主要完成任務：
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read read并行化 -
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read write不允許 -
3.
write write不允許
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public class ReaderWorker extends Thread { private final SharedData data; public ReaderWorker(SharedData data) { this.data = data; } @Override public void run() { while (true) { try { char[] readBuf = data.read(); System.out.println(Thread.currentThread().getName() + " reads " + String.valueOf(readBuf)); } catch (InterruptedException e) { e.printStackTrace(); } } }} |
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public class ReadWriteLock { /** * 當前有幾個線程 在對它進行讀操作 */ private int readingReaders = 0; /** * 當前有幾個線程 等待讀操作 */ private int waitingReaders = 0; /** * 當前有幾個線程 正在寫操作 */ private int writingWriters = 0; /** * 當前有幾個線程 正在寫操作 */ private int waitingWriters = 0; /** * 偏向于寫 */ private boolean preferWriter = true; public ReadWriteLock() { this(true); } public ReadWriteLock(boolean preferWriter) { this.preferWriter = preferWriter; } public synchronized void readLock() throws InterruptedException { this.waitingReaders++; try { /** * 讓寫的線程先運行 */ while (writingWriters > 0||(preferWriter&&waitingWriters>0)) { this.wait(); } this.readingReaders++; } finally { this.waitingReaders--; } } public synchronized void readUnLock() { this.readingReaders--; this.notifyAll(); } public synchronized void writeLock() throws InterruptedException { this.waitingWriters++; try { while (readingReaders > 0 || writingWriters > 0) { this.wait(); } this.writingWriters++; } finally { this.waitingWriters--; } } public synchronized void writeUnlock() { this.writingWriters--; this.notifyAll(); }}public class SharedData { private final char[] buffer; private final ReadWriteLock lock = new ReadWriteLock(); public SharedData(int size) { this.buffer = new char[size]; for (int i = 0; i < size; i++) { this.buffer[i] = '*'; } } public char[] read() throws InterruptedException { try { lock.readLock(); return this.doRead(); } finally { lock.readUnLock(); } } public void write(char c) throws InterruptedException { try { lock.writeLock(); this.doWrite(c); } finally { lock.writeUnlock(); } } private void doWrite(char c) { for (int i = 0; i < buffer.length; i++) { buffer[i] = c; slowly(10); } } private char[] doRead() { char[] newBuf = new char[buffer.length]; for (int i = 0; i < buffer.length; i++) { newBuf[i] = buffer[i]; } slowly(50); return newBuf; } private void slowly(int millisecond) { try { Thread.sleep(millisecond); } catch (InterruptedException e) { e.printStackTrace(); } }} |
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public class WriterWorker extends Thread { private static final Random random = new Random(System.currentTimeMillis()); private final SharedData data; private final String filter; private int index = 0; public WriterWorker(SharedData data, String filter) { this.data = data; this.filter = filter; } @Override public void run() { try { while (true) { char c = nextChar(); data.write(c); Thread.sleep(random.nextInt(1000)); } } catch (InterruptedException e) { e.printStackTrace(); } } private char nextChar() { char c = filter.charAt(index); index++; if (index >= filter.length()) index = 0; return c; }} |
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/** * * ReadWriteLock */public class ReadWriteLockClient { public static void main(String[] args) { final SharedData sharedData = new SharedData(10); new ReaderWorker(sharedData).start(); new ReaderWorker(sharedData).start(); new ReaderWorker(sharedData).start(); new ReaderWorker(sharedData).start(); new ReaderWorker(sharedData).start(); new WriterWorker(sharedData,"123456").start(); new WriterWorker(sharedData,"abcdef").start(); }} |
結果：
Thread-0 reads **********
Thread-1 reads **********
Thread-2 reads **********
Thread-3 reads **********
Thread-1 reads aaaaaaaaaa
Thread-3 reads aaaaaaaaaa
Thread-0 reads aaaaaaaaaa
Thread-2 reads aaaaaaaaaa
Thread-1 reads aaaaaaaaaa
Thread-2 reads aaaaaaaaaa
Thread-0 reads aaaaaaaaaa
Thread-3 reads aaaaaaaaaa
Thread-1 reads aaaaaaaaaa
Thread-3 reads aaaaaaaaaa
Thread-0 reads aaaaaaaaaa
Thread-2 reads aaaaaaaaaa
Thread-2 reads aaaaaaaaaa
Thread-0 reads aaaaaaaaaa
Thread-1 reads aaaaaaaaaa
Thread-3 reads aaaaaaaaaa
Thread-2 reads aaaaaaaaaa
Thread-0 reads aaaaaaaaaa
Thread-1 reads aaaaaaaaaa
Thread-3 reads aaaaaaaaaa
Thread-0 reads bbbbbbbbbb
Thread-1 reads bbbbbbbbbb
Thread-2 reads bbbbbbbbbb
Thread-3 reads bbbbbbbbbb
Thread-0 reads bbbbbbbbbb
Thread-1 reads bbbbbbbbbb
Thread-3 reads bbbbbbbbbb
Thread-2 reads bbbbbbbbbb
Thread-0 reads bbbbbbbbbb
Thread-1 reads bbbbbbbbbb
Thread-2 reads bbbbbbbbbb
Thread-3 reads bbbbbbbbbb
Thread-0 reads bbbbbbbbbb
Thread-1 reads bbbbbbbbbb
Thread-3 reads bbbbbbbbbb
Thread-2 reads bbbbbbbbbb
Thread-1 reads 3333333333
Thread-2 reads 3333333333
Thread-3 reads 3333333333
...... 省略
到此這篇關于Java多線程之讀寫鎖分離設計模式的文章就介紹到這了,更多相關Java多線程 讀寫鎖分離內容請搜索服務器之家以前的文章或繼續瀏覽下面的相關文章希望大家以后多多支持服務器之家！
原文鏈接：https://juejin.cn/post/7021759134072569887
