scheduler

The scheduler sorts and schedules disk I/O, manages bit pump buffers, performs admission control, and schedules output driver activity.

bit pump

The bit pump is responsible for allocating internal buffering and efficiently transferring data between the disk and the output drivers using the internal buffers. It is responsible for fine-grain scheduling and rate control of the output driver. The bit pump is dependent on the particular output driver used, whether it be for Fast Ethernet or ATM.

disk driver

The output driver is responsible for low-level output device management and encapsulating outgoing data according to the rules of the output medium, and for efficiently transferring data from the internal buffers to the output medium.

See Chapter 7 for a description of the format of output data.

output driver

The disk driver is responsible for efficiently transferring disk data to the fixed internal buffers. It consists of a SCSI disk driver and a modified SCSI host adapter driver.

The MFS components listed above are illustrated in FIGURE 1-3.

Media File System

Layout Manager

Scheduler

Bit Pump

Buffers

Disk

Driver

Output

Driver

FIGURE 1-3Media File System Components

1.3.2Media Stream Manager

The MSM controls the video streams stored in the MFS. The MSM implements a set of procedures that interact with the MFS to allow you to stop, start, pause, and resume video bit streams. A central notion of the MSM is the playlist, from which titles can be played on a time-synchronized basis. Each playlist is associated with a player, which can be passed among multiple clients.

Chapter 1 Introduction 1-7

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Sun Microsystems 2.1 manual Media Stream Manager, 3Media File System Components