_data->clear();
_vm_data->clear();
}
inline MemPointerArray* malloc_data() { return _malloc_data; }
inline MemPointerArray* vm_data() { return _vm_data; }
};
class MemBaseline;
class MemSnapshot : public CHeapObj<mtNMT> {
private:
// the following two arrays contain records of all known lived memory blocks
// live malloc-ed memory pointers
MemPointerArray* _alloc_ptrs;
// live virtual memory pointers
MemPointerArray* _vm_ptrs;
StagingArea _staging_area;
// the lock to protect this snapshot
Monitor* _lock;
NOT_PRODUCT(size_t _untracked_count;)
friend class MemBaseline;
public:
MemSnapshot();
virtual ~MemSnapshot();
// if we are running out of native memory
bool out_of_memory() {
return (_alloc_ptrs == NULL ||
_staging_area.malloc_data() == NULL ||
_staging_area.vm_data() == NULL ||
_vm_ptrs == NULL || _lock == NULL ||
_alloc_ptrs->out_of_memory() ||
_vm_ptrs->out_of_memory());
}
// merge a per-thread memory recorder into staging area
bool merge(MemRecorder* rec);
// promote staged data to snapshot
bool promote();
void wait(long timeout) {
assert(_lock != NULL, "Just check");
MonitorLockerEx locker(_lock);
locker.wait(true, timeout);
}
NOT_PRODUCT(void print_snapshot_stats(outputStream* st);)
NOT_PRODUCT(void check_staging_data();)
NOT_PRODUCT(void check_malloc_pointers();)
NOT_PRODUCT(bool has_allocation_record(address addr);)
// dump all virtual memory pointers in snapshot
DEBUG_ONLY( void dump_all_vm_pointers();)
private:
// copy pointer data from src to dest
void copy_pointer(MemPointerRecord* dest, const MemPointerRecord* src);
bool promote_malloc_records(MemPointerArrayIterator* itr);
bool promote_virtual_memory_records(MemPointerArrayIterator* itr);
};
#endif // SHARE_VM_SERVICES_MEM_SNAPSHOT_HPP