[urcu.git] / configure.ac

AC_PREREQ(2.59)
AC_INIT([userspace-rcu],[0.9.0],[mathieu dot desnoyers at efficios dot com], [], [http://liburcu.org/])

# Following the numbering scheme proposed by libtool for the library version
# http://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
AC_SUBST([URCU_LIBRARY_VERSION], [5:0:1])

AC_CONFIG_SRCDIR([urcu.h])
AC_CONFIG_HEADERS([config.h urcu/config.h])
AC_CONFIG_AUX_DIR([config])
AC_CONFIG_MACRO_DIR([m4])

AC_CANONICAL_TARGET
AC_CANONICAL_HOST

AM_INIT_AUTOMAKE([foreign dist-bzip2 no-dist-gzip])
AM_MAINTAINER_MODE([enable])

# Enable silent rules if available (Introduced in AM 1.11)
m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])

AH_TEMPLATE([CONFIG_RCU_SMP], [Enable SMP support. With SMP support enabled, uniprocessors are also supported. With SMP support disabled, UP systems work fine, but the behavior of SMP systems is undefined.])
AH_TEMPLATE([CONFIG_RCU_HAVE_FENCE], [Defined when on a system that has memory fence instructions.])
AH_TEMPLATE([CONFIG_RCU_HAVE_FUTEX], [Defined when on a system with futex support.])
AH_TEMPLATE([CONFIG_RCU_COMPAT_ARCH], [Compatibility mode for i386 which lacks cmpxchg instruction.])
AH_TEMPLATE([CONFIG_RCU_ARM_HAVE_DMB], [Use the dmb instruction if available for use on ARM.])
AH_TEMPLATE([CONFIG_RCU_TLS], [TLS provided by the compiler.])
AH_TEMPLATE([CONFIG_RCU_HAVE_CLOCK_GETTIME], [clock_gettime() is detected.])

# Allow overriding storage used for TLS variables.
AC_ARG_ENABLE([compiler-tls],
	AS_HELP_STRING([--disable-compiler-tls], [Use pthread_getspecific() to emulate Thread Local Storage (TLS) variables.]),
	[def_compiler_tls=$enableval],
	[def_compiler_tls="yes"])

# If not overridden, use ax_tls.m4 to check if TLS is available.
AS_IF([test "x$def_compiler_tls" = "xyes"],
	[AX_TLS([def_tls_detect=$ac_cv_tls], [:])],
	[:])

AS_IF([test "x$def_tls_detect" = "x"],
	[:],
	[AC_DEFINE_UNQUOTED([CONFIG_RCU_TLS], $def_tls_detect)])

# Checks for C compiler
AC_USE_SYSTEM_EXTENSIONS
AC_PROG_CC
AC_PROG_CC_STDC

# Checks for programs.
AC_PROG_AWK
AC_PROG_MAKE_SET
AC_CHECK_PROGS(NPROC, [nproc gnproc])
AC_CHECK_PROGS(GETCONF, [getconf])
AS_IF([test "x$NPROC" != "x"],
	[NPROC_CMD=$NPROC],
	[AS_IF([test "x$GETCONF" != "x"],
		[NPROC_CMD="$GETCONF _NPROCESSORS_ONLN"],
		[NPROC_CMD="echo 1"]
	)]
)
AC_SUBST([NPROC_CMD], [$NPROC_CMD])

LT_INIT

# Checks for typedefs, structures, and compiler characteristics.
AC_C_INLINE
AC_TYPE_PID_T
AC_TYPE_SIZE_T
AC_TYPE_SSIZE_T
AC_TYPE_UINT16_T
AC_TYPE_INT32_T
AC_TYPE_UINT32_T
AC_TYPE_UINT64_T
AC_TYPE_UINT8_T

AX_C___ATTRIBUTE__
AS_IF([test "x$ax_cv___attribute__" = "xyes"],
	[:],
	[AC_MSG_ERROR([The compiler does not support __attribute__ extensions])])

AX_PTHREAD(,[AC_MSG_ERROR([Could not configure pthreads support])])
LIBS="$PTHREAD_LIBS $LIBS"
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
CC="$PTHREAD_CC"

