OS_IPC_DIRECT_READ_WRITE definition

The OS_IPC_DIRECT_READ_WRITE flag may be used in conjunction with OS_IPC_WAIT_IF_EMPTY and OS_IPC_WAIT_IF_FULL flags. This flag enables the direct read-write mode. When a task is waiting for data transfer completion (e.g. reading from empty queue), the direct read-write mode ensures, that the data will be sent directly from one task to another, without storing it in the object buffer. This flag may be specified during IPC object creation, in Mode parameter of osCreateStream, osCreateQueue or osCreateMailbox functions.

SpaceShadow documentation