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commit f982cbc85e9ffff24a6a348c3637b54a7e8cbc34
Author: Vadim Troshchinskiy <vtroshchinskiy@qindel.com>
Date: Wed May 20 15:47:45 2015 +0200
Fix negotiation in stage 10 error
Problem fixed by adding a select() call to implement a timeout,
and retrying writes if needed.
v2: backport to nx-libs 3.5.0.x (Mihai Moldovan)
--- a/nxcomp/Loop.cpp
+++ b/nxcomp/Loop.cpp
@@ -8073,16 +8073,52 @@ int ReadRemoteData(int fd, char *buffer,
int WriteLocalData(int fd, const char *buffer, int size)
{
int position = 0;
+ int ret = 0;
+ fd_set writeSet;
+ struct timeval selectTs = {30, 0};
while (position < size)
{
+
+ // A write to a non-blocking socket may fail with EAGAIN. The problem is
+ // that cache data is done in several writes, and there's no easy way
+ // to handle failure without rewriting a significant amount of code.
+ //
+ // Bailing out of the outer loop would result in restarting the sending
+ // of the entire cache list, which would confuse the other side.
+
+ FD_ZERO(&writeSet);
+ FD_SET(fd, &writeSet);
+
+ ret = select(fd+1, NULL, &writeSet, NULL, &selectTs);
+
+ #ifdef DEBUG
+ *logofs << "Loop: WriteLocalData: select() returned with a code of " << ret << " and remaining timeout of "
+ << selectTs.tv_sec << " sec, " << selectTs.tv_usec << "usec\n" << logofs_flush;
+ #endif
+
+ if ( ret < 0 )
+ {
+ *logofs << "Loop: Error in select() when writing data to FD#" << fd << ": " << strerror(EGET()) << "\n" << logofs_flush;
+
+ if ( EGET() == EINTR )
+ continue;
+
+ return -1;
+ }
+ else if ( ret == 0 )
+ {
+ *logofs << "Loop: Timeout expired in select() when writing data to FD#" << fd << ": " << strerror(EGET()) << "\n" << logofs_flush;
+ return -1;
+ }
+
int result = write(fd, buffer + position, size - position);
getNewTimestamp();
if (result <= 0)
{
- if (result < 0 && EGET() == EINTR)
+ if (result < 0 && (EGET() == EINTR || EGET() == EAGAIN || EGET() == EWOULDBLOCK))
{
continue;
}
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