libdill: Structured Concurrency for C


fdin - waits on a filedescriptor to become readable


#include <libdill.h>

int fdin(int fd, int64_t deadline);


Waits on a file descriptor (true OS file descriptor, not libdill socket handle) to either become readable or get into an error state. Either case leads to a successful return from the function. To distinguish the two outcomes, follow up with a read operation on the file descriptor.

deadline is a point in time when the operation should time out. Use the now function to get your current point in time. 0 means immediate timeout, i.e., perform the operation if possible or return without blocking if not. -1 means no deadline, i.e., the call will block forever if need be.


The function returns 0 on success. On error, it returns -1 and sets errno to one of the values below.



int result = fcntl(fd, F_SETFL, O_NONBLOCK); assert(result == 0);
while(1) {
    result = fdin(fd, -1); assert(result == 0);
    char buf[1024];
    ssize_t len = recv(fd, buf, sizeof(buf), 0);
    assert(len > 0);
    process_input(buf, len);