jdk8-mips64-public/hotspot: src/share/vm/services/management.cpp@f7702f8c0e25 (annotated)

src/share/vm/services/management.cpp@f7702f8c0e25 (annotated)

src/share/vm/services/management.cpp

Mon, 14 Feb 2011 22:21:18 -0500

author: tonyp
date: Mon, 14 Feb 2011 22:21:18 -0500
changeset 2538: f7702f8c0e25
parent 2511: bf8517f4e4d0
parent 2537: 55cc33cf55bc
child 2574: 02f78cfa4656
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 2003, 2011, 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.
  *
  */
 #include "precompiled.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "compiler/compileBroker.hpp"
 #include "memory/iterator.hpp"
 #include "memory/oopFactory.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/klass.hpp"
 #include "oops/klassOop.hpp"
 #include "oops/objArrayKlass.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/arguments.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/interfaceSupport.hpp"
 #include "runtime/javaCalls.hpp"
 #include "runtime/jniHandles.hpp"
 #include "runtime/os.hpp"
 #include "runtime/serviceThread.hpp"
 #include "services/classLoadingService.hpp"
 #include "services/heapDumper.hpp"
 #include "services/lowMemoryDetector.hpp"
 #include "services/management.hpp"
 #include "services/memoryManager.hpp"
 #include "services/memoryPool.hpp"
 #include "services/memoryService.hpp"
 #include "services/runtimeService.hpp"
 #include "services/threadService.hpp"
 PerfVariable* Management::_begin_vm_creation_time = NULL;
 PerfVariable* Management::_end_vm_creation_time = NULL;
 PerfVariable* Management::_vm_init_done_time = NULL;
 klassOop Management::_sensor_klass = NULL;
 klassOop Management::_threadInfo_klass = NULL;
 klassOop Management::_memoryUsage_klass = NULL;
 klassOop Management::_memoryPoolMXBean_klass = NULL;
 klassOop Management::_memoryManagerMXBean_klass = NULL;
 klassOop Management::_garbageCollectorMXBean_klass = NULL;
 klassOop Management::_managementFactory_klass = NULL;
 jmmOptionalSupport Management::_optional_support = {0};
 TimeStamp Management::_stamp;
 void management_init() {
   Management::init();
   ThreadService::init();
   RuntimeService::init();
   ClassLoadingService::init();
 }
 void Management::init() {
   EXCEPTION_MARK;
   // These counters are for java.lang.management API support.
   // They are created even if -XX:-UsePerfData is set and in
   // that case, they will be allocated on C heap.
   _begin_vm_creation_time =
             PerfDataManager::create_variable(SUN_RT, "createVmBeginTime",
                                              PerfData::U_None, CHECK);
   _end_vm_creation_time =
             PerfDataManager::create_variable(SUN_RT, "createVmEndTime",
                                              PerfData::U_None, CHECK);
   _vm_init_done_time =
             PerfDataManager::create_variable(SUN_RT, "vmInitDoneTime",
                                              PerfData::U_None, CHECK);
   // Initialize optional support
   _optional_support.isLowMemoryDetectionSupported = 1;
   _optional_support.isCompilationTimeMonitoringSupported = 1;
   _optional_support.isThreadContentionMonitoringSupported = 1;
   if (os::is_thread_cpu_time_supported()) {
     _optional_support.isCurrentThreadCpuTimeSupported = 1;
     _optional_support.isOtherThreadCpuTimeSupported = 1;
   } else {
     _optional_support.isCurrentThreadCpuTimeSupported = 0;
     _optional_support.isOtherThreadCpuTimeSupported = 0;
   }
   _optional_support.isBootClassPathSupported = 1;
   _optional_support.isObjectMonitorUsageSupported = 1;
 #ifndef SERVICES_KERNEL
   // This depends on the heap inspector
   _optional_support.isSynchronizerUsageSupported = 1;
 #endif // SERVICES_KERNEL
   _optional_support.isThreadAllocatedMemorySupported = 1;
 }
 void Management::initialize(TRAPS) {
   // Start the service thread
   ServiceThread::initialize();
   if (ManagementServer) {
     ResourceMark rm(THREAD);
     HandleMark hm(THREAD);
     // Load and initialize the sun.management.Agent class
     // invoke startAgent method to start the management server
     Handle loader = Handle(THREAD, SystemDictionary::java_system_loader());
     klassOop k = SystemDictionary::resolve_or_fail(vmSymbols::sun_management_Agent(),
                                                    loader,
                                                    Handle(),
                                                    true,
                                                    CHECK);
     instanceKlassHandle ik (THREAD, k);
     JavaValue result(T_VOID);
     JavaCalls::call_static(&result,
                            ik,
                            vmSymbols::startAgent_name(),
                            vmSymbols::void_method_signature(),
                            CHECK);
   }
 }
 void Management::get_optional_support(jmmOptionalSupport* support) {
   memcpy(support, &_optional_support, sizeof(jmmOptionalSupport));
 }
 klassOop Management::load_and_initialize_klass(Symbol* sh, TRAPS) {
   klassOop k = SystemDictionary::resolve_or_fail(sh, true, CHECK_NULL);
   instanceKlassHandle ik (THREAD, k);
   if (ik->should_be_initialized()) {
     ik->initialize(CHECK_NULL);
   }
   return ik();
 }
 void Management::record_vm_startup_time(jlong begin, jlong duration) {
   // if the performance counter is not initialized,
   // then vm initialization failed; simply return.
   if (_begin_vm_creation_time == NULL) return;
   _begin_vm_creation_time->set_value(begin);
   _end_vm_creation_time->set_value(begin + duration);
   PerfMemory::set_accessible(true);
 }
 jlong Management::timestamp() {
   TimeStamp t;
   t.update();
   return t.ticks() - _stamp.ticks();
 }
 void Management::oops_do(OopClosure* f) {
   MemoryService::oops_do(f);
   ThreadService::oops_do(f);
   f->do_oop((oop*) &_sensor_klass);
   f->do_oop((oop*) &_threadInfo_klass);
   f->do_oop((oop*) &_memoryUsage_klass);
   f->do_oop((oop*) &_memoryPoolMXBean_klass);
   f->do_oop((oop*) &_memoryManagerMXBean_klass);
   f->do_oop((oop*) &_garbageCollectorMXBean_klass);
   f->do_oop((oop*) &_managementFactory_klass);
 }
 klassOop Management::java_lang_management_ThreadInfo_klass(TRAPS) {
   if (_threadInfo_klass == NULL) {
     _threadInfo_klass = load_and_initialize_klass(vmSymbols::java_lang_management_ThreadInfo(), CHECK_NULL);
   }
   return _threadInfo_klass;
 }
 klassOop Management::java_lang_management_MemoryUsage_klass(TRAPS) {
   if (_memoryUsage_klass == NULL) {
     _memoryUsage_klass = load_and_initialize_klass(vmSymbols::java_lang_management_MemoryUsage(), CHECK_NULL);
   }
   return _memoryUsage_klass;
 }
 klassOop Management::java_lang_management_MemoryPoolMXBean_klass(TRAPS) {
   if (_memoryPoolMXBean_klass == NULL) {
     _memoryPoolMXBean_klass = load_and_initialize_klass(vmSymbols::java_lang_management_MemoryPoolMXBean(), CHECK_NULL);
   }
   return _memoryPoolMXBean_klass;
 }
 klassOop Management::java_lang_management_MemoryManagerMXBean_klass(TRAPS) {
   if (_memoryManagerMXBean_klass == NULL) {
     _memoryManagerMXBean_klass = load_and_initialize_klass(vmSymbols::java_lang_management_MemoryManagerMXBean(), CHECK_NULL);
   }
   return _memoryManagerMXBean_klass;
 }
 klassOop Management::java_lang_management_GarbageCollectorMXBean_klass(TRAPS) {
   if (_garbageCollectorMXBean_klass == NULL) {
       _garbageCollectorMXBean_klass = load_and_initialize_klass(vmSymbols::java_lang_management_GarbageCollectorMXBean(), CHECK_NULL);
   }
   return _garbageCollectorMXBean_klass;
 }
 klassOop Management::sun_management_Sensor_klass(TRAPS) {
   if (_sensor_klass == NULL) {
     _sensor_klass = load_and_initialize_klass(vmSymbols::sun_management_Sensor(), CHECK_NULL);
   }
   return _sensor_klass;
 }
 klassOop Management::sun_management_ManagementFactory_klass(TRAPS) {
   if (_managementFactory_klass == NULL) {
     _managementFactory_klass = load_and_initialize_klass(vmSymbols::sun_management_ManagementFactory(), CHECK_NULL);
   }
   return _managementFactory_klass;
 }
 static void initialize_ThreadInfo_constructor_arguments(JavaCallArguments* args, ThreadSnapshot* snapshot, TRAPS) {
   Handle snapshot_thread(THREAD, snapshot->threadObj());
   jlong contended_time;
   jlong waited_time;
   if (ThreadService::is_thread_monitoring_contention()) {
     contended_time = Management::ticks_to_ms(snapshot->contended_enter_ticks());
     waited_time = Management::ticks_to_ms(snapshot->monitor_wait_ticks() + snapshot->sleep_ticks());
   } else {
     // set them to -1 if thread contention monitoring is disabled.
