1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/services/mallocSiteTable.hpp Wed Aug 27 08:19:12 2014 -0400
1.3 @@ -0,0 +1,268 @@
1.4 +/*
1.5 + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_SERVICES_MALLOC_SITE_TABLE_HPP
1.29 +#define SHARE_VM_SERVICES_MALLOC_SITE_TABLE_HPP
1.30 +
1.31 +#if INCLUDE_NMT
1.32 +
1.33 +#include "memory/allocation.hpp"
1.34 +#include "runtime/atomic.hpp"
1.35 +#include "services/allocationSite.hpp"
1.36 +#include "services/mallocTracker.hpp"
1.37 +#include "services/nmtCommon.hpp"
1.38 +
1.39 +// MallocSite represents a code path that eventually calls
1.40 +// os::malloc() to allocate memory
1.41 +class MallocSite : public AllocationSite<MemoryCounter> {
1.42 + public:
1.43 + MallocSite() :
1.44 + AllocationSite<MemoryCounter>(emptyStack) { }
1.45 +
1.46 + MallocSite(const NativeCallStack& stack) :
1.47 + AllocationSite<MemoryCounter>(stack) { }
1.48 +
1.49 + void allocate(size_t size) { data()->allocate(size); }
1.50 + void deallocate(size_t size) { data()->deallocate(size); }
1.51 +
1.52 + // Memory allocated from this code path
1.53 + size_t size() const { return peek()->size(); }
1.54 + // The number of calls were made
1.55 + size_t count() const { return peek()->count(); }
1.56 +};
1.57 +
1.58 +// Malloc site hashtable entry
1.59 +class MallocSiteHashtableEntry : public CHeapObj<mtNMT> {
1.60 + private:
1.61 + MallocSite _malloc_site;
1.62 + MallocSiteHashtableEntry* _next;
1.63 +
1.64 + public:
1.65 + MallocSiteHashtableEntry() : _next(NULL) { }
1.66 +
1.67 + MallocSiteHashtableEntry(NativeCallStack stack):
1.68 + _malloc_site(stack), _next(NULL) { }
1.69 +
1.70 + inline const MallocSiteHashtableEntry* next() const {
1.71 + return _next;
1.72 + }
1.73 +
1.74 + // Insert an entry atomically.
1.75 + // Return true if the entry is inserted successfully.
1.76 + // The operation can be failed due to contention from other thread.
1.77 + bool atomic_insert(const MallocSiteHashtableEntry* entry) {
1.78 + return (Atomic::cmpxchg_ptr((void*)entry, (volatile void*)&_next,
1.79 + NULL) == NULL);
1.80 + }
1.81 +
1.82 + void set_callsite(const MallocSite& site) {
1.83 + _malloc_site = site;
1.84 + }
1.85 +
1.86 + inline const MallocSite* peek() const { return &_malloc_site; }
1.87 + inline MallocSite* data() { return &_malloc_site; }
1.88 +
1.89 + inline long hash() const { return _malloc_site.hash(); }
1.90 + inline bool equals(const NativeCallStack& stack) const {
1.91 + return _malloc_site.equals(stack);
1.92 + }
1.93 + // Allocation/deallocation on this allocation site
1.94 + inline void allocate(size_t size) { _malloc_site.allocate(size); }
1.95 + inline void deallocate(size_t size) { _malloc_site.deallocate(size); }
1.96 + // Memory counters
1.97 + inline size_t size() const { return _malloc_site.size(); }
1.98 + inline size_t count() const { return _malloc_site.count(); }
1.99 +};
1.100 +
1.101 +// The walker walks every entry on MallocSiteTable
1.102 +class MallocSiteWalker : public StackObj {
1.103 + public:
1.104 + virtual bool do_malloc_site(const MallocSite* e) { return false; }
1.105 +};
1.106 +
1.107 +/*
1.108 + * Native memory tracking call site table.
1.109 + * The table is only needed when detail tracking is enabled.
1.110 + */
1.111 +class MallocSiteTable : AllStatic {
1.112 + private:
1.113 + // The number of hash bucket in this hashtable. The number should
1.114 + // be tuned if malloc activities changed significantly.
1.115 + // The statistics data can be obtained via Jcmd
1.116 + // jcmd <pid> VM.native_memory statistics.
1.117 +
1.118 + // Currently, (number of buckets / number of entires) ratio is
1.119 + // about 1 / 6
1.120 + enum {
1.121 + table_base_size = 128, // The base size is calculated from statistics to give
1.122 + // table ratio around 1:6
1.123 + table_size = (table_base_size * NMT_TrackingStackDepth - 1)
1.124 + };
1.125 +
1.126 +
1.127 + // This is a very special lock, that allows multiple shared accesses (sharedLock), but
1.128 + // once exclusive access (exclusiveLock) is requested, all shared accesses are
1.129 + // rejected forever.
1.130 + class AccessLock : public StackObj {
1.131 + enum LockState {
1.132 + NoLock,
1.133 + SharedLock,
1.134 + ExclusiveLock
1.135 + };
1.136 +
1.137 + private:
1.138 + // A very large negative number. The only possibility to "overflow"
1.139 + // this number is when there are more than -min_jint threads in
1.140 + // this process, which is not going to happen in foreseeable future.
1.141 + const static int _MAGIC_ = min_jint;
1.142 +
1.143 + LockState _lock_state;
1.144 + volatile int* _lock;
1.145 + public:
1.146 + AccessLock(volatile int* lock) :
1.147 + _lock(lock), _lock_state(NoLock) {
1.148 + }
1.149 +
1.150 + ~AccessLock() {
1.151 + if (_lock_state == SharedLock) {
1.152 + Atomic::dec((volatile jint*)_lock);
1.153 + }
1.154 + }
1.155 + // Acquire shared lock.
