--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/services/mallocSiteTable.hpp Thu Aug 07 12:18:58 2014 -0700
@@ -0,0 +1,268 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * 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).
+ *
+ * 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.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_SERVICES_MALLOC_SITE_TABLE_HPP
+#define SHARE_VM_SERVICES_MALLOC_SITE_TABLE_HPP
+
+#if INCLUDE_NMT
+
+#include "memory/allocation.hpp"
+#include "runtime/atomic.hpp"
+#include "services/allocationSite.hpp"
+#include "services/mallocTracker.hpp"
+#include "services/nmtCommon.hpp"
+
+// MallocSite represents a code path that eventually calls
+// os::malloc() to allocate memory
+class MallocSite : public AllocationSite<MemoryCounter> {
+ public:
+ MallocSite() :
+ AllocationSite<MemoryCounter>(emptyStack) { }
+
+ MallocSite(const NativeCallStack& stack) :
+ AllocationSite<MemoryCounter>(stack) { }
+
+ void allocate(size_t size) { data()->allocate(size); }
+ void deallocate(size_t size) { data()->deallocate(size); }
+
+ // Memory allocated from this code path
+ size_t size() const { return peek()->size(); }
+ // The number of calls were made
+ size_t count() const { return peek()->count(); }
+};
+
+// Malloc site hashtable entry
+class MallocSiteHashtableEntry : public CHeapObj<mtNMT> {
+ private:
+ MallocSite _malloc_site;
+ MallocSiteHashtableEntry* _next;
+
+ public:
+ MallocSiteHashtableEntry() : _next(NULL) { }
+
+ MallocSiteHashtableEntry(NativeCallStack stack):
+ _malloc_site(stack), _next(NULL) { }
+
+ inline const MallocSiteHashtableEntry* next() const {
+ return _next;
+ }
+
+ // Insert an entry atomically.
+ // Return true if the entry is inserted successfully.
+ // The operation can be failed due to contention from other thread.
+ bool atomic_insert(const MallocSiteHashtableEntry* entry) {
+ return (Atomic::cmpxchg_ptr((void*)entry, (volatile void*)&_next,
+ NULL) == NULL);
+ }
+
+ void set_callsite(const MallocSite& site) {
+ _malloc_site = site;
+ }
+
+ inline const MallocSite* peek() const { return &_malloc_site; }
+ inline MallocSite* data() { return &_malloc_site; }
+
+ inline long hash() const { return _malloc_site.hash(); }
+ inline bool equals(const NativeCallStack& stack) const {
+ return _malloc_site.equals(stack);
+ }
+ // Allocation/deallocation on this allocation site
+ inline void allocate(size_t size) { _malloc_site.allocate(size); }
+ inline void deallocate(size_t size) { _malloc_site.deallocate(size); }
+ // Memory counters
+ inline size_t size() const { return _malloc_site.size(); }
+ inline size_t count() const { return _malloc_site.count(); }
+};
+
+// The walker walks every entry on MallocSiteTable
+class MallocSiteWalker : public StackObj {
+ public:
+ virtual bool do_malloc_site(const MallocSite* e) { return false; }
+};
+
+/*
+ * Native memory tracking call site table.
+ * The table is only needed when detail tracking is enabled.
+ */
+class MallocSiteTable : AllStatic {
+ private:
+ // The number of hash bucket in this hashtable. The number should
+ // be tuned if malloc activities changed significantly.
+ // The statistics data can be obtained via Jcmd
+ // jcmd <pid> VM.native_memory statistics.
+
+ // Currently, (number of buckets / number of entires) ratio is
+ // about 1 / 6
+ enum {
+ table_base_size = 128, // The base size is calculated from statistics to give
+ // table ratio around 1:6
+ table_size = (table_base_size * NMT_TrackingStackDepth - 1)
+ };
+
+
+ // This is a very special lock, that allows multiple shared accesses (sharedLock), but
+ // once exclusive access (exclusiveLock) is requested, all shared accesses are
+ // rejected forever.
+ class AccessLock : public StackObj {
+ enum LockState {
+ NoLock,
+ SharedLock,
+ ExclusiveLock
+ };
+
+ private:
+ // A very large negative number. The only possibility to "overflow"
+ // this number is when there are more than -min_jint threads in
+ // this process, which is not going to happen in foreseeable future.
+ const static int _MAGIC_ = min_jint;
+
+ LockState _lock_state;
+ volatile int* _lock;
+ public:
+ AccessLock(volatile int* lock) :
+ _lock(lock), _lock_state(NoLock) {
+ }
+
+ ~AccessLock() {
+ if (_lock_state == SharedLock) {
+ Atomic::dec((volatile jint*)_lock);
+ }
+ }
+ // Acquire shared lock.
