ADC Home > Reference Library > Reference > Darwin > Kernel Framework Reference

---

IOBlockStorageDriver.h

Overview

This header contains the definition of the IOBlockStorageDriver class, which serves as the common base class for generic block storage drivers.

For more information on the IOBlockStorageDriver class, see Writing Drivers for Mass Storage Devices.

---

Classes

IOBlockStorageDriver

The common base class for generic block storage drivers.

---

Enumerations

---

IOMediaState

---

The different states that getMediaState() can report.

enum { 
    kIOMediaStateOffline = 0, 
    kIOMediaStateOnline = 1, 
    kIOMediaStateBusy = 2 
};  

Constants

kIOMediaStateOffline

Media is not available.

kIOMediaStateOnline

Media is available and ready for operations.

kIOMediaStateBusy

Media is available, but not ready for operations.

#defines

---

kIOBlockStorageDriverClass

---

The name of the IOBlockStorageDriver class.

#define kIOBlockStorageDriverClass "IOBlockStorageDriver" 

---

kIOBlockStorageDriverStatisticsBytesReadKey

---

Describes the number of bytes read since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsBytesReadKey "Bytes (Read)" 

Discussion

This property describes the number of bytes read since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsBytesWrittenKey

---

Describes the number of bytes written since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsBytesWrittenKey "Bytes (Write)" 

Discussion

This property describes the number of bytes written since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsKey

---

Holds a table of numeric values describing the driver's operating statistics.

#define kIOBlockStorageDriverStatisticsKey "Statistics" 

Discussion

This property holds a table of numeric values describing the driver's operating statistics. The table is an OSDictionary, where each entry describes one given statistic.

---

kIOBlockStorageDriverStatisticsLatentReadTimeKey

---

Describes the number of nanoseconds of latency during reads since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsLatentReadTimeKey "Latency Time (Read)" 

Discussion

This property describes the number of nanoseconds of latency during reads since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsLatentWriteTimeKey

---

Describes the number of nanoseconds of latency during writes since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsLatentWriteTimeKey "Latency Time (Write)" 

Discussion

This property describes the number of nanoseconds of latency during writes since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsReadErrorsKey

---

Describes the number of read errors encountered since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsReadErrorsKey "Errors (Read)" 

Discussion

This property describes the number of read errors encountered since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsReadRetriesKey

---

Describes the number of read retries required since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsReadRetriesKey "Retries (Read)" 

Discussion

This property describes the number of read retries required since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsReadsKey

---

Describes the number of read operations processed since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsReadsKey "Operations (Read)" 

Discussion

This property describes the number of read operations processed since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsTotalReadTimeKey

---

Describes the number of nanoseconds spent performing reads since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsTotalReadTimeKey "Total Time (Read)" 

Discussion

This property describes the number of nanoseconds spent performing reads since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsTotalWriteTimeKey

---

Describes the number of nanoseconds spent performing writes since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsTotalWriteTimeKey "Total Time (Write)" 

Discussion

This property describes the number of nanoseconds spent performing writes since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsWriteErrorsKey

---

Describes the number of write errors encountered since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsWriteErrorsKey "Errors (Write)" 

Discussion

This property describes the number of write errors encountered since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsWriteRetriesKey

---

Describes the number of write retries required since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsWriteRetriesKey "Retries (Write)" 

Discussion

This property describes the number of write retries required since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

---

kIOBlockStorageDriverStatisticsWritesKey

---

Describes the number of write operations processed since the block storage driver was instantiated.

#define kIOBlockStorageDriverStatisticsWritesKey "Operations (Write)" 

Discussion

This property describes the number of write operations processed since the block storage driver was instantiated. It is one of the statistic entries listed under the top-level kIOBlockStorageDriverStatisticsKey property table. It has an OSNumber value.

Did this document help you? Yes: Tell us what works for you. It’s good, but: Report typos, inaccuracies, and so forth. It wasn’t helpful: Tell us what would have helped.

 

Last Updated: 2008-12-19