OS_SEM Class Reference

Semaphores are used to control access to shared resource critical section, or to communicate between tasks. More...

#include <nbrtos.h>

Inherits OS_TASK_DLY_OBJ.

Public Member Functions
	OS_SEM (int32_t cnt=0)
	Create and initialize a semaphore. More...
uint8_t	Init (int32_t cnt=0)
	This function is used to initialize a semaphore structure. Note: This must be done before using a semaphore. More...
uint8_t	Post ()
	This function increases the value of the semaphore by one. Note: If any higher priority tasks were waiting on the semaphore - it releases them. More...
uint8_t	Pend (uint32_t timeoutTicks=WAIT_FOREVER)
	Wait timeout ticks for the value of the semaphore to be non zero. Note: A timeout value of 0 (zero) waits forever. More...
uint8_t	PendNoWait ()
	Pend on a semaphore with no waiting period. More...

Detailed Description

Semaphores are used to control access to shared resource critical section, or to communicate between tasks.

Constructor & Destructor Documentation

OS_SEM()

OS_SEM::OS_SEM ( int32_t  cnt = 0 )

inline

Create and initialize a semaphore.

Parameters

cnt	Starting count

Member Function Documentation

Init()

uint8_t OS_SEM::Init

(

int32_t

cnt = 0

)

This function is used to initialize a semaphore structure. Note: This must be done before using a semaphore.

Parameters

cnt	Starting count

Return values

OS_NO_ERR	If successful
OS_SEM_ERR	If it fails

See also

NBRTOS Error Codes

Pend()

uint8_t OS_SEM::Pend

(

uint32_t

timeoutTicks = WAIT_FOREVER

)

Wait timeout ticks for the value of the semaphore to be non zero. Note: A timeout value of 0 (zero) waits forever.

Parameters

timeoutTicks

Number of system time ticks to wait. If no value is specified, it will wait forever.

Return values

OS_NO_ERR	If successful
OS_TIMEOUT	If it timed out

See also

NBRTOS Error Codes

PendNoWait()

PendNoWait()

uint8_t OS_SEM::PendNoWait

(

)

Pend on a semaphore with no waiting period.

Identical to the Pend() function, but it does not wait.

Return values

OS_NO_ERR	If successful
OS_TIMEOUT	If it failed

See also

NBRTOS Error Codes

Pend(uint32_t timeoutTicks)

Post()

uint8_t OS_SEM::Post

(

)

This function increases the value of the semaphore by one. Note: If any higher priority tasks were waiting on the semaphore - it releases them.

Return values

OS_NO_ERR

If successful

See also

NBRTOS Error Codes

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The documentation for this class was generated from the following files:

• nbrtos.h
• nbrtos.cpp