Hi all,
besides the thing with the zero period. shouldn't there be a call to
pthread_wait_np() in the thread code routine "fun"? i am new to
rt-linux and i only checked the examples coming with it and there i
found in the parallel port example (which is very similar to this one)
the stated call.
am i right that in this case the task never waits for the next period?
bye
alexander
Friday, May 05, 2000, 12:46:55 AM, you wrote:
yfc> On Thu, May 04, 2000 at 02:34:44PM -0400, Elliott Wolin wrote:
>> Hi,
>>
>> I must be missing something fundamental. I don't know why the program below
>> doesn't generate a single rectangular pulse on the parallel port with a width of
>> 50 microsec. (rtlinux 2.2.13, PIII 450).
>>
>> Rather than the 2nd thread running 50 microsec after the 1st, it runs
>> immediately after the 1st, giving 10 microsec pulses.
>>
>> How do you delay the startup of a thread?
yfc> You gave them 0 period and RTL scheduler picked a semi-safe 10microseconds
yfc> Try making the period 50000 -- see below.
>>
>>
>> Sincerely,
>> Elliott Wolin
>>
>>
>> ===================================================================================
>>
>>
>> /* Produce a single rectangular pulse on parallel port */
>>
>> #include <asm/io.h>
>> #include <rtl.h>
>> #include <pthread.h>
>>
>> #define LPT_PORT 0x378
>>
>> pthread_t t1,t2;
>>
>>
>> void *fun(void *arg) {
>> outb((int)arg, LPT_PORT);
pthread_wait_np(); // ??
>> return(0);
>> }
>>
>>
>> int init_module(void) {
>> pthread_create (&t1, NULL, fun, (void*)~0x0); /* rising edge */
>> pthread_create (&t2, NULL, fun, (void*) 0x0); /* falling edge */
>>
>> /* pulse width is 50 microsec */
>> pthread_make_periodic_np (t1, gethrtime(), 0); /* rising edge */
yfc> 50000
>> pthread_make_periodic_np (t2, gethrtime()+50000, 0); /* falling edge */
yfc> 50000
>>
>> return(0);
>> }
>>
>>
>> void cleanup_module(void) {
>> pthread_delete_np (t1);
>> pthread_delete_np (t2);
>> }
yfc> Content-Description: Card for Elliott Wolin
CU
Alexander mailto:[EMAIL PROTECTED]
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