/*
* Copyright 2016 higherfrequencytrading.com
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package net.openhft.affinity;
import org.jetbrains.annotations.NotNull;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.NavigableMap;
import java.util.TreeMap;
class LockInventory {
private static final Logger LOGGER = LoggerFactory.getLogger(LockInventory.class);
/**
* The locks belonging to physical cores. Since a physical core can host multiple logical cores
* the relationship is one to many.
*/
private final NavigableMap<Integer, AffinityLock[]> physicalCoreLocks = new TreeMap<Integer, AffinityLock[]>();
private CpuLayout cpuLayout;
/**
* The lock belonging to each logical core. 1-to-1 relationship
*/
private AffinityLock[] logicalCoreLocks;
public LockInventory(CpuLayout cpuLayout) {
set(cpuLayout);
}
public static String dumpLocks(@NotNull AffinityLock[] locks) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < locks.length; i++) {
AffinityLock al = locks[i];
sb.append(i).append(": ");
sb.append(al.toString());
sb.append('\n');
}
return sb.toString();
}
public final synchronized CpuLayout getCpuLayout() {
return cpuLayout;
}
public final synchronized void set(CpuLayout cpuLayout) {
if (cpuLayout.equals(this.cpuLayout)) {
return;
}
reset(cpuLayout);
for (int i = 0; i < cpuLayout.cpus(); i++) {
final boolean base = AffinityLock.BASE_AFFINITY.get(i);
final boolean reservable = AffinityLock.RESERVED_AFFINITY.get(i);
LOGGER.trace("cpu " + i + " base={} reservable= {}", i, base, reservable);
AffinityLock lock = logicalCoreLocks[i] = newLock(i, base, reservable);
int layoutId = lock.cpuId();
int physicalCore = toPhysicalCore(layoutId);
AffinityLock[] locks = physicalCoreLocks.get(physicalCore);
if (locks == null) {
physicalCoreLocks.put(physicalCore, locks = new AffinityLock[cpuLayout.threadsPerCore()]);
}
locks[cpuLayout.threadId(layoutId)] = lock;
}
}
public final synchronized AffinityLock acquireLock(boolean bind, int cpuId, AffinityStrategy... strategies) {
for (AffinityStrategy strategy : strategies) {
// consider all processors except cpu 0 which is usually used by the OS.
// if you have only one core, this library is not appropriate in any case.
for (int i = logicalCoreLocks.length - 1; i > 0; i--) {
AffinityLock al = logicalCoreLocks[i];
if (al.canReserve() && (cpuId < 0 || strategy.matches(cpuId, al.cpuId()))) {
al.assignCurrentThread(bind, false);
LockCheck.updateCpu(al.cpuId());
return al;
}
}
}
LOGGER.warn("No reservable CPU for {}", Thread.currentThread());
return newLock(-1, false, false);
}
public final synchronized AffinityLock acquireCore(boolean bind, int cpuId, AffinityStrategy... strategies) {
for (AffinityStrategy strategy : strategies) {
LOOP:
for (AffinityLock[] als : physicalCoreLocks.descendingMap().values()) {
for (AffinityLock al : als)
if (!al.canReserve() || !strategy.matches(cpuId, al.cpuId()))
continue LOOP;
final AffinityLock al = als[0];
al.assignCurrentThread(bind, true);
LockCheck.updateCpu(al.cpuId());
return al;
}
}
LOGGER.warn("No reservable Core for {}", Thread.currentThread());
return acquireLock(bind, cpuId, strategies);
}
public final synchronized void bindWholeCore(int logicalCoreID) {
if (logicalCoreID < 0) {
LOGGER.warn("Can't bind core since it was not possible to reserve it!");
return;
}
int core = toPhysicalCore(logicalCoreID);
for (AffinityLock al : physicalCoreLocks.get(core)) {
if (al.isBound() && al.assignedThread != null && al.assignedThread.isAlive()) {
LOGGER.warn("cpu {} already bound to {}", al.cpuId(), al.assignedThread);
} else {
al.bound = true;
al.assignedThread = Thread.currentThread();
}
}
if (LOGGER.isInfoEnabled()) {
StringBuilder sb = new StringBuilder().append("Assigning core ").append(core);
String sep = ": cpus ";
for (AffinityLock al : physicalCoreLocks.get(core)) {
sb.append(sep).append(al.cpuId());
sep = ", ";
}
sb.append(" to ").append(Thread.currentThread());
LOGGER.info(sb.toString());
}
}
public final synchronized void release() {
Thread t = Thread.currentThread();
for (AffinityLock al : logicalCoreLocks) {
Thread at = al.assignedThread;
if (at == t) {
LOGGER.info("Releasing cpu {} from {}", al.cpuId(), t);
al.assignedThread = null;
al.bound = false;
al.boundHere = null;
} else if (at != null && !at.isAlive()) {
LOGGER.warn("Releasing cpu {} from {} as it is not alive.", al.cpuId(), t);
al.assignedThread = null;
al.bound = false;
al.boundHere = null;
}
}
Affinity.resetToBaseAffinity();
}
public final synchronized String dumpLocks() {
return dumpLocks(logicalCoreLocks);
}
protected AffinityLock newLock(int cpuId, boolean base, boolean reservable) {
return new AffinityLock(cpuId, base, reservable, this);
}
private void reset(CpuLayout cpuLayout) {
this.cpuLayout = cpuLayout;
this.logicalCoreLocks = new AffinityLock[cpuLayout.cpus()];
this.physicalCoreLocks.clear();
}
private int toPhysicalCore(int layoutId) {
return cpuLayout.socketId(layoutId) * cpuLayout.coresPerSocket() + cpuLayout.coreId(layoutId);
}
}