# Checks for library functions.
AC_FUNC_MALLOC
AC_FUNC_MMAP
AC_FUNC_FORK
AC_CHECK_FUNCS([ \
	atexit \
	getcpuid \
	gettid \
	gettimeofday \
	memeset \
	memset \
	munmap \
	sched_getcpu \
	strerror \
	strtoul \
	sysconf \
])

# Check for headers
AC_HEADER_STDBOOL
AC_CHECK_HEADERS([ \
	limits.h \
	stddef.h \
	sys/param.h \
	sys/time.h \
])

# Find arch type
AS_CASE([$host_cpu],
	[k1om], [ARCHTYPE="x86"],
	[i386], [ARCHTYPE="x86" && SUBARCHTYPE="x86compat"],
	[i486], [ARCHTYPE="x86"],
	[i586], [ARCHTYPE="x86"],
	[i686], [ARCHTYPE="x86"],
	[amd64], [ARCHTYPE="x86"],
	[x86_64], [ARCHTYPE="x86"],
	[powerpc], [ARCHTYPE="ppc"],
	[ppc64], [ARCHTYPE="ppc"],
	[powerpc64], [ARCHTYPE="ppc"],
	[powerpc64le], [ARCHTYPE="ppc"],
	[ppc], [ARCHTYPE="ppc"],
	[s390], [ARCHTYPE="s390"],
	[s390x], [ARCHTYPE="s390"],
	[sparc], [ARCHTYPE="sparc64"],
	[sparc64], [ARCHTYPE="sparc64"],
	[alpha*], [ARCHTYPE="alpha"],
	[ia64], [ARCHTYPE="ia64"],
	[arm*], [ARCHTYPE="arm"],
	[aarch64*], [ARCHTYPE="aarch64"],
	[mips*], [ARCHTYPE="mips"],
	[nios2*], [ARCHTYPE="nios2"],
	[tile*], [ARCHTYPE="tile"],
	[hppa*], [ARCHTYPE="hppa"],
	[ARCHTYPE="unknown"]
)

AS_CASE([$host],[*-cygwin*],
	[AM_CONDITIONAL(USE_CYGWIN, true)],
	[AM_CONDITIONAL(USE_CYGWIN, false)]
)

AC_SUBST(ARCHTYPE)
AC_SUBST(SUBARCHTYPE)

UATOMICSRC=urcu/uatomic/$ARCHTYPE.h
ARCHSRC=urcu/arch/$ARCHTYPE.h

AS_IF([test "x$SUBARCHTYPE" = xx86compat],[
	AC_DEFINE([CONFIG_RCU_COMPAT_ARCH], [1])
])

AS_IF([test "$host_cpu" = "armv7l"],[
	CFLAGS="$CFLAGS -mcpu=cortex-a9 -mtune=cortex-a9 -O1"
])

# ARM-specific checks
AS_IF([test "x$ARCHTYPE" = "xarm"],[
	AC_MSG_CHECKING([for dmb instruction])
	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
				int main()
				{
					asm volatile("dmb":::"memory");
					return 0;
				}
		]])
	],[
		AC_MSG_RESULT([yes])
		AC_DEFINE([CONFIG_RCU_ARM_HAVE_DMB], [1])
	],[
		AC_MSG_RESULT([no])
	])
])

# Tile-specific checks
AS_IF([echo "$host_cpu" | grep "^tile"],[
	AC_MSG_CHECKING([for Tile architecture type])
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
				#ifndef __tilegx__
				#error
				#endif
		]])
	],[
		AC_MSG_RESULT([ok])
	],[
		AC_MSG_FAILURE([URCU has only been tested on the TileGx architecture. For other Tile* architectures, please run the tests first and report the results to the maintainer so that proper support can be added.])
	])
])

# x86-specific checks
AS_IF([test "x$ARCHTYPE" = "xx86"],[
	AC_MSG_CHECKING([if architecture really supports the mfence instruction])
	#For now, using lock; addl compatibility mode even for i686, because the
	#Pentium III is seen as a i686, but lacks mfence instruction.
	#Only using fence for x86_64.
	#
	#k1om is the name for the Intel MIC family (Xeon Phi). It is an x86_64
	#variant but lacks fence instructions.
	AS_IF([test "x$host_cpu" != "xi386" -a "x$host_cpu" != "xi486" -a "x$host_cpu" != "xi586" -a "x$host_cpu" != "xi686" -a "x$host_vendor" != "xk1om" -a "x$host_cpu" != "xk1om"],[
		AC_MSG_RESULT([yes])
		AC_DEFINE([CONFIG_RCU_HAVE_FENCE], [1])
	],[
		AC_MSG_RESULT([no])
	])
])