     contended_time = max_julong;
     waited_time = max_julong;
   }
   int thread_status = snapshot->thread_status();
   assert((thread_status & JMM_THREAD_STATE_FLAG_MASK) == 0, "Flags already set in thread_status in Thread object");
   if (snapshot->is_ext_suspended()) {
     thread_status |= JMM_THREAD_STATE_FLAG_SUSPENDED;
   }
   if (snapshot->is_in_native()) {
     thread_status |= JMM_THREAD_STATE_FLAG_NATIVE;
   }
   ThreadStackTrace* st = snapshot->get_stack_trace();
   Handle stacktrace_h;
   if (st != NULL) {
     stacktrace_h = st->allocate_fill_stack_trace_element_array(CHECK);
   } else {
     stacktrace_h = Handle();
   }
   args->push_oop(snapshot_thread);
   args->push_int(thread_status);
   args->push_oop(Handle(THREAD, snapshot->blocker_object()));
   args->push_oop(Handle(THREAD, snapshot->blocker_object_owner()));
   args->push_long(snapshot->contended_enter_count());
   args->push_long(contended_time);
   args->push_long(snapshot->monitor_wait_count() + snapshot->sleep_count());
   args->push_long(waited_time);
   args->push_oop(stacktrace_h);
 }
 // Helper function to construct a ThreadInfo object
 instanceOop Management::create_thread_info_instance(ThreadSnapshot* snapshot, TRAPS) {
   klassOop k = Management::java_lang_management_ThreadInfo_klass(CHECK_NULL);
   instanceKlassHandle ik (THREAD, k);
   JavaValue result(T_VOID);
   JavaCallArguments args(14);
   // First allocate a ThreadObj object and
   // push the receiver as the first argument
   Handle element = ik->allocate_instance_handle(CHECK_NULL);
   args.push_oop(element);
   // initialize the arguments for the ThreadInfo constructor
   initialize_ThreadInfo_constructor_arguments(&args, snapshot, CHECK_NULL);
   // Call ThreadInfo constructor with no locked monitors and synchronizers
   JavaCalls::call_special(&result,
                           ik,
                           vmSymbols::object_initializer_name(),
                           vmSymbols::java_lang_management_ThreadInfo_constructor_signature(),
                           &args,
                           CHECK_NULL);
   return (instanceOop) element();
 }
 instanceOop Management::create_thread_info_instance(ThreadSnapshot* snapshot,
                                                     objArrayHandle monitors_array,
                                                     typeArrayHandle depths_array,
                                                     objArrayHandle synchronizers_array,
                                                     TRAPS) {
   klassOop k = Management::java_lang_management_ThreadInfo_klass(CHECK_NULL);
   instanceKlassHandle ik (THREAD, k);
   JavaValue result(T_VOID);
   JavaCallArguments args(17);
   // First allocate a ThreadObj object and
   // push the receiver as the first argument
   Handle element = ik->allocate_instance_handle(CHECK_NULL);
   args.push_oop(element);
   // initialize the arguments for the ThreadInfo constructor
   initialize_ThreadInfo_constructor_arguments(&args, snapshot, CHECK_NULL);
   // push the locked monitors and synchronizers in the arguments
   args.push_oop(monitors_array);
   args.push_oop(depths_array);
   args.push_oop(synchronizers_array);
   // Call ThreadInfo constructor with locked monitors and synchronizers
   JavaCalls::call_special(&result,
                           ik,
                           vmSymbols::object_initializer_name(),
                           vmSymbols::java_lang_management_ThreadInfo_with_locks_constructor_signature(),
                           &args,
                           CHECK_NULL);
   return (instanceOop) element();
 }
 // Helper functions
 static JavaThread* find_java_thread_from_id(jlong thread_id) {
   assert(Threads_lock->owned_by_self(), "Must hold Threads_lock");
   JavaThread* java_thread = NULL;
   // Sequential search for now.  Need to do better optimization later.
   for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
     oop tobj = thread->threadObj();
     if (!thread->is_exiting() &&
         tobj != NULL &&
         thread_id == java_lang_Thread::thread_id(tobj)) {
       java_thread = thread;
       break;
     }
   }
   return java_thread;
 }
 static GCMemoryManager* get_gc_memory_manager_from_jobject(jobject mgr, TRAPS) {
   if (mgr == NULL) {
     THROW_(vmSymbols::java_lang_NullPointerException(), NULL);
   }
   oop mgr_obj = JNIHandles::resolve(mgr);
   instanceHandle h(THREAD, (instanceOop) mgr_obj);
   klassOop k = Management::java_lang_management_GarbageCollectorMXBean_klass(CHECK_NULL);
   if (!h->is_a(k)) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "the object is not an instance of java.lang.management.GarbageCollectorMXBean class",
                NULL);
   }
   MemoryManager* gc = MemoryService::get_memory_manager(h);
   if (gc == NULL || !gc->is_gc_memory_manager()) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "Invalid GC memory manager",
                NULL);
   }
   return (GCMemoryManager*) gc;
 }
 static MemoryPool* get_memory_pool_from_jobject(jobject obj, TRAPS) {
   if (obj == NULL) {
     THROW_(vmSymbols::java_lang_NullPointerException(), NULL);
   }
   oop pool_obj = JNIHandles::resolve(obj);
   assert(pool_obj->is_instance(), "Should be an instanceOop");
   instanceHandle ph(THREAD, (instanceOop) pool_obj);
   return MemoryService::get_memory_pool(ph);
 }
 static void validate_thread_id_array(typeArrayHandle ids_ah, TRAPS) {
   int num_threads = ids_ah->length();
   // Validate input thread IDs
   int i = 0;
   for (i = 0; i < num_threads; i++) {
     jlong tid = ids_ah->long_at(i);
     if (tid <= 0) {
       // throw exception if invalid thread id.
       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
                 "Invalid thread ID entry");
     }
   }
 }
 static void validate_thread_info_array(objArrayHandle infoArray_h, TRAPS) {
   // check if the element of infoArray is of type ThreadInfo class
   klassOop threadinfo_klass = Management::java_lang_management_ThreadInfo_klass(CHECK);
   klassOop element_klass = objArrayKlass::cast(infoArray_h->klass())->element_klass();
   if (element_klass != threadinfo_klass) {
     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
               "infoArray element type is not ThreadInfo class");
   }
 }
 static MemoryManager* get_memory_manager_from_jobject(jobject obj, TRAPS) {
   if (obj == NULL) {
     THROW_(vmSymbols::java_lang_NullPointerException(), NULL);
   }
   oop mgr_obj = JNIHandles::resolve(obj);
   assert(mgr_obj->is_instance(), "Should be an instanceOop");
   instanceHandle mh(THREAD, (instanceOop) mgr_obj);
   return MemoryService::get_memory_manager(mh);
 }
 // Returns a version string and sets major and minor version if
 // the input parameters are non-null.
 JVM_LEAF(jint, jmm_GetVersion(JNIEnv *env))
   return JMM_VERSION;
 JVM_END
 // Gets the list of VM monitoring and management optional supports
 // Returns 0 if succeeded; otherwise returns non-zero.
 JVM_LEAF(jint, jmm_GetOptionalSupport(JNIEnv *env, jmmOptionalSupport* support))
   if (support == NULL) {
     return -1;
   }
   Management::get_optional_support(support);
   return 0;
 JVM_END
 // Returns a java.lang.String object containing the input arguments to the VM.
 JVM_ENTRY(jobject, jmm_GetInputArguments(JNIEnv *env))
   ResourceMark rm(THREAD);
   if (Arguments::num_jvm_args() == 0 && Arguments::num_jvm_flags() == 0) {
     return NULL;
   }
   char** vm_flags = Arguments::jvm_flags_array();
   char** vm_args  = Arguments::jvm_args_array();
   int num_flags   = Arguments::num_jvm_flags();
   int num_args    = Arguments::num_jvm_args();
   size_t length = 1; // null terminator
   int i;
   for (i = 0; i < num_flags; i++) {
     length += strlen(vm_flags[i]);
   }
   for (i = 0; i < num_args; i++) {
     length += strlen(vm_args[i]);
   }
   // add a space between each argument
   length += num_flags + num_args - 1;
   // Return the list of input arguments passed to the VM
   // and preserve the order that the VM processes.
   char* args = NEW_RESOURCE_ARRAY(char, length);
   args[0] = '\0';
   // concatenate all jvm_flags
   if (num_flags > 0) {
     strcat(args, vm_flags[0]);
     for (i = 1; i < num_flags; i++) {
       strcat(args, " ");
       strcat(args, vm_flags[i]);
     }
   }
   if (num_args > 0 && num_flags > 0) {
     // append a space if args already contains one or more jvm_flags
     strcat(args, " ");
   }
   // concatenate all jvm_args
   if (num_args > 0) {
     strcat(args, vm_args[0]);
     for (i = 1; i < num_args; i++) {
       strcat(args, " ");
       strcat(args, vm_args[i]);
     }
   }
   Handle hargs = java_lang_String::create_from_platform_dependent_str(args, CHECK_NULL);
   return JNIHandles::make_local(env, hargs());
 JVM_END
 // Returns an array of java.lang.String object containing the input arguments to the VM.
 JVM_ENTRY(jobjectArray, jmm_GetInputArgumentArray(JNIEnv *env))
   ResourceMark rm(THREAD);
   if (Arguments::num_jvm_args() == 0 && Arguments::num_jvm_flags() == 0) {
     return NULL;
   }
   char** vm_flags = Arguments::jvm_flags_array();
   char** vm_args = Arguments::jvm_args_array();
   int num_flags = Arguments::num_jvm_flags();
   int num_args = Arguments::num_jvm_args();
   instanceKlassHandle ik (THREAD, SystemDictionary::String_klass());
   objArrayOop r = oopFactory::new_objArray(ik(), num_args + num_flags, CHECK_NULL);
   objArrayHandle result_h(THREAD, r);
   int index = 0;
   for (int j = 0; j < num_flags; j++, index++) {
     Handle h = java_lang_String::create_from_platform_dependent_str(vm_flags[j], CHECK_NULL);
     result_h->obj_at_put(index, h());
   }
   for (int i = 0; i < num_args; i++, index++) {
     Handle h = java_lang_String::create_from_platform_dependent_str(vm_args[i], CHECK_NULL);
     result_h->obj_at_put(index, h());
   }
   return (jobjectArray) JNIHandles::make_local(env, result_h());
 JVM_END
 // Returns an array of java/lang/management/MemoryPoolMXBean object
 // one for each memory pool if obj == null; otherwise returns
 // an array of memory pools for a given memory manager if
 // it is a valid memory manager.
