Semaphore

Typedefs
typedef ix_sem_s	ix_sem_t
Enumerations
enum	ix_sem_e { IX_SEM_LOCAL = 0x01, IX_SEM_GLOBAL = 0x02, IX_SEM_FD = 0x03 }
Functions
ix_sem_t *	ix_sem_new (int id, ix_sem_e mode)
int	ix_sem_v (ix_sem_t *psem)
int	ix_sem_p (ix_sem_t *psem)
int	ix_sem_free (ix_sem_t *psem)

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Detailed Description

Interprocess locking.

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Typedef Documentation

typedef struct ix_sem_s ix_sem_t

semaphore class

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Enumeration Type Documentation

enum ix_sem_e

mode of semaphore

Enumerator:

IX_SEM_LOCAL	semaphore local
IX_SEM_FD	use descriptor of open file as id, i.e. file locking

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Function Documentation

int ix_sem_free

(

ix_sem_t *

psem

)

free memory and locks

Returns:

• 0: ok
• !0: error

ix_sem_t* ix_sem_new	(	int	id,
		ix_sem_e	mode
	)

Creates new semaphore with file-locking fcntl-call.

Parameters:

	id	unique id
	mode	global or local semaphore. IX_SEM_GLOBAL: lockfile is opened in ix_global_path()/sem (otherwise ix_path()/sem)

Returns:

• handle
• NULL: Error

int ix_sem_p

(

ix_sem_t *

psem

)

Enter semaphore: paseer = betreten, enter critical section

Returns:

• 0: ok
• !0: Error

int ix_sem_v

(

ix_sem_t *

psem

)

Leave semaphore: verlaat = verlassen, leave critical section

Returns:

• 0 ok
• !0 Error

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