# Check if sys_futex() is available
AC_MSG_CHECKING([for sys_futex()])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
		#include <sys/syscall.h>
		#ifndef __NR_futex
		#error "futexes not available"
		#endif
	]])
],[
	AC_MSG_RESULT([yes])
	AC_DEFINE([CONFIG_RCU_HAVE_FUTEX], [1])
	compat_futex_test=0
],[
	AC_MSG_RESULT([no])
	compat_futex_test=1
])

# Search for clock_gettime
AC_SEARCH_LIBS([clock_gettime], [rt], [
	AC_DEFINE([CONFIG_RCU_HAVE_CLOCK_GETTIME], [1])
], [])

AM_CONDITIONAL([COMPAT_FUTEX], [test "x$compat_futex_test" = "x1"])
AM_CONDITIONAL([COMPAT_ARCH], [test "x$SUBARCHTYPE" = "xx86compat"])
AM_CONDITIONAL([NO_SHARED], [test "x$enable_shared" = "xno"])

# smp-support configure option
AC_ARG_ENABLE([smp-support], 
	AS_HELP_STRING([--disable-smp-support], [Disable SMP support. Warning: only use this on uniprocessor systems. [default=enabled]]),
	[def_smp_support=$enableval],
	[def_smp_support="yes"])
AS_IF([test "x$def_smp_support" = "xyes"], [AC_DEFINE([CONFIG_RCU_SMP], [1])])


# From the sched_setaffinity(2)'s man page:
# ~~~~
# The CPU affinity system calls were introduced in Linux kernel 2.5.8.
# The library interfaces were introduced in glibc 2.3.  Initially, the
# glibc interfaces included a cpusetsize argument.  In glibc 2.3.3,
# the cpuset size argument was removed, but this argument was
# restored in glibc 2.3.4.
# ~~~~

# In addition to that, some vendors ported the system call to 2.4
# kernels.

# Furthermore, when the function first appeared, the MASK argument was
# an unsigned long pointer, while later it was made into a cpu_set_t
# pointer.  Systems that have the cpu_set_t version also should have
# the CPU_ZERO, CPU_SET, etc. macros.

# All this mess means we have to cater for at least 3 different
# sched_setaffinity prototypes:

# ~~~~
#  int sched_setaffinity (pid_t pid, unsigned int len, unsigned long *mask);
#  int sched_setaffinity (pid_t __pid, size_t __cpusetsize, const cpu_set_t *__cpuset);
#  int sched_setaffinity (pid_t __pid, const cpu_set_t *__mask);
# ~~~~

# Since we define _GNU_SOURCE in the sources, must do so too in the
# autoconf tests, as defining _GNU_SOURCE or not exposes
# sched_setaffinity bits differently.
saved_CFLAGS=$CFLAGS
CFLAGS="$CFLAGS -D_GNU_SOURCE"

AC_CHECK_TYPES([cpu_set_t],
	[have_cpu_set_t="yes"],
	[have_cpu_set_t="no"],
	[#include <sched.h>])

# Confirm that we have CPU_ZERO, and it actually works.
AC_MSG_CHECKING([whether CPU_ZERO works])
AH_TEMPLATE([HAVE_CPU_ZERO], [Defined to 1 if we have CPU_ZERO and it works])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
		#define _GNU_SOURCE
		#include <sched.h>
		int main()
		{
			cpu_set_t foo; CPU_ZERO(&foo);
			return 0;
		}
	]])
],[
	AC_DEFINE(HAVE_CPU_ZERO, 1)
	AC_MSG_RESULT([yes])
],[
	AC_MSG_RESULT([no])
])

