jdk8-mips64-public/hotspot: src/share/vm/services/mallocSiteTable.hpp@833b0f92429a (annotated)

src/share/vm/services/mallocSiteTable.hpp@833b0f92429a (annotated)

src/share/vm/services/mallocSiteTable.hpp

Wed, 27 Aug 2014 08:19:12 -0400

author: zgu
date: Wed, 27 Aug 2014 08:19:12 -0400
changeset 7074: 833b0f92429a
child 7078: c6211b707068
permissions: -rw-r--r--

8046598: Scalable Native memory tracking development
Summary: Enhance scalability of native memory tracking
Reviewed-by: coleenp, ctornqvi, gtriantafill

 /*
  * 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

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/services/mallocSiteTable.hpp@833b0f92429a (annotated)

src/share/vm/services/mallocSiteTable.hpp