fdin - waits on a file descriptor to become readable
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#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.
fd: file descriptor (OS-level one, not a libdill
handle)
deadline: A point in time when the operation should time
out, in milliseconds. 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 the operation cannot be performed.
In case of success the function returns 0. In case of error it returns -1 and
sets errno to one of the values below.
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- EBADF: Not a file descriptor.
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- EBUSY: Another coroutine already blocked on fdin with this
file descriptor.
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- ECANCELED: Current coroutine was canceled.
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- ETIMEDOUT: Deadline was reached.
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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);
}
fdclean(3) fdout(3) now(3)