/* Prevent garbage collection of an object */
jvmtiError
commonRef_pin(jlong id)
{
JNIEnv *env = getEnv();
jvmtiError error = JVMTI_ERROR_NONE;
RefNode *node;
if (id == NULL_OBJECT_ID) {
return JNI_FALSE;
}
debugMonitorEnter(refLock);
node = findNodeByID(env, id);
if (node == NULL) {
error = JVMTI_ERROR_INVALID_OBJECT;
} else {
jobject strongRef = strengthenNode(env, node);
if (strongRef == NULL) {
/*
* Referent has been collected, clean up now.
*/
error = JVMTI_ERROR_INVALID_OBJECT;
deleteNodeByID(env, id, ALL_REFS);
}
}
debugMonitorExit(refLock);
return error;
}
/*
* Given an object ID obtained from the debugger front end, return a
* strong, global reference to that object (or NULL if the object
* has been collected). The reference can then be used for JNI and
* JVMTI calls. Caller is resposible for deleting the returned reference.
*/
jobject
commonRef_idToRef(JNIEnv *env, jlong id)
{
jobject ref;
ref = NULL;
debugMonitorEnter(gdata->refLock); {
RefNode *node;
node = findNodeByID(env, id);
if (node != NULL) {
if (node->isStrong) {
saveGlobalRef(env, node->ref, &ref);
} else {
jobject lref;
lref = JNI_FUNC_PTR(env,NewLocalRef)(env, node->ref);
if ( lref == NULL ) {
/* Object was GC'd shortly after we found the node */
deleteNodeByID(env, node->seqNum, ALL_REFS);
} else {
saveGlobalRef(env, node->ref, &ref);
JNI_FUNC_PTR(env,DeleteLocalRef)(env, lref);
}
}
}
} debugMonitorExit(gdata->refLock);
return ref;
}
/*
* Given an object ID obtained from the debugger front end, return a
* strong, global reference to that object (or NULL if the object
* has been collected). The reference can then be used for JNI and
* JVMTI calls. Caller is resposible for deleting the returned reference.
*/
jobject
commonRef_idToRef(jlong id)
{
JNIEnv *env = getEnv();
jobject ref = NULL;
RefNode *node;
debugMonitorEnter(refLock);
node = findNodeByID(env, id);
if (node != NULL) {
saveGlobalRef(env, node->ref, &ref);
}
debugMonitorExit(refLock);
return ref;
}
/* Permit garbage collection of an object */
jvmtiError
commonRef_unpin(jlong id)
{
JNIEnv *env = getEnv();
jvmtiError error = JVMTI_ERROR_NONE;
RefNode *node;
debugMonitorEnter(refLock);
node = findNodeByID(env, id);
if (node != NULL) {
jweak weakRef = weakenNode(env, node);
if (weakRef == NULL) {
error = JVMTI_ERROR_OUT_OF_MEMORY;
}
}
debugMonitorExit(refLock);
return error;
}
