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udp: wait longer for transmit time stamps 

Some hardware is a bit pokey. We now wait forever on EINTR and just a
little bit on EAGAIN.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
master
Richard Cochran 2011-12-13 05:28:54 +01:00
parent 87e61f9770
commit cecc20a307
1 changed files with 19 additions and 7 deletions
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26
udp.c
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@ -230,7 +230,7 @@ static int receive(int fd, void *buf, int buflen,
struct hw_timestamp *hwts, int flags) struct hw_timestamp *hwts, int flags)
{ {
char control[256]; char control[256];
int cnt, level, type; int cnt, level, try_again, type;
struct cmsghdr *cm; struct cmsghdr *cm;
struct iovec iov = { buf, buflen }; struct iovec iov = { buf, buflen };
struct msghdr msg; struct msghdr msg;
@ -241,11 +241,21 @@ static int receive(int fd, void *buf, int buflen,
msg.msg_iovlen = 1; msg.msg_iovlen = 1;
msg.msg_control = control; msg.msg_control = control;
msg.msg_controllen = sizeof(control); msg.msg_controllen = sizeof(control);
again:
cnt = recvmsg(fd, &msg, flags); try_again = flags == MSG_ERRQUEUE ? 2 : 1;
if (cnt < 0) {
if (EINTR == errno) for ( ; try_again; try_again--) {
goto again; cnt = recvmsg(fd, &msg, flags);
if (cnt >= 0) {
break;
}
if (errno == EINTR) {
try_again++;
} else if (errno == EAGAIN) {
usleep(1);
} else {
break;
}
} }
for (cm = CMSG_FIRSTHDR(&msg); cm != NULL; cm = CMSG_NXTHDR(&msg, cm)) { for (cm = CMSG_FIRSTHDR(&msg); cm != NULL; cm = CMSG_NXTHDR(&msg, cm)) {
@ -298,8 +308,10 @@ int udp_send(struct fdarray *fda, int event,
addr.sin_port = htons(event ? EVENT_PORT : GENERAL_PORT); addr.sin_port = htons(event ? EVENT_PORT : GENERAL_PORT);
cnt = sendto(fd, buf, len, 0, (struct sockaddr *)&addr, sizeof(addr)); cnt = sendto(fd, buf, len, 0, (struct sockaddr *)&addr, sizeof(addr));
if (cnt < 1) if (cnt < 1) {
perror("sendto");
return cnt; return cnt;
}
/* /*
* Get the time stamp right away. * Get the time stamp right away.
*/ */