# Confirm that we have CPU_SET, and it actually works.
AC_MSG_CHECKING([whether CPU_SET works])
AH_TEMPLATE([HAVE_CPU_SET], [Defined to 1 if we have CPU_SET and it works])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
		#define _GNU_SOURCE
		#include <sched.h>
		int main()
		{
			cpu_set_t foo, mask; CPU_SET(0, &foo);
			return 0;
		}
	]])
],[
	AC_DEFINE(HAVE_CPU_SET, 1)
	AC_MSG_RESULT([yes])
],[
	AC_MSG_RESULT([no])
])

# First check if the function is available at all.
AC_CHECK_FUNCS([sched_setaffinity],[
	# Okay, we have it.  Check if also have cpu_set_t.  If we don't,
	# then we have the first version using unsigned long, and no
	# CPU_ZERO, etc. macros.  If we do have cpu_set_t, we may have the
	# version with 2 or 3 arguments.  In that case, CPU_ZERO, etc.,
	# should also be present, but we confirm nonetheless.

	AS_IF([test "x$have_cpu_set_t" = "xyes"], [
		# We do have it.
		# Check how many arguments does sched_setaffinity take.
		# Should be 3 or 2.
		AC_MSG_CHECKING([how many arguments sched_setaffinity takes])
		AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
				#include <sched.h>
				int main()
				{
					cpu_set_t foo;
					sched_setaffinity(0, sizeof (foo), &foo);
					return 0;
				}
			]])
		],
		[sched_set_affinity_args=3],
		[sched_set_affinity_args=2])
		AC_DEFINE_UNQUOTED(SCHED_SETAFFINITY_ARGS,
			$sched_set_affinity_args,
			[Defined to sched_setaffinity's number of arguments.])
		AC_MSG_RESULT([$sched_set_affinity_args])
	],[
		# No cpu_set_t, always 3 args.
		AC_DEFINE(SCHED_SETAFFINITY_ARGS, 3)
	])
])

CFLAGS=$saved_CFLAGS

AC_CONFIG_LINKS([
	urcu/arch.h:$ARCHSRC
	urcu/uatomic.h:$UATOMICSRC
])
AC_CONFIG_FILES([
	Makefile
	doc/Makefile
	doc/examples/Makefile
	tests/Makefile
	tests/common/Makefile
	tests/unit/Makefile
	tests/benchmark/Makefile
	tests/regression/Makefile
	tests/regression/regression_tests
	tests/utils/Makefile
	liburcu.pc
	liburcu-bp.pc
	liburcu-cds.pc
	liburcu-qsbr.pc
	liburcu-mb.pc
	liburcu-signal.pc
])
AC_OUTPUT

# Report on selected configure options
AS_IF([test "x$def_smp_support" = "xyes"],[
	AS_ECHO("SMP support enabled.")
],[
	AS_ECHO("SMP support disabled.")
])

