Notifies a kernel thread of the occurrence of one or more events.
#include <sys/types.h> #include <sys/errno.h> #include <sys/sleep.h> void et_post ( events, tid) unsigned long events; tid_t tid;
| Item | Description |
|---|---|
| events | Identifies the masks of events to be posted. |
| tid | Specifies the thread identifier of the kernel thread to be notified. |
The et_post kernel service is used to notify a kernel thread that one or more events occurred.
The et_post service provides the fastest method of interprocess communication, although only the event numbers are passed.
The event numbers must be known by the cooperating components, either through programming convention or the passing of initialization parameters.
The et_post service is performed automatically when sending a request to a device queue serviced by a kernel thread or when sending an acknowledgment.
The EVENT_KERNEL mask defines the event bits reserved for use by the kernel. For example, a bit with a value of 1 indicates an event bit reserved for the kernel. Kernel extensions should assign their events starting with the most significant bits and working down. If threads using the et_post service are also using the device queue management kernel extensions, care must be taken not to use the event bits registered for device queue management.
The et_wait service does not sleep but returns immediately if a specified event has already been posted by the et_post service.
The et_post kernel service can be called from either the process or interrupt environment.
The et_post service has no return values.