Comtrol eCos - Manual (Page 100)

Kernel Real-time Characterization
Trywait [1] semaphore
This test measures the cyg_semaphore_trywait() call. The semaphore has a value of 1 when the call is
made. The purpose of this test is to measure the cost of seeing if a semaphore can be “taken” without blocking.
In this case, the answer would be yes.
Peek semaphore
This test measures the cyg_semaphore_peek() call. The purpose of this test is to measure the cost of ob-
taining the current semaphore count value.
Destroy semaphore
This test measures the cyg_semaphore_destroy() call. The purpose of this test is to measure the cost of
deleting a semaphore from the system.
Post/Wait semaphore
In this round-trip test, two threads are passing control back and forth by using a semaphore. The time from
when one thread calls
cyg_semaphore_post() until the other thread completes its cyg_semaphore_wait()
is measured. Note that each iteration of this test will involve a thread switch.
Counters
Create counter
This test measures the cyg_counter_create() call. A number of separate counters are created. The purpose
of this test is to measure the cost of creating a new counter and introducing it to the system.
Get counter value
This test measures the cyg_counter_current_value() call. The current value of each counter is obtained.
Set counter value
This test measures the cyg_counter_set_value() call. Each counter is set to a new value.
Tick counter
This test measures the cyg_counter_tick() call. Each counter is “ticked” once.
Delete counter
This test measures the cyg_counter_delete() call. Each counter is deleted from the system. The purpose
of this test is to measure the cost of deleting a counter object.
Alarms
Create alarm
This test measures the cyg_alarm_create() call. A number of separate alarms are created, all attached to the
same counter object. The purpose of this test is to measure the cost of creating a new counter and introducing
it to the system.
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