+#define FIFO_SEGMENT_MIN_FIFO_SIZE 4096
+#define FIFO_SEGMENT_MAX_FIFO_SIZE (8<<20) /* 8mb max fifo size */
+#define FIFO_SEGMENT_ALLOC_CHUNK_SIZE 32 /* Allocation quantum */
+
+#define FIFO_SEGMENT_F_IS_PRIVATE 1 << 0 /* Private segment */
+#define FIFO_SEGMENT_F_IS_MAIN_HEAP 1 << 1 /* Segment is main heap */
+#define FIFO_SEGMENT_F_IS_PREALLOCATED 1 << 2 /* Segment is preallocated */
+