+ // Return true if shared access is granted.
+ inline bool sharedLock() {
+ jint res = Atomic::add(1, _lock);
+ if (res < 0) {
+ Atomic::add(-1, _lock);
+ return false;
+ }
+ _lock_state = SharedLock;
+ return true;
+ }
+ // Acquire exclusive lock
+ void exclusiveLock();
+ };
+
+ public:
+ static bool initialize();
+ static void shutdown();
+
+ NOT_PRODUCT(static int access_peak_count() { return _peak_count; })
+
+ // Number of hash buckets
+ static inline int hash_buckets() { return (int)table_size; }
+
+ // Access and copy a call stack from this table. Shared lock should be
+ // acquired before access the entry.
+ static inline bool access_stack(NativeCallStack& stack, size_t bucket_idx,
+ size_t pos_idx) {
+ AccessLock locker(&_access_count);
+ if (locker.sharedLock()) {
+ NOT_PRODUCT(_peak_count = MAX2(_peak_count, _access_count);)
+ MallocSite* site = malloc_site(bucket_idx, pos_idx);
+ if (site != NULL) {
+ stack = *site->call_stack();
+ return true;
+ }
+ }
+ return false;
+ }
+
+ // Record a new allocation from specified call path.
+ // Return true if the allocation is recorded successfully, bucket_idx
+ // and pos_idx are also updated to indicate the entry where the allocation
+ // information was recorded.
+ // Return false only occurs under rare scenarios:
+ // 1. out of memory
+ // 2. overflow hash bucket
+ static inline bool allocation_at(const NativeCallStack& stack, size_t size,
+ size_t* bucket_idx, size_t* pos_idx) {
+ AccessLock locker(&_access_count);
+ if (locker.sharedLock()) {
+ NOT_PRODUCT(_peak_count = MAX2(_peak_count, _access_count);)
+ MallocSite* site = lookup_or_add(stack, bucket_idx, pos_idx);
+ if (site != NULL) site->allocate(size);
+ return site != NULL;
+ }
+ return false;
+ }
+
+ // Record memory deallocation. bucket_idx and pos_idx indicate where the allocation
+ // information was recorded.
+ static inline bool deallocation_at(size_t size, size_t bucket_idx, size_t pos_idx) {
+ AccessLock locker(&_access_count);
+ if (locker.sharedLock()) {
+ NOT_PRODUCT(_peak_count = MAX2(_peak_count, _access_count);)
+ MallocSite* site = malloc_site(bucket_idx, pos_idx);
+ if (site != NULL) {
+ site->deallocate(size);
+ return true;
+ }
+ }
+ return false;
+ }
+
+ // Walk this table.
+ static bool walk_malloc_site(MallocSiteWalker* walker);
+
+ private:
+ static MallocSiteHashtableEntry* new_entry(const NativeCallStack& key);
+ static void reset();
+
+ // Delete a bucket linked list
+ static void delete_linked_list(MallocSiteHashtableEntry* head);
+
+ static MallocSite* lookup_or_add(const NativeCallStack& key, size_t* bucket_idx, size_t* pos_idx);
+ static MallocSite* malloc_site(size_t bucket_idx, size_t pos_idx);
+ static bool walk(MallocSiteWalker* walker);
+
+ static inline int hash_to_index(int hash) {
+ hash = (hash > 0) ? hash : (-hash);
+ return (hash % table_size);
+ }
+
+ static inline const NativeCallStack* hash_entry_allocation_stack() {
+ return (NativeCallStack*)_hash_entry_allocation_stack;
+ }
+
+ private:
+ // Counter for counting concurrent access
+ static volatile int _access_count;
+
+ // The callsite hashtable. It has to be a static table,
+ // since malloc call can come from C runtime linker.
+ static MallocSiteHashtableEntry* _table[table_size];
+
+
+ // Reserve enough memory for placing the objects
+
+ // The memory for hashtable entry allocation stack object
+ static size_t _hash_entry_allocation_stack[CALC_OBJ_SIZE_IN_TYPE(NativeCallStack, size_t)];
+ // The memory for hashtable entry allocation callsite object
+ static size_t _hash_entry_allocation_site[CALC_OBJ_SIZE_IN_TYPE(MallocSiteHashtableEntry, size_t)];
+ NOT_PRODUCT(static int _peak_count;)
+};
+
+#endif // INCLUDE_NMT
+#endif // SHARE_VM_SERVICES_MALLOC_SITE_TABLE_HPP