/**
* Copyright 2018 Nikita Koksharov
*
* 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 org.redisson;
import java.util.Arrays;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import org.redisson.api.RFuture;
import org.redisson.api.RLock;
import org.redisson.client.codec.LongCodec;
import org.redisson.client.protocol.RedisCommands;
import org.redisson.client.protocol.RedisStrictCommand;
import org.redisson.command.CommandExecutor;
import org.redisson.pubsub.LockPubSub;
/**
* Distributed implementation of {@link java.util.concurrent.locks.Lock}
* Implements reentrant lock.
* Implements a fair locking so it guarantees an acquire order by threads.
*
* @author Nikita Koksharov
*
*/
public class RedissonFairLock extends RedissonLock implements RLock {
private final long threadWaitTime = 5000;
private final CommandExecutor commandExecutor;
private final String threadsQueueName;
private final String timeoutSetName;
protected RedissonFairLock(CommandExecutor commandExecutor, String name) {
super(commandExecutor, name);
this.commandExecutor = commandExecutor;
threadsQueueName = prefixName("redisson_lock_queue", name);
timeoutSetName = prefixName("redisson_lock_timeout", name);
}
@Override
protected RedissonLockEntry getEntry(long threadId) {
return PUBSUB.getEntry(getEntryName() + ":" + threadId);
}
@Override
protected RFuture subscribe(long threadId) {
return PUBSUB.subscribe(getEntryName() + ":" + threadId,
getChannelName() + ":" + getLockName(threadId), commandExecutor.getConnectionManager().getSubscribeService());
}
@Override
protected void unsubscribe(RFuture future, long threadId) {
PUBSUB.unsubscribe(future.getNow(), getEntryName() + ":" + threadId,
getChannelName() + ":" + getLockName(threadId), commandExecutor.getConnectionManager().getSubscribeService());
}
@Override
protected RFuture acquireFailedAsync(long threadId) {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, RedisCommands.EVAL_VOID,
"local firstThreadId = redis.call('lindex', KEYS[1], 0); " +
"if firstThreadId == ARGV[1] then " +
"local keys = redis.call('zrange', KEYS[2], 0, -1); " +
"for i = 1, #keys, 1 do " +
"redis.call('zincrby', KEYS[2], -tonumber(ARGV[2]), keys[i]);" +
"end;" +
"end;" +
"redis.call('zrem', KEYS[2], ARGV[1]); " +
"redis.call('lrem', KEYS[1], 0, ARGV[1]); ",
Arrays.asList(threadsQueueName, timeoutSetName),
getLockName(threadId), threadWaitTime);
}
@Override
RFuture tryLockInnerAsync(long leaseTime, TimeUnit unit, long threadId, RedisStrictCommand command) {
internalLockLeaseTime = unit.toMillis(leaseTime);
long currentTime = System.currentTimeMillis();
if (command == RedisCommands.EVAL_NULL_BOOLEAN) {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, command,
// remove stale threads
"while true do "
+ "local firstThreadId2 = redis.call('lindex', KEYS[2], 0);"
+ "if firstThreadId2 == false then "
+ "break;"
+ "end; "
+ "local timeout = tonumber(redis.call('zscore', KEYS[3], firstThreadId2));"
+ "if timeout <= tonumber(ARGV[3]) then "
+ "redis.call('zrem', KEYS[3], firstThreadId2); "
+ "redis.call('lpop', KEYS[2]); "
+ "else "
+ "break;"
+ "end; "
+ "end;"
+
"if (redis.call('exists', KEYS[1]) == 0) and ((redis.call('exists', KEYS[2]) == 0) "
+ "or (redis.call('lindex', KEYS[2], 0) == ARGV[2])) then " +
"redis.call('lpop', KEYS[2]); " +
"redis.call('zrem', KEYS[3], ARGV[2]); " +
"redis.call('hset', KEYS[1], ARGV[2], 1); " +
"redis.call('pexpire', KEYS[1], ARGV[1]); " +
"return nil; " +
"end; " +
"if (redis.call('hexists', KEYS[1], ARGV[2]) == 1) then " +
"redis.call('hincrby', KEYS[1], ARGV[2], 1); " +
"redis.call('pexpire', KEYS[1], ARGV[1]); " +
"return nil; " +
"end; " +
"return 1;",
Arrays.asList(getName(), threadsQueueName, timeoutSetName),
internalLockLeaseTime, getLockName(threadId), currentTime);
}
if (command == RedisCommands.EVAL_LONG) {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, command,
// remove stale threads
"while true do "
+ "local firstThreadId2 = redis.call('lindex', KEYS[2], 0);"
+ "if firstThreadId2 == false then "
+ "break;"
+ "end; "
+ "local timeout = tonumber(redis.call('zscore', KEYS[3], firstThreadId2));"
+ "if timeout <= tonumber(ARGV[4]) then "
+ "redis.call('zrem', KEYS[3], firstThreadId2); "
+ "redis.call('lpop', KEYS[2]); "
+ "else "
+ "break;"
+ "end; "
+ "end;"
+ "if (redis.call('exists', KEYS[1]) == 0) and ((redis.call('exists', KEYS[2]) == 0) "
+ "or (redis.call('lindex', KEYS[2], 0) == ARGV[2])) then " +
"redis.call('lpop', KEYS[2]); " +
"redis.call('zrem', KEYS[3], ARGV[2]); " +
"redis.call('hset', KEYS[1], ARGV[2], 1); " +
"redis.call('pexpire', KEYS[1], ARGV[1]); " +
