kal.md

# KAL
## **Overview**
Defines the kernel adaptation layer \(KAL\), which provides compatible interfaces across different types of OpenHarmony devices.
**Since:**
1.0
**Version:**
1.0
## **Summary**
## Files

File Name	Description
kal.h	Defines the kernel adaptation layer (KAL), which provides compatible interfaces across different types of OpenHarmony devices.

## Data Structures

Data Structure Name	Description
ThreadInfo	Describes a thread.
MemInfo	Describes a memory pool.

## Macros

Macro Name and Value	Description
KAL_TASK_NAME_LEN 32	Indicates the maximum length of a thread name.

## Enumerations

Enumeration Name	Description
KalTimerType { KAL_TIMER_ONCE = 0, KAL_TIMER_PERIODIC = 1 }	Enumerates timer types.
KalErrCode { KAL_OK = 0, KAL_ERR_PARA = 1, KAL_ERR_INNER = 2, KAL_ERR_TIMER_STATE = 0x100 }	Enumerates return values of the KAL function.

## Functions

Function Name	Description
KalThreadGetInfo (unsigned int threadId, ThreadInfo *info)	unsigned int Obtains thread information.
KalDelayUs (unsigned int us)	void Delays a thread.
KalTimerCreate (KalTimerProc func, KalTimerType type, void *arg, unsigned int ticks)	KalTimerId Creates a timer.
KalTimerStart (KalTimerId timerId)	KalErrCode Starts a timer.
KalTimerChange (KalTimerId timerId, unsigned int ticks)	KalErrCode Changes the duration of a timer.
KalTimerStop (KalTimerId timerId)	KalErrCode Stops a timer.
KalTimerDelete (KalTimerId timerId)	KalErrCode Deletes a timer.
KalTimerIsRunning (KalTimerId timerId)	unsigned int Checks whether a timer is running.
KalTickToMs (unsigned int ticks)	unsigned int Converts system ticks into milliseconds.
KalMsToTick (unsigned int millisec)	unsigned int Converts milliseconds into system ticks.
KalGetMemInfo (MemInfo *pmemInfo)	KalErrCode Obtains memory information.

## **Details**
## **Enumeration Type Documentation**
## KalErrCode
```
enum [KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36)
```
**Description:**
Enumerates return values of the KAL function.

Enumerator	Description
KAL_OK	A successful execution
KAL_ERR_PARA	Incorrect parameter
KAL_ERR_INNER	Internal execution error
KAL_ERR_TIMER_STATE	Timer status error

## KalTimerType
```
enum [KalTimerType](kal.md#gacde4b0c553c297f66311b87c4bbbb27d)
```
**Description:**
Enumerates timer types.

Enumerator	Description
KAL_TIMER_ONCE	One-shot timer
KAL_TIMER_PERIODIC	Repetitive timer

## **Function Documentation**
## KalDelayUs\(\)
```
void KalDelayUs (unsigned int us)
```
**Description:**
Delays a thread.
The delay unit is microsecond. The actual delay precision can reach only the tick level.
**Parameters:**

Name	Description
us	Indicates the number of microseconds to delay. The actual delay precision is one tick.

## KalGetMemInfo\(\)
```
[KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36) KalGetMemInfo ([MemInfo](meminfo.md) * pmemInfo)
```
**Description:**
Obtains memory information.
**Parameters:**

Name	Description
pmemInfo	Indicates the pointer to the memory information.

**Returns:**
Returns an enumerated value defined by [KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36), where [KAL\_OK](kal.md#gga595e811b5dcad5dc834be507d6839c36a249642877a22187565c646fcb4c43228) indicates a success.
## KalMsToTick\(\)
```
unsigned int KalMsToTick (unsigned int millisec)
```
**Description:**
Converts milliseconds into system ticks.
**Parameters:**

Name	Description
millisec	Indicates the milliseconds to convert.

**Returns:**
Returns the system ticks generated.
## KalThreadGetInfo\(\)
```
unsigned int KalThreadGetInfo (unsigned int threadId, [ThreadInfo](threadinfo.md) * info )
```
**Description:**
Obtains thread information.
**Parameters:**

Name	Description
threadId	Indicates the thread ID.
info	Indicates the pointer to the buffer for storing the obtained thread information.

**Returns:**
Returns **0** if the thread information is obtained; returns a negative value otherwise.
## KalTickToMs\(\)
```
unsigned int KalTickToMs (unsigned int ticks)
```
**Description:**
Converts system ticks into milliseconds.
**Parameters:**

Name	Description
ticks	Indicates the number of ticks to convert.

**Returns:**
Returns the milliseconds generated.
## KalTimerChange\(\)
```
[KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36) KalTimerChange (KalTimerId timerId, unsigned int ticks )
```
**Description:**
Changes the duration of a timer.
The timer duration can be changed only before the timer is started.
**Parameters:**

Name	Description
timerId	Indicates the ID of the timer whose duration is to change, which is the value returned by KalTimerCreate.
ticks	Indicates the new duration of the timer.

**Returns:**
Returns an enumerated value defined by [KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36), where [KAL\_OK](kal.md#gga595e811b5dcad5dc834be507d6839c36a249642877a22187565c646fcb4c43228) indicates a success.
## KalTimerCreate\(\)
```
KalTimerId KalTimerCreate (KalTimerProc func, [KalTimerType](kal.md#gacde4b0c553c297f66311b87c4bbbb27d) type, void * arg, unsigned int ticks )
```
**Description:**
Creates a timer.
**Parameters:**

Name	Description
func	Indicates the entry to timer callback. The callback is triggered when the timer expires.
type	Indicates the timer type.
arg	Indicates the pointer to the argument used in timer callback.
ticks	Indicates the duration of the timer to create.

