Comtrol eCos - Manual (Page 42)

Thread creation
cyg_thread_create(PRODUCER_PRIORITY, &producer, 0, "producer",
producer_stack, PRODUCER_STACKSIZE,
&producer_handle, &producer_thread);
cyg_thread_resume(producer_handle);
for (i = 0; i < NUMBER_OF_WORKERS; i++) {
cyg_thread_create(WORKER_PRIORITY, &worker, i, "worker",
worker_stacks[i], WORKER_STACKSIZE,
&(worker_handles[i]), &(worker_threads[i]));
cyg_thread_resume(worker_handles[i]);
}
}
Thread Entry Points and C++
For code written in C++ the thread entry function must be either a static member function of a class or an ordinary
function outside any class. It cannot be a normal member function of a class because such member functions take
an implicit additional argument
this , and the kernel has no way of knowing what value to use for this argument.
One way around this problem is to make use of a special static member function, for example:
class fred {
public:
void thread_function();
static void static_thread_aux(cyg_addrword_t);
};
void
fred::static_thread_aux(cyg_addrword_t objptr)
{
fred* object = static_cast < fred* > (objptr);
object- > thread_function();
}
static fred instance;
extern "C" void
cyg_start( void )
{
...
cyg_thread_create( ...,
&fred::static_thread_aux,
static_cast < cyg_addrword_t > (&instance),
...);
...
}
Effectively this uses the entry_data argument to cyg_thread_create to hold the this pointer. Unfortunately
this approach does require the use of some C++ casts, so some of the type safety that can be achieved when
programming in C++ is lost.
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