src/share/vm/services/memoryManager.cpp

Fri, 30 Jul 2010 22:43:50 +0100

author
kevinw
date
Fri, 30 Jul 2010 22:43:50 +0100
changeset 2058
f6f3eef8a521
parent 1907
c18cbe5936b8
child 2314
f95d63e2154a
permissions
-rw-r--r--

6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
Summary: Management code enabled for use by a concurrent collector.
Reviewed-by: mchung, ysr

     1 /*
     2  * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 # include "incls/_precompiled.incl"
    26 # include "incls/_memoryManager.cpp.incl"
    28 HS_DTRACE_PROBE_DECL8(hotspot, mem__pool__gc__begin, char*, int, char*, int,
    29   size_t, size_t, size_t, size_t);
    30 HS_DTRACE_PROBE_DECL8(hotspot, mem__pool__gc__end, char*, int, char*, int,
    31   size_t, size_t, size_t, size_t);
    33 MemoryManager::MemoryManager() {
    34   _num_pools = 0;
    35   _memory_mgr_obj = NULL;
    36 }
    38 void MemoryManager::add_pool(MemoryPool* pool) {
    39   assert(_num_pools < MemoryManager::max_num_pools, "_num_pools exceeds the max");
    40   if (_num_pools < MemoryManager::max_num_pools) {
    41     _pools[_num_pools] = pool;
    42     _num_pools++;
    43   }
    44   pool->add_manager(this);
    45 }
    47 MemoryManager* MemoryManager::get_code_cache_memory_manager() {
    48   return (MemoryManager*) new CodeCacheMemoryManager();
    49 }
    51 GCMemoryManager* MemoryManager::get_copy_memory_manager() {
    52   return (GCMemoryManager*) new CopyMemoryManager();
    53 }
    55 GCMemoryManager* MemoryManager::get_msc_memory_manager() {
    56   return (GCMemoryManager*) new MSCMemoryManager();
    57 }
    59 GCMemoryManager* MemoryManager::get_parnew_memory_manager() {
    60   return (GCMemoryManager*) new ParNewMemoryManager();
    61 }
    63 GCMemoryManager* MemoryManager::get_cms_memory_manager() {
    64   return (GCMemoryManager*) new CMSMemoryManager();
    65 }
    67 GCMemoryManager* MemoryManager::get_psScavenge_memory_manager() {
    68   return (GCMemoryManager*) new PSScavengeMemoryManager();
    69 }
    71 GCMemoryManager* MemoryManager::get_psMarkSweep_memory_manager() {
    72   return (GCMemoryManager*) new PSMarkSweepMemoryManager();
    73 }
    75 GCMemoryManager* MemoryManager::get_g1YoungGen_memory_manager() {
    76   return (GCMemoryManager*) new G1YoungGenMemoryManager();
    77 }
    79 GCMemoryManager* MemoryManager::get_g1OldGen_memory_manager() {
    80   return (GCMemoryManager*) new G1OldGenMemoryManager();
    81 }
    83 instanceOop MemoryManager::get_memory_manager_instance(TRAPS) {
    84   // Must do an acquire so as to force ordering of subsequent
    85   // loads from anything _memory_mgr_obj points to or implies.
    86   instanceOop mgr_obj = (instanceOop)OrderAccess::load_ptr_acquire(&_memory_mgr_obj);
    87   if (mgr_obj == NULL) {
    88     // It's ok for more than one thread to execute the code up to the locked region.
    89     // Extra manager instances will just be gc'ed.
    90     klassOop k = Management::sun_management_ManagementFactory_klass(CHECK_0);
    91     instanceKlassHandle ik(THREAD, k);
    93     Handle mgr_name = java_lang_String::create_from_str(name(), CHECK_0);
    95     JavaValue result(T_OBJECT);
    96     JavaCallArguments args;
    97     args.push_oop(mgr_name);    // Argument 1
    99     symbolHandle method_name;
   100     symbolHandle signature;
   101     if (is_gc_memory_manager()) {
   102       method_name = vmSymbolHandles::createGarbageCollector_name();
   103       signature = vmSymbolHandles::createGarbageCollector_signature();
   104       args.push_oop(Handle());      // Argument 2 (for future extension)
   105     } else {
   106       method_name = vmSymbolHandles::createMemoryManager_name();
   107       signature = vmSymbolHandles::createMemoryManager_signature();
   108     }
   110     JavaCalls::call_static(&result,
   111                            ik,
   112                            method_name,
   113                            signature,