AS_IF([test "x$def_tls_detect" = "x"],[
	AS_ECHO("Thread Local Storage (TLS): pthread_getspecific().")
],[
	AS_ECHO("Thread Local Storage (TLS): $def_tls_detect.")
])
Commit	Line	Data
	1	AC_PREREQ(2.59)
	2	AC_INIT([userspace-rcu],[0.9.0],[mathieu dot desnoyers at efficios dot com], [], [http://liburcu.org/])
	3
	4	# Following the numbering scheme proposed by libtool for the library version
	5	# http://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
	6	AC_SUBST([URCU_LIBRARY_VERSION], [5:0:1])
	7
	8	AC_CONFIG_SRCDIR([urcu.h])
	9	AC_CONFIG_HEADERS([config.h urcu/config.h])
	10	AC_CONFIG_AUX_DIR([config])
	11	AC_CONFIG_MACRO_DIR([m4])
	12
	13	AC_CANONICAL_TARGET
	14	AC_CANONICAL_HOST
	15
	16	AM_INIT_AUTOMAKE([foreign dist-bzip2 no-dist-gzip])
	17	AM_MAINTAINER_MODE([enable])
	18
	19	# Enable silent rules if available (Introduced in AM 1.11)
	20	m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
	21
	22	AH_TEMPLATE([CONFIG_RCU_SMP], [Enable SMP support. With SMP support enabled, uniprocessors are also supported. With SMP support disabled, UP systems work fine, but the behavior of SMP systems is undefined.])
	23	AH_TEMPLATE([CONFIG_RCU_HAVE_FENCE], [Defined when on a system that has memory fence instructions.])
	24	AH_TEMPLATE([CONFIG_RCU_HAVE_FUTEX], [Defined when on a system with futex support.])
	25	AH_TEMPLATE([CONFIG_RCU_COMPAT_ARCH], [Compatibility mode for i386 which lacks cmpxchg instruction.])
	26	AH_TEMPLATE([CONFIG_RCU_ARM_HAVE_DMB], [Use the dmb instruction if available for use on ARM.])
	27	AH_TEMPLATE([CONFIG_RCU_TLS], [TLS provided by the compiler.])
	28	AH_TEMPLATE([CONFIG_RCU_HAVE_CLOCK_GETTIME], [clock_gettime() is detected.])
	29
	30	# Allow overriding storage used for TLS variables.
	31	AC_ARG_ENABLE([compiler-tls],
	32	AS_HELP_STRING([--disable-compiler-tls], [Use pthread_getspecific() to emulate Thread Local Storage (TLS) variables.]),
	33	[def_compiler_tls=$enableval],
	34	[def_compiler_tls="yes"])
	35
	36	# If not overridden, use ax_tls.m4 to check if TLS is available.
	37	AS_IF([test "x$def_compiler_tls" = "xyes"],
	38	[AX_TLS([def_tls_detect=$ac_cv_tls], [:])],
	39	[:])
	40
	41	AS_IF([test "x$def_tls_detect" = "x"],
	42	[:],
	43	[AC_DEFINE_UNQUOTED([CONFIG_RCU_TLS], $def_tls_detect)])
	44
	45	# Checks for C compiler
	46	AC_USE_SYSTEM_EXTENSIONS
	47	AC_PROG_CC
	48	AC_PROG_CC_STDC
	49
	50	# Checks for programs.
	51	AC_PROG_AWK
	52	AC_PROG_MAKE_SET
	53	AC_CHECK_PROGS(NPROC, [nproc gnproc])
	54	AC_CHECK_PROGS(GETCONF, [getconf])
	55	AS_IF([test "x$NPROC" != "x"],
	56	[NPROC_CMD=$NPROC],
	57	[AS_IF([test "x$GETCONF" != "x"],
	58	[NPROC_CMD="$GETCONF _NPROCESSORS_ONLN"],
	59	[NPROC_CMD="echo 1"]
	60	)]
	61	)
	62	AC_SUBST([NPROC_CMD], [$NPROC_CMD])
	63
	64	LT_INIT
	65
	66	# Checks for typedefs, structures, and compiler characteristics.
	67	AC_C_INLINE
	68	AC_TYPE_PID_T
	69	AC_TYPE_SIZE_T
	70	AC_TYPE_SSIZE_T
	71	AC_TYPE_UINT16_T
	72	AC_TYPE_INT32_T
	73	AC_TYPE_UINT32_T
	74	AC_TYPE_UINT64_T
	75	AC_TYPE_UINT8_T
	76
	77	AX_C___ATTRIBUTE__
	78	AS_IF([test "x$ax_cv___attribute__" = "xyes"],
	79	[:],
	80	[AC_MSG_ERROR([The compiler does not support __attribute__ extensions])])
	81
