From dd5c770f329a345f86ae196c83ab00f6ea237a4e Mon Sep 17 00:00:00 2001
From: Jim Morrison <jim@twist.com>
Date: Wed, 8 Feb 2012 11:08:27 -0800
Subject: [PATCH] Check for openssl >= 1.0.1.  Conditionally compile spdyd
 based on having epoll

---
 configure.ac         |   4 +-
 examples/Makefile.am |   7 ++-
 m4/ax_have_epoll.m4  | 104 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+), 2 deletions(-)
 create mode 100644 m4/ax_have_epoll.m4

diff --git a/configure.ac b/configure.ac
index 448998f0..4a3eb921 100644
--- a/configure.ac
+++ b/configure.ac
@@ -66,9 +66,11 @@ if test "x${have_cunit}" = "xno"; then
   fi
 fi
 AM_CONDITIONAL([HAVE_CUNIT], [ test "x${have_cunit}" = "xyes" ])
+AX_HAVE_EPOLL([have_epoll=yes], [have_epoll=no])
+AM_CONDITIONAL([HAVE_EPOLL], [ test "x${have_epoll}" = "xyes" ])
 
 # openssl (for examples)
-PKG_CHECK_MODULES([OPENSSL], [openssl >= 1.0.0])
+PKG_CHECK_MODULES([OPENSSL], [openssl >= 1.0.1])
 
 # Checks for header files.
 AC_CHECK_HEADERS([ \
diff --git a/examples/Makefile.am b/examples/Makefile.am
index 480c455d..a0e8b70a 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -27,8 +27,13 @@ AM_CPPFLAGS = -I$(srcdir)/../lib/includes -I$(builddir)/../lib/includes \
 AM_LDFLAGS = @OPENSSL_LIBS@
 LDADD = $(top_builddir)/lib/libspdylay.la
 
-bin_PROGRAMS = spdycat spdyd
+bin_PROGRAMS = spdycat
 
 spdycat_SOURCES = uri.cc spdylay_ssl.cc util.cc spdycat.cc
 
+if HAVE_EPOLL
+
 spdyd_SOURCES = uri.cc spdylay_ssl.cc util.cc spdyd.cc
+bin_PROGRAMS += spdyd
+
+endif # HAVE_EPOLL
diff --git a/m4/ax_have_epoll.m4 b/m4/ax_have_epoll.m4
new file mode 100644
index 00000000..07ceb49f
--- /dev/null
+++ b/m4/ax_have_epoll.m4
@@ -0,0 +1,104 @@
+# ===========================================================================
+#       http://www.gnu.org/software/autoconf-archive/ax_have_epoll.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_HAVE_EPOLL([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+#   AX_HAVE_EPOLL_PWAIT([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+#
+# DESCRIPTION
+#
+#   This macro determines whether the system supports the epoll I/O event
+#   interface. A neat usage example would be:
+#
+#     AX_HAVE_EPOLL(
+#       [AX_CONFIG_FEATURE_ENABLE(epoll)],
+#       [AX_CONFIG_FEATURE_DISABLE(epoll)])
+#     AX_CONFIG_FEATURE(
+#       [epoll], [This platform supports epoll(7)],
+#       [HAVE_EPOLL], [This platform supports epoll(7).])
+#
+#   The epoll interface was added to the Linux kernel in version 2.5.45, and
+#   the macro verifies that a kernel newer than this is installed. This
+#   check is somewhat unreliable if <linux/version.h> doesn't match the
+#   running kernel, but it is necessary regardless, because glibc comes with
+#   stubs for the epoll_create(), epoll_wait(), etc. that allow programs to
+#   compile and link even if the kernel is too old; the problem would then
+#   be detected only at runtime.
+#
+#   Linux kernel version 2.6.19 adds the epoll_pwait() call in addition to
+#   epoll_wait(). The availability of that function can be tested with the
+#   second macro. Generally speaking, it is safe to assume that
+#   AX_HAVE_EPOLL would succeed if AX_HAVE_EPOLL_PWAIT has, but not the
+#   other way round.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Peter Simons <simons@cryp.to>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 10
+
+AC_DEFUN([AX_HAVE_EPOLL], [dnl
+  ax_have_epoll_cppflags="${CPPFLAGS}"
+  AC_CHECK_HEADER([linux/version.h], [CPPFLAGS="${CPPFLAGS} -DHAVE_LINUX_VERSION_H"])
+  AC_MSG_CHECKING([for Linux epoll(7) interface])
+  AC_CACHE_VAL([ax_cv_have_epoll], [dnl
+    AC_LINK_IFELSE([dnl
+      AC_LANG_PROGRAM([dnl
+#include <sys/epoll.h>
+#ifdef HAVE_LINUX_VERSION_H
+#  include <linux/version.h>
+#  if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,45)
+#    error linux kernel version is too old to have epoll
+#  endif
+#endif
+], [dnl
+int fd, rc;
+struct epoll_event ev;
+fd = epoll_create(128);
+rc = epoll_wait(fd, &ev, 1, 0);])],
+      [ax_cv_have_epoll=yes],
+      [ax_cv_have_epoll=no])])
+  CPPFLAGS="${ax_have_epoll_cppflags}"
+  AS_IF([test "${ax_cv_have_epoll}" = "yes"],
+    [AC_MSG_RESULT([yes])
+$1],[AC_MSG_RESULT([no])
+$2])
+])dnl
+
+AC_DEFUN([AX_HAVE_EPOLL_PWAIT], [dnl
+  ax_have_epoll_cppflags="${CPPFLAGS}"
+  AC_CHECK_HEADER([linux/version.h],
+    [CPPFLAGS="${CPPFLAGS} -DHAVE_LINUX_VERSION_H"])
+  AC_MSG_CHECKING([for Linux epoll(7) interface with signals extension])
+  AC_CACHE_VAL([ax_cv_have_epoll_pwait], [dnl
+    AC_LINK_IFELSE([dnl
+      AC_LANG_PROGRAM([dnl
+#ifdef HAVE_LINUX_VERSION_H
+#  include <linux/version.h>
+#  if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
+#    error linux kernel version is too old to have epoll_pwait
+#  endif
+#endif
+#include <sys/epoll.h>
+#include <signal.h>
+], [dnl
+int fd, rc;
+struct epoll_event ev;
+fd = epoll_create(128);
+rc = epoll_wait(fd, &ev, 1, 0);
+rc = epoll_pwait(fd, &ev, 1, 0, (sigset_t const *)(0));])],
+      [ax_cv_have_epoll_pwait=yes],
+      [ax_cv_have_epoll_pwait=no])])
+  CPPFLAGS="${ax_have_epoll_cppflags}"
+  AS_IF([test "${ax_cv_have_epoll_pwait}" = "yes"],
+    [AC_MSG_RESULT([yes])
+$1],[AC_MSG_RESULT([no])
+$2])
+])dnl