   114                            &args,
   115                            CHECK_0);
   117     instanceOop m = (instanceOop) result.get_jobject();
   118     instanceHandle mgr(THREAD, m);
   120     {
   121       // Get lock before setting _memory_mgr_obj
   122       // since another thread may have created the instance
   123       MutexLocker ml(Management_lock);
   125       // Check if another thread has created the management object.  We reload
   126       // _memory_mgr_obj here because some other thread may have initialized
   127       // it while we were executing the code before the lock.
   128       //
   129       // The lock has done an acquire, so the load can't float above it, but
   130       // we need to do a load_acquire as above.
   131       mgr_obj = (instanceOop)OrderAccess::load_ptr_acquire(&_memory_mgr_obj);
   132       if (mgr_obj != NULL) {
   133          return mgr_obj;
   134       }
   136       // Get the address of the object we created via call_special.
   137       mgr_obj = mgr();
   139       // Use store barrier to make sure the memory accesses associated
   140       // with creating the management object are visible before publishing
   141       // its address.  The unlock will publish the store to _memory_mgr_obj
   142       // because it does a release first.
   143       OrderAccess::release_store_ptr(&_memory_mgr_obj, mgr_obj);
   144     }
   145   }
   147   return mgr_obj;
   148 }
   150 void MemoryManager::oops_do(OopClosure* f) {
   151   f->do_oop((oop*) &_memory_mgr_obj);
   152 }
   154 GCStatInfo::GCStatInfo(int num_pools) {
   155   // initialize the arrays for memory usage
   156   _before_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
   157   _after_gc_usage_array  = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
   158   size_t len = num_pools * sizeof(MemoryUsage);
   159   memset(_before_gc_usage_array, 0, len);
   160   memset(_after_gc_usage_array, 0, len);
   161   _usage_array_size = num_pools;
   162 }
   164 GCStatInfo::~GCStatInfo() {
   165   FREE_C_HEAP_ARRAY(MemoryUsage*, _before_gc_usage_array);
   166   FREE_C_HEAP_ARRAY(MemoryUsage*, _after_gc_usage_array);
   167 }
   169 void GCStatInfo::set_gc_usage(int pool_index, MemoryUsage usage, bool before_gc) {
   170   MemoryUsage* gc_usage_array;
   171   if (before_gc) {
   172     gc_usage_array = _before_gc_usage_array;
   173   } else {
   174     gc_usage_array = _after_gc_usage_array;
   175   }
   176   gc_usage_array[pool_index] = usage;
   177 }
   179 void GCStatInfo::clear() {
   180   _index = 0;
   181   _start_time = 0L;
   182   _end_time = 0L;
   183   size_t len = _usage_array_size * sizeof(MemoryUsage);
   184   memset(_before_gc_usage_array, 0, len);
   185   memset(_after_gc_usage_array, 0, len);
   186 }
   189 GCMemoryManager::GCMemoryManager() : MemoryManager() {
   190   _num_collections = 0;
   191   _last_gc_stat = NULL;
   192   _last_gc_lock = new Mutex(Mutex::leaf, "_last_gc_lock", true);
   193   _current_gc_stat = NULL;
   194   _num_gc_threads = 1;
   195 }
   197 GCMemoryManager::~GCMemoryManager() {
   198   delete _last_gc_stat;
   199   delete _last_gc_lock;
   200   delete _current_gc_stat;
   201 }
   203 void GCMemoryManager::initialize_gc_stat_info() {
   204   assert(MemoryService::num_memory_pools() > 0, "should have one or more memory pools");
   205   _last_gc_stat = new GCStatInfo(MemoryService::num_memory_pools());
   206   _current_gc_stat = new GCStatInfo(MemoryService::num_memory_pools());
   207   // tracking concurrent collections we need two objects: one to update, and one to
   208   // hold the publicly available "last (completed) gc" information.
   209 }
   211 void GCMemoryManager::gc_begin(bool recordGCBeginTime, bool recordPreGCUsage,
   212                                bool recordAccumulatedGCTime) {
   213   assert(_last_gc_stat != NULL && _current_gc_stat != NULL, "Just checking");
   214   if (recordAccumulatedGCTime) {
