java.util.concurrent鍖呭簲鐢

newSingleThreadExecutor锛堝崟涓悗鍙扮嚎绋嬶級
鍒涘缓涓€涓娇鐢ㄥ崟涓?worker 绾跨▼鐨?Executor锛屼互鏃犵晫闃熷垪鏂瑰紡鏉ヨ繍琛岃绾跨▼銆傦紙娉ㄦ剰锛屽鏋滃洜涓哄湪鍏抽棴鍓嶇殑鎵ц鏈熼棿鍑虹幇澶辫触鑰岀粓姝簡姝ゅ崟涓嚎绋嬶紝閭ｄ箞濡傛灉闇€瑕侊紝涓€涓柊绾跨▼灏嗕唬鏇垮畠鎵ц鍚庣画鐨勪换鍔★級銆傚彲淇濊瘉椤哄簭鍦版墽琛屽悇涓换鍔★紝骞朵笖鍦ㄤ换鎰忕粰瀹氱殑鏃堕棿涓嶄細鏈夊涓嚎绋嬫槸娲诲姩鐨勩€備笌鍏朵粬绛夋晥鐨?newFixedThreadPool(1) 涓嶅悓锛屽彲淇濊瘉鏃犻渶閲嶆柊閰嶇疆姝ゆ柟娉曟墍杩斿洖鐨勬墽琛岀▼搴忓嵆鍙娇鐢ㄥ叾浠栫殑绾跨▼銆?/p>

杩欎簺鏂规硶杩斿洖鐨勯兘鏄疎xecutorService瀵硅薄锛岃繖涓璞″彲浠ョ悊瑙ｄ负灏辨槸涓€涓嚎绋嬫睜銆?br>杩欎釜绾跨▼姹犵殑鍔熻兘杩樻槸姣旇緝瀹屽杽鐨勩€傚彲浠ユ彁浜や换鍔ubmit()鍙互缁撴潫绾跨▼姹爏hutdown()銆?/p>

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class MyExecutor extends Thread {
private int index;
public MyExecutor(int i){
聽聽 this.index=i;
}
public void run(){
聽聽 try{
聽聽聽 System.out.println("["+this.index+"] start....");
聽聽聽 Thread.sleep((int)(Math.random()*1000));
聽聽聽 System.out.println("["+this.index+"] end.");
聽聽 }
聽聽 catch(Exception e){
聽聽聽 e.printStackTrace();
聽聽 }
}

public static void main(String args[]){
聽聽 ExecutorService service=Executors.newFixedThreadPool(4);
聽聽 for(int i=0;i<10;i++){
聽聽聽 service.execute(new MyExecutor(i));
聽聽聽 //service.submit(new MyExecutor(i));
聽聽 }
聽聽 System.out.println("submit finish");
聽聽 service.shutdown();
}
}

铏界劧鎵撳嵃浜嗕竴浜涗俊鎭紝浣嗘槸鐪嬬殑涓嶆槸闈炲父娓呮櫚锛岃繖涓嚎绋嬫睜鏄浣曞伐浣滅殑锛屾垜浠潵灏嗕紤鐪犵殑鏃堕棿璋冮暱10鍊嶃€?br>Thread.sleep((int)(Math.random()*10000));

鍐嶆潵鐪嬶紝浼氭竻妤氱湅鍒板彧鑳芥墽琛?涓嚎绋嬨€傚綋鎵ц瀹屼竴涓嚎绋嬪悗锛屾墠浼氬張鎵ц涓€涓柊鐨勭嚎绋嬶紝涔熷氨鏄锛屾垜浠皢鎵€鏈夌殑绾跨▼鎻愪氦鍚庯紝绾跨▼姹犱細绛夊緟鎵ц瀹屾渶鍚巗hutdown銆傛垜浠篃浼氬彂鐜帮紝鎻愪氦鐨勭嚎绋嬭鏀惧埌涓€涓€滄棤鐣岄槦鍒楅噷鈥濄€傝繖鏄竴涓湁搴忛槦鍒楋紙BlockingQueue锛岃繖涓笅闈細璇村埌锛夈€?/p>

鍙﹀瀹冧娇鐢ㄤ簡Executors鐨勯潤鎬佸嚱鏁扮敓鎴愪竴涓浐瀹氱殑绾跨▼姹狅紝椤惧悕鎬濅箟锛岀嚎绋嬫睜鐨勭嚎绋嬫槸涓嶄細閲婃斁鐨勶紝鍗充娇瀹冩槸Idle銆?br>杩欏氨浼氫骇鐢熸€ц兘闂锛屾瘮濡傚鏋滅嚎绋嬫睜鐨勫ぇ灏忎负200锛屽綋鍏ㄩ儴浣跨敤瀹屾瘯鍚庯紝鎵€鏈夌殑绾跨▼浼氱户缁暀鍦ㄦ睜涓紝鐩稿簲鐨勫唴瀛樺拰绾跨▼鍒囨崲锛坵hile(true)+sleep寰幆锛夐兘浼氬鍔犮€?br>濡傛灉瑕侀伩鍏嶈繖涓棶棰橈紝灏卞繀椤荤洿鎺ヤ娇鐢═hreadPoolExecutor()鏉ユ瀯閫犮€傚彲浠ュ儚閫氱敤鐨勭嚎绋嬫睜涓€鏍疯缃€滄渶澶х嚎绋嬫暟鈥濄€佲€滄渶灏忕嚎绋嬫暟鈥濆拰鈥滅┖闂茬嚎绋媖eepAlive鐨勬椂闂粹€濄€?/p>

