sanei_access.h File Reference

Interface file for the sanei_access functions. More...

Go to the source code of this file.

Functions
void	sanei_access_init (const char *backend)
	Initialize sanei_access. More...
SANE_Status	sanei_access_lock (const char *devicename, SANE_Word timeout)
	Set a lock. More...
SANE_Status	sanei_access_unlock (const char *devicename)
	Unlock a previously set lock. More...

Detailed Description

Interface file for the sanei_access functions.

The idea is to provide some simple locking/unlocking mechanism, which can be used to protect device access from more than one frontend simultaneously.

Function Documentation

sanei_access_init()

void sanei_access_init

(

const char *

backend

)

Initialize sanei_access.

This function must be called before any other sanei_access function.

Parameters

backend

- backend name, who uses this lib

sanei_access_lock()

SANE_Status sanei_access_lock	(	const char *	devicename,
		SANE_Word	timeout
	)

Set a lock.

The function tries to open/create exclusively a lock file in $PATH_SANE_LOCK_DIR. If the file could be created successfully, the function fills in the process ID. The complete filename of the lockfile is created as follows: $PATH_SANE_LOCK_DIR/LCK..<devicename> If the lock could not be set, the function tries it until the timeout period has been elapsed.

Parameters

devicename	- unique part of the lockfile name
timeout	- time in seconds to try to set a lock

Returns

• SANE_STATUS_GOOD - if the lock has been successfully set
• SANE_STATUS_ACCESS_DENIED - the lock could not set

sanei_access_unlock()

SANE_Status sanei_access_unlock

(

const char *

devicename

)

Unlock a previously set lock.

The function tries to unlock a previously created lock. The lockfile will be closed and removed.

Parameters

devicename

- part of the lockfile name, use for sanei_acess_lock()

Returns

• SANE_STATUS_GOOD - currently the one and only return value