????????????????????????????妫�??????CPU??????????????????????????????????????????妫�?????CPU???????谢????????写?????????????娴�??妫�????????????????????械???????flush????????JVM??????????????????JVM?????????????????????????????os???械??????????????????e????????????????????

????JVM???????????????????6?????????娲�???????????????????Heap??????6???????????锟�?

JVM????????????

???????娼�????????????????????????????????????

????PC Register??PC???????

????PC???????????小??????????????????????????????械????????泻???????????????????????????????????????????????????????????????魏畏???????????????????卸???????????????????????????????????????????????????

????????Java??????????????????????谢???????????????????????????魏??????????????????????????????????????????械???睢�????????????????????????????位????校??????????????????????????????????????????泻????????????????????????????????????“??????”????妾�

??????????????????native?????PC??????胁??娲�?魏??????

?????? JVM?

????JVM????????械?????????????????????JVM???JVM??写???????????芯????????????????java?卸???????????????boolean??char??byte??short??int??long??float??double?????????????????Stack Frame?????????????????JVM????????????????????????Java?谢????????????????????????????????????????????Sun JDK???????JVM????????????????????????????????????

????????JVM????????械?????????????????????效????????????????????些??????????????

??????JVM???????????????StackOverflowError???????Sun JDK?锌??????-Xss?????????小?????????鈥�???
new Thread(new Runnable(){
           public void run() {
              loop(0);
           }       
           private void loop (int i){
              if(i!=1000){
                  i++;
loop (i);
              }
              else{
                  return;
              }
           }
          }).start();

??????JVM?????????-Xss1K?????泻????????????????

????Exception in thread "Thread-0"java.lang.StackOverflowError

?????? ???Heap??

????Heap??????????????????JVM?????娲�????????????????????????????Java?????????new????????????娑�??????Heap?械??????????????GC???谢????Heap??32位???????????2G????64位??????????????????????小???-Xms??-Xmx???????-Xms?JVM?????????小Heap??妫�????????????1/64??小??1G??-Xmx?JVM????????Heap??妫�????????????1/4??????????????小??40%???JVM??????Heap???小??-Xmx??????小???????-XX??MinHeapFreeRatio=???????????????????????????70%???JVM??Heap???小??-Xms??????小???????????-XX??MaxHeapFreeRatio=??????????????????????????????????????????Heap Size???小?????????-Xms??-Xmx?????????????????????????????????????????????????jvm?卸?????????????谩????????????懈????????????????????JVM?????????薪???????????

???????????????????娉�??????????小????????OutOfMemory??????????