Hello, it might be the socket is bind()ing to a local address when it does not need to; would you be able to file a bug report with a program to reproduce the problem?
Thanks, Peter On 02/26/2014 09:28 AM, Mauro Brenna wrote: > Hello Jan, > > Thanks for the suggestion. > > The answer is YES they are behaving quite differently: > > Here the output while in the for loop: > > QT4.8.5 > > > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > sendto(7, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET, > sin_port=htons(45454), sin_addr=inet_addr("255.255.255.255")}, 16) = 19 > > > QT 5.1.1 > > > sendto(6, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET6, > sin6_port=htons(45454), inet_pton(AF_INET6, "::ffff:255.255.255.255", > &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 19 > socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 7 > ioctl(7, SIOCGIFINDEX, {ifr_name="", ???}) = -1 ENODEV (No such device) > close(7) = 0 > sendto(6, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET6, > sin6_port=htons(45454), inet_pton(AF_INET6, "::ffff:255.255.255.255", > &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 19 > socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 7 > ioctl(7, SIOCGIFINDEX, {ifr_name="", ???}) = -1 ENODEV (No such device) > close(7) = 0 > sendto(6, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET6, > sin6_port=htons(45454), inet_pton(AF_INET6, "::ffff:255.255.255.255", > &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 19 > socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 7 > ioctl(7, SIOCGIFINDEX, {ifr_name="", ???}) = -1 ENODEV (No such device) > close(7) = 0 > sendto(6, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET6, > sin6_port=htons(45454), inet_pton(AF_INET6, "::ffff:255.255.255.255", > &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 19 > socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 7 > ioctl(7, SIOCGIFINDEX, {ifr_name="", ???}) = -1 ENODEV (No such device) > close(7) = 0 > sendto(6, "Broadcast message 0", 19, MSG_NOSIGNAL, {sa_family=AF_INET6, > sin6_port=htons(45454), inet_pton(AF_INET6, "::ffff:255.255.255.255", > &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 19 > socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 7 > ioctl(7, SIOCGIFINDEX, {ifr_name="", ???}) = -1 ENODEV (No such device) > close(7) = 0 > > What can I do to have the same behaviour as QT 4.8.5. It sounds like a > QT5 .1.1 is trying to set a connection or something like that. > > Kind regards, > > Mauro > > > > > > > > On 25 February 2014 18:46, Jan Kundrát <j...@flaska.net > <mailto:j...@flaska.net>> wrote: > > On Tuesday, 25 February 2014 16:56:53 CEST, Mauro Brenna wrote: > > I looked a bit in the qt code and saw a bind() inside the QT5 > > writeDatagram method, which I do not immediately understand but I > do not > > know if might cause the issue. > > Is there any difference in `strace` when you instrument the Qt4 and Qt5 > versions of the test? > > Cheers, > Jan > > -- > Trojitá, a fast Qt IMAP e-mail client -- http://trojita.flaska.net/ > _______________________________________________ > Development mailing list > Development@qt-project.org <mailto:Development@qt-project.org> > http://lists.qt-project.org/mailman/listinfo/development > > > > > _______________________________________________ > Development mailing list > Development@qt-project.org > http://lists.qt-project.org/mailman/listinfo/development > _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development