| |
| /* |
| * Copyright (c) 2019, 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 "runtime/interfaceSupport.inline.hpp" |
| #include "runtime/thread.hpp" |
| #include "runtime/threadSMR.hpp" |
| #include "runtime/timerTrace.hpp" |
| #include "services/threadIdTable.hpp" |
| #include "utilities/resourceHash.hpp" |
| #include "utilities/concurrentHashTable.inline.hpp" |
| #include "utilities/concurrentHashTableTasks.inline.hpp" |
| |
| class ThreadIdTableEntry; |
| |
| typedef ConcurrentHashTable<ThreadIdTableEntry*, ThreadIdTableConfig, mtInternal> ThreadIdTableHash; |
| |
| // 2^24 is max size |
| static const size_t END_SIZE = 24; |
| // Default initial size 256 |
| static const size_t DEFAULT_TABLE_SIZE_LOG = 8; |
| // Prefer short chains of avg 2 |
| static const double PREF_AVG_LIST_LEN = 2.0; |
| static ThreadIdTableHash* volatile _local_table = NULL; |
| static volatile size_t _current_size = 0; |
| static volatile size_t _items_count = 0; |
| |
| volatile bool ThreadIdTable::_is_initialized = false; |
| |
| class ThreadIdTableEntry : public CHeapObj<mtInternal> { |
| private: |
| jlong _tid; |
| JavaThread* _java_thread; |
| public: |
| ThreadIdTableEntry(jlong tid, JavaThread* java_thread) : |
| _tid(tid), _java_thread(java_thread) {} |
| |
| jlong tid() const { return _tid; } |
| JavaThread* thread() const { return _java_thread; } |
| }; |
| |
| class ThreadIdTableConfig : public AllStatic { |
| public: |
| typedef ThreadIdTableEntry* Value; |
| |
| static uintx get_hash(Value const& value, bool* is_dead) { |
| jlong tid = value->tid(); |
| return primitive_hash(tid); |
| } |
| static void* allocate_node(size_t size, Value const& value) { |
| ThreadIdTable::item_added(); |
| return AllocateHeap(size, mtInternal); |
| } |
| static void free_node(void* memory, Value const& value) { |
| delete value; |
| FreeHeap(memory); |
| ThreadIdTable::item_removed(); |
| } |
| }; |
| |
| static size_t ceil_log2(size_t val) { |
| size_t ret; |
| for (ret = 1; ((size_t)1 << ret) < val; ++ret); |
| return ret; |
| } |
| |
| // Lazily creates the table and populates it with the given |
| // thread list |
| void ThreadIdTable::lazy_initialize(const ThreadsList *threads) { |
| if (!_is_initialized) { |
| { |
| // There is no obvious benefits in allowing the thread table |
| // to be concurently populated during the initalization. |
| MutexLocker ml(ThreadIdTableCreate_lock); |
| if (_is_initialized) { |
| return; |
| } |
| create_table(threads->length()); |
| _is_initialized = true; |
| } |
| for (uint i = 0; i < threads->length(); i++) { |
| JavaThread* thread = threads->thread_at(i); |
| oop tobj = thread->threadObj(); |
| if (tobj != NULL) { |
| jlong java_tid = java_lang_Thread::thread_id(tobj); |
| MutexLocker ml(Threads_lock); |
| if (!thread->is_exiting()) { |
| // Must be inside the lock to ensure that we don't add a thread to the table |
| // that has just passed the removal point in ThreadsSMRSupport::remove_thread() |
| add_thread(java_tid, thread); |
| } |
| } |
| } |
| } |
| } |
| |
| void ThreadIdTable::create_table(size_t size) { |
| assert(_local_table == NULL, "Thread table is already created"); |
| size_t size_log = ceil_log2(size); |
| size_t start_size_log = |
| size_log > DEFAULT_TABLE_SIZE_LOG ? size_log : DEFAULT_TABLE_SIZE_LOG; |
| _current_size = (size_t)1 << start_size_log; |
| _local_table = new ThreadIdTableHash(start_size_log, END_SIZE); |
