test/hotspot/jtreg/compiler/arraycopy/TestTightlyCoupledAllocationAssert.java

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/*
 * @test
 * @bug 8237945
 * @summary Test that triggers the too strong assertion "just_allocated_object(alloc_ctl) == ptr" in LibraryCallKit::tightly_coupled_allocation()
 *
 * @run main/othervm -Xbatch compiler.arraycopy.TestTightlyCoupledAllocationAssert
 */

package compiler.arraycopy;

public class TestTightlyCoupledAllocationAssert {

    static A a;
    static byte[] bArr = new byte[8];

    public static void main(String[] strArr) {
        for (int i = 0; i < 10000; i++ ) {
            test(i % 20);
        }
    }

    public static void test(int i) {
        byte [] bArrLocal = new byte[8]; // (1)
        if (i < 16) {
            a = new A(); // (2)
            return;
        }
        // The assertion "just_allocated_object(alloc_ctl) == ptr" in LibraryCallKit::tightly_coupled_allocation() fails during parsing here since
        // the most recent allocation is (2) and not (1). The earlier bailout checks about the memory state (involving the variable "rawmem") pass
        // because the if branch returns and the memory state from (2) is not merged with the memory state from (1) for the array copy.
        System.arraycopy(bArr, 0, bArrLocal, 0, 8);
    }
}

class A { }