src/share/vm/memory/metaspace.cpp
Print this page
rev 6853 : 8046070: Class Data Sharing clean up and refactoring
Summary: Cleaned up CDS to be more configurable, maintainable and extensible
Reviewed-by: dholmes, coleenp, acorn, mchung
@@ -411,10 +411,11 @@
// byte_size is the size of the associated virtualspace.
VirtualSpaceNode::VirtualSpaceNode(size_t bytes) : _top(NULL), _next(NULL), _rs(), _container_count(0) {
assert_is_size_aligned(bytes, Metaspace::reserve_alignment());
+#if INCLUDE_CDS
// This allocates memory with mmap. For DumpSharedspaces, try to reserve
// configurable address, generally at the top of the Java heap so other
// memory addresses don't conflict.
if (DumpSharedSpaces) {
bool large_pages = false; // No large pages when dumping the CDS archive.
@@ -426,11 +427,13 @@
} else {
// Get a mmap region anywhere if the SharedBaseAddress fails.
_rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
}
MetaspaceShared::set_shared_rs(&_rs);
- } else {
+ } else
+#endif
+ {
bool large_pages = should_commit_large_pages_when_reserving(bytes);
_rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
}
@@ -2937,15 +2940,18 @@
// narrow_klass_base is the lower of the metaspace base and the cds base
// (if cds is enabled). The narrow_klass_shift depends on the distance
// between the lower base and higher address.
address lower_base;
address higher_address;
+#if INCLUDE_CDS
if (UseSharedSpaces) {
higher_address = MAX2((address)(cds_base + FileMapInfo::shared_spaces_size()),
(address)(metaspace_base + compressed_class_space_size()));
lower_base = MIN2(metaspace_base, cds_base);
- } else {
+ } else
+#endif
+ {
higher_address = metaspace_base + compressed_class_space_size();
lower_base = metaspace_base;
uint64_t klass_encoding_max = UnscaledClassSpaceMax << LogKlassAlignmentInBytes;
// If compressed class space fits in lower 32G, we don't need a base.
@@ -2962,20 +2968,22 @@
assert(!UseSharedSpaces, "Cannot shift with UseSharedSpaces");
Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
}
}
+#if INCLUDE_CDS
// Return TRUE if the specified metaspace_base and cds_base are close enough
// to work with compressed klass pointers.
bool Metaspace::can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base) {
assert(cds_base != 0 && UseSharedSpaces, "Only use with CDS");
assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
address lower_base = MIN2((address)metaspace_base, cds_base);
address higher_address = MAX2((address)(cds_base + FileMapInfo::shared_spaces_size()),
(address)(metaspace_base + compressed_class_space_size()));
return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax);
}
+#endif
// Try to allocate the metaspace at the requested addr.
void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) {
assert(using_class_space(), "called improperly");
assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
@@ -2991,10 +2999,11 @@
ReservedSpace metaspace_rs = ReservedSpace(compressed_class_space_size(),
_reserve_alignment,
large_pages,
requested_addr, 0);
if (!metaspace_rs.is_reserved()) {
+#if INCLUDE_CDS
if (UseSharedSpaces) {
size_t increment = align_size_up(1*G, _reserve_alignment);
// Keep trying to allocate the metaspace, increasing the requested_addr
// by 1GB each time, until we reach an address that will no longer allow
@@ -3005,11 +3014,11 @@
addr = addr + increment;
metaspace_rs = ReservedSpace(compressed_class_space_size(),
_reserve_alignment, large_pages, addr, 0);
}
}
-
+#endif
// If no successful allocation then try to allocate the space anywhere. If
// that fails then OOM doom. At this point we cannot try allocating the
// metaspace as if UseCompressedClassPointers is off because too much
// initialization has happened that depends on UseCompressedClassPointers.
// So, UseCompressedClassPointers cannot be turned off at this point.
@@ -3024,16 +3033,17 @@
}
// If we got here then the metaspace got allocated.
MemTracker::record_virtual_memory_type((address)metaspace_rs.base(), mtClass);
+#if INCLUDE_CDS
// Verify that we can use shared spaces. Otherwise, turn off CDS.
if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(metaspace_rs.base(), cds_base)) {
FileMapInfo::stop_sharing_and_unmap(
"Could not allocate metaspace at a compatible address");
}
-
+#endif
set_narrow_klass_base_and_shift((address)metaspace_rs.base(),
UseSharedSpaces ? (address)cds_base : 0);
initialize_class_space(metaspace_rs);
@@ -3113,10 +3123,11 @@
size_t cds_total = 0;
MetaspaceShared::set_max_alignment(max_alignment);
if (DumpSharedSpaces) {
+#if INCLUDE_CDS
SharedReadOnlySize = align_size_up(SharedReadOnlySize, max_alignment);
SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
SharedMiscDataSize = align_size_up(SharedMiscDataSize, max_alignment);
SharedMiscCodeSize = align_size_up(SharedMiscCodeSize, max_alignment);
@@ -3150,49 +3161,50 @@
gclog_or_tty->print_cr("Setting_narrow_klass_base to Address: " PTR_FORMAT,
_space_list->current_virtual_space()->bottom());
}
Universe::set_narrow_klass_shift(0);
-#endif
-
+#endif // _LP64
+#endif // INCLUDE_CDS
} else {
+#if INCLUDE_CDS
// If using shared space, open the file that contains the shared space
// and map in the memory before initializing the rest of metaspace (so
// the addresses don't conflict)
address cds_address = NULL;
if (UseSharedSpaces) {
FileMapInfo* mapinfo = new FileMapInfo();
- memset(mapinfo, 0, sizeof(FileMapInfo));
// Open the shared archive file, read and validate the header. If
// initialization fails, shared spaces [UseSharedSpaces] are
// disabled and the file is closed.