| } |
| |
| void ThreadIdTable::item_added() { |
| Atomic::inc(&_items_count); |
| log_trace(thread, table) ("Thread entry added"); |
| } |
| |
| void ThreadIdTable::item_removed() { |
| Atomic::dec(&_items_count); |
| log_trace(thread, table) ("Thread entry removed"); |
| } |
| |
| double ThreadIdTable::get_load_factor() { |
| return ((double)_items_count) / _current_size; |
| } |
| |
| size_t ThreadIdTable::table_size() { |
| return (size_t)1 << _local_table->get_size_log2(Thread::current()); |
| } |
| |
| void ThreadIdTable::grow(JavaThread* jt) { |
| ThreadIdTableHash::GrowTask gt(_local_table); |
| if (!gt.prepare(jt)) { |
| return; |
| } |
| log_trace(thread, table)("Started to grow"); |
| TraceTime timer("Grow", TRACETIME_LOG(Debug, membername, table, perf)); |
| while (gt.do_task(jt)) { |
| gt.pause(jt); |
| { |
| ThreadBlockInVM tbivm(jt); |
| } |
| gt.cont(jt); |
| } |
| gt.done(jt); |
| _current_size = table_size(); |
| log_info(thread, table)("Grown to size:" SIZE_FORMAT, _current_size); |
| } |
| |
| class ThreadIdTableLookup : public StackObj { |
| private: |
| jlong _tid; |
| uintx _hash; |
| public: |
| ThreadIdTableLookup(jlong tid) |
| : _tid(tid), _hash(primitive_hash(tid)) {} |
| uintx get_hash() const { |
| return _hash; |
| } |
| bool equals(ThreadIdTableEntry** value, bool* is_dead) { |
| bool equals = primitive_equals(_tid, (*value)->tid()); |
| if (!equals) { |
| return false; |
| } |
| return true; |
| } |
| }; |
| |
| class ThreadGet : public StackObj { |
| private: |
| JavaThread* _return; |
| public: |
| ThreadGet(): _return(NULL) {} |
| void operator()(ThreadIdTableEntry** val) { |
| _return = (*val)->thread(); |
| } |
| JavaThread* get_res_thread() { |
| return _return; |
| } |
| }; |
| |
| void ThreadIdTable::grow_if_required() { |
| assert(Thread::current()->is_Java_thread(),"Must be Java thread"); |
| assert(_is_initialized, "Thread table is not initialized"); |
| double load_factor = get_load_factor(); |
| log_debug(thread, table)("Concurrent work, load factor: %g", load_factor); |
| if (load_factor > PREF_AVG_LIST_LEN && !_local_table->is_max_size_reached()) { |
| grow(JavaThread::current()); |
| } |
| } |
| |
| JavaThread* ThreadIdTable::add_thread(jlong tid, JavaThread* java_thread) { |
| assert(_is_initialized, "Thread table is not initialized"); |
| Thread* thread = Thread::current(); |
| ThreadIdTableLookup lookup(tid); |
| ThreadGet tg; |
| while (true) { |
| if (_local_table->get(thread, lookup, tg)) { |
| return tg.get_res_thread(); |
| } |
| ThreadIdTableEntry* entry = new ThreadIdTableEntry(tid, java_thread); |
| // The hash table takes ownership of the ThreadTableEntry, |
| // even if it's not inserted. |
| if (_local_table->insert(thread, lookup, entry)) { |
| grow_if_required(); |
| return java_thread; |
| } |
| } |
| } |
| |
| JavaThread* ThreadIdTable::find_thread_by_tid(jlong tid) { |
| assert(_is_initialized, "Thread table is not initialized"); |
| Thread* thread = Thread::current(); |
| ThreadIdTableLookup lookup(tid); |
| ThreadGet tg; |
| _local_table->get(thread, lookup, tg); |
| return tg.get_res_thread(); |
| } |
| |
| bool ThreadIdTable::remove_thread(jlong tid) { |
| assert(_is_initialized, "Thread table is not initialized"); |
| Thread* thread = Thread::current(); |
| ThreadIdTableLookup lookup(tid); |
| return _local_table->remove(thread, lookup); |
| } |