杩欎釜灏辨槸绾跨▼姹犲熀鏈敤娉曘€?br>
Semaphore
涓€涓鏁颁俊鍙烽噺銆備粠姒傚康涓婅锛屼俊鍙烽噺缁存姢浜嗕竴涓鍙泦鍚堛€傚鏈夊繀瑕侊紝鍦ㄨ鍙彲鐢ㄥ墠浼氶樆濉炴瘡涓€涓?acquire()锛岀劧鍚庡啀鑾峰彇璇ヨ鍙€傛瘡涓?release() 娣诲姞涓€涓鍙紝浠庤€屽彲鑳介噴鏀句竴涓鍦ㄩ樆濉炵殑鑾峰彇鑰呫€備絾鏄紝涓嶄娇鐢ㄥ疄闄呯殑璁稿彲瀵硅薄锛孲emaphore 鍙鍙敤璁稿彲鐨勫彿鐮佽繘琛岃鏁帮紝骞堕噰鍙栫浉搴旂殑琛屽姩銆?/p>

Semaphore 閫氬父鐢ㄤ簬闄愬埗鍙互璁块棶鏌愪簺璧勬簮锛堢墿鐞嗘垨閫昏緫鐨勶級鐨勭嚎绋嬫暟鐩€備緥濡傦紝涓嬮潰鐨勭被浣跨敤淇″彿閲忔帶鍒跺鍐呭姹犵殑璁块棶锛?/p>

杩欓噷鏄竴涓疄闄呯殑鎯呭喌锛屽ぇ瀹舵帓闃熶笂鍘曟墍锛屽帟鎵€鍙湁涓や釜浣嶇疆锛屾潵浜?0涓汉闇€瑕佹帓闃熴€?/p>

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;

public class MySemaphore extends Thread {
Semaphore position;
private int id;
public MySemaphore(int i,Semaphore s){
聽聽 this.id=i;
聽聽 this.position=s;
}

public void run(){
聽聽 try{
聽聽聽 if(position.availablePermits()>0){
聽聽聽聽 System.out.println("椤惧["+this.id+"]杩涘叆鍘曟墍锛屾湁绌轰綅");
聽聽聽 }
聽聽聽 else{
聽聽聽聽 System.out.println("椤惧["+this.id+"]杩涘叆鍘曟墍锛屾病绌轰綅锛屾帓闃?);
聽聽聽 }
聽聽聽 position.acquire();
聽聽聽 System.out.println("椤惧["+this.id+"]鑾峰緱鍧戜綅");
聽聽聽 Thread.sleep((int)(Math.random()*1000));
聽聽聽 System.out.println("椤惧["+this.id+"]浣跨敤瀹屾瘯");
聽聽聽 position.release();
聽聽 }
聽聽 catch(Exception e){
聽聽聽 e.printStackTrace();
聽聽 }
}
public static void main(String args[]){
聽聽 ExecutorService list=Executors.newCachedThreadPool();
聽聽 Semaphore position=new Semaphore(2);
聽聽 for(int i=0;i<10;i++){
聽聽聽 list.submit(new MySemaphore(i+1,position));
聽聽 }
聽聽 list.shutdown();
聽聽 position.acquireUninterruptibly(2);
聽聽 System.out.println("浣跨敤瀹屾瘯锛岄渶瑕佹竻鎵簡");
聽聽 position.release(2);
}
}

聽

ReentrantLock
涓€涓彲閲嶅叆鐨勪簰鏂ラ攣瀹?Lock锛屽畠鍏锋湁涓庝娇鐢?synchronized 鏂规硶鍜岃鍙ユ墍璁块棶鐨勯殣寮忕洃瑙嗗櫒閿佸畾鐩稿悓鐨勪竴浜涘熀鏈涓哄拰璇箟锛屼絾鍔熻兘鏇村己澶с€?/p>

