Semaphore

Data Structures
struct	OSSemaphore

Macros
#define	OS_SEMAPHORE_TAG   0x73506852u

Typedefs
typedef struct OSSemaphore	OSSemaphore

Functions
void	OSInitSemaphore (OSSemaphore *semaphore, int32_t count)
void	OSInitSemaphoreEx (OSSemaphore *semaphore, int32_t count, const char *name)
int32_t	OSGetSemaphoreCount (OSSemaphore *semaphore)
int32_t	OSSignalSemaphore (OSSemaphore *semaphore)
int32_t	OSWaitSemaphore (OSSemaphore *semaphore)
int32_t	OSTryWaitSemaphore (OSSemaphore *semaphore)

Detailed Description

Similar to Windows Semaphore Objects.

Macro Definition Documentation

#define OS_SEMAPHORE_TAG   0x73506852u

Definition at line 19 of file semaphore.h.

Typedef Documentation

typedef struct OSSemaphore OSSemaphore

Definition at line 17 of file semaphore.h.

Function Documentation

void OSInitSemaphore	(	OSSemaphore *	semaphore,
		int32_t	count
	)

Initialise semaphore object with count.

void OSInitSemaphoreEx	(	OSSemaphore *	semaphore,
		int32_t	count,
		const char *	name
	)

Initialise semaphore object with count and name.

int32_t OSGetSemaphoreCount

(

OSSemaphore *

semaphore

)

Get the current semaphore count.

int32_t OSSignalSemaphore

(

OSSemaphore *

semaphore

)

Increase the semaphore value.

If any threads are waiting for semaphore, they are woken.

int32_t OSWaitSemaphore

(

OSSemaphore *

semaphore

)

Decrease the semaphore value.

If the value is less than or equal to zero the current thread will be put to sleep until the count is above zero and it can decrement it safely.

int32_t OSTryWaitSemaphore

(

OSSemaphore *

semaphore

)

Try to decrease the semaphore value.

If the value is greater than zero then it will be decremented, else the function will return immediately with a value <= 0 indicating a failure.

Returns

Returns previous semaphore count, before the decrement in this function. If the value is >0 then it means the call was succesful.