1.156 + // Return true if shared access is granted.
1.157 + inline bool sharedLock() {
1.158 + jint res = Atomic::add(1, _lock);
1.159 + if (res < 0) {
1.160 + Atomic::add(-1, _lock);
1.161 + return false;
1.162 + }
1.163 + _lock_state = SharedLock;
1.164 + return true;
1.165 + }
1.166 + // Acquire exclusive lock
1.167 + void exclusiveLock();
1.168 + };
1.169 +
1.170 + public:
1.171 + static bool initialize();
1.172 + static void shutdown();
1.173 +
1.174 + NOT_PRODUCT(static int access_peak_count() { return _peak_count; })
1.175 +
1.176 + // Number of hash buckets
1.177 + static inline int hash_buckets() { return (int)table_size; }
1.178 +
1.179 + // Access and copy a call stack from this table. Shared lock should be
1.180 + // acquired before access the entry.
1.181 + static inline bool access_stack(NativeCallStack& stack, size_t bucket_idx,
1.182 + size_t pos_idx) {
1.183 + AccessLock locker(&_access_count);
1.184 + if (locker.sharedLock()) {
1.185 + NOT_PRODUCT(_peak_count = MAX2(_peak_count, _access_count);)
1.186 + MallocSite* site = malloc_site(bucket_idx, pos_idx);
1.187 + if (site != NULL) {
1.188 + stack = *site->call_stack();
1.189 + return true;
1.190 + }
1.191 + }
1.192 + return false;
1.193 + }
1.194 +
1.195 + // Record a new allocation from specified call path.
1.196 + // Return true if the allocation is recorded successfully, bucket_idx
1.197 + // and pos_idx are also updated to indicate the entry where the allocation
1.198 + // information was recorded.
1.199 + // Return false only occurs under rare scenarios:
1.200 + // 1. out of memory
1.201 + // 2. overflow hash bucket
1.202 + static inline bool allocation_at(const NativeCallStack& stack, size_t size,
1.203 + size_t* bucket_idx, size_t* pos_idx) {
1.204 + AccessLock locker(&_access_count);
1.205 + if (locker.sharedLock()) {
1.206 + NOT_PRODUCT(_peak_count = MAX2(_peak_count, _access_count);)
1.207 + MallocSite* site = lookup_or_add(stack, bucket_idx, pos_idx);
1.208 + if (site != NULL) site->allocate(size);
1.209 + return site != NULL;
1.210 + }
1.211 + return false;
1.212 + }
1.213 +
1.214 + // Record memory deallocation. bucket_idx and pos_idx indicate where the allocation
1.215 + // information was recorded.
1.216 + static inline bool deallocation_at(size_t size, size_t bucket_idx, size_t pos_idx) {
1.217 + AccessLock locker(&_access_count);
1.218 + if (locker.sharedLock()) {
1.219 + NOT_PRODUCT(_peak_count = MAX2(_peak_count, _access_count);)
1.220 + MallocSite* site = malloc_site(bucket_idx, pos_idx);
1.221 + if (site != NULL) {
1.222 + site->deallocate(size);
1.223 + return true;
1.224 + }
1.225 + }
1.226 + return false;
1.227 + }
1.228 +
1.229 + // Walk this table.
1.230 + static bool walk_malloc_site(MallocSiteWalker* walker);
1.231 +
1.232 + private:
1.233 + static MallocSiteHashtableEntry* new_entry(const NativeCallStack& key);
1.234 + static void reset();
1.235 +
1.236 + // Delete a bucket linked list
1.237 + static void delete_linked_list(MallocSiteHashtableEntry* head);
1.238 +
1.239 + static MallocSite* lookup_or_add(const NativeCallStack& key, size_t* bucket_idx, size_t* pos_idx);
1.240 + static MallocSite* malloc_site(size_t bucket_idx, size_t pos_idx);
1.241 + static bool walk(MallocSiteWalker* walker);
1.242 +
1.243 + static inline int hash_to_index(int hash) {
1.244 + hash = (hash > 0) ? hash : (-hash);
1.245 + return (hash % table_size);
1.246 + }
1.247 +
1.248 + static inline const NativeCallStack* hash_entry_allocation_stack() {
1.249 + return (NativeCallStack*)_hash_entry_allocation_stack;
1.250 + }
1.251 +
1.252 + private:
1.253 + // Counter for counting concurrent access
1.254 + static volatile int _access_count;
1.255 +
1.256 + // The callsite hashtable. It has to be a static table,
1.257 + // since malloc call can come from C runtime linker.
1.258 + static MallocSiteHashtableEntry* _table[table_size];
1.259 +
1.260 +
1.261 + // Reserve enough memory for placing the objects
1.262 +
1.263 + // The memory for hashtable entry allocation stack object
1.264 + static size_t _hash_entry_allocation_stack[CALC_OBJ_SIZE_IN_TYPE(NativeCallStack, size_t)];
1.265 + // The memory for hashtable entry allocation callsite object
1.266 + static size_t _hash_entry_allocation_site[CALC_OBJ_SIZE_IN_TYPE(MallocSiteHashtableEntry, size_t)];
1.267 + NOT_PRODUCT(static int _peak_count;)
1.268 +};
1.269 +
1.270 +#endif // INCLUDE_NMT
1.271 +#endif // SHARE_VM_SERVICES_MALLOC_SITE_TABLE_HPP