 JVM_ENTRY(jobjectArray, jmm_GetMemoryPools(JNIEnv* env, jobject obj))
   ResourceMark rm(THREAD);
   int num_memory_pools;
   MemoryManager* mgr = NULL;
   if (obj == NULL) {
     num_memory_pools = MemoryService::num_memory_pools();
   } else {
     mgr = get_memory_manager_from_jobject(obj, CHECK_NULL);
     if (mgr == NULL) {
       return NULL;
     }
     num_memory_pools = mgr->num_memory_pools();
   }
   // Allocate the resulting MemoryPoolMXBean[] object
   klassOop k = Management::java_lang_management_MemoryPoolMXBean_klass(CHECK_NULL);
   instanceKlassHandle ik (THREAD, k);
   objArrayOop r = oopFactory::new_objArray(ik(), num_memory_pools, CHECK_NULL);
   objArrayHandle poolArray(THREAD, r);
   if (mgr == NULL) {
     // Get all memory pools
     for (int i = 0; i < num_memory_pools; i++) {
       MemoryPool* pool = MemoryService::get_memory_pool(i);
       instanceOop p = pool->get_memory_pool_instance(CHECK_NULL);
       instanceHandle ph(THREAD, p);
       poolArray->obj_at_put(i, ph());
     }
   } else {
     // Get memory pools managed by a given memory manager
     for (int i = 0; i < num_memory_pools; i++) {
       MemoryPool* pool = mgr->get_memory_pool(i);
       instanceOop p = pool->get_memory_pool_instance(CHECK_NULL);
       instanceHandle ph(THREAD, p);
       poolArray->obj_at_put(i, ph());
     }
   }
   return (jobjectArray) JNIHandles::make_local(env, poolArray());
 JVM_END
 // Returns an array of java/lang/management/MemoryManagerMXBean object
 // one for each memory manager if obj == null; otherwise returns
 // an array of memory managers for a given memory pool if
 // it is a valid memory pool.
 JVM_ENTRY(jobjectArray, jmm_GetMemoryManagers(JNIEnv* env, jobject obj))
   ResourceMark rm(THREAD);
   int num_mgrs;
   MemoryPool* pool = NULL;
   if (obj == NULL) {
     num_mgrs = MemoryService::num_memory_managers();
   } else {
     pool = get_memory_pool_from_jobject(obj, CHECK_NULL);
     if (pool == NULL) {
       return NULL;
     }
     num_mgrs = pool->num_memory_managers();
   }
   // Allocate the resulting MemoryManagerMXBean[] object
   klassOop k = Management::java_lang_management_MemoryManagerMXBean_klass(CHECK_NULL);
   instanceKlassHandle ik (THREAD, k);
   objArrayOop r = oopFactory::new_objArray(ik(), num_mgrs, CHECK_NULL);
   objArrayHandle mgrArray(THREAD, r);
   if (pool == NULL) {
     // Get all memory managers
     for (int i = 0; i < num_mgrs; i++) {
       MemoryManager* mgr = MemoryService::get_memory_manager(i);
       instanceOop p = mgr->get_memory_manager_instance(CHECK_NULL);
       instanceHandle ph(THREAD, p);
       mgrArray->obj_at_put(i, ph());
     }
   } else {
     // Get memory managers for a given memory pool
     for (int i = 0; i < num_mgrs; i++) {
       MemoryManager* mgr = pool->get_memory_manager(i);
       instanceOop p = mgr->get_memory_manager_instance(CHECK_NULL);
       instanceHandle ph(THREAD, p);
       mgrArray->obj_at_put(i, ph());
     }
   }
   return (jobjectArray) JNIHandles::make_local(env, mgrArray());
 JVM_END
 // Returns a java/lang/management/MemoryUsage object containing the memory usage
 // of a given memory pool.
 JVM_ENTRY(jobject, jmm_GetMemoryPoolUsage(JNIEnv* env, jobject obj))
   ResourceMark rm(THREAD);
   MemoryPool* pool = get_memory_pool_from_jobject(obj, CHECK_NULL);
   if (pool != NULL) {
     MemoryUsage usage = pool->get_memory_usage();
     Handle h = MemoryService::create_MemoryUsage_obj(usage, CHECK_NULL);
     return JNIHandles::make_local(env, h());
   } else {
     return NULL;
   }
 JVM_END
 // Returns a java/lang/management/MemoryUsage object containing the memory usage
 // of a given memory pool.
 JVM_ENTRY(jobject, jmm_GetPeakMemoryPoolUsage(JNIEnv* env, jobject obj))
   ResourceMark rm(THREAD);
   MemoryPool* pool = get_memory_pool_from_jobject(obj, CHECK_NULL);
   if (pool != NULL) {
     MemoryUsage usage = pool->get_peak_memory_usage();
     Handle h = MemoryService::create_MemoryUsage_obj(usage, CHECK_NULL);
     return JNIHandles::make_local(env, h());
   } else {
     return NULL;
   }
 JVM_END
 // Returns a java/lang/management/MemoryUsage object containing the memory usage
 // of a given memory pool after most recent GC.
 JVM_ENTRY(jobject, jmm_GetPoolCollectionUsage(JNIEnv* env, jobject obj))
   ResourceMark rm(THREAD);
   MemoryPool* pool = get_memory_pool_from_jobject(obj, CHECK_NULL);
   if (pool != NULL && pool->is_collected_pool()) {
     MemoryUsage usage = pool->get_last_collection_usage();
     Handle h = MemoryService::create_MemoryUsage_obj(usage, CHECK_NULL);
     return JNIHandles::make_local(env, h());
   } else {
     return NULL;
   }
 JVM_END
 // Sets the memory pool sensor for a threshold type
 JVM_ENTRY(void, jmm_SetPoolSensor(JNIEnv* env, jobject obj, jmmThresholdType type, jobject sensorObj))
   if (obj == NULL || sensorObj == NULL) {
     THROW(vmSymbols::java_lang_NullPointerException());
   }
   klassOop sensor_klass = Management::sun_management_Sensor_klass(CHECK);
   oop s = JNIHandles::resolve(sensorObj);
   assert(s->is_instance(), "Sensor should be an instanceOop");
   instanceHandle sensor_h(THREAD, (instanceOop) s);
   if (!sensor_h->is_a(sensor_klass)) {
     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
               "Sensor is not an instance of sun.management.Sensor class");
   }
   MemoryPool* mpool = get_memory_pool_from_jobject(obj, CHECK);
   assert(mpool != NULL, "MemoryPool should exist");
   switch (type) {
     case JMM_USAGE_THRESHOLD_HIGH:
     case JMM_USAGE_THRESHOLD_LOW:
       // have only one sensor for threshold high and low
       mpool->set_usage_sensor_obj(sensor_h);
       break;
     case JMM_COLLECTION_USAGE_THRESHOLD_HIGH:
     case JMM_COLLECTION_USAGE_THRESHOLD_LOW:
       // have only one sensor for threshold high and low
       mpool->set_gc_usage_sensor_obj(sensor_h);
       break;
     default:
       assert(false, "Unrecognized type");
   }
 JVM_END
 // Sets the threshold of a given memory pool.
 // Returns the previous threshold.
 //
 // Input parameters:
 //   pool      - the MemoryPoolMXBean object
 //   type      - threshold type
 //   threshold - the new threshold (must not be negative)
 //
 JVM_ENTRY(jlong, jmm_SetPoolThreshold(JNIEnv* env, jobject obj, jmmThresholdType type, jlong threshold))
   if (threshold < 0) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "Invalid threshold value",
                -1);
   }
   if ((size_t)threshold > max_uintx) {
     stringStream st;
     st.print("Invalid valid threshold value. Threshold value (" UINT64_FORMAT ") > max value of size_t (" SIZE_FORMAT ")", (size_t)threshold, max_uintx);
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), st.as_string(), -1);
   }
   MemoryPool* pool = get_memory_pool_from_jobject(obj, CHECK_(0L));
   assert(pool != NULL, "MemoryPool should exist");
   jlong prev = 0;
   switch (type) {
     case JMM_USAGE_THRESHOLD_HIGH:
       if (!pool->usage_threshold()->is_high_threshold_supported()) {
         return -1;
       }
       prev = pool->usage_threshold()->set_high_threshold((size_t) threshold);
       break;
     case JMM_USAGE_THRESHOLD_LOW:
       if (!pool->usage_threshold()->is_low_threshold_supported()) {
         return -1;
       }
       prev = pool->usage_threshold()->set_low_threshold((size_t) threshold);
       break;
     case JMM_COLLECTION_USAGE_THRESHOLD_HIGH:
       if (!pool->gc_usage_threshold()->is_high_threshold_supported()) {
         return -1;
       }
       // return and the new threshold is effective for the next GC
       return pool->gc_usage_threshold()->set_high_threshold((size_t) threshold);
     case JMM_COLLECTION_USAGE_THRESHOLD_LOW:
       if (!pool->gc_usage_threshold()->is_low_threshold_supported()) {
         return -1;
       }
       // return and the new threshold is effective for the next GC
       return pool->gc_usage_threshold()->set_low_threshold((size_t) threshold);
     default:
       assert(false, "Unrecognized type");
       return -1;
   }
   // When the threshold is changed, reevaluate if the low memory
   // detection is enabled.
   if (prev != threshold) {
     LowMemoryDetector::recompute_enabled_for_collected_pools();
     LowMemoryDetector::detect_low_memory(pool);
   }
   return prev;
 JVM_END
 // Gets an array containing the amount of memory allocated on the Java
 // heap for a set of threads (in bytes).  Each element of the array is
 // the amount of memory allocated for the thread ID specified in the
 // corresponding entry in the given array of thread IDs; or -1 if the
 // thread does not exist or has terminated.
 JVM_ENTRY(void, jmm_GetThreadAllocatedMemory(JNIEnv *env, jlongArray ids,
                                              jlongArray sizeArray))
   // Check if threads is null
   if (ids == NULL || sizeArray == NULL) {
     THROW(vmSymbols::java_lang_NullPointerException());
   }
   ResourceMark rm(THREAD);
   typeArrayOop ta = typeArrayOop(JNIHandles::resolve_non_null(ids));
   typeArrayHandle ids_ah(THREAD, ta);
   typeArrayOop sa = typeArrayOop(JNIHandles::resolve_non_null(sizeArray));
   typeArrayHandle sizeArray_h(THREAD, sa);
   // validate the thread id array
   validate_thread_id_array(ids_ah, CHECK);
   // sizeArray must be of the same length as the given array of thread IDs
   int num_threads = ids_ah->length();
   if (num_threads != sizeArray_h->length()) {
     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
               "The length of the given long array does not match the length of "
               "the given array of thread IDs");
   }
   MutexLockerEx ml(Threads_lock);
   for (int i = 0; i < num_threads; i++) {
     JavaThread* java_thread = find_java_thread_from_id(ids_ah->long_at(i));
     if (java_thread != NULL) {
       sizeArray_h->long_at_put(i, java_thread->cooked_allocated_bytes());
     }
   }
 JVM_END
 // Returns a java/lang/management/MemoryUsage object representing
 // the memory usage for the heap or non-heap memory.
