Method getFieldList

src/com/sun/jna/Structure.java:1021–1059

Look up all fields in this class and superclasses. @return ordered list of public java.lang.reflect.Field available on this Structure class.

()

     * this {@link Structure} class.
     */
    protected List<Field> getFieldList() {
        Class<?> clazz = getClass();
        // Try to read the value under the read lock
        cacheStructureLock.readLock().lock();
        try {
            List<Field> fields = fieldList.get(clazz);
            if (fields != null) {
                return fields; // Return the cached result if found
            }
        } finally {
            cacheStructureLock.readLock().unlock();
        }

        // If not found, compute the value under the write lock
        cacheStructureLock.writeLock().lock();
        try {
            // Double-check if another thread has computed the value before we do
            return fieldList.computeIfAbsent(clazz, (c) -> {
                List<Field> flist = new ArrayList<>();
                List<Field> classFields = new ArrayList<>();
                for (Class<?> cls = clazz;
                     !cls.equals(Structure.class);
                     cls = cls.getSuperclass()) {
                    for (Field field : cls.getDeclaredFields()) {
                        int modifiers = field.getModifiers();
                        if (Modifier.isStatic(modifiers) || !Modifier.isPublic(modifiers)) {
                            continue;
                        }
                        classFields.add(field);
                    }
                    flist.addAll(0, classFields);
                    classFields.clear();
                }
                return flist;
            });
        } finally {
            cacheStructureLock.writeLock().unlock();
        }
    }

    /** Cache field order per-class.
     * @return (cached) ordered list of fields