Problem: regression with "select" on *nix (#2940)

* Problem: build failure with select as polling mechanism

Solution: cast mailbox_handle argument to (poller_t::handle_t) like in
the reaper thread class.

* Problem: build failure due to INT_MAX use without include

Solution: include limits and climits in src/select.cpp where INT_MAX is
used

* Problem: build failure due to unused variable in select.cpp

Solution: move the declaration of int rc inside the ifdef block where
it is actually used

* Problem: reference to wrong variable in select.cpp breaks build

Solution: fix it

* Problem: family_entry_t constructor has no body, build fails on *nix

Solution: add empty inline function in the struct

* Problem: no test coverage for poll and select

Solution: add Travis jobs for them on Linux

* Problem: Travis jobs cannot run in container infra

Solution: set sudo: false as it is not required anymore

.travis.yml

@@ -92,8 +92,12 @@ matrix:
         - llvm-toolchain-trusty-5.0
       packages:
         - clang-5.0
+  - env: BUILD_TYPE=default POLLER=poll
+    os: linux
+  - env: BUILD_TYPE=default POLLER=select
+    os: linux
 
-sudo: required
+sudo: false
 
 before_install:
 - if [ $TRAVIS_OS_NAME == "osx" -a $BUILD_TYPE == "android" ] ; then brew update; brew install binutils ; fi

ci_build.sh

@@ -48,6 +48,10 @@ if [ $BUILD_TYPE == "default" ]; then
         CONFIG_OPTS+=("--with-norm=yes")
     fi
 
+    if [ -n "$POLLER" ]; then
+        CONFIG_OPTS+=("--with-poller=${POLLER}")
+    fi
+
     if [ -z $DRAFT ] || [ $DRAFT == "disabled" ]; then
         CONFIG_OPTS+=("--enable-drafts=no")
     elif [ $DRAFT == "enabled" ]; then

src/io_thread.cpp

@@ -38,7 +38,7 @@
 
 zmq::io_thread_t::io_thread_t (ctx_t *ctx_, uint32_t tid_) :
     object_t (ctx_, tid_),
-    mailbox_handle (NULL)
+    mailbox_handle ((poller_t::handle_t) NULL)
 {
     poller = new (std::nothrow) poller_t (*ctx_);
     alloc_assert (poller);

src/select.cpp

@@ -48,6 +48,8 @@
 #include "i_poll_events.hpp"
 
 #include <algorithm>
+#include <limits>
+#include <climits>
 
 zmq::select_t::select_t (const zmq::ctx_t &ctx_) :
     ctx (ctx_),
@@ -211,7 +213,7 @@ void zmq::select_t::rm_fd (handle_t handle_)
 #else
     fd_entries_t::iterator fd_entry_it =
       find_fd_entry_by_handle (family_entry.fd_entries, handle_);
-    assert (fd_entry_it != fd_entries.end ());
+    assert (fd_entry_it != family_entry.fd_entries.end ());
 
     zmq_assert (fd_entry_it->fd != retired_fd);
     fd_entry_it->fd = retired_fd;
@@ -321,8 +323,6 @@ void zmq::select_t::loop ()
                              (long) (timeout % 1000 * 1000)};
 #endif
 
-        int rc = 0;
-
 #if defined ZMQ_HAVE_WINDOWS
         /*
             On Windows select does not allow to mix descriptors from different
@@ -340,6 +340,7 @@ void zmq::select_t::loop ()
         */
 
         //  If there is just one family, there is no reason to use WSA events.
+        int rc = 0;
         const bool use_wsa_events = family_entries.size () > 1;
         if (use_wsa_events) {
             // TODO: I don't really understand why we are doing this. If any of

src/select.hpp

@@ -115,7 +115,11 @@ class select_t : public poller_base_t
 
     struct family_entry_t
     {
+#ifndef ZMQ_HAVE_WINDOWS
+        family_entry_t () {};
+#else
         family_entry_t ();
+#endif
 
         fd_entries_t fd_entries;
         fds_set_t fds_set;