Wait Group

#co::wait_group

co::wait_group is similar to sync.WaitGroup in golang and can be used to wait for the exit of a coroutine or thread.

#constructor

1. explicit wait_group(uint32 n);
2. wait_group();
3. wait_group(wait_group&& wg);
4. wait_group(const wait_group& wg);

1, initializes the internal counter to n.
2, default constructor, initializes the internal counter to 0.
3, move constructor.
4, copy constructor, only increases the internal reference count by 1.

#add

void add(uint32 n=1) const;

Increment internal counter by n, n defaults to 1.

#done

void done() const;

Decrement internal counter by 1.

#wait

void wait() const;

Wait until the internal counter reaches 0.

#Code Example

#include "co/co.h"
#include "co/cout.h"

DEF_uint32(n, 8, "coroutine number");

int main(int argc, char** argv) {
     flag::parse(argc, argv);
    
     co::wait_group wg;
     wg.add(FLG_n);

     for (uint32 i = 0; i < FLG_n; ++i) {
         go([wg]() {
             co::print("sched: ", co::sched_id(), " co: ", co::coroutine_id());
             wg.done();
         });
     }

     wg. wait();
     return 0;
}