static
enum mad_flow receive(int fd, void **message, unsigned int *size)
{
enum mad_flow result;
unsigned int actual;
if (*message == 0)
*size = 0;
/* receive size */
result = receive_io(fd, &actual, sizeof(actual));
/* receive message */
if (result == MAD_FLOW_CONTINUE) {
if (actual > *size)
actual -= *size;
else {
*size = actual;
actual = 0;
}
if (*size > 0) {
if (*message == 0) {
*message = malloc(*size);
if (*message == 0)
return MAD_FLOW_BREAK;
}
result = receive_io_blocking(fd, *message, *size);
}
/* throw away remainder of message */
while (actual && result == MAD_FLOW_CONTINUE) {
char sink[256];
unsigned int len;
len = actual > sizeof(sink) ? sizeof(sink) : actual;
result = receive_io_blocking(fd, sink, len);
actual -= len;
}
}
return result;
}
static
enum mad_flow receive_io_blocking(int fd, void *buffer, size_t len) {
int flags, blocking;
enum mad_flow result;
flags = fcntl(fd, F_GETFL);
if (flags == -1)
return MAD_FLOW_BREAK;
blocking = flags & ~O_NONBLOCK;
if (blocking != flags &&
fcntl(fd, F_SETFL, blocking) == -1)
return MAD_FLOW_BREAK;
result = receive_io(fd, buffer, len);
if (flags != blocking &&
fcntl(fd, F_SETFL, flags) == -1)
return MAD_FLOW_BREAK;
return result;
}