 JVM_ENTRY(jobject, jmm_GetMemoryUsage(JNIEnv* env, jboolean heap))
   ResourceMark rm(THREAD);
   // Calculate the memory usage
   size_t total_init = 0;
   size_t total_used = 0;
   size_t total_committed = 0;
   size_t total_max = 0;
   bool   has_undefined_init_size = false;
   bool   has_undefined_max_size = false;
   for (int i = 0; i < MemoryService::num_memory_pools(); i++) {
     MemoryPool* pool = MemoryService::get_memory_pool(i);
     if ((heap && pool->is_heap()) || (!heap && pool->is_non_heap())) {
       MemoryUsage u = pool->get_memory_usage();
       total_used += u.used();
       total_committed += u.committed();
       // if any one of the memory pool has undefined init_size or max_size,
       // set it to -1
       if (u.init_size() == (size_t)-1) {
         has_undefined_init_size = true;
       }
       if (!has_undefined_init_size) {
         total_init += u.init_size();
       }
       if (u.max_size() == (size_t)-1) {
         has_undefined_max_size = true;
       }
       if (!has_undefined_max_size) {
         total_max += u.max_size();
       }
     }
   }
   // In our current implementation, we make sure that all non-heap
   // pools have defined init and max sizes. Heap pools do not matter,
   // as we never use total_init and total_max for them.
   assert(heap || !has_undefined_init_size, "Undefined init size");
   assert(heap || !has_undefined_max_size,  "Undefined max size");
   MemoryUsage usage((heap ? InitialHeapSize : total_init),
                     total_used,
                     total_committed,
                     (heap ? Universe::heap()->max_capacity() : total_max));
   Handle obj = MemoryService::create_MemoryUsage_obj(usage, CHECK_NULL);
   return JNIHandles::make_local(env, obj());
 JVM_END
 // Returns the boolean value of a given attribute.
 JVM_LEAF(jboolean, jmm_GetBoolAttribute(JNIEnv *env, jmmBoolAttribute att))
   switch (att) {
   case JMM_VERBOSE_GC:
     return MemoryService::get_verbose();
   case JMM_VERBOSE_CLASS:
     return ClassLoadingService::get_verbose();
   case JMM_THREAD_CONTENTION_MONITORING:
     return ThreadService::is_thread_monitoring_contention();
   case JMM_THREAD_CPU_TIME:
     return ThreadService::is_thread_cpu_time_enabled();
   case JMM_THREAD_ALLOCATED_MEMORY:
     return ThreadService::is_thread_allocated_memory_enabled();
   default:
     assert(0, "Unrecognized attribute");
     return false;
   }
 JVM_END
 // Sets the given boolean attribute and returns the previous value.
 JVM_ENTRY(jboolean, jmm_SetBoolAttribute(JNIEnv *env, jmmBoolAttribute att, jboolean flag))
   switch (att) {
   case JMM_VERBOSE_GC:
     return MemoryService::set_verbose(flag != 0);
   case JMM_VERBOSE_CLASS:
     return ClassLoadingService::set_verbose(flag != 0);
   case JMM_THREAD_CONTENTION_MONITORING:
     return ThreadService::set_thread_monitoring_contention(flag != 0);
   case JMM_THREAD_CPU_TIME:
     return ThreadService::set_thread_cpu_time_enabled(flag != 0);
   case JMM_THREAD_ALLOCATED_MEMORY:
     return ThreadService::set_thread_allocated_memory_enabled(flag != 0);
   default:
     assert(0, "Unrecognized attribute");
     return false;
   }
 JVM_END
 static jlong get_gc_attribute(GCMemoryManager* mgr, jmmLongAttribute att) {
   switch (att) {
   case JMM_GC_TIME_MS:
     return mgr->gc_time_ms();
   case JMM_GC_COUNT:
     return mgr->gc_count();
   case JMM_GC_EXT_ATTRIBUTE_INFO_SIZE:
     // current implementation only has 1 ext attribute
     return 1;
   default:
     assert(0, "Unrecognized GC attribute");
     return -1;
   }
 }
 class VmThreadCountClosure: public ThreadClosure {
  private:
   int _count;
  public:
   VmThreadCountClosure() : _count(0) {};
   void do_thread(Thread* thread);
   int count() { return _count; }
 };
 void VmThreadCountClosure::do_thread(Thread* thread) {
   // exclude externally visible JavaThreads
   if (thread->is_Java_thread() && !thread->is_hidden_from_external_view()) {
     return;
   }
   _count++;
 }
 static jint get_vm_thread_count() {
   VmThreadCountClosure vmtcc;
   {
     MutexLockerEx ml(Threads_lock);
     Threads::threads_do(&vmtcc);
   }
   return vmtcc.count();
 }
 static jint get_num_flags() {
   // last flag entry is always NULL, so subtract 1
   int nFlags = (int) Flag::numFlags - 1;
   int count = 0;
   for (int i = 0; i < nFlags; i++) {
     Flag* flag = &Flag::flags[i];
     // Exclude the locked (diagnostic, experimental) flags
     if (flag->is_unlocked() || flag->is_unlocker()) {
       count++;
     }
   }
   return count;
 }
 static jlong get_long_attribute(jmmLongAttribute att) {
   switch (att) {
   case JMM_CLASS_LOADED_COUNT:
     return ClassLoadingService::loaded_class_count();
   case JMM_CLASS_UNLOADED_COUNT:
     return ClassLoadingService::unloaded_class_count();
   case JMM_THREAD_TOTAL_COUNT:
     return ThreadService::get_total_thread_count();
   case JMM_THREAD_LIVE_COUNT:
     return ThreadService::get_live_thread_count();
   case JMM_THREAD_PEAK_COUNT:
     return ThreadService::get_peak_thread_count();
   case JMM_THREAD_DAEMON_COUNT:
     return ThreadService::get_daemon_thread_count();
   case JMM_JVM_INIT_DONE_TIME_MS:
     return Management::vm_init_done_time();
   case JMM_COMPILE_TOTAL_TIME_MS:
     return Management::ticks_to_ms(CompileBroker::total_compilation_ticks());
   case JMM_OS_PROCESS_ID:
     return os::current_process_id();
   // Hotspot-specific counters
   case JMM_CLASS_LOADED_BYTES:
     return ClassLoadingService::loaded_class_bytes();
   case JMM_CLASS_UNLOADED_BYTES:
     return ClassLoadingService::unloaded_class_bytes();
   case JMM_SHARED_CLASS_LOADED_COUNT:
     return ClassLoadingService::loaded_shared_class_count();
   case JMM_SHARED_CLASS_UNLOADED_COUNT:
     return ClassLoadingService::unloaded_shared_class_count();
   case JMM_SHARED_CLASS_LOADED_BYTES:
     return ClassLoadingService::loaded_shared_class_bytes();
   case JMM_SHARED_CLASS_UNLOADED_BYTES:
     return ClassLoadingService::unloaded_shared_class_bytes();
   case JMM_TOTAL_CLASSLOAD_TIME_MS:
     return ClassLoader::classloader_time_ms();
   case JMM_VM_GLOBAL_COUNT:
     return get_num_flags();
   case JMM_SAFEPOINT_COUNT:
     return RuntimeService::safepoint_count();
   case JMM_TOTAL_SAFEPOINTSYNC_TIME_MS:
     return RuntimeService::safepoint_sync_time_ms();
   case JMM_TOTAL_STOPPED_TIME_MS:
     return RuntimeService::safepoint_time_ms();
   case JMM_TOTAL_APP_TIME_MS:
     return RuntimeService::application_time_ms();
   case JMM_VM_THREAD_COUNT:
     return get_vm_thread_count();
   case JMM_CLASS_INIT_TOTAL_COUNT:
     return ClassLoader::class_init_count();
   case JMM_CLASS_INIT_TOTAL_TIME_MS:
     return ClassLoader::class_init_time_ms();
   case JMM_CLASS_VERIFY_TOTAL_TIME_MS:
     return ClassLoader::class_verify_time_ms();
   case JMM_METHOD_DATA_SIZE_BYTES:
     return ClassLoadingService::class_method_data_size();
   case JMM_OS_MEM_TOTAL_PHYSICAL_BYTES:
     return os::physical_memory();
   default:
     return -1;
   }
 }
 // Returns the long value of a given attribute.
 JVM_ENTRY(jlong, jmm_GetLongAttribute(JNIEnv *env, jobject obj, jmmLongAttribute att))
   if (obj == NULL) {
     return get_long_attribute(att);
   } else {
     GCMemoryManager* mgr = get_gc_memory_manager_from_jobject(obj, CHECK_(0L));
     if (mgr != NULL) {
       return get_gc_attribute(mgr, att);
     }
   }
   return -1;
 JVM_END
 // Gets the value of all attributes specified in the given array
 // and sets the value in the result array.
 // Returns the number of attributes found.
 JVM_ENTRY(jint, jmm_GetLongAttributes(JNIEnv *env,
                                       jobject obj,
                                       jmmLongAttribute* atts,
                                       jint count,
                                       jlong* result))
   int num_atts = 0;
   if (obj == NULL) {
     for (int i = 0; i < count; i++) {
       result[i] = get_long_attribute(atts[i]);
       if (result[i] != -1) {
         num_atts++;
       }
     }
   } else {
     GCMemoryManager* mgr = get_gc_memory_manager_from_jobject(obj, CHECK_0);
     for (int i = 0; i < count; i++) {
       result[i] = get_gc_attribute(mgr, atts[i]);
       if (result[i] != -1) {
         num_atts++;
       }
     }
   }
   return num_atts;
 JVM_END
 // Helper function to do thread dump for a specific list of threads
 static void do_thread_dump(ThreadDumpResult* dump_result,
                            typeArrayHandle ids_ah,  // array of thread ID (long[])
                            int num_threads,
                            int max_depth,
                            bool with_locked_monitors,
                            bool with_locked_synchronizers,
                            TRAPS) {
   // First get an array of threadObj handles.
