Add support to configure.ac for checking thread local support

and also check IPADDR_LOOPBACK is defined. In test use
loopback if we can to prevent firewall issues and use correct
thread local qualifier in sever. Plus ensure server.h qualifies
calls to std::bind to prevent clash with C socket API.

configure.ac

@@ -135,6 +135,9 @@ AC_TYPE_UINT32_T
 AC_TYPE_UINT64_T
 AC_TYPE_UINT8_T
 
+CT_CHECK_TLS
+AC_CHECK_DECLS([INADDR_LOOPBACK], [], [], [#include <netinet/in.h>])
+
 AC_MSG_CHECKING([whether pthread_t is a pointer])
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([
 #include <pthread.h>

cpp/net/url_fetcher_test.cc

@@ -1,3 +1,5 @@
+#include "config.h"
+
 #include <csignal>
 #include <fcntl.h>
 #include <gflags/gflags.h>
@@ -7,6 +9,9 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 #include <unistd.h>
+#ifdef HAVE_VFORK_H
+#include <vfork.h>
+#endif
 
 #include "net/connection_pool.h"
 #include "net/url_fetcher.h"
@@ -57,7 +62,12 @@ class LocalhostResolver : public libevent::Base::Resolver {
 pid_t RunOpenSSLServer(uint16_t port, const std::string& cert_file,
                        const std::string& key_file,
                        const std::string& mode = "-www") {
+#ifdef HAVE_WORKING_VFORK
+  pid_t pid(vfork());
+#else
   pid_t pid(fork());
+#endif
+
   if (pid == -1) {
     LOG(INFO) << "fork() failed: " << pid;
   } else if (pid == 0) {
@@ -315,7 +325,13 @@ int main(int argc, char** argv) {
   struct sockaddr_in hang_addr;
   bzero((char*)&hang_addr, sizeof(hang_addr));
   hang_addr.sin_family = AF_INET;
-  hang_addr.sin_addr.s_addr = INADDR_ANY;
+  // Prefer to use INADDR_LOOPBACK if available as it avoids the firewall
+  // triggering on some platforms if we bind a non-local address.
+#ifdef HAVE_INADDR_LOOPBACK
+  hang_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+#else
+  hang_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+#endif
   hang_addr.sin_port = htons(cert_trans::kHangPort);
   CHECK_EQ(0, bind(hang_fd, reinterpret_cast<struct sockaddr*>(&hang_addr),
                    sizeof(hang_addr)));

cpp/server/event.cc

@@ -251,7 +251,7 @@ bool Services::InitServer(int* sock, int port, const char* ip, int type) {
   server.sin_family = AF_INET;
   server.sin_port = htons((unsigned short)port);
   if (ip == NULL)
-    server.sin_addr.s_addr = INADDR_ANY;
+    server.sin_addr.s_addr = htonl(INADDR_ANY);
   else
     memcpy(&server.sin_addr.s_addr, ip, 4);
 

cpp/server/server.h

@@ -36,6 +36,8 @@
 #include "util/thread_pool.h"
 #include "util/uuid.h"
 
+using std::bind;
+
 DEFINE_int32(node_state_refresh_seconds, 10,
              "How often to refresh the ClusterNodeState entry for this node.");
 DEFINE_int32(watchdog_seconds, 120,

m4/ct_check_tls.m4

@@ -0,0 +1,37 @@
+dnl Checks for thread-local storage support.
+dnl
+dnl Taken from the openvswitch config code (Apache 2.0 License)
+dnl with some local modifications. Does not include <threads.h>
+dnl as this does not currently exist on GCC.
+dnl Checks whether the compiler and linker support the C11
+dnl thread_local macro from <threads.h>, and if so defines
+dnl HAVE_THREAD_LOCAL.  If not, checks whether the compiler and linker
+dnl support the GCC __thread extension, and if so defines
+dnl HAVE___THREAD.
+AC_DEFUN([CT_CHECK_TLS],
+  [AC_CACHE_CHECK(
+     [whether $CC has <threads.h> that supports thread_local],
+     [ct_cv_thread_local],
+     [AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM([ static thread_local int var;], [return var;])],
+        [ct_cv_thread_local=yes],
+        [ct_cv_thread_local=no])])
+   if test $ct_cv_thread_local = yes; then
+     AC_DEFINE([HAVE_THREAD_LOCAL], [1],
+               [Define to 1 if the C compiler and linker supports the C11
+                thread_local macro defined in <threads.h>.])
+   else
+     AC_CACHE_CHECK(
+       [whether $CC supports __thread],
+       [ct_cv___thread],
+       [AC_LINK_IFELSE(
+          [AC_LANG_PROGRAM([static __thread int var;], [return var;])],
+          [ct_cv___thread=yes],
+          [ct_cv___thread=no])])
+     if test $ct_cv___thread = yes; then
+       AC_DEFINE([HAVE___THREAD], [1],
+                 [Define to 1 if the C compiler and linker supports the
+                  GCC __thread extensions.])
+     fi
+   fi])
+