le_semaphore.h File Reference

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Typedefs

typedef struct le_sem_t * le_sem_Ref_t
 

Functions

le_sem_Ref_t le_sem_Create (const char *name, int32_t initialCount)
 
void le_sem_Delete (le_sem_Ref_t semaphorePtr)
 
le_sem_Ref_t le_sem_FindSemaphore (const char *name)
 
void le_sem_Wait (le_sem_Ref_t semaphorePtr)
 
le_result_t le_sem_TryWait (le_sem_Ref_t semaphorePtr)
 
le_result_t le_sem_WaitWithTimeOut (le_sem_Ref_t semaphorePtr, le_clk_Time_t timeToWait)
 
void le_sem_Post (le_sem_Ref_t semaphorePtr)
 
int le_sem_GetValue (le_sem_Ref_t semaphorePtr)
 

Detailed Description

Legato Semaphore API include file.

Typedef Documentation

◆ le_sem_Ref_t

typedef struct le_sem_t* le_sem_Ref_t

Reference to Semaphore structure.

Function Documentation

◆ le_sem_Create()

le_sem_Ref_t le_sem_Create ( const char *  name,
int32_t  initialCount 
)

Create a semaphore shared by threads within the same process.

Parameters
[in]nameName of the semaphore.
[in]initialCountInitial number of semaphore.
Note
Terminates the process on failure, no need to check the return value for errors.

◆ le_sem_Delete()

void le_sem_Delete ( le_sem_Ref_t  semaphorePtr)

Delete a semaphore.

Parameters
[in]semaphorePtrPointer to the semaphore.

◆ le_sem_FindSemaphore()

le_sem_Ref_t le_sem_FindSemaphore ( const char *  name)

Finds a specified semaphore's name.

Parameters
[in]nameName of the semaphore.
Returns
Reference to the semaphore, or NULL if the semaphore doesn't exist.

◆ le_sem_GetValue()

int le_sem_GetValue ( le_sem_Ref_t  semaphorePtr)

Get the value of a semaphore.

Returns
value of the semaphore
Parameters
[in]semaphorePtrPointer to the semaphore.

◆ le_sem_Post()

void le_sem_Post ( le_sem_Ref_t  semaphorePtr)

Post a semaphore.

Returns
Nothing.
Parameters
[in]semaphorePtrPointer to the semaphore.

◆ le_sem_TryWait()

le_result_t le_sem_TryWait ( le_sem_Ref_t  semaphorePtr)

Try to wait for a semaphore.

It's the same as le_sem_Wait, except if it can't be immediately performed, then returns an LE_WOULD_BLOCK instead of blocking it.

Returns
Upon successful completion, returns LE_OK (0), otherwise it returns LE_WOULD_BLOCK as the call would block if it was a blocking call.
Parameters
[in]semaphorePtrPointer to the semaphore.

◆ le_sem_Wait()

void le_sem_Wait ( le_sem_Ref_t  semaphorePtr)

Wait for a semaphore.

Returns
Nothing.
Parameters
[in]semaphorePtrPointer to the semaphore.

◆ le_sem_WaitWithTimeOut()

le_result_t le_sem_WaitWithTimeOut ( le_sem_Ref_t  semaphorePtr,
le_clk_Time_t  timeToWait 
)

Wait for a semaphore with a limit on how long to wait.

Returns
  • LE_OK The function succeed
  • LE_TIMEOUT timeToWait elapsed
Note
When LE_TIMEOUT occurs the semaphore is not decremented.
Parameters
[in]semaphorePtrPointer to the semaphore.
[in]timeToWaitTime to wait