   // A JavaThread may terminate before we get the stack trace.
   GrowableArray<instanceHandle>* thread_handle_array = new GrowableArray<instanceHandle>(num_threads);
   {
     MutexLockerEx ml(Threads_lock);
     for (int i = 0; i < num_threads; i++) {
       jlong tid = ids_ah->long_at(i);
       JavaThread* jt = find_java_thread_from_id(tid);
       oop thread_obj = (jt != NULL ? jt->threadObj() : (oop)NULL);
       instanceHandle threadObj_h(THREAD, (instanceOop) thread_obj);
       thread_handle_array->append(threadObj_h);
     }
   }
   // Obtain thread dumps and thread snapshot information
   VM_ThreadDump op(dump_result,
                    thread_handle_array,
                    num_threads,
                    max_depth, /* stack depth */
                    with_locked_monitors,
                    with_locked_synchronizers);
   VMThread::execute(&op);
 }
 // Gets an array of ThreadInfo objects. Each element is the ThreadInfo
 // for the thread ID specified in the corresponding entry in
 // the given array of thread IDs; or NULL if the thread does not exist
 // or has terminated.
 //
 // Input parameters:
 //   ids       - array of thread IDs
 //   maxDepth  - the maximum depth of stack traces to be dumped:
 //               maxDepth == -1 requests to dump entire stack trace.
 //               maxDepth == 0  requests no stack trace.
 //   infoArray - array of ThreadInfo objects
 //
 // QQQ - Why does this method return a value instead of void?
 JVM_ENTRY(jint, jmm_GetThreadInfo(JNIEnv *env, jlongArray ids, jint maxDepth, jobjectArray infoArray))
   // Check if threads is null
   if (ids == NULL || infoArray == NULL) {
     THROW_(vmSymbols::java_lang_NullPointerException(), -1);
   }
   if (maxDepth < -1) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "Invalid maxDepth", -1);
   }
   ResourceMark rm(THREAD);
   typeArrayOop ta = typeArrayOop(JNIHandles::resolve_non_null(ids));
   typeArrayHandle ids_ah(THREAD, ta);
   oop infoArray_obj = JNIHandles::resolve_non_null(infoArray);
   objArrayOop oa = objArrayOop(infoArray_obj);
   objArrayHandle infoArray_h(THREAD, oa);
   // validate the thread id array
   validate_thread_id_array(ids_ah, CHECK_0);
   // validate the ThreadInfo[] parameters
   validate_thread_info_array(infoArray_h, CHECK_0);
   // infoArray must be of the same length as the given array of thread IDs
   int num_threads = ids_ah->length();
   if (num_threads != infoArray_h->length()) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "The length of the given ThreadInfo array does not match the length of the given array of thread IDs", -1);
   }
   if (JDK_Version::is_gte_jdk16x_version()) {
     // make sure the AbstractOwnableSynchronizer klass is loaded before taking thread snapshots
     java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(CHECK_0);
   }
   // Must use ThreadDumpResult to store the ThreadSnapshot.
   // GC may occur after the thread snapshots are taken but before
   // this function returns. The threadObj and other oops kept
   // in the ThreadSnapshot are marked and adjusted during GC.
   ThreadDumpResult dump_result(num_threads);
   if (maxDepth == 0) {
     // no stack trace dumped - do not need to stop the world
     {
       MutexLockerEx ml(Threads_lock);
       for (int i = 0; i < num_threads; i++) {
         jlong tid = ids_ah->long_at(i);
         JavaThread* jt = find_java_thread_from_id(tid);
         ThreadSnapshot* ts;
         if (jt == NULL) {
           // if the thread does not exist or now it is terminated,
           // create dummy snapshot
           ts = new ThreadSnapshot();
         } else {
           ts = new ThreadSnapshot(jt);
         }
         dump_result.add_thread_snapshot(ts);
       }
     }
   } else {
     // obtain thread dump with the specific list of threads with stack trace
     do_thread_dump(&dump_result,
                    ids_ah,
                    num_threads,
                    maxDepth,
                    false, /* no locked monitor */
                    false, /* no locked synchronizers */
                    CHECK_0);
   }
   int num_snapshots = dump_result.num_snapshots();
   assert(num_snapshots == num_threads, "Must match the number of thread snapshots");
   int index = 0;
   for (ThreadSnapshot* ts = dump_result.snapshots(); ts != NULL; index++, ts = ts->next()) {
     // For each thread, create an java/lang/management/ThreadInfo object
     // and fill with the thread information
     if (ts->threadObj() == NULL) {
      // if the thread does not exist or now it is terminated, set threadinfo to NULL
       infoArray_h->obj_at_put(index, NULL);
       continue;
     }
     // Create java.lang.management.ThreadInfo object
     instanceOop info_obj = Management::create_thread_info_instance(ts, CHECK_0);
     infoArray_h->obj_at_put(index, info_obj);
   }
   return 0;
 JVM_END
 // Dump thread info for the specified threads.
 // It returns an array of ThreadInfo objects. Each element is the ThreadInfo
 // for the thread ID specified in the corresponding entry in
 // the given array of thread IDs; or NULL if the thread does not exist
 // or has terminated.
 //
 // Input parameter:
 //    ids - array of thread IDs; NULL indicates all live threads
 //    locked_monitors - if true, dump locked object monitors
 //    locked_synchronizers - if true, dump locked JSR-166 synchronizers
 //
 JVM_ENTRY(jobjectArray, jmm_DumpThreads(JNIEnv *env, jlongArray thread_ids, jboolean locked_monitors, jboolean locked_synchronizers))
   ResourceMark rm(THREAD);
   if (JDK_Version::is_gte_jdk16x_version()) {
     // make sure the AbstractOwnableSynchronizer klass is loaded before taking thread snapshots
     java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(CHECK_NULL);
   }
   typeArrayOop ta = typeArrayOop(JNIHandles::resolve(thread_ids));
   int num_threads = (ta != NULL ? ta->length() : 0);
   typeArrayHandle ids_ah(THREAD, ta);
   ThreadDumpResult dump_result(num_threads);  // can safepoint
   if (ids_ah() != NULL) {
     // validate the thread id array
     validate_thread_id_array(ids_ah, CHECK_NULL);
     // obtain thread dump of a specific list of threads
     do_thread_dump(&dump_result,
                    ids_ah,
                    num_threads,
                    -1, /* entire stack */
                    (locked_monitors ? true : false),      /* with locked monitors */
                    (locked_synchronizers ? true : false), /* with locked synchronizers */
                    CHECK_NULL);
   } else {
     // obtain thread dump of all threads
     VM_ThreadDump op(&dump_result,
                      -1, /* entire stack */
                      (locked_monitors ? true : false),     /* with locked monitors */
                      (locked_synchronizers ? true : false) /* with locked synchronizers */);
     VMThread::execute(&op);
   }
   int num_snapshots = dump_result.num_snapshots();
   // create the result ThreadInfo[] object
   klassOop k = Management::java_lang_management_ThreadInfo_klass(CHECK_NULL);
   instanceKlassHandle ik (THREAD, k);
   objArrayOop r = oopFactory::new_objArray(ik(), num_snapshots, CHECK_NULL);
   objArrayHandle result_h(THREAD, r);
   int index = 0;
   for (ThreadSnapshot* ts = dump_result.snapshots(); ts != NULL; ts = ts->next(), index++) {
     if (ts->threadObj() == NULL) {
      // if the thread does not exist or now it is terminated, set threadinfo to NULL
       result_h->obj_at_put(index, NULL);
       continue;
     }
     ThreadStackTrace* stacktrace = ts->get_stack_trace();
     assert(stacktrace != NULL, "Must have a stack trace dumped");
     // Create Object[] filled with locked monitors
     // Create int[] filled with the stack depth where a monitor was locked
     int num_frames = stacktrace->get_stack_depth();
     int num_locked_monitors = stacktrace->num_jni_locked_monitors();
     // Count the total number of locked monitors
     for (int i = 0; i < num_frames; i++) {
       StackFrameInfo* frame = stacktrace->stack_frame_at(i);
       num_locked_monitors += frame->num_locked_monitors();
     }
     objArrayHandle monitors_array;
     typeArrayHandle depths_array;
     objArrayHandle synchronizers_array;
     if (locked_monitors) {
       // Constructs Object[] and int[] to contain the object monitor and the stack depth
       // where the thread locked it
       objArrayOop array = oopFactory::new_system_objArray(num_locked_monitors, false, CHECK_NULL);
       objArrayHandle mh(THREAD, array);
       monitors_array = mh;
       typeArrayOop tarray = oopFactory::new_typeArray(T_INT, num_locked_monitors, CHECK_NULL);
       typeArrayHandle dh(THREAD, tarray);
       depths_array = dh;
       int count = 0;
       int j = 0;
       for (int depth = 0; depth < num_frames; depth++) {
         StackFrameInfo* frame = stacktrace->stack_frame_at(depth);
         int len = frame->num_locked_monitors();
         GrowableArray<oop>* locked_monitors = frame->locked_monitors();
         for (j = 0; j < len; j++) {
           oop monitor = locked_monitors->at(j);
           assert(monitor != NULL && monitor->is_instance(), "must be a Java object");
           monitors_array->obj_at_put(count, monitor);
           depths_array->int_at_put(count, depth);
           count++;
         }
       }
       GrowableArray<oop>* jni_locked_monitors = stacktrace->jni_locked_monitors();
       for (j = 0; j < jni_locked_monitors->length(); j++) {
         oop object = jni_locked_monitors->at(j);
         assert(object != NULL && object->is_instance(), "must be a Java object");
         monitors_array->obj_at_put(count, object);
         // Monitor locked via JNI MonitorEnter call doesn't have stack depth info
         depths_array->int_at_put(count, -1);
         count++;
       }
       assert(count == num_locked_monitors, "number of locked monitors doesn't match");
     }
     if (locked_synchronizers) {
       // Create Object[] filled with locked JSR-166 synchronizers
       assert(ts->threadObj() != NULL, "Must be a valid JavaThread");
       ThreadConcurrentLocks* tcl = ts->get_concurrent_locks();
       GrowableArray<instanceOop>* locks = (tcl != NULL ? tcl->owned_locks() : NULL);
       int num_locked_synchronizers = (locks != NULL ? locks->length() : 0);
       objArrayOop array = oopFactory::new_system_objArray(num_locked_synchronizers, false, CHECK_NULL);
       objArrayHandle sh(THREAD, array);
       synchronizers_array = sh;
       for (int k = 0; k < num_locked_synchronizers; k++) {
         synchronizers_array->obj_at_put(k, locks->at(k));
       }
     }
     // Create java.lang.management.ThreadInfo object
     instanceOop info_obj = Management::create_thread_info_instance(ts,
                                                                    monitors_array,
                                                                    depths_array,
                                                                    synchronizers_array,
                                                                    CHECK_NULL);
     result_h->obj_at_put(index, info_obj);
   }
   return (jobjectArray) JNIHandles::make_local(env, result_h());
 JVM_END
 // Returns an array of Class objects.