   215     _accumulated_timer.start();
   216   }
   217   // _num_collections now increases in gc_end, to count completed collections
   218   if (recordGCBeginTime) {
   219     _current_gc_stat->set_index(_num_collections+1);
   220     _current_gc_stat->set_start_time(Management::timestamp());
   221   }
   223   if (recordPreGCUsage) {
   224     // Keep memory usage of all memory pools
   225     for (int i = 0; i < MemoryService::num_memory_pools(); i++) {
   226       MemoryPool* pool = MemoryService::get_memory_pool(i);
   227       MemoryUsage usage = pool->get_memory_usage();
   228       _current_gc_stat->set_before_gc_usage(i, usage);
   229       HS_DTRACE_PROBE8(hotspot, mem__pool__gc__begin,
   230         name(), strlen(name()),
   231         pool->name(), strlen(pool->name()),
   232         usage.init_size(), usage.used(),
   233         usage.committed(), usage.max_size());
   234     }
   235   }
   236 }
   238 // A collector MUST, even if it does not complete for some reason,
   239 // make a TraceMemoryManagerStats object where countCollection is true,
   240 // to ensure the current gc stat is placed in _last_gc_stat.
   241 void GCMemoryManager::gc_end(bool recordPostGCUsage,
   242                              bool recordAccumulatedGCTime,
   243                              bool recordGCEndTime, bool countCollection) {
   244   if (recordAccumulatedGCTime) {
   245     _accumulated_timer.stop();
   246   }
   247   if (recordGCEndTime) {
   248     _current_gc_stat->set_end_time(Management::timestamp());
   249   }
   251   if (recordPostGCUsage) {
   252     int i;
   253     // keep the last gc statistics for all memory pools
   254     for (i = 0; i < MemoryService::num_memory_pools(); i++) {
   255       MemoryPool* pool = MemoryService::get_memory_pool(i);
   256       MemoryUsage usage = pool->get_memory_usage();
   258       HS_DTRACE_PROBE8(hotspot, mem__pool__gc__end,
   259         name(), strlen(name()),
   260         pool->name(), strlen(pool->name()),
   261         usage.init_size(), usage.used(),
   262         usage.committed(), usage.max_size());
   264       _current_gc_stat->set_after_gc_usage(i, usage);
   265     }
   267     // Set last collection usage of the memory pools managed by this collector
   268     for (i = 0; i < num_memory_pools(); i++) {
   269       MemoryPool* pool = get_memory_pool(i);
   270       MemoryUsage usage = pool->get_memory_usage();
   272       // Compare with GC usage threshold
   273       pool->set_last_collection_usage(usage);
   274       LowMemoryDetector::detect_after_gc_memory(pool);
   275     }
   276   }
   277   if (countCollection) {
   278     _num_collections++;
   279     // alternately update two objects making one public when complete
   280     {
   281       MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
   282       GCStatInfo *tmp = _last_gc_stat;
   283       _last_gc_stat = _current_gc_stat;
   284       _current_gc_stat = tmp;
   285       // reset the current stat for diagnosability purposes
   286       _current_gc_stat->clear();
   287     }
   288   }
   289 }
   291 size_t GCMemoryManager::get_last_gc_stat(GCStatInfo* dest) {
   292   MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
   293   if (_last_gc_stat->gc_index() != 0) {
   294     dest->set_index(_last_gc_stat->gc_index());
   295     dest->set_start_time(_last_gc_stat->start_time());
   296     dest->set_end_time(_last_gc_stat->end_time());
   297     assert(dest->usage_array_size() == _last_gc_stat->usage_array_size(),
   298            "Must have same array size");
   299     size_t len = dest->usage_array_size() * sizeof(MemoryUsage);
   300     memcpy(dest->before_gc_usage_array(), _last_gc_stat->before_gc_usage_array(), len);
   301     memcpy(dest->after_gc_usage_array(), _last_gc_stat->after_gc_usage_array(), len);
   302   }
   303   return _last_gc_stat->gc_index();
   304 }

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