Coroutine in C

This project is the Unix style of coroutine mechanism in C language. It uses the file descriptor number to control the coroutine system and the job function.

Building

To build the static library coroutine.a:

$ make

How to use

In your project, include the coroutine.h header for the API:

#include "coroutine.h"

Then compile the project with coroutine.a. For example:

$ gcc -o main main.c coroutine.a -g

The routine

First of all, define the job function you want to work. The variable is used in the job function which needs to be declared by VAR_DEFINEn() macro, The n is the number of the variable you want to declare. Also, the variable defines must happen before the cr_begin macro.

COROUTINE_DEFINE(myjob)
{
    VAR_DEFINE2(int, val1, val2);
    ARRAY_DEFINE(int, arr, 20);
    cr_begin();
    cr_set(val1, 2 /* value */);
    cr_set(arr, 2 /* value */, 3 /* index */);
    cr_yield();
    int temp = cr_dref(val1);
    temp = cr_dref(arr, 3 /* index */);
    cr_end();
}

Second, create the coroutine with coroutine_create() function, it will return the fd number of the coroutine you created. Then, add the job function into the coroutine by the coroutine_add function and start working. At least, use the coroutine_join to join with the terminated coroutine.

int main(void)
{
  int crfd, tfd;
  
  crfd = coroutine_create(CR_FIFO);
  tfd = coroutine_add(crfd, myjob, NULL);
  coroutine_start(crfd);
  coroutine_join(crfd);
  
  return 0;
}