 JVM_ENTRY(jobjectArray, jmm_GetLoadedClasses(JNIEnv *env))
   ResourceMark rm(THREAD);
   LoadedClassesEnumerator lce(THREAD);  // Pass current Thread as parameter
   int num_classes = lce.num_loaded_classes();
   objArrayOop r = oopFactory::new_objArray(SystemDictionary::Class_klass(), num_classes, CHECK_0);
   objArrayHandle classes_ah(THREAD, r);
   for (int i = 0; i < num_classes; i++) {
     KlassHandle kh = lce.get_klass(i);
     oop mirror = Klass::cast(kh())->java_mirror();
     classes_ah->obj_at_put(i, mirror);
   }
   return (jobjectArray) JNIHandles::make_local(env, classes_ah());
 JVM_END
 // Reset statistic.  Return true if the requested statistic is reset.
 // Otherwise, return false.
 //
 // Input parameters:
 //  obj  - specify which instance the statistic associated with to be reset
 //         For PEAK_POOL_USAGE stat, obj is required to be a memory pool object.
 //         For THREAD_CONTENTION_COUNT and TIME stat, obj is required to be a thread ID.
 //  type - the type of statistic to be reset
 //
 JVM_ENTRY(jboolean, jmm_ResetStatistic(JNIEnv *env, jvalue obj, jmmStatisticType type))
   ResourceMark rm(THREAD);
   switch (type) {
     case JMM_STAT_PEAK_THREAD_COUNT:
       ThreadService::reset_peak_thread_count();
       return true;
     case JMM_STAT_THREAD_CONTENTION_COUNT:
     case JMM_STAT_THREAD_CONTENTION_TIME: {
       jlong tid = obj.j;
       if (tid < 0) {
         THROW_(vmSymbols::java_lang_IllegalArgumentException(), JNI_FALSE);
       }
       // Look for the JavaThread of this given tid
       MutexLockerEx ml(Threads_lock);
       if (tid == 0) {
         // reset contention statistics for all threads if tid == 0
         for (JavaThread* java_thread = Threads::first(); java_thread != NULL; java_thread = java_thread->next()) {
           if (type == JMM_STAT_THREAD_CONTENTION_COUNT) {
             ThreadService::reset_contention_count_stat(java_thread);
           } else {
             ThreadService::reset_contention_time_stat(java_thread);
           }
         }
       } else {
         // reset contention statistics for a given thread
         JavaThread* java_thread = find_java_thread_from_id(tid);
         if (java_thread == NULL) {
           return false;
         }
         if (type == JMM_STAT_THREAD_CONTENTION_COUNT) {
           ThreadService::reset_contention_count_stat(java_thread);
         } else {
           ThreadService::reset_contention_time_stat(java_thread);
         }
       }
       return true;
       break;
     }
     case JMM_STAT_PEAK_POOL_USAGE: {
       jobject o = obj.l;
       if (o == NULL) {
         THROW_(vmSymbols::java_lang_NullPointerException(), JNI_FALSE);
       }
       oop pool_obj = JNIHandles::resolve(o);
       assert(pool_obj->is_instance(), "Should be an instanceOop");
       instanceHandle ph(THREAD, (instanceOop) pool_obj);
       MemoryPool* pool = MemoryService::get_memory_pool(ph);
       if (pool != NULL) {
         pool->reset_peak_memory_usage();
         return true;
       }
       break;
     }
     case JMM_STAT_GC_STAT: {
       jobject o = obj.l;
       if (o == NULL) {
         THROW_(vmSymbols::java_lang_NullPointerException(), JNI_FALSE);
       }
       GCMemoryManager* mgr = get_gc_memory_manager_from_jobject(o, CHECK_0);
       if (mgr != NULL) {
         mgr->reset_gc_stat();
         return true;
       }
       break;
     }
     default:
       assert(0, "Unknown Statistic Type");
   }
   return false;
 JVM_END
 // Returns the fast estimate of CPU time consumed by
 // a given thread (in nanoseconds).
 // If thread_id == 0, return CPU time for the current thread.
 JVM_ENTRY(jlong, jmm_GetThreadCpuTime(JNIEnv *env, jlong thread_id))
   if (!os::is_thread_cpu_time_supported()) {
     return -1;
   }
   if (thread_id < 0) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "Invalid thread ID", -1);
   }
   JavaThread* java_thread = NULL;
   if (thread_id == 0) {
     // current thread
     return os::current_thread_cpu_time();
   } else {
     MutexLockerEx ml(Threads_lock);
     java_thread = find_java_thread_from_id(thread_id);
     if (java_thread != NULL) {
       return os::thread_cpu_time((Thread*) java_thread);
     }
   }
   return -1;
 JVM_END
 // Returns the CPU time consumed by a given thread (in nanoseconds).
 // If thread_id == 0, CPU time for the current thread is returned.
 // If user_sys_cpu_time = true, user level and system CPU time of
 // a given thread is returned; otherwise, only user level CPU time
 // is returned.
 JVM_ENTRY(jlong, jmm_GetThreadCpuTimeWithKind(JNIEnv *env, jlong thread_id, jboolean user_sys_cpu_time))
   if (!os::is_thread_cpu_time_supported()) {
     return -1;
   }
   if (thread_id < 0) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "Invalid thread ID", -1);
   }
   JavaThread* java_thread = NULL;
   if (thread_id == 0) {
     // current thread
     return os::current_thread_cpu_time(user_sys_cpu_time != 0);
   } else {
     MutexLockerEx ml(Threads_lock);
     java_thread = find_java_thread_from_id(thread_id);
     if (java_thread != NULL) {
       return os::thread_cpu_time((Thread*) java_thread, user_sys_cpu_time != 0);
     }
   }
   return -1;
 JVM_END
 // Gets an array containing the CPU times consumed by a set of threads
 // (in nanoseconds).  Each element of the array is the CPU time for the
 // thread ID specified in the corresponding entry in the given array
 // of thread IDs; or -1 if the thread does not exist or has terminated.
 // If user_sys_cpu_time = true, the sum of user level and system CPU time
 // for the given thread is returned; otherwise, only user level CPU time
 // is returned.
 JVM_ENTRY(void, jmm_GetThreadCpuTimesWithKind(JNIEnv *env, jlongArray ids,
                                               jlongArray timeArray,
                                               jboolean user_sys_cpu_time))
   // Check if threads is null
   if (ids == NULL || timeArray == NULL) {
     THROW(vmSymbols::java_lang_NullPointerException());
   }
   ResourceMark rm(THREAD);
   typeArrayOop ta = typeArrayOop(JNIHandles::resolve_non_null(ids));
   typeArrayHandle ids_ah(THREAD, ta);
   typeArrayOop tia = typeArrayOop(JNIHandles::resolve_non_null(timeArray));
   typeArrayHandle timeArray_h(THREAD, tia);
   // validate the thread id array
   validate_thread_id_array(ids_ah, CHECK);
   // timeArray must be of the same length as the given array of thread IDs
   int num_threads = ids_ah->length();
   if (num_threads != timeArray_h->length()) {
     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
               "The length of the given long array does not match the length of "
               "the given array of thread IDs");
   }
   MutexLockerEx ml(Threads_lock);
   for (int i = 0; i < num_threads; i++) {
     JavaThread* java_thread = find_java_thread_from_id(ids_ah->long_at(i));
     if (java_thread != NULL) {
       timeArray_h->long_at_put(i, os::thread_cpu_time((Thread*)java_thread,
                                                       user_sys_cpu_time != 0));
     }
   }
 JVM_END
 // Returns a String array of all VM global flag names
 JVM_ENTRY(jobjectArray, jmm_GetVMGlobalNames(JNIEnv *env))
   // last flag entry is always NULL, so subtract 1
   int nFlags = (int) Flag::numFlags - 1;
   // allocate a temp array
   objArrayOop r = oopFactory::new_objArray(SystemDictionary::String_klass(),
                                            nFlags, CHECK_0);
   objArrayHandle flags_ah(THREAD, r);
   int num_entries = 0;
   for (int i = 0; i < nFlags; i++) {
     Flag* flag = &Flag::flags[i];
     // Exclude the locked (experimental, diagnostic) flags
     if (flag->is_unlocked() || flag->is_unlocker()) {
       Handle s = java_lang_String::create_from_str(flag->name, CHECK_0);
       flags_ah->obj_at_put(num_entries, s());
       num_entries++;
     }
   }
   if (num_entries < nFlags) {
     // Return array of right length
     objArrayOop res = oopFactory::new_objArray(SystemDictionary::String_klass(), num_entries, CHECK_0);
     for(int i = 0; i < num_entries; i++) {
       res->obj_at_put(i, flags_ah->obj_at(i));
     }
     return (jobjectArray)JNIHandles::make_local(env, res);
   }
   return (jobjectArray)JNIHandles::make_local(env, flags_ah());
 JVM_END
 // Utility function used by jmm_GetVMGlobals.  Returns false if flag type
 // can't be determined, true otherwise.  If false is returned, then *global
 // will be incomplete and invalid.
