关于Java的共享内存总是抛出java.lang.OutOfMemoryError: Map failed

飞火流云 2015-02-02 10:22:38

	RandomAccessFile raf;

		try {

	  	    raf = new RandomAccessFile(IncBspConstants.MEMORY_SHARE_FILE+"_part_"+peer.getPeerIndex(), "rw");

		    FileChannel fc = raf.getChannel();

		    mbb = fc.map(MapMode.READ_WRITE, 0, bufferSize);

		    readData() ;

		} catch (FileNotFoundException e) {

			e.printStackTrace();

		} catch (IOException e) {

			e.printStackTrace();

		} 

	private void readData(){

		try{

		    int flag = mbb.get() ; //取读写数据的标志

		    if(mbb==null)   LOG.info(" mbb is NULL! " + "flag :" + flag) ;

		    if(flag!=1)

		    	mbb.clear() ;

		    else   //=1说明已经写入则读取

		    {

		    	        dataLength = mbb.getInt() ;

			    	buf = new byte[dataLength] ;

				mbb = (MappedByteBuffer) mbb.get(buf);

		    }

		}  catch (Exception e) {

			e.printStackTrace();

		}

	}

bufferSize是200M
此外这个JVM的启动参数设为: -Xmx2304m，这个没问题，没有超过JVM的堆内存限制。

但是一运行到 mbb = fc.map(MapMode.READ_WRITE, 0, bufferSize) 时就报如下错误:

java.io.IOException: Map failed
at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:849)
at org.apache.hama.bsp.incBsp.IncGraphProcessor.<init>(IncGraphProcessor.java:45)
at org.apache.hama.graph.GraphJobRunner.setupFields(GraphJobRunner.java:454)
at org.apache.hama.graph.GraphJobRunner.setup(GraphJobRunner.java:123)
at org.apache.hama.bsp.BSPTask.runBSP(BSPTask.java:170)
at org.apache.hama.bsp.BSPTask.run(BSPTask.java:144)
at org.apache.hama.bsp.GroomServer$BSPPeerChild.main(GroomServer.java:1243)
Caused by: java.lang.OutOfMemoryError: Map failed
at sun.nio.ch.FileChannelImpl.map0(Native Method)
at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:846)
... 6 more

是buffersize设的太大么？这里我就是需要进行大量数据的共享啊，所以设的很大，可是一初始化就报错了。。。。

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