Adding test showing failure to close socket/context in forked child

.gitignore

@@ -60,6 +60,7 @@ tests/test_spec_req
 tests/test_spec_router
 tests/test_req_request_ids
 tests/test_req_strict
+tests/test_fork
 src/platform.hpp*
 src/stamp-h1
 perf/local_lat

configure.ac

@@ -388,7 +388,7 @@ AM_CONDITIONAL(ON_ANDROID, test "x$libzmq_on_android" = "xyes")
 
 # Checks for library functions.
 AC_TYPE_SIGNAL
-AC_CHECK_FUNCS(perror gettimeofday clock_gettime memset socket getifaddrs freeifaddrs)
+AC_CHECK_FUNCS(perror gettimeofday clock_gettime memset socket getifaddrs freeifaddrs fork)
 AC_CHECK_HEADERS([alloca.h])
 LIBZMQ_CHECK_SOCK_CLOEXEC([AC_DEFINE(
                               [ZMQ_HAVE_SOCK_CLOEXEC],

tests/Makefile.am

@@ -38,7 +38,8 @@ if !ON_MINGW
 noinst_PROGRAMS += test_shutdown_stress \
                    test_pair_ipc \
                    test_reqrep_ipc \
-                   test_timeo
+                   test_timeo \
+                   test_fork
 endif
 
 test_pair_inproc_SOURCES = test_pair_inproc.cpp testutil.hpp
@@ -76,6 +77,7 @@ test_shutdown_stress_SOURCES = test_shutdown_stress.cpp
 test_pair_ipc_SOURCES = test_pair_ipc.cpp testutil.hpp
 test_reqrep_ipc_SOURCES = test_reqrep_ipc.cpp testutil.hpp
 test_timeo_SOURCES = test_timeo.cpp
+test_fork_SOURCES = test_fork.cpp
 endif
 
 #  Deprecated test cases

tests/test_fork.cpp

+/*
+    Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "../include/zmq.h"
+#include "../include/zmq_utils.h"
+#include <stdio.h>
+#include <string.h>
+#include "testutil.hpp"
+#include <unistd.h>
+#include <signal.h>
+
+const char* address = "tcp://127.0.0.1:6571";
+void my_handler(int, siginfo_t *info, void *uap);
+volatile int child_exited = 0;
+volatile int child_exit_code = 0;
+
+int main (void)
+{
+    int rc;
+    
+    setup_test_environment();
+    
+    printf("parent: process id = %d\n", (int)getpid());
+    void *ctx = zmq_ctx_new ();
+    assert (ctx);
+    
+    void* sock = zmq_socket(ctx, ZMQ_PULL);
+    assert(sock);
+    
+    rc = zmq_connect(sock, address);
+    assert(rc == 0);
+    
+    // wait for io threads to be running
+    usleep(100000);
+    
+    int pid = fork();
+    if (pid == 0) {
+        sleep(1);
+        printf("child: process id = %d\n", (int)getpid());
+        printf("child: terminating inherited context...\n");
+        // close the socket, or the context gets stuck indefinitely
+        zmq_close(sock);
+        zmq_term(ctx);
+        printf("child done\n");
+        exit(0);
+    } else {
+        int child_status;
+        while (true) {
+            rc = waitpid(pid, &child_status, 0);
+            if (rc == -1 && errno == EINTR) continue;
+            printf("parent: child exit code = %d, rc = %d, errno = %d\n", WEXITSTATUS(child_status), rc, errno);
+            assert(WEXITSTATUS(child_status) == 0);
+            break;
+        }
+        printf("parent done.\n");
+        exit(0);
+    }
+    return 0;
+}