	82	AX_PTHREAD(,[AC_MSG_ERROR([Could not configure pthreads support])])
	83	LIBS="$PTHREAD_LIBS $LIBS"
	84	CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
	85	CC="$PTHREAD_CC"
	86
	87	# Checks for library functions.
	88	AC_FUNC_MALLOC
	89	AC_FUNC_MMAP
	90	AC_FUNC_FORK
	91	AC_CHECK_FUNCS([ \
	92	atexit \
	93	getcpuid \
	94	gettid \
	95	gettimeofday \
	96	memeset \
	97	memset \
	98	munmap \
	99	sched_getcpu \
	100	strerror \
	101	strtoul \
	102	sysconf \
	103	])
	104
	105	# Check for headers
	106	AC_HEADER_STDBOOL
	107	AC_CHECK_HEADERS([ \
	108	limits.h \
	109	stddef.h \
	110	sys/param.h \
	111	sys/time.h \
	112	])
	113
	114	# Find arch type
	115	AS_CASE([$host_cpu],
	116	[k1om], [ARCHTYPE="x86"],
	117	[i386], [ARCHTYPE="x86" && SUBARCHTYPE="x86compat"],
	118	[i486], [ARCHTYPE="x86"],
	119	[i586], [ARCHTYPE="x86"],
	120	[i686], [ARCHTYPE="x86"],
	121	[amd64], [ARCHTYPE="x86"],
	122	[x86_64], [ARCHTYPE="x86"],
	123	[powerpc], [ARCHTYPE="ppc"],
	124	[ppc64], [ARCHTYPE="ppc"],
	125	[powerpc64], [ARCHTYPE="ppc"],
	126	[powerpc64le], [ARCHTYPE="ppc"],
	127	[ppc], [ARCHTYPE="ppc"],
	128	[s390], [ARCHTYPE="s390"],
	129	[s390x], [ARCHTYPE="s390"],
	130	[sparc], [ARCHTYPE="sparc64"],
	131	[sparc64], [ARCHTYPE="sparc64"],
	132	[alpha*], [ARCHTYPE="alpha"],
	133	[ia64], [ARCHTYPE="ia64"],
	134	[arm*], [ARCHTYPE="arm"],
	135	[aarch64*], [ARCHTYPE="aarch64"],
	136	[mips*], [ARCHTYPE="mips"],
	137	[nios2*], [ARCHTYPE="nios2"],
	138	[tile*], [ARCHTYPE="tile"],
	139	[hppa*], [ARCHTYPE="hppa"],
	140	[ARCHTYPE="unknown"]
	141	)
	142
	143	AS_CASE([$host],[-cygwin],
	144	[AM_CONDITIONAL(USE_CYGWIN, true)],
	145	[AM_CONDITIONAL(USE_CYGWIN, false)]
	146	)
	147
	148	AC_SUBST(ARCHTYPE)
	149	AC_SUBST(SUBARCHTYPE)
	150
	151	UATOMICSRC=urcu/uatomic/$ARCHTYPE.h
	152	ARCHSRC=urcu/arch/$ARCHTYPE.h
	153
	154	AS_IF([test "x$SUBARCHTYPE" = xx86compat],[
	155	AC_DEFINE([CONFIG_RCU_COMPAT_ARCH], [1])
	156	])
	157
	158	AS_IF([test "$host_cpu" = "armv7l"],[
	159	CFLAGS="$CFLAGS -mcpu=cortex-a9 -mtune=cortex-a9 -O1"
	160	])
	161
	162	# ARM-specific checks
	163	AS_IF([test "x$ARCHTYPE" = "xarm"],[
	164	AC_MSG_CHECKING([for dmb instruction])
	165	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
	166	int main()
	167	{
	168	asm volatile("dmb":::"memory");
	169	return 0;
	170	}
	171	]])
	172	],[
	173	AC_MSG_RESULT([yes])
	174	AC_DEFINE([CONFIG_RCU_ARM_HAVE_DMB], [1])
	175	],[
	176	AC_MSG_RESULT([no])
	177	])
	178	])
	179
	180	# Tile-specific checks
	181	AS_IF([echo "$host_cpu" \| grep "^tile"],[
	182	AC_MSG_CHECKING([for Tile architecture type])
	183	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
	184	#ifndef __tilegx__
	185	#error
	186	#endif
	187	]])
	188	],[
	189	AC_MSG_RESULT([ok])
	190	],[
	191	AC_MSG_FAILURE([URCU has only been tested on the TileGx architecture. For other Tile* architectures, please run the tests first and report the results to the maintainer so that proper support can be added.])
	192	])
	193	])
	194
	195	# x86-specific checks
	196	AS_IF([test "x$ARCHTYPE" = "xx86"],[
	197	AC_MSG_CHECKING([if architecture really supports the mfence instruction])
	198	#For now, using lock; addl compatibility mode even for i686, because the
