-Xss1m / -XX:ThreadStackSize=512k

news2024/9/21 14:40:01

`-Xss / -XX:ThreadStackSize`
指定线程最大栈空间

jdk1.4里默认的栈大小是`256KB`
jdk1.5里默认的栈大小为`1M`


配置JVM启动参数：-Xmx20m -Xms20m -`Xss1m` -XX:+PrintCommandLineFlags
-XX:ConcGCThreads=3 -XX:G1ConcRefinementThreads=13 -XX:GCDrainStackTargetSize=64 -XX:InitialHeapSize=20971520 -XX:MarkStackSize=4194304 -XX:MaxHeapSize=20971520 -XX:MinHeapSize=20971520 -XX:+PrintCommandLineFlags -XX:ReservedCodeCacheSize=251658240 -XX:+SegmentedCodeCache `-XX:ThreadStackSize=1024` -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseG1GC -XX:-UseLargePagesIndividualAllocation

配置JVM启动参数： -Xmx20m -Xms20m `-XX:ThreadStackSize=512K` -XX:+PrintCommandLineFlags
-XX:ConcGCThreads=3 -XX:G1ConcRefinementThreads=13 -XX:GCDrainStackTargetSize=64 -XX:InitialHeapSize=20971520 -XX:MarkStackSize=4194304 -XX:MaxHeapSize=20971520 -XX:MinHeapSize=20971520 -XX:+PrintCommandLineFlags -XX:ReservedCodeCacheSize=251658240 -XX:+SegmentedCodeCache `-XX:ThreadStackSize=524288` -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseG1GC -XX:-UseLargePagesIndividualAllocation

这个参数直接会影响创建线程数量，值越小创建线程数越多；（估算jvm进程的最大线程数）
这个参数直接决定了函数可调用的最大深度，值越大调用最大深度越大；(参照如下代码)

public class Jvm4_Xss {
	private static int count;

	private static void recursion() {
		count++;
		recursion();
	}

	public static void main(String[] args) {
		try {
			recursion();
		} catch (Throwable e) {
			System.out.println("调用最大深度：" + count);
			e.printStackTrace();
		}
	}
}
------------------------------------------------------------------
//JVM 启动参数
-Xmx20m -Xms20m -Xss1m

//运行结果：
调用最大深度：43909
java.lang.StackOverflowError
	at jvm.Jvm4_Xss.recursion(Jvm4_Xss.java:8)
	at jvm.Jvm4_Xss.recursion(Jvm4_Xss.java:8)
------------------------------------------------------------------
//JVM 启动参数
-Xmx20m -Xms20m -Xss2m

//运行结果：
调用最大深度：103720
java.lang.StackOverflowError
	at jvm.Jvm4_Xss.recursion(Jvm4_Xss.java:8)
	at jvm.Jvm4_Xss.recursion(Jvm4_Xss.java:8)