ReentrantLock 灏嗙敱鏈€杩戞垚鍔熻幏寰楅攣瀹氾紝骞朵笖杩樻病鏈夐噴鏀捐閿佸畾鐨勭嚎绋嬫墍鎷ユ湁銆傚綋閿佸畾娌℃湁琚彟涓€涓嚎绋嬫墍鎷ユ湁鏃讹紝璋冪敤 lock 鐨勭嚎绋嬪皢鎴愬姛鑾峰彇璇ラ攣瀹氬苟杩斿洖銆傚鏋滃綋鍓嶇嚎绋嬪凡缁忔嫢鏈夎閿佸畾锛屾鏂规硶灏嗙珛鍗宠繑鍥炪€傚彲浠ヤ娇鐢?isHeldByCurrentThread() 鍜?getHoldCount() 鏂规硶鏉ユ鏌ユ鎯呭喌鏄惁鍙戠敓銆?/p>

姝ょ被鐨勬瀯閫犳柟娉曟帴鍙椾竴涓彲閫夌殑鍏钩鍙傛暟銆?br>褰撹缃负 true鏃讹紝鍦ㄥ涓嚎绋嬬殑浜夌敤涓嬶紝杩欎簺閿佸畾鍊惧悜浜庡皢璁块棶鏉冩巿浜堢瓑寰呮椂闂存渶闀跨殑绾跨▼銆傚惁鍒欐閿佸畾灏嗘棤娉曚繚璇佷换浣曠壒瀹氳闂『搴忋€?br>涓庨噰鐢ㄩ粯璁よ缃紙浣跨敤涓嶅叕骞抽攣瀹氾級鐩告瘮锛屼娇鐢ㄥ叕骞抽攣瀹氱殑绋嬪簭鍦ㄨ澶氱嚎绋嬭闂椂琛ㄧ幇涓哄緢浣庣殑鎬讳綋鍚炲悙閲忥紙鍗抽€熷害寰堟參锛屽父甯告瀬鍏舵參锛夛紝浣嗘槸鍦ㄨ幏寰楅攣瀹氬拰淇濊瘉閿佸畾鍒嗛厤鐨勫潎琛℃€ф椂宸紓杈冨皬銆備笉杩囪娉ㄦ剰鐨勬槸锛屽叕骞抽攣瀹氫笉鑳戒繚璇佺嚎绋嬭皟搴︾殑鍏钩鎬с€傚洜姝わ紝浣跨敤鍏钩閿佸畾鐨勪紬澶氱嚎绋嬩腑鐨勪竴鍛樺彲鑳借幏寰楀鍊嶇殑鎴愬姛鏈轰細锛岃繖绉嶆儏鍐靛彂鐢熷湪鍏朵粬娲诲姩绾跨▼娌℃湁琚鐞嗗苟涓旂洰鍓嶅苟鏈寔鏈夐攣瀹氭椂銆傝繕瑕佹敞鎰忕殑鏄紝鏈畾鏃剁殑 tryLock 鏂规硶骞舵病鏈変娇鐢ㄥ叕骞宠缃€傚洜涓哄嵆浣垮叾浠栫嚎绋嬫鍦ㄧ瓑寰咃紝鍙璇ラ攣瀹氭槸鍙敤鐨勶紝姝ゆ柟娉曞氨鍙互鑾峰緱鎴愬姛銆?/p>

寤鸿鎬绘槸 绔嬪嵆瀹炶返锛屼娇鐢?try 鍧楁潵璋冪敤 lock锛屽湪涔嬪墠/涔嬪悗鐨勬瀯閫犱腑锛屾渶鍏稿瀷鐨勪唬鐮佸涓嬶細
class X {
聽聽 private final ReentrantLock lock = new ReentrantLock();
聽聽 // ...

聽聽 public void m() {
聽聽聽聽 lock.lock(); // block until condition holds
聽聽聽聽 try {
聽聽聽聽聽聽 // ... method body
聽聽聽聽 } finally {
聽聽聽聽聽聽 lock.unlock()
聽聽聽聽 }
聽聽 }
}

鎴戠殑渚嬪瓙锛?br>import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.locks.ReentrantLock;

public class MyReentrantLock extends Thread{
TestReentrantLock lock;
private int id;
public MyReentrantLock(int i,TestReentrantLock test){
聽聽 this.id=i;
聽聽 this.lock=test;
}

public void run(){
聽聽 lock.print(id);
}

public static void main(String args[]){
聽聽 ExecutorService service=Executors.newCachedThreadPool();
聽聽 TestReentrantLock lock=new TestReentrantLock();
聽聽 for(int i=0;i<10;i++){
聽聽聽 service.submit(new MyReentrantLock(i,lock));
聽聽 }
聽聽 service.shutdown();
}
}
class TestReentrantLock{
private ReentrantLock lock=new ReentrantLock();
public void print(int str){
聽聽 try{
聽聽聽 lock.lock();
聽聽聽 System.out.println(str+"鑾峰緱");
聽聽聽 Thread.sleep((int)(Math.random()*1000));
聽聽 }
聽聽 catch(Exception e){
聽聽聽 e.printStackTrace();
聽聽 }
聽聽 finally{
聽聽聽 System.out.println(str+"閲婃斁");
聽聽聽 lock.unlock();
聽聽 }
}
}