[ale] Help with C project

[Christopher Hagler]

It is being called from the scheduler thread
On Jan 23, 2016 5:24 PM, "Pete Hardie" <pete.hardie at gmail.com> wrote:

> Is process_stop() being called from the running thread, or from the
> scheduler thread?
>
> On Sat, Jan 23, 2016 at 2:41 PM, Christopher Hagler <
> haglerchristopher at gmail.com> wrote:
>
>> Thank you for the reply. When I create a process, I give each thread
>> their own condition variable because I can control which threads are run. I
>> have a function called process_create that in turn calls pthread_cond_init.
>> From my understanding a call to pthread_cond_signal does not guarantee
>> scheduling order. Threads are not scheduled in the order they call
>> pthread_cond_wait. This is why I give each thread their own condition
>> variable. The scheduler will call process_start that will call
>> pthread_cond_signal on the process struct passed in as a parameter. All of
>> that works correctly. However a call to process_stop which calls
>> pthread_cond_wait does not seem to work. From what I have read, it all
>> seems correct, but the threads continue to run.
>> On Jan 23, 2016 12:40 PM, "Pete Hardie" <pete.hardie at gmail.com> wrote:
>>
>>> It's been a while since I use pthreads directly, but the modus operandi
>>> of condition variables is that you declare one before the
>>> threads that use it are started, and the threads that you want to wait
>>> will call wait() to pause until the another thread signals a change,
>>> and then you would check the condition variable value to see if it is
>>> the desired value to proceed.
>>>
>>> On Sat, Jan 23, 2016 at 11:52 AM, Christopher Hagler <
>>> haglerchristopher at gmail.com> wrote:
>>>
>>>> I am working on a home automation project written in C. It allows a
>>>> user to automate daily task with open source hardware and software.
>>>> However, since I am lacking experience with pthreads, I have run into a
>>>> couple of issues that I cant seem to resolve. The intentions of the code
>>>> where the issues reside are:
>>>>
>>>> The project allows drivers to be written as shared objects that, which
>>>> in turn, will control a remote hardware device or devices with all
>>>> communication happening through shared memory. The Scheduler module will
>>>> take the shared object, and schedule it to run via process queues. Once the
>>>> process, a struct containing the shared object and an abstraction for a
>>>> pthread, runs for its time slot, the scheduler will stop the process and
>>>> place it in another process queue. The whole idea was to simulate an
>>>> operating system scheduler because potentially there could be a few hundred
>>>> threads. This is where the first issue resides. I am having trouble putting
>>>> the process to sleep. I have done some research on pthreads and supposedly
>>>> this can be accomplished via pthread condition variables. This is the
>>>> solution I have attempted, and apparently I have not implemented it
>>>> correctly. It will start the process which will run, but when I try to put
>>>> it to sleep, it keeps running.
>>>>
>>>> The second issue is when ever you run the program, it fails to link the
>>>> shared object sometimes. However, if you have to quickly run the program
>>>> back-to-back, it will start and run fine. I am not sure why this is
>>>> happening. It could possibly be linked to my setup, but I am not sure. I am
>>>> running Opensuse in Virtual Box.
>>>>
>>>> Any advice on these issues would be greatly appreciated. I also know
>>>> there are a couple of people who have been wanting to learn C, and you are
>>>> more than welcome to join the project if you want.
>>>>
>>>> The code base:
>>>> https://github.com/haglerchristopher/automation/tree/development
>>>>
>>>> Thanks for the help.
>>>>
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>>>>
>>>
>>>
>>> --
>>> Pete Hardie
>>> --------
>>> Better Living Through Bitmaps
>>>
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>>>
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>>
>
>
> --
> Pete Hardie
> --------
> Better Living Through Bitmaps
>
> _______________________________________________
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> Ale at ale.org
> http://mail.ale.org/mailman/listinfo/ale
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> http://mail.ale.org/mailman/listinfo
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>
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