The
xdc.runtime.knl package contains modules that provide typical
OS services. These xdc.runtime.knl modules require proxies to be
bound to an OS specific delegate. This specifies the interface to
be implemented by the OS specific delegate for
xdc.runtime.knl.GateThread module.
The implementation of IGateThreadSupport should try to implement a gate
that supports priority inversion.
const IGateThreadSupport.Q_BLOCKING |
 |
Blocking quality
const Int Q_BLOCKING = 1;
DETAILS
Gates with this "quality" may cause the calling thread to block;
i.e., suspend execution until another thread leaves the gate.
const IGateThreadSupport.Q_PREEMPTING |
 |
Preempting quality
const Int Q_PREEMPTING = 2;
DETAILS
Gates with this "quality" allow other threads to preempt the thread
that has already entered the gate.
metaonly config IGateThreadSupport.common$ // module-wide |
 |
Common module configuration parameters
DETAILS
All modules have this configuration parameter. Its name contains the '$'
character to ensure it does not conflict with configuration parameters
declared by the module. This allows new configuration parameters to be
added in the future without any chance of breaking existing modules.
IGateThreadSupport.query() // module-wide |
 |
Runtime test for a particular gate quality
ARGUMENTS
qual
constant describing a quality
RETURNS
Returns TRUE if the gate has the given quality,
and FALSE otherwise, which includes the case when the gate does not
recognize the constant describing the quality.
metaonly IGateThreadSupport.queryMeta() // module-wide |
 |
Configuration time test for a particular gate quality
metaonly Bool queryMeta(Int qual);
ARGUMENTS
qual
constant describing a quality
RETURNS
Returns TRUE if the gate has the given quality,
and FALSE otherwise, which includes the case when the gate does not
recognize the constant describing the quality.
Static Instance Creation |
 |
create();
// Create an instance-object
IGateThreadSupport.enter() // instance |
 |
Enter this gate
DETAILS
Each gate provider can implement mutual exclusion using different
algorithms; e.g., disabling all scheduling, disabling the scheduling
of all threads below a specified "priority level", suspending the caller
when the gate has been entered by another thread and re-enabling it when
the the other thread leaves the gate. However, in all cases, after this
method returns that caller has exclusive access to the data protected by
this gate.
A thread may reenter a gate without blocking or failing.
RETURNS
Returns a "key" that is used to
leave this gate; this value
is used to restore thread preemption to the state that existed just
prior to entering this gate.
IGateThreadSupport.leave() // instance |
 |
Leave this gate
ARGUMENTS
key
the value returned by a matching call to enter
DETAILS
This method is only called by threads that have previously entered this
gate via
enter. After this method returns, the caller must
not access the data structure protected by this gate (unless the caller
has entered the gate more than once and other calls to
leave remain
to balance the number of previous calls to
enter).