 bool add_global_entry(JNIEnv* env, Handle name, jmmVMGlobal *global, Flag *flag, TRAPS) {
   Handle flag_name;
   if (name() == NULL) {
     flag_name = java_lang_String::create_from_str(flag->name, CHECK_false);
   } else {
     flag_name = name;
   }
   global->name = (jstring)JNIHandles::make_local(env, flag_name());
   if (flag->is_bool()) {
     global->value.z = flag->get_bool() ? JNI_TRUE : JNI_FALSE;
     global->type = JMM_VMGLOBAL_TYPE_JBOOLEAN;
   } else if (flag->is_intx()) {
     global->value.j = (jlong)flag->get_intx();
     global->type = JMM_VMGLOBAL_TYPE_JLONG;
   } else if (flag->is_uintx()) {
     global->value.j = (jlong)flag->get_uintx();
     global->type = JMM_VMGLOBAL_TYPE_JLONG;
   } else if (flag->is_uint64_t()) {
     global->value.j = (jlong)flag->get_uint64_t();
     global->type = JMM_VMGLOBAL_TYPE_JLONG;
   } else if (flag->is_ccstr()) {
     Handle str = java_lang_String::create_from_str(flag->get_ccstr(), CHECK_false);
     global->value.l = (jobject)JNIHandles::make_local(env, str());
     global->type = JMM_VMGLOBAL_TYPE_JSTRING;
   } else {
     global->type = JMM_VMGLOBAL_TYPE_UNKNOWN;
     return false;
   }
   global->writeable = flag->is_writeable();
   global->external = flag->is_external();
   switch (flag->origin) {
     case DEFAULT:
       global->origin = JMM_VMGLOBAL_ORIGIN_DEFAULT;
       break;
     case COMMAND_LINE:
       global->origin = JMM_VMGLOBAL_ORIGIN_COMMAND_LINE;
       break;
     case ENVIRON_VAR:
       global->origin = JMM_VMGLOBAL_ORIGIN_ENVIRON_VAR;
       break;
     case CONFIG_FILE:
       global->origin = JMM_VMGLOBAL_ORIGIN_CONFIG_FILE;
       break;
     case MANAGEMENT:
       global->origin = JMM_VMGLOBAL_ORIGIN_MANAGEMENT;
       break;
     case ERGONOMIC:
       global->origin = JMM_VMGLOBAL_ORIGIN_ERGONOMIC;
       break;
     default:
       global->origin = JMM_VMGLOBAL_ORIGIN_OTHER;
   }
   return true;
 }
 // Fill globals array of count length with jmmVMGlobal entries
 // specified by names. If names == NULL, fill globals array
 // with all Flags. Return value is number of entries
 // created in globals.
 // If a Flag with a given name in an array element does not
 // exist, globals[i].name will be set to NULL.
 JVM_ENTRY(jint, jmm_GetVMGlobals(JNIEnv *env,
                                  jobjectArray names,
                                  jmmVMGlobal *globals,
                                  jint count))
   if (globals == NULL) {
     THROW_(vmSymbols::java_lang_NullPointerException(), 0);
   }
   ResourceMark rm(THREAD);
   if (names != NULL) {
     // return the requested globals
     objArrayOop ta = objArrayOop(JNIHandles::resolve_non_null(names));
     objArrayHandle names_ah(THREAD, ta);
     // Make sure we have a String array
     klassOop element_klass = objArrayKlass::cast(names_ah->klass())->element_klass();
     if (element_klass != SystemDictionary::String_klass()) {
       THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                  "Array element type is not String class", 0);
     }
     int names_length = names_ah->length();
     int num_entries = 0;
     for (int i = 0; i < names_length && i < count; i++) {
       oop s = names_ah->obj_at(i);
       if (s == NULL) {
         THROW_(vmSymbols::java_lang_NullPointerException(), 0);
       }
       Handle sh(THREAD, s);
       char* str = java_lang_String::as_utf8_string(s);
       Flag* flag = Flag::find_flag(str, strlen(str));
       if (flag != NULL &&
           add_global_entry(env, sh, &globals[i], flag, THREAD)) {
         num_entries++;
       } else {
         globals[i].name = NULL;
       }
     }
     return num_entries;
   } else {
     // return all globals if names == NULL
     // last flag entry is always NULL, so subtract 1
     int nFlags = (int) Flag::numFlags - 1;
     Handle null_h;
     int num_entries = 0;
     for (int i = 0; i < nFlags && num_entries < count;  i++) {
       Flag* flag = &Flag::flags[i];
       // Exclude the locked (diagnostic, experimental) flags
       if ((flag->is_unlocked() || flag->is_unlocker()) &&
           add_global_entry(env, null_h, &globals[num_entries], flag, THREAD)) {
         num_entries++;
       }
     }
     return num_entries;
   }
 JVM_END
 JVM_ENTRY(void, jmm_SetVMGlobal(JNIEnv *env, jstring flag_name, jvalue new_value))
   ResourceMark rm(THREAD);
   oop fn = JNIHandles::resolve_external_guard(flag_name);
   if (fn == NULL) {
     THROW_MSG(vmSymbols::java_lang_NullPointerException(),
               "The flag name cannot be null.");
   }
   char* name = java_lang_String::as_utf8_string(fn);
   Flag* flag = Flag::find_flag(name, strlen(name));
   if (flag == NULL) {
     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
               "Flag does not exist.");
   }
   if (!flag->is_writeable()) {
     THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
               "This flag is not writeable.");
   }
   bool succeed;
   if (flag->is_bool()) {
     bool bvalue = (new_value.z == JNI_TRUE ? true : false);
     succeed = CommandLineFlags::boolAtPut(name, &bvalue, MANAGEMENT);
   } else if (flag->is_intx()) {
     intx ivalue = (intx)new_value.j;
     succeed = CommandLineFlags::intxAtPut(name, &ivalue, MANAGEMENT);
   } else if (flag->is_uintx()) {
     uintx uvalue = (uintx)new_value.j;
     succeed = CommandLineFlags::uintxAtPut(name, &uvalue, MANAGEMENT);
   } else if (flag->is_uint64_t()) {
     uint64_t uvalue = (uint64_t)new_value.j;
     succeed = CommandLineFlags::uint64_tAtPut(name, &uvalue, MANAGEMENT);
   } else if (flag->is_ccstr()) {
     oop str = JNIHandles::resolve_external_guard(new_value.l);
     if (str == NULL) {
       THROW(vmSymbols::java_lang_NullPointerException());
     }
     ccstr svalue = java_lang_String::as_utf8_string(str);
     succeed = CommandLineFlags::ccstrAtPut(name, &svalue, MANAGEMENT);
   }
   assert(succeed, "Setting flag should succeed");
 JVM_END
 class ThreadTimesClosure: public ThreadClosure {
  private:
   objArrayOop _names;
   typeArrayOop _times;
   int _names_len;
   int _times_len;
   int _count;
  public:
   ThreadTimesClosure(objArrayOop names, typeArrayOop times);
   virtual void do_thread(Thread* thread);
   int count() { return _count; }
 };
 ThreadTimesClosure::ThreadTimesClosure(objArrayOop names,
                                        typeArrayOop times) {
   assert(names != NULL, "names was NULL");
   assert(times != NULL, "times was NULL");
   _names = names;
   _names_len = names->length();
   _times = times;
   _times_len = times->length();
   _count = 0;
 }
 void ThreadTimesClosure::do_thread(Thread* thread) {
   Handle s;
   assert(thread != NULL, "thread was NULL");
   // exclude externally visible JavaThreads
   if (thread->is_Java_thread() && !thread->is_hidden_from_external_view()) {
     return;
   }
   if (_count >= _names_len || _count >= _times_len) {
     // skip if the result array is not big enough
     return;
   }
   EXCEPTION_MARK;
   assert(thread->name() != NULL, "All threads should have a name");
   s = java_lang_String::create_from_str(thread->name(), CHECK);
   _names->obj_at_put(_count, s());
   _times->long_at_put(_count, os::is_thread_cpu_time_supported() ?
                         os::thread_cpu_time(thread) : -1);
   _count++;
 }
 // Fills names with VM internal thread names and times with the corresponding
 // CPU times.  If names or times is NULL, a NullPointerException is thrown.
 // If the element type of names is not String, an IllegalArgumentException is
 // thrown.
 // If an array is not large enough to hold all the entries, only the entries
 // that fit will be returned.  Return value is the number of VM internal
 // threads entries.
 JVM_ENTRY(jint, jmm_GetInternalThreadTimes(JNIEnv *env,
                                            jobjectArray names,
                                            jlongArray times))
   if (names == NULL || times == NULL) {
      THROW_(vmSymbols::java_lang_NullPointerException(), 0);
   }
   objArrayOop na = objArrayOop(JNIHandles::resolve_non_null(names));
   objArrayHandle names_ah(THREAD, na);
   // Make sure we have a String array
   klassOop element_klass = objArrayKlass::cast(names_ah->klass())->element_klass();
   if (element_klass != SystemDictionary::String_klass()) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "Array element type is not String class", 0);
   }
   typeArrayOop ta = typeArrayOop(JNIHandles::resolve_non_null(times));
   typeArrayHandle times_ah(THREAD, ta);
   ThreadTimesClosure ttc(names_ah(), times_ah());
   {
     MutexLockerEx ml(Threads_lock);
     Threads::threads_do(&ttc);
   }
   return ttc.count();
 JVM_END
 static Handle find_deadlocks(bool object_monitors_only, TRAPS) {
   ResourceMark rm(THREAD);
   VM_FindDeadlocks op(!object_monitors_only /* also check concurrent locks? */);
   VMThread::execute(&op);
   DeadlockCycle* deadlocks = op.result();
   if (deadlocks == NULL) {
     // no deadlock found and return
     return Handle();
   }
   int num_threads = 0;
   DeadlockCycle* cycle;
   for (cycle = deadlocks; cycle != NULL; cycle = cycle->next()) {
     num_threads += cycle->num_threads();
   }
   objArrayOop r = oopFactory::new_objArray(SystemDictionary::Thread_klass(), num_threads, CHECK_NH);
   objArrayHandle threads_ah(THREAD, r);
   int index = 0;
   for (cycle = deadlocks; cycle != NULL; cycle = cycle->next()) {
     GrowableArray<JavaThread*>* deadlock_threads = cycle->threads();
     int len = deadlock_threads->length();
     for (int i = 0; i < len; i++) {
       threads_ah->obj_at_put(index, deadlock_threads->at(i)->threadObj());
       index++;
     }
   }
   return threads_ah;
 }
 // Finds cycles of threads that are deadlocked involved in object monitors
 // and JSR-166 synchronizers.
