NAME

SYNOPSIS

#include <libdill.h>
int bundle_go_mem(
    int bndl,
    expression,
    void* mem,
    size_t memlen);

    

DESCRIPTION

The stack for the coroutine is supplied by the user. The stack has no guard page and stack overflow will result in overwriting memory.

bndl: Bundle to launch the coroutine in.

expression: Expression to evaluate as a coroutine.

mem: Buffer to store coroutine's stack.

memlen: Size of th buffer, in bytes.

The coroutine is executed concurrently, and its lifetime may exceed the lifetime of the caller coroutine. The return value of the coroutine, if any, is discarded and cannot be retrieved by the caller.

Any function to be invoked as a coroutine must be declared with the coroutine specifier.

Use hclose to cancel the coroutine. When the coroutine is canceled all the blocking calls within the coroutine will start failing with ECANCELED error.

WARNING: Coroutines will most likely work even without the coroutine specifier. However, they may fail in random non-deterministic ways, depending on the code in question and the particular combination of compiler and optimization level. Additionally, arguments to a coroutine must not be function calls. If they are, the program may fail non-deterministically. If you need to pass a result of a computation to a coroutine, do the computation first, and then pass the result as an argument. Instead of:

go(bar(foo(a)));

    

Do this:

int a = foo();
go(bar(a));

    

RETURN VALUE

ERRORS

•

EBADF: Invalid handle.

•

ECANCELED: Current coroutine was canceled.

•

ENOTSUP: The handle does not support this operation.

EXAMPLE

int b = bundle();
bundle_go(b, worker());
bundle_go(b, worker());
bundle_go(b, worker());
/* Give wrokers 1 second to finish. */
bundle_wait(b, now() + 1000);
/* Cancel any remaining workers. */
hclose(b);

    

SEE ALSO