"return nil; " +
"end; " +
"if (redis.call('hexists', KEYS[1], ARGV[2]) == 1) then " +
"redis.call('hincrby', KEYS[1], ARGV[2], 1); " +
"redis.call('pexpire', KEYS[1], ARGV[1]); " +
"return nil; " +
"end; " +
"local firstThreadId = redis.call('lindex', KEYS[2], 0); " +
"local ttl; " +
"if firstThreadId ~= false and firstThreadId ~= ARGV[2] then " +
"ttl = tonumber(redis.call('zscore', KEYS[3], firstThreadId)) - tonumber(ARGV[4]);" +
"else "
+ "ttl = redis.call('pttl', KEYS[1]);" +
"end; " +
"local timeout = ttl + tonumber(ARGV[3]);" +
"if redis.call('zadd', KEYS[3], timeout, ARGV[2]) == 1 then " +
"redis.call('rpush', KEYS[2], ARGV[2]);" +
"end; " +
"return ttl;",
Arrays.asList(getName(), threadsQueueName, timeoutSetName),
internalLockLeaseTime, getLockName(threadId), currentTime + threadWaitTime, currentTime);
}
throw new IllegalArgumentException();
}
@Override
protected RFuture unlockInnerAsync(long threadId) {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, RedisCommands.EVAL_BOOLEAN,
// remove stale threads
"while true do "
+ "local firstThreadId2 = redis.call('lindex', KEYS[2], 0);"
+ "if firstThreadId2 == false then "
+ "break;"
+ "end; "
+ "local timeout = tonumber(redis.call('zscore', KEYS[3], firstThreadId2));"
+ "if timeout <= tonumber(ARGV[4]) then "
+ "redis.call('zrem', KEYS[3], firstThreadId2); "
+ "redis.call('lpop', KEYS[2]); "
+ "else "
+ "break;"
+ "end; "
+ "end;"
+ "if (redis.call('exists', KEYS[1]) == 0) then " +
"local nextThreadId = redis.call('lindex', KEYS[2], 0); " +
"if nextThreadId ~= false then " +
"redis.call('publish', KEYS[4] .. ':' .. nextThreadId, ARGV[1]); " +
"end; " +
"return 1; " +
"end;" +
"if (redis.call('hexists', KEYS[1], ARGV[3]) == 0) then " +
"return nil;" +
"end; " +
"local counter = redis.call('hincrby', KEYS[1], ARGV[3], -1); " +
"if (counter > 0) then " +
"redis.call('pexpire', KEYS[1], ARGV[2]); " +
"return 0; " +
"end; " +
"redis.call('del', KEYS[1]); " +
"local nextThreadId = redis.call('lindex', KEYS[2], 0); " +
"if nextThreadId ~= false then " +
"redis.call('publish', KEYS[4] .. ':' .. nextThreadId, ARGV[1]); " +
"end; " +
"return 1; ",
Arrays.asList(getName(), threadsQueueName, timeoutSetName, getChannelName()),
LockPubSub.unlockMessage, internalLockLeaseTime, getLockName(threadId), System.currentTimeMillis());
}
@Override
public Condition newCondition() {
throw new UnsupportedOperationException();
}
@Override
public RFuture deleteAsync() {
return commandExecutor.writeAsync(getName(), RedisCommands.DEL_OBJECTS, getName(), threadsQueueName, timeoutSetName);
}
@Override
public RFuture expireAsync(long timeToLive, TimeUnit timeUnit) {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, RedisCommands.EVAL_BOOLEAN,
"redis.call('pexpire', KEYS[1], ARGV[1]); " +
"redis.call('pexpire', KEYS[2], ARGV[1]); " +
"return redis.call('pexpire', KEYS[3], ARGV[1]); ",
Arrays.asList(getName(), threadsQueueName, timeoutSetName),
timeUnit.toMillis(timeToLive));
}
@Override
public RFuture expireAtAsync(long timestamp) {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, RedisCommands.EVAL_BOOLEAN,
"redis.call('pexpireat', KEYS[1], ARGV[1]); " +
"redis.call('pexpireat', KEYS[2], ARGV[1]); " +
"return redis.call('pexpireat', KEYS[3], ARGV[1]); ",
Arrays.asList(getName(), threadsQueueName, timeoutSetName),
timestamp);
}
@Override
public RFuture clearExpireAsync() {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, RedisCommands.EVAL_BOOLEAN,
"redis.call('persist', KEYS[1]); " +
"redis.call('persist', KEYS[2]); " +
"return redis.call('persist', KEYS[3]); ",
Arrays.asList(getName(), threadsQueueName, timeoutSetName));
}
@Override
public RFuture forceUnlockAsync() {
cancelExpirationRenewal();
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, RedisCommands.EVAL_BOOLEAN,
// remove stale threads
"while true do "
+ "local firstThreadId2 = redis.call('lindex', KEYS[2], 0);"
+ "if firstThreadId2 == false then "
+ "break;"
+ "end; "
+ "local timeout = tonumber(redis.call('zscore', KEYS[3], firstThreadId2));"
+ "if timeout <= tonumber(ARGV[2]) then "
+ "redis.call('zrem', KEYS[3], firstThreadId2); "
+ "redis.call('lpop', KEYS[2]); "
+ "else "
+ "break;"
+ "end; "
+ "end;"
+
"if (redis.call('del', KEYS[1]) == 1) then " +
"local nextThreadId = redis.call('lindex', KEYS[2], 0); " +
"if nextThreadId ~= false then " +
"redis.call('publish', KEYS[4] .. ':' .. nextThreadId, ARGV[1]); " +
"end; " +
"return 1; " +
"end; " +
"return 0;",
Arrays.asList(getName(), threadsQueueName, timeoutSetName, getChannelName()),
LockPubSub.unlockMessage, System.currentTimeMillis());
}
}
