1_helloworld.cpp

Basic Zth usage.

Basic Zth usage.This program will print:

Hello
World!!1

/*
 * SPDX-FileCopyrightText: 2019-2026 Jochem Rutgers
 *
 * SPDX-License-Identifier: CC0-1.0
 */
 
// Default Zth header include.
#include <zth>
 
// Include anything else your program needs, as usual.
#include <cstdio>
 
// This is a normal function, which we are going to use as a fiber entry point.
void world()
{
        printf("World!!1\n");
}
// The zth_fiber() marks the given list of function as fiber entries and does
// everything that is required to allow `zth_async world()'.
zth_fiber(world)
 
void hello()
{
        // The following line does not call the function world() directly, but
        // creates a fiber and schedules it at the current Worker.  world()
        // will now be executed asynchronously to hello().
        zth_async world();
 
        // Even though world() was started before the following print
        // statement, 'Hello' will always be printed first, as we did not yield
        // the processor to any other fiber in between. So, the output is
        // deterministic; the printf()s will not be reordered.
        printf("Hello\n");
}
zth_fiber(hello)
 
// main() is weakly defined by Zth. If not implemented by the program, Zth
// supplies one that just starts a worker and schedules main_fiber() as the
// only fiber. So, this is a convenient entry point of your fibered program.
// If you have to do some pre-Zth initialization to be done, such as enabling
// peripherals of an embedded system, override the weakly defined
// zth_preinit(), which is by default doing nothing. It is called before any
// Zth functionality is used.
int main_fiber(int /*argc*/, char** /*argv*/)
{
        zth_async hello();
 
        // This is the exit code of the application.  Although the application
        // has not finished, the hello fiber is still running, this value is
        // saved and used at exit later on. If you have to return a non-zero
        // value, depending on the state of your application, do not let the
        // main fiber return yet.
        return 0;
}
// There is no need to call zth_fiber(main_fiber), as that is implicit for
// main_fiber().