jdk/src/hotspot/share/runtime/threadIdentifier.cpp
Kim Barrett 9e843f56ec 8367014: Rename class Atomic to AtomicAccess
Reviewed-by: dholmes, aph, stefank
2025-09-12 06:35:55 +00:00

58 lines
2.0 KiB
C++

/*
* Copyright (c) 2022, 2025, 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.
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#include "runtime/atomicAccess.hpp"
#include "runtime/threadIdentifier.hpp"
// starting at 3, excluding reserved values defined in ObjectMonitor.hpp
static const int64_t INITIAL_TID = 3;
static volatile int64_t next_thread_id = INITIAL_TID;
int64_t ThreadIdentifier::initial() {
return INITIAL_TID;
}
int64_t ThreadIdentifier::unsafe_offset() {
return reinterpret_cast<int64_t>(&next_thread_id);
}
int64_t ThreadIdentifier::current() {
return AtomicAccess::load(&next_thread_id);
}
int64_t ThreadIdentifier::next() {
int64_t next_tid;
do {
next_tid = AtomicAccess::load(&next_thread_id);
} while (AtomicAccess::cmpxchg(&next_thread_id, next_tid, next_tid + 1) != next_tid);
return next_tid;
}
#ifdef ASSERT
void ThreadIdentifier::verify_id(int64_t id) {
int64_t current_id = current();
assert(id >= initial() && id < current_id, "invalid id, " INT64_FORMAT " and current is " INT64_FORMAT, id, current_id);
}
#endif