dtimeout(D3)dtimeout(D3)NAMEdtimeout - execute a function on a specified processor after a specified
length of time
SYNOPSIS
#include <sys/types.h>
#include <sys/ddi.h>
toid_t dtimeout(void (*fn)(), void *arg, long ticks, pl_t pl,
processorid_t processor, arg2, arg3, arg4);
Arguments
fn Function to execute on the specified processor when the time
increment expires.
arg, arg2, arg3, arg4
Argument to the function.
ticks Number of clock ticks to wait before the function is called.
pl The interrupt priority level at which the function will be
called.
processor Processor on which the function must execute.
DESCRIPTIONdtimeout causes the function specified by fn to be called after the time
interval specified by ticks, on the processor specified by processor, at
the interrupt priority level specified by pl. arg will be passed as the
only argument to function fn. The dtimeout call returns immediately
without waiting for the specified function to execute.
Return Values
If the function specified by fn is successfully scheduled, dtimeout
returns a non-zero identifier that can be passed to untimeout to cancel
the request. If the function could not be scheduled on the specified
processor, dtimeout returns a value of 0.
USAGE
This directed timeout capability provides a form of dynamic processor
binding for driver code.
Drivers should be careful to cancel any pending dtimeout functions that
access data structures before these structures are de-initialized or
deallocated.
fn Argument
The function specified by fn must not lower the priority level below pl.
After the time interval has expired, fn only runs if the processor is at
base level. Otherwise, fn is deferred until some time in the near
future.
Page 1
dtimeout(D3)dtimeout(D3)
If dtimeout is called holding a lock that is contended for by fn, the
caller must hold the lock at a processor level greater than the base
processor level.
ticks Argument
The length of time before the function is called is not guaranteed to be
exactly equal to the requested time, but will be at least ticks-1 clock
ticks in length.
A ticks argument of 0 has the same effect as a ticks argument of 1. Both
will result in an approximate wait of between 0 and 1 tick (possibly
longer).
pl Argument
pl must specify a priority level greater than or equal to pltimeout;
thus, plbase cannot be used. See LOCK_ALLOC(D3) for a list of values for
pl. Your driver should treat pl as an "opaque" and should not try to
compare or do any operation
Level
Base or Interrupt.
Synchronization Constraints
Driver-defined basic locks, read/write locks, and sleep locks may be held
across calls to this function.
REFERENCESitimeout(D3), LOCK_ALLOC(D3), untimeout(D3)
Page 2
