Add qt_safe_poll

This function is introduced to safely provide poll(2)-like semantics for
socket multiplexing on Unix-like platforms. For platforms where no poll
system call is available, an implementation based on select(2) is provided.

Change-Id: I320e97dae5924316675a74d1897c48cae292ac6d
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/corelib/kernel/qcore_unix_p.h b/src/corelib/kernel/qcore_unix_p.h
index d82b2651e7..d5434888d0 100644
--- a/src/corelib/kernel/qcore_unix_p.h
+++ b/src/corelib/kernel/qcore_unix_p.h
@@ -66,6 +66,28 @@
 #  include <ioLib.h>
 #endif
 
+#ifndef QT_NO_NATIVE_POLL
+# include <poll.h>
+#else
+struct pollfd {
+   int   fd;
+   short events, revents;
+};
+
+typedef unsigned long int nfds_t;
+
+# define POLLIN      0x001
+# define POLLPRI     0x002
+# define POLLOUT     0x004
+# define POLLERR     0x008
+# define POLLHUP     0x010
+# define POLLNVAL    0x020
+# define POLLRDNORM  0x040
+# define POLLRDBAND  0x080
+# define POLLWRNORM  0x100
+# define POLLWRBAND  0x200
+#endif
+
 struct sockaddr;
 
 #define EINTR_LOOP(var, cmd)                    \
@@ -303,6 +325,8 @@ static inline pid_t qt_safe_waitpid(pid_t pid, int *status, int options)
 timespec qt_gettime() Q_DECL_NOTHROW;
 void qt_nanosleep(timespec amount);
 
+Q_CORE_EXPORT int qt_safe_poll(struct pollfd *fds, nfds_t nfds, const struct timespec *timeout_ts);
+
 Q_CORE_EXPORT int qt_safe_select(int nfds, fd_set *fdread, fd_set *fdwrite, fd_set *fdexcept,
                                  const struct timespec *tv);