escape-analysis

The code: func MaxSmallSize() { a := make([]int64, 8191) b := make([]int64, 8192) _ = a _ = b } Then run go build -gcflags='-m' . 2>&1 to check memory allocation details. The result: ./mem.go:10: can inline MaxSmallSize ./mem.go:12: make([]int64, 8192) escapes to heap ./mem.go:11: MaxSmallSize make([]int64, 8191) does not escape My question is why a is small object and b is large object? make 64KB will escape to heap and less will allocate in stack. Does the _MaxSmallSize = 32 << 10 is the reason? go env GOARCH="amd64" GOBIN="" GOEXE="" GOHOSTARCH="amd64" GOHOSTOS="linux" GOOS="linux" GOPATH="

I am doing some tests with escape analysis in Java 7 in order to better understand what objects are eligible to stack allocation. Here is the code I wrote to test stack allocation: import java.util.ArrayList; import java.util.Iterator; public class EscapeAnalysis { private static final long TIME_TO_TEST = 10L * 1000L; // 10s static class Timestamp { private long millis; public Timestamp(long millis) { this.millis = millis; } public long getTime() { return millis; } public void setTime(long time) { millis = time; } } public static void main(String[] args) { long r = 0; System.out.println("test1

As far as I know the JVM uses escape analysis for some performance optimisations like lock coarsening and lock elision. I'm interested if there is a possibility for the JVM to decide that any particular object can be allocated on stack using escape analysis. Some resources make me think that I am right. Is there JVMs that actually do it? benmmurphy I don't think it does escape analysis for stack allocation. example: public class EscapeAnalysis { private static class Foo { private int x; private static int counter; public Foo() { x = (++counter); } } public static void main(String[] args) {