// Map in spaces now also
if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
- FileMapInfo::set_current_info(mapinfo);
cds_total = FileMapInfo::shared_spaces_size();
cds_address = (address)mapinfo->region_base(0);
} else {
assert(!mapinfo->is_open() && !UseSharedSpaces,
"archive file not closed or shared spaces not disabled.");
}
}
-
+#endif // INCLUDE_CDS
#ifdef _LP64
// If UseCompressedClassPointers is set then allocate the metaspace area
// above the heap and above the CDS area (if it exists).
if (using_class_space()) {
if (UseSharedSpaces) {
+#if INCLUDE_CDS
char* cds_end = (char*)(cds_address + cds_total);
cds_end = (char *)align_ptr_up(cds_end, _reserve_alignment);
allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
+#endif
} else {
char* base = (char*)align_ptr_up(Universe::heap()->reserved_region().end(), _reserve_alignment);
allocate_metaspace_compressed_klass_ptrs(base, 0);
}
}
-#endif
+#endif // _LP64
// Initialize these before initializing the VirtualSpaceList
_first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
_first_chunk_word_size = align_word_size_up(_first_chunk_word_size);
// Make the first class chunk bigger than a medium chunk so it's not put
@@ -3378,10 +3390,14 @@
void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
assert(!SafepointSynchronize::is_at_safepoint()
|| Thread::current()->is_VM_thread(), "should be the VM thread");
+ if (DumpSharedSpaces && PrintSharedSpaces) {
+ record_deallocation(ptr, vsm()->get_raw_word_size(word_size));
+ }
+
MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
if (word_size < TreeChunk<Metablock, FreeList<Metablock> >::min_size()) {
// Dark matter. Too small for dictionary.
#ifdef ASSERT
@@ -3415,12 +3431,13 @@
Metaspace* space = read_only ? loader_data->ro_metaspace() : loader_data->rw_metaspace();
MetaWord* result = space->allocate(word_size, NonClassType);
if (result == NULL) {
report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
}
-
+ if (PrintSharedSpaces) {
space->record_allocation(result, type, space->vsm()->get_raw_word_size(word_size));
+ }
// Zero initialize.
Copy::fill_to_aligned_words((HeapWord*)result, word_size, 0);
return result;
@@ -3515,19 +3532,59 @@
}
void Metaspace::record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size) {
assert(DumpSharedSpaces, "sanity");
- AllocRecord *rec = new AllocRecord((address)ptr, type, (int)word_size * HeapWordSize);
+ int byte_size = (int)word_size * HeapWordSize;
+ AllocRecord *rec = new AllocRecord((address)ptr, type, byte_size);
+
if (_alloc_record_head == NULL) {
_alloc_record_head = _alloc_record_tail = rec;
- } else {
+ } else if (_alloc_record_tail->_ptr + _alloc_record_tail->_byte_size == (address)ptr) {
_alloc_record_tail->_next = rec;
_alloc_record_tail = rec;
+ } else {
+ // slow linear search, but this doesn't happen that often, and only when dumping
+ for (AllocRecord *old = _alloc_record_head; old; old = old->_next) {
+ if (old->_ptr == ptr) {
+ assert(old->_type == MetaspaceObj::DeallocatedType, "sanity");
+ int remain_bytes = old->_byte_size - byte_size;
+ assert(remain_bytes >= 0, "sanity");
+ old->_type = type;
+
+ if (remain_bytes == 0) {
+ delete(rec);
+ } else {
+ address remain_ptr = address(ptr) + byte_size;
+ rec->_ptr = remain_ptr;
+ rec->_byte_size = remain_bytes;
+ rec->_type = MetaspaceObj::DeallocatedType;
+ rec->_next = old->_next;
+ old->_byte_size = byte_size;
+ old->_next = rec;
+ }
+ return;
+ }
+ }
+ assert(0, "reallocating a freed pointer that was not recorded");
}
}
+void Metaspace::record_deallocation(void* ptr, size_t word_size) {
+ assert(DumpSharedSpaces, "sanity");
+
+ for (AllocRecord *rec = _alloc_record_head; rec; rec = rec->_next) {
+ if (rec->_ptr == ptr) {
+ assert(rec->_byte_size == (int)word_size * HeapWordSize, "sanity");
+ rec->_type = MetaspaceObj::DeallocatedType;
+ return;
+ }
+ }
+
+ assert(0, "deallocating a pointer that was not recorded");
+}
+
void Metaspace::iterate(Metaspace::AllocRecordClosure *closure) {
assert(DumpSharedSpaces, "unimplemented for !DumpSharedSpaces");
address last_addr = (address)bottom();