jnr.ffi on ppc64le ubuntu 14.10 and IBM JDK fails PointerTest.

[ralphbellofatto]

Under the IBM JDK we get the following error:

------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running jnr.ffi.PointerTest
RB: PointerTest::pointerArraySetElement
ptr_set_array_element (nil), 0
Unhandled exception
Type=Segmentation error vmState=0x00040000
J9Generic_Signal_Number=00000004 Signal_Number=0000000b Error_Value=00000000 Signal_Code=00000001

I added instrumentation to isolate the problem:

diff --git a/libtest/PointerTest.c b/libtest/PointerTest.c
index ce642bb..c291c6e 100644
--- a/libtest/PointerTest.c
+++ b/libtest/PointerTest.c
@@ -54,12 +54,15 @@ TEST(pointer);
 void*
 ptr_return_array_element(void **ptrArray, int arrayIndex)
 {
+    printf("ptr_return_array_element %p, %d\n", ptrArray, arrayIndex);  fflush(stdout);
     return ptrArray[arrayIndex];
 }

 void
 ptr_set_array_element(void **ptrArray, int arrayIndex, void *value)
 {
+       printf("ptr_set_array_element %p, %d\n", ptrArray, arrayIndex);  fflush(stdout);
+       printf("ptr_set_array_element *%p, %d\n", *ptrArray, arrayIndex);  fflush(stdout);
     ptrArray[arrayIndex] = value;
 }

diff --git a/src/test/java/jnr/ffi/PointerTest.java b/src/test/java/jnr/ffi/PointerTest.java
index ac6afbf..faa2a18 100644
--- a/src/test/java/jnr/ffi/PointerTest.java
+++ b/src/test/java/jnr/ffi/PointerTest.java
@@ -381,6 +381,7 @@ public class PointerTest {

     @Test
     public void pointerArraySetElement() {
+        System.out.print("RB: PointerTest::pointerArraySetElement\n");
         Pointer[] ary = new Pointer[10];
         Pointer p1 = runtime.getMemoryManager().newPointer(0xdeadbeef & runtime.addressMask());
         Pointer p2 = runtime.getMemoryManager().newPointer(0xfee1dead & runtime.addressMask());
@@ -388,6 +389,7 @@ public class PointerTest {
         assertEquals(p1, ary[0]);
         testlib.ptr_set_array_element(ary, 9, p2);
         assertEquals(p2, ary[9]);
+        System.out.print("RB: PointerTest::pointerArraySetElement-\n");
     }

     @Test public void mixObjectsAndPrimitives() {

The telemetry above shows that we enter the "ptr_set_array_element" function but our pointer is nill.

This is similar to [https://github.com//issues/32,](#32, but not quite the same,

We get through the pointerSetArrayElement test, but fail on the pointerGetArrayElement test for that one.

[lbianc]

Fix for this issue - #40

[headius]

Fixed by #40.