	199	#Pentium III is seen as a i686, but lacks mfence instruction.
	200	#Only using fence for x86_64.
	201	#
	202	#k1om is the name for the Intel MIC family (Xeon Phi). It is an x86_64
	203	#variant but lacks fence instructions.
	204	AS_IF([test "x$host_cpu" != "xi386" -a "x$host_cpu" != "xi486" -a "x$host_cpu" != "xi586" -a "x$host_cpu" != "xi686" -a "x$host_vendor" != "xk1om" -a "x$host_cpu" != "xk1om"],[
	205	AC_MSG_RESULT([yes])
	206	AC_DEFINE([CONFIG_RCU_HAVE_FENCE], [1])
	207	],[
	208	AC_MSG_RESULT([no])
	209	])
	210	])
	211
	212	# Check if sys_futex() is available
	213	AC_MSG_CHECKING([for sys_futex()])
	214	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
	215	#include <sys/syscall.h>
	216	#ifndef __NR_futex
	217	#error "futexes not available"
	218	#endif
	219	]])
	220	],[
	221	AC_MSG_RESULT([yes])
	222	AC_DEFINE([CONFIG_RCU_HAVE_FUTEX], [1])
	223	compat_futex_test=0
	224	],[
	225	AC_MSG_RESULT([no])
	226	compat_futex_test=1
	227	])
	228
	229	# Search for clock_gettime
	230	AC_SEARCH_LIBS([clock_gettime], [rt], [
	231	AC_DEFINE([CONFIG_RCU_HAVE_CLOCK_GETTIME], [1])
	232	], [])
	233
	234	AM_CONDITIONAL([COMPAT_FUTEX], [test "x$compat_futex_test" = "x1"])
	235	AM_CONDITIONAL([COMPAT_ARCH], [test "x$SUBARCHTYPE" = "xx86compat"])
	236	AM_CONDITIONAL([NO_SHARED], [test "x$enable_shared" = "xno"])
	237
	238	# smp-support configure option
	239	AC_ARG_ENABLE([smp-support],
	240	AS_HELP_STRING([--disable-smp-support], [Disable SMP support. Warning: only use this on uniprocessor systems. [default=enabled]]),
	241	[def_smp_support=$enableval],
	242	[def_smp_support="yes"])
	243	AS_IF([test "x$def_smp_support" = "xyes"], [AC_DEFINE([CONFIG_RCU_SMP], [1])])
	244
	245
	246	# From the sched_setaffinity(2)'s man page:
	247	# ~~~~
	248	# The CPU affinity system calls were introduced in Linux kernel 2.5.8.
	249	# The library interfaces were introduced in glibc 2.3. Initially, the
	250	# glibc interfaces included a cpusetsize argument. In glibc 2.3.3,
	251	# the cpuset size argument was removed, but this argument was
	252	# restored in glibc 2.3.4.
	253	# ~~~~
	254
	255	# In addition to that, some vendors ported the system call to 2.4
	256	# kernels.
	257
	258	# Furthermore, when the function first appeared, the MASK argument was
	259	# an unsigned long pointer, while later it was made into a cpu_set_t
	260	# pointer. Systems that have the cpu_set_t version also should have
	261	# the CPU_ZERO, CPU_SET, etc. macros.
	262
	263	# All this mess means we have to cater for at least 3 different
	264	# sched_setaffinity prototypes:
	265
	266	# ~~~~
	267	# int sched_setaffinity (pid_t pid, unsigned int len, unsigned long *mask);
	268	# int sched_setaffinity (pid_t __pid, size_t __cpusetsize, const cpu_set_t *__cpuset);
	269	# int sched_setaffinity (pid_t __pid, const cpu_set_t *__mask);
	270	# ~~~~
	271
	272	# Since we define _GNU_SOURCE in the sources, must do so too in the
	273	# autoconf tests, as defining _GNU_SOURCE or not exposes
	274	# sched_setaffinity bits differently.
	275	saved_CFLAGS=$CFLAGS
	276	CFLAGS="$CFLAGS -D_GNU_SOURCE"
	277
	278	AC_CHECK_TYPES([cpu_set_t],
	279	[have_cpu_set_t="yes"],
	280	[have_cpu_set_t="no"],
	281	[#include <sched.h>])
