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A real-time operating system, developed uniquely by Hitachi Ltd., suitable for streaming. HiTactix provides the following basic functions listed for realizing high-performance, high-quality streaming.

(1) High-speed I/O mechanism

Network I/O and disk I/O are provided as zero-copy operations. Moreover, applications can carry out multiple asynchronous I/O requests as a job block with one system call, so I/O completion-notification overhead is kept down.

(2) Isochronous scheduler

The isochronous scheduler uses a table in advance to reserve CPU assignment time of a thread that requires periodic drive. Exclusive control and interrupt processing of the kernel interior are managed in such a manner that the relevant thread can occupy the CPU for the reserved time.

(3) Cyclic disk scheduling

The cyclic disk scheduling ensures that execution time of disk I/O of high-priority streaming (which must guarantee disk I/O rate) is reserved in advance and that execution lag due to disk I/O of other (low-priority) streaming does not become large. By applying the cyclic disk scheduling, even in the case that the disk is under a heavy load, dropping the disk I/O rate of low-priority streaming enables disk I/O rate of high-priority streaming to be guaranteed and streaming to continue.

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