 // Returns an array of Thread objects which are in deadlock, if any.
 // Otherwise, returns NULL.
 //
 // Input parameter:
 //    object_monitors_only - if true, only check object monitors
 //
 JVM_ENTRY(jobjectArray, jmm_FindDeadlockedThreads(JNIEnv *env, jboolean object_monitors_only))
   Handle result = find_deadlocks(object_monitors_only != 0, CHECK_0);
   return (jobjectArray) JNIHandles::make_local(env, result());
 JVM_END
 // Finds cycles of threads that are deadlocked on monitor locks
 // Returns an array of Thread objects which are in deadlock, if any.
 // Otherwise, returns NULL.
 JVM_ENTRY(jobjectArray, jmm_FindMonitorDeadlockedThreads(JNIEnv *env))
   Handle result = find_deadlocks(true, CHECK_0);
   return (jobjectArray) JNIHandles::make_local(env, result());
 JVM_END
 // Gets the information about GC extension attributes including
 // the name of the attribute, its type, and a short description.
 //
 // Input parameters:
 //   mgr   - GC memory manager
 //   info  - caller allocated array of jmmExtAttributeInfo
 //   count - number of elements of the info array
 //
 // Returns the number of GC extension attributes filled in the info array; or
 // -1 if info is not big enough
 //
 JVM_ENTRY(jint, jmm_GetGCExtAttributeInfo(JNIEnv *env, jobject mgr, jmmExtAttributeInfo* info, jint count))
   // All GC memory managers have 1 attribute (number of GC threads)
   if (count == 0) {
     return 0;
   }
   if (info == NULL) {
    THROW_(vmSymbols::java_lang_NullPointerException(), 0);
   }
   info[0].name = "GcThreadCount";
   info[0].type = 'I';
   info[0].description = "Number of GC threads";
   return 1;
 JVM_END
 // verify the given array is an array of java/lang/management/MemoryUsage objects
 // of a given length and return the objArrayOop
 static objArrayOop get_memory_usage_objArray(jobjectArray array, int length, TRAPS) {
   if (array == NULL) {
     THROW_(vmSymbols::java_lang_NullPointerException(), 0);
   }
   objArrayOop oa = objArrayOop(JNIHandles::resolve_non_null(array));
   objArrayHandle array_h(THREAD, oa);
   // array must be of the given length
   if (length != array_h->length()) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "The length of the given MemoryUsage array does not match the number of memory pools.", 0);
   }
   // check if the element of array is of type MemoryUsage class
   klassOop usage_klass = Management::java_lang_management_MemoryUsage_klass(CHECK_0);
   klassOop element_klass = objArrayKlass::cast(array_h->klass())->element_klass();
   if (element_klass != usage_klass) {
     THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(),
                "The element type is not MemoryUsage class", 0);
   }
   return array_h();
 }
 // Gets the statistics of the last GC of a given GC memory manager.
 // Input parameters:
 //   obj     - GarbageCollectorMXBean object
 //   gc_stat - caller allocated jmmGCStat where:
 //     a. before_gc_usage - array of MemoryUsage objects
 //     b. after_gc_usage  - array of MemoryUsage objects
 //     c. gc_ext_attributes_values_size is set to the
 //        gc_ext_attribute_values array allocated
 //     d. gc_ext_attribute_values is a caller allocated array of jvalue.
 //
 // On return,
 //   gc_index == 0 indicates no GC statistics available
 //
 //   before_gc_usage and after_gc_usage - filled with per memory pool
 //      before and after GC usage in the same order as the memory pools
 //      returned by GetMemoryPools for a given GC memory manager.
 //   num_gc_ext_attributes indicates the number of elements in
 //      the gc_ext_attribute_values array is filled; or
 //      -1 if the gc_ext_attributes_values array is not big enough
 //
 JVM_ENTRY(void, jmm_GetLastGCStat(JNIEnv *env, jobject obj, jmmGCStat *gc_stat))
   ResourceMark rm(THREAD);
   if (gc_stat->gc_ext_attribute_values_size > 0 && gc_stat->gc_ext_attribute_values == NULL) {
     THROW(vmSymbols::java_lang_NullPointerException());
   }
   // Get the GCMemoryManager
   GCMemoryManager* mgr = get_gc_memory_manager_from_jobject(obj, CHECK);
   // Make a copy of the last GC statistics
   // GC may occur while constructing the last GC information
   int num_pools = MemoryService::num_memory_pools();
   GCStatInfo* stat = new GCStatInfo(num_pools);
   if (mgr->get_last_gc_stat(stat) == 0) {
     gc_stat->gc_index = 0;
     return;
   }
   gc_stat->gc_index = stat->gc_index();
   gc_stat->start_time = Management::ticks_to_ms(stat->start_time());
   gc_stat->end_time = Management::ticks_to_ms(stat->end_time());
   // Current implementation does not have GC extension attributes
   gc_stat->num_gc_ext_attributes = 0;
   // Fill the arrays of MemoryUsage objects with before and after GC
   // per pool memory usage
   objArrayOop bu = get_memory_usage_objArray(gc_stat->usage_before_gc,
                                              num_pools,
                                              CHECK);
   objArrayHandle usage_before_gc_ah(THREAD, bu);
   objArrayOop au = get_memory_usage_objArray(gc_stat->usage_after_gc,
                                              num_pools,
                                              CHECK);
   objArrayHandle usage_after_gc_ah(THREAD, au);
   for (int i = 0; i < num_pools; i++) {
     Handle before_usage = MemoryService::create_MemoryUsage_obj(stat->before_gc_usage_for_pool(i), CHECK);
     Handle after_usage;
     MemoryUsage u = stat->after_gc_usage_for_pool(i);
     if (u.max_size() == 0 && u.used() > 0) {
       // If max size == 0, this pool is a survivor space.
       // Set max size = -1 since the pools will be swapped after GC.
       MemoryUsage usage(u.init_size(), u.used(), u.committed(), (size_t)-1);
       after_usage = MemoryService::create_MemoryUsage_obj(usage, CHECK);
     } else {
       after_usage = MemoryService::create_MemoryUsage_obj(stat->after_gc_usage_for_pool(i), CHECK);
     }
     usage_before_gc_ah->obj_at_put(i, before_usage());
     usage_after_gc_ah->obj_at_put(i, after_usage());
   }
   if (gc_stat->gc_ext_attribute_values_size > 0) {
     // Current implementation only has 1 attribute (number of GC threads)
     // The type is 'I'
     gc_stat->gc_ext_attribute_values[0].i = mgr->num_gc_threads();
   }
 JVM_END
 // Dump heap - Returns 0 if succeeds.
 JVM_ENTRY(jint, jmm_DumpHeap0(JNIEnv *env, jstring outputfile, jboolean live))
 #ifndef SERVICES_KERNEL
   ResourceMark rm(THREAD);
   oop on = JNIHandles::resolve_external_guard(outputfile);
   if (on == NULL) {
     THROW_MSG_(vmSymbols::java_lang_NullPointerException(),
                "Output file name cannot be null.", -1);
   }
   char* name = java_lang_String::as_utf8_string(on);
   if (name == NULL) {
     THROW_MSG_(vmSymbols::java_lang_NullPointerException(),
                "Output file name cannot be null.", -1);
   }
   HeapDumper dumper(live ? true : false);
   if (dumper.dump(name) != 0) {
     const char* errmsg = dumper.error_as_C_string();
     THROW_MSG_(vmSymbols::java_io_IOException(), errmsg, -1);
   }
   return 0;
 #else  // SERVICES_KERNEL
   return -1;
 #endif // SERVICES_KERNEL
 JVM_END
 jlong Management::ticks_to_ms(jlong ticks) {
   assert(os::elapsed_frequency() > 0, "Must be non-zero");
   return (jlong)(((double)ticks / (double)os::elapsed_frequency())
                  * (double)1000.0);
 }
 const struct jmmInterface_1_ jmm_interface = {
   NULL,
   NULL,
   jmm_GetVersion,
   jmm_GetOptionalSupport,
   jmm_GetInputArguments,
   jmm_GetThreadInfo,
   jmm_GetInputArgumentArray,
   jmm_GetMemoryPools,
   jmm_GetMemoryManagers,
   jmm_GetMemoryPoolUsage,
   jmm_GetPeakMemoryPoolUsage,
   jmm_GetThreadAllocatedMemory,
   jmm_GetMemoryUsage,
   jmm_GetLongAttribute,
   jmm_GetBoolAttribute,
   jmm_SetBoolAttribute,
   jmm_GetLongAttributes,
   jmm_FindMonitorDeadlockedThreads,
   jmm_GetThreadCpuTime,
   jmm_GetVMGlobalNames,
   jmm_GetVMGlobals,
   jmm_GetInternalThreadTimes,
   jmm_ResetStatistic,
   jmm_SetPoolSensor,
   jmm_SetPoolThreshold,
   jmm_GetPoolCollectionUsage,
   jmm_GetGCExtAttributeInfo,
   jmm_GetLastGCStat,
   jmm_GetThreadCpuTimeWithKind,
   jmm_GetThreadCpuTimesWithKind,
   jmm_DumpHeap0,
   jmm_FindDeadlockedThreads,
   jmm_SetVMGlobal,
   NULL,
   jmm_DumpThreads
 };
 void* Management::get_jmm_interface(int version) {
   if (version == JMM_VERSION_1_0) {
     return (void*) &jmm_interface;
   }
   return NULL;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/services/management.cpp@f7702f8c0e25 (annotated)

src/share/vm/services/management.cpp