source: src/libcfa/concurrency/threads.c@ 9129a84

#include "threads"
#include "assert"

#include <stddef.h>

#include <fstream>
 
static coroutine main_coroutine;
static coroutine* current_coroutine = &main_coroutine;

void ctxSwitchDirect(void* src, void* dst) {
        current_coroutine = dst;
}

coroutine* this_coroutine() {
        return current_coroutine;
}

void ?{}(coroutine* this)
{
        this->last = NULL;
      this->name = "A Coroutine";
      this->notHalted = true;
}

void suspend() {
      coroutine* src = this_coroutine();                // optimization

        assertf( src->last == (coroutine*)0, 
                "Attempt to suspend coroutine %.256s (%p) that has never been resumed.\n"
                "Possible cause is a suspend executed in a member called by a coroutine user rather than by the coroutine main.",
                src->name, src );
        assertf( src->last->notHalted, 
                "Attempt by coroutine %.256s (%p) to suspend back to terminated coroutine %.256s (%p).\n"
                "Possible cause is terminated coroutine's main routine has already returned.",
                src->name, src, src->last->name, src->last );

        ctxSwitchDirect( src, src->last );
}

forall(dtype T | coroutine_t(T))
void resume(T* cor) {
        coroutine* src = this_coroutine();              // optimization
        coroutine* dst = this_coroutine(cor);

        if ( src != dst ) {                             // not resuming self ?
                assertf( dst->notHalted , 
                        "Attempt by coroutine %.256s (%p) to resume terminated coroutine %.256s (%p).\n"
                        "Possible cause is terminated coroutine's main routine has already returned.",
                        src->name, src, dst->name, dst );
                dst->last = src;                                        // set last resumer
        } // if
        ctxSwitchDirect( src, dst );                            // always done for performance testing
}