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blocking for n events
- From: Heiko Panther <heiko dot panther at web dot de>
- To: ecos-discuss at sources dot redhat dot com
- Date: Thu, 08 Dec 2005 10:32:51 -0800
- Subject: [ECOS] blocking for n events
Hi-
I have the following interesting synchronization problem.
I am triggering a random number of transaction. Only after the last one I will
know how many I actually triggered. Then I need to wait for all of them to complete.
In my imagination, I have a semaphore that I can decrease by n, and then wake up
when it was posted n times and so is back to 0.
However, eCos semaphores don't work that way, and maybe they seldomly do. So, do
you have a suggestion what to do instead? As I said, I don't have the number of
transcations before, so I can't just set a variable and decrease it from the
callback, and then trigger an event flag.
What I could do is to wait for the semaphore in a for() loop, but I want to
avoid the overhead of task switches.
Heiko
do
{
transaction=get_another_transaction();
trigger_transaction(transaction);
transaction_count++;
}
while ( ! transaction->isLastTransaction);
cyg_semaphore_wait_multiple(&my_sema, transaction_count);
...
void TransactionCallback()
{
cyg_semaphore_post(&my_sema);
};
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