From c528cec4dbfdb6e367a6ac0ed72e2e768a9c4392 Mon Sep 17 00:00:00 2001 From: "Heiko Schlittermann (HS12-RIPE)" Date: Wed, 12 Aug 2015 23:45:44 +0200 Subject: [PATCH] Adjust the timeout after interrupted select() --- src/src/ip.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/src/src/ip.c b/src/src/ip.c index cb54f1617..7991a5850 100644 --- a/src/src/ip.c +++ b/src/src/ip.c @@ -451,8 +451,8 @@ BOOL fd_ready(int fd, int timeout) { fd_set select_inset; -struct timeval tv; time_t start_recv = time(NULL); +int time_left = timeout; int rc; if (timeout <= 0) @@ -464,10 +464,9 @@ if (timeout <= 0) do { + struct timeval tv = { time_left, 0 }; FD_ZERO (&select_inset); FD_SET (fd, &select_inset); - tv.tv_sec = timeout; - tv.tv_usec = 0; /*DEBUG(D_transport) debug_printf("waiting for data on fd\n");*/ rc = select(fd + 1, (SELECT_ARG2_TYPE *)&select_inset, NULL, NULL, &tv); @@ -479,25 +478,24 @@ do Aug 2004: Somebody set up a cron job that ran exiwhat every 2 minutes, making the interrupt not at all rare. Since the timeout is typically more than 2 minutes, the effect was to block the timeout completely. To prevent this - happening again, we do an explicit time test. */ + happening again, we do an explicit time test and adjust the timeout + accordingly */ if (rc < 0 && errno == EINTR) { DEBUG(D_transport) debug_printf("EINTR while waiting for socket data\n"); - if (time(NULL) - start_recv < timeout) continue; - DEBUG(D_transport) debug_printf("total wait time exceeds timeout\n"); + /* Watch out, 'continue' jumps to the condition, not to the loops top */ + if (time_left = timeout - (time(NULL) - start_recv)) continue; } - /* Handle a timeout, and treat any other select error as a timeout, including - an EINTR when we have been in this loop for longer than timeout. */ - if (rc <= 0) { errno = ETIMEDOUT; return FALSE; } - /* If the socket is ready, break out of the loop. */ + /* Checking the FD_ISSET is not enough, if we're interrupted, the + select_inset may still contain the 'input'. */ } while (rc < 0 || !FD_ISSET(fd, &select_inset)); return TRUE; -- 2.25.1