	282
	283	# Confirm that we have CPU_ZERO, and it actually works.
	284	AC_MSG_CHECKING([whether CPU_ZERO works])
	285	AH_TEMPLATE([HAVE_CPU_ZERO], [Defined to 1 if we have CPU_ZERO and it works])
	286	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
	287	#define _GNU_SOURCE
	288	#include <sched.h>
	289	int main()
	290	{
	291	cpu_set_t foo; CPU_ZERO(&foo);
	292	return 0;
	293	}
	294	]])
	295	],[
	296	AC_DEFINE(HAVE_CPU_ZERO, 1)
	297	AC_MSG_RESULT([yes])
	298	],[
	299	AC_MSG_RESULT([no])
	300	])
	301
	302	# Confirm that we have CPU_SET, and it actually works.
	303	AC_MSG_CHECKING([whether CPU_SET works])
	304	AH_TEMPLATE([HAVE_CPU_SET], [Defined to 1 if we have CPU_SET and it works])
	305	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
	306	#define _GNU_SOURCE
	307	#include <sched.h>
	308	int main()
	309	{
	310	cpu_set_t foo, mask; CPU_SET(0, &foo);
	311	return 0;
	312	}
	313	]])
	314	],[
	315	AC_DEFINE(HAVE_CPU_SET, 1)
	316	AC_MSG_RESULT([yes])
	317	],[
	318	AC_MSG_RESULT([no])
	319	])
	320
	321	# First check if the function is available at all.
	322	AC_CHECK_FUNCS([sched_setaffinity],[
	323	# Okay, we have it. Check if also have cpu_set_t. If we don't,
	324	# then we have the first version using unsigned long, and no
	325	# CPU_ZERO, etc. macros. If we do have cpu_set_t, we may have the
	326	# version with 2 or 3 arguments. In that case, CPU_ZERO, etc.,
	327	# should also be present, but we confirm nonetheless.
	328
	329	AS_IF([test "x$have_cpu_set_t" = "xyes"], [
	330	# We do have it.
	331	# Check how many arguments does sched_setaffinity take.
	332	# Should be 3 or 2.
	333	AC_MSG_CHECKING([how many arguments sched_setaffinity takes])
	334	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
	335	#include <sched.h>
	336	int main()
	337	{
	338	cpu_set_t foo;
	339	sched_setaffinity(0, sizeof (foo), &foo);
	340	return 0;
	341	}
	342	]])
	343	],
	344	[sched_set_affinity_args=3],
	345	[sched_set_affinity_args=2])
	346	AC_DEFINE_UNQUOTED(SCHED_SETAFFINITY_ARGS,
	347	$sched_set_affinity_args,
	348	[Defined to sched_setaffinity's number of arguments.])
	349	AC_MSG_RESULT([$sched_set_affinity_args])
	350	],[
	351	# No cpu_set_t, always 3 args.
	352	AC_DEFINE(SCHED_SETAFFINITY_ARGS, 3)
	353	])
	354	])
	355
	356	CFLAGS=$saved_CFLAGS
	357
	358	AC_CONFIG_LINKS([
	359	urcu/arch.h:$ARCHSRC
	360	urcu/uatomic.h:$UATOMICSRC
	361	])
	362	AC_CONFIG_FILES([
	363	Makefile
	364	doc/Makefile
	365	doc/examples/Makefile
	366	tests/Makefile
	367	tests/common/Makefile
	368	tests/unit/Makefile
	369	tests/benchmark/Makefile
	370	tests/regression/Makefile
	371	tests/regression/regression_tests
	372	tests/utils/Makefile
	373	liburcu.pc
	374	liburcu-bp.pc
	375	liburcu-cds.pc
	376	liburcu-qsbr.pc
	377	liburcu-mb.pc
	378	liburcu-signal.pc
	379	])
	380	AC_OUTPUT
	381
	382	# Report on selected configure options
	383	AS_IF([test "x$def_smp_support" = "xyes"],[
	384	AS_ECHO("SMP support enabled.")
	385	],[
	386	AS_ECHO("SMP support disabled.")
	387	])
	388
	389	AS_IF([test "x$def_tls_detect" = "x"],[
	390	AS_ECHO("Thread Local Storage (TLS): pthread_getspecific().")
	391	],[
	392	AS_ECHO("Thread Local Storage (TLS): $def_tls_detect.")
	393	])