| |
Would it be possible for you to send the entire source? I would like to see
how it interacts with the rest of the program.
Thanks for your help.
"kenneth johansen" <kennethj@stud.cs.uit.no> wrote in message
news:3CDAC372.34D72C5C@stud.cs.uit.no...
> a short example:
> #include <semaphore.h> // for semaphore opperations
>
>
> // global buffer, used to store incoming messages.
> // the buffer is checked by the application waiting for the message.
> struct inn_msg{
> char *msg;
> sem_t lock;
> };
>
> //create a semaphora struct
> struct inn_msg *message;
>
> // initiate the semaphora->lock to 0 (zero)
> sem_init(&message->lock,NULL,0);
>
>
> // process 1
> int process_1{){
> //whenever i copy something to message->msg i must update the
> message->msg = some memory _location;
> // update the semaphora
> sem_post(&message->lock);
> }
>
> //process 2
> int process_2(){
> //wait for something to happend
> ret = sem_wait(&message->lock);
> //do something with message->msg
> }
>
> after included the semahopra.h, creating a semaphora
> and initializing it, the idea here is that sem_post will increase
> message->lock by 1. the process doing the sem_wait will wait for
> message->lock to be nonzero before it starts executing further.
> this is how access to shared memory can be handled.
>
> hope this helps, if not, lemme know :)
>
> kenneth
>
>
>
> Samuel Winchenbach wrote:
>
> > Does anyone have any code that implements semaphores and shows where • they
> > might be useful? That is one place that the documentation seems a • little
> > weak. Thanks,
> >
> > Sam
>
|
|
Message is in Reply To:
 | | Re: semaphores
|
| a short example: #include <semaphore.h> // for semaphore opperations // global buffer, used to store incoming messages. // the buffer is checked by the application waiting for the message. struct inn_msg{ char *msg; sem_t lock; }; //create a (...) (24 years ago, 9-May-02, to lugnet.robotics.rcx.legos)
|
3 Messages in This Thread:
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