**Returns:**
Returns the timer ID; returns **NULL** in the case of an error.
## KalTimerDelete\(\)
```
[KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36) KalTimerDelete (KalTimerId timerId)
```
**Description:**
Deletes a timer.
**Parameters:**

Name	Description
timerId	Indicates the ID of the timer to delete, which is the value returned by KalTimerCreate.

**Returns:**
Returns an enumerated value defined by [KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36), where [KAL\_OK](kal.md#gga595e811b5dcad5dc834be507d6839c36a249642877a22187565c646fcb4c43228) indicates a success.
## KalTimerIsRunning\(\)
```
unsigned int KalTimerIsRunning (KalTimerId timerId)
```
**Description:**
Checks whether a timer is running.
**Parameters:**

Name	Description
timerId	Indicates the ID of the timer to check, which is the value returned by KalTimerCreate.

**Returns:**
Returns **1** if the timer is running; returns **0** if the timer is not running or the input parameter is incorrect.
## KalTimerStart\(\)
```
[KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36) KalTimerStart (KalTimerId timerId)
```
**Description:**
Starts a timer.
**Parameters:**

Name	Description
timerId	Indicates the ID of the timer to start, which is the value returned by KalTimerCreate.

**Returns:**
Returns an enumerated value defined by [KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36), where [KAL\_OK](kal.md#gga595e811b5dcad5dc834be507d6839c36a249642877a22187565c646fcb4c43228) indicates a success.
## KalTimerStop\(\)
```
[KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36) KalTimerStop (KalTimerId timerId)
```
**Description:**
Stops a timer.
**Parameters:**

Name	Description
timerId	Indicates the ID of the timer to stop, which is the value returned by KalTimerCreate.

**Returns:**
Returns an enumerated value defined by [KalErrCode](kal.md#ga595e811b5dcad5dc834be507d6839c36), where [KAL\_OK](kal.md#gga595e811b5dcad5dc834be507d6839c36a249642877a22187565c646fcb4c43228) indicates a success.
## **Variable Documentation**
## bottomOfStack
```
unsigned int ThreadInfo::bottomOfStack
```
**Description:**
Thread stack bottom
## currUsed
```
unsigned int ThreadInfo::currUsed
```
**Description:**
Current stack space usage
## eventMask
```
unsigned int ThreadInfo::eventMask
```
**Description:**
Thread event mask
## eventStru
```
unsigned int ThreadInfo::eventStru[3]
```
**Description:**
Thread event
## free
```
unsigned int MemInfo::free
```
**Description:**
Available space of the memory pool, in bytes
## freeLmp
```
unsigned int MemInfo::freeLmp
```
**Description:**
Available space of the small memory pool, in bytes
## freeNodeNum
```
unsigned int MemInfo::freeNodeNum
```
**Description:**
Number of available nodes in the memory pool
## id
```
unsigned int ThreadInfo::id
```
**Description:**
Thread ID
## mallocFailCount
```
unsigned int MemInfo::mallocFailCount
```
**Description:**
Number of memory allocation failures
## maxFreeNodeSize
```
unsigned int MemInfo::maxFreeNodeSize
```
**Description:**
Size of the largest available node in the memory pool, in bytes
## mepc
```
unsigned int ThreadInfo::mepc
```
**Description:**
Current thread MEPC
## mstatus
```
unsigned int ThreadInfo::mstatus
```
**Description:**
Current thread status
## name
```
char ThreadInfo::name[[KAL_TASK_NAME_LEN](kal.md#ga5c36b53bd6e8cbdbcd79f702eda94fdc)]
```
**Description:**
Thread name
## overflowFlag
```
unsigned int ThreadInfo::overflowFlag
```
**Description:**
Thread stack overflow flag
## peakUsed
```
unsigned int ThreadInfo::peakUsed
```
**Description:**
Peak stack space usage
## peekSize
```
unsigned int MemInfo::peekSize
```
**Description:**
Peak memory usage of the memory pool
## priority
```
unsigned short ThreadInfo::priority
```
**Description:**
Thread priority
## ra
```
unsigned int ThreadInfo::ra
```
**Description:**
Current thread RA
## sp
```
unsigned int ThreadInfo::sp
```
**Description:**
Thread stack pointer
## stackSize
```
unsigned int ThreadInfo::stackSize
```
**Description:**
Thread stack size
## status
```
unsigned short ThreadInfo::status
```
**Description:**
Thread status
## taskMutex
```
void* ThreadInfo::taskMutex
```
**Description:**
Thread mutex
## taskSem
```
void* ThreadInfo::taskSem
```
**Description:**
Thread semaphore
## topOfStack
```
unsigned int ThreadInfo::topOfStack
```
**Description:**
Thread stack top
## total
```
unsigned int MemInfo::total
```
**Description:**
Total space of the memory pool, in bytes
## totalLmp
```
unsigned int MemInfo::totalLmp
```
**Description:**
Total space of the small memory pool, in bytes
## tp
```
unsigned int ThreadInfo::tp
```
**Description:**
Current thread TP
## used
```
unsigned int MemInfo::used
```
**Description:**
Used space of the memory pool, in bytes
## usedLmp
```
unsigned int MemInfo::usedLmp
```
**Description:**
Used space of the small memory pool, in bytes
## usedNodeNum
```
unsigned int MemInfo::usedNodeNum
```
**Description:**
Number of used nodes in the memory pool