openbcm

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lock.h (1335B)

      1 /*
      2  * 
      3  * This license is set out in https://raw.githubusercontent.com/Broadcom-Network-Switching-Software/OpenBCM/master/Legal/LICENSE file.
      4  * 
      5  * Copyright 2007-2019 Broadcom Inc. All rights reserved.
      6  *
      7  * This file contains locking definitions internal to the BCM library.
      8  */
      9 
     10 #ifndef _BCM_INT_LOCK_H
     11 #define _BCM_INT_LOCK_H
     12 
     13 #include <bcm/types.h>
     14 
     15 #include <sal/core/sync.h>
     16 
     17 /*
     18  * BCM Locking
     19  *
     20  * (1) BCM calls that need to perform multiple operations on a resource
     21  *     atomically, such as read/modify/write a table entry, should lock
     22  *     the resource.
     23  *
     24  * (2) Module routines that call outside their module must be very
     25  *     careful to avoid deadlocks.  Deadlocks result from two or more
     26  *     threads trying to take the same locks but in a different order.
     27  *
     28  * (3) BCM_LOCK should be taken during all major configuration changes
     29  *     to prevent corruption that could result if two tasks (like a CLI
     30  *     and a SNMP server) try to alter configuration simultaneously.
     31  *
     32  * (4) BCM_LOCK may also be useful in avoiding deadlocks if multiple
     33  *     resources are needed.
     34  */
     35 
     36 extern sal_mutex_t _bcm_lock[BCM_MAX_NUM_UNITS];
     37 
     38 #define BCM_LOCK(unit) \
     39         sal_mutex_take(_bcm_lock[unit], sal_mutex_FOREVER)
     40 
     41 #define BCM_UNLOCK(unit) \
     42         sal_mutex_give(_bcm_lock[unit])
     43 
     44 #endif	/* !_BCM_INT_LOCK_H */