A computer system is provided that utilizes a buffer construct to manage memory access operations to a region of memory. The buffer construct may correspond to a data item or structure that represents a region of memory. Each task may control the buffer construct exclusively of other tasks, so that the region of memory that is represented by the buffer construct is only available to the controlling task. Another task that requires access to the region of memory must wait until the controlling task makes the buffer construct available. The controlling task makes the buffer construct available only when DMA or other memory access operations that are in progress become complete. In this way, the buffer construct acts as a token that synchronizes each of the concurrent tasks execution and ensures mutually exclusive access to the common region of memory.