SCO OpenServer

mdi_trylock(D3mdi)

mdi_trylock, mdi_tryunlock, mdi_tryunlock_init -- MDI trylock functions

Synopsis (Not in SVR5 version)

   #include <sys/mdi.h>
   
   int mdi_trylock(trylock_t * trylock);
   

   void mdi_tryunlock(trylock_t * trylock);
   

   void mdi_trylock_init(trylock_t * trylock);

Description

The mdi_trylock( ) functions handle the trylocks used to code MP-aware MDI drivers.

mdi_trylock( ) attempts to acquire the specified trylock.

mdi_tryunlock( ) Frees the specified trylock. If the trylock is not held, mdi_tryunlock( ) panics the system by calling cmn_err(D3) with the CE_PANIC flag set.

mdi_trylock_init( ) initializes the specified trylock. This function is usually called from the driver's open( ) routine to ensure that any locks held from a previous open are cleared to the initial, unlocked state.

Context and synchronization

Blockable context.

Hardware applicability

All

Version applicability

mdi: 1

Differences between versions

This function is not supported in MDI on SVR5 systems.

Return values

mdi_trylock( ) returns non-zero if successful, 0 if lock already held.