From 23381d2c5ea84cb45e41163b81c3b7bb43a9db75 Mon Sep 17 00:00:00 2001 From: Corey Farrell Date: Thu, 25 Jan 2018 02:37:32 -0500 Subject: [PATCH] Build System: Require __sync or __atomic functions. This change causes the configure script to throw an error if neither __sync nor __atomic builtin functions are available. ASTERISK-27619 Change-Id: Ie01a281e0f5c41dfeeb5f250c1ccea8752f56ef9 --- README.md | 2 +- configure | 17 ++---- configure.ac | 9 ++- include/asterisk/autoconfig.h.in | 3 - include/asterisk/lock.h | 102 ++++++------------------------- main/utils.c | 12 ---- utils/check_expr.c | 7 --- 7 files changed, 30 insertions(+), 122 deletions(-) diff --git a/README.md b/README.md index 153c4f3e4a..10158b3747 100644 --- a/README.md +++ b/README.md @@ -69,7 +69,7 @@ list of new features in this version of Asterisk, see the [CHANGES] file. Ensure that your system contains a compatible compiler and development libraries. Asterisk requires either the GNU Compiler Collection (GCC) version -3.0 or higher, or a compiler that supports the C99 specification and some of +4.1 or higher, or a compiler that supports the C99 specification and some of the gcc language extensions. In addition, your system needs to have the C library headers available, and the headers and libraries for ncurses. diff --git a/configure b/configure index f000c66f18..f6e83d9ebe 100755 --- a/configure +++ b/configure @@ -17909,6 +17909,7 @@ _ACEOF if ac_fn_c_try_link "$LINENO"; then : { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5 $as_echo "yes" >&6; } +ax_cv_have_gcc_atomics=1 $as_echo "#define HAVE_GCC_ATOMICS 1" >>confdefs.h @@ -17936,6 +17937,7 @@ _ACEOF if ac_fn_c_try_link "$LINENO"; then : { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5 $as_echo "yes" >&6; } +ax_cv_have_c_atomics=1 $as_echo "#define HAVE_C_ATOMICS 1" >>confdefs.h @@ -17947,6 +17949,10 @@ fi rm -f core conftest.err conftest.$ac_objext \ conftest$ac_exeext conftest.$ac_ext +if test -z $ax_cv_have_c_atomics$ax_cv_have_gcc_atomics; then + as_fn_error $? "*** Atomic operations are not supported by your compiler." "$LINENO" 5 +fi + # glibc, AFAIK, is the only C library that makes printing a NULL to a string safe. { $as_echo "$as_me:${as_lineno-$LINENO}: checking if your system printf is NULL-safe." >&5 $as_echo_n "checking if your system printf is NULL-safe.... " >&6; } @@ -19357,17 +19363,6 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext -ac_fn_c_check_header_mongrel "$LINENO" "libkern/OSAtomic.h" "ac_cv_header_libkern_OSAtomic_h" "$ac_includes_default" -if test "x$ac_cv_header_libkern_OSAtomic_h" = xyes; then : - -cat >>confdefs.h <<_ACEOF -#define HAVE_OSX_ATOMICS 1 -_ACEOF - -fi - - - # The cast to long int works around a bug in the HP C Compiler # version HP92453-01 B.11.11.23709.GP, which incorrectly rejects # declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'. diff --git a/configure.ac b/configure.ac index 07ff3b3f8f..6e54f3c517 100644 --- a/configure.ac +++ b/configure.ac @@ -1074,6 +1074,7 @@ AC_MSG_CHECKING(for compiler sync operations) AC_LINK_IFELSE( [AC_LANG_PROGRAM([], [int foo1; int foo2 = __sync_fetch_and_add(&foo1, 1);])], AC_MSG_RESULT(yes) +ax_cv_have_gcc_atomics=1 AC_DEFINE([HAVE_GCC_ATOMICS], 1, [Define to 1 if your GCC C compiler provides __sync atomic operations.]), AC_MSG_RESULT(no) ) @@ -1082,10 +1083,15 @@ AC_MSG_CHECKING(for compiler atomic operations) AC_LINK_IFELSE( [AC_LANG_PROGRAM([], [int foo1; int foo2 = __atomic_fetch_add(&foo1, 1, __ATOMIC_RELAXED);])], AC_MSG_RESULT(yes) +ax_cv_have_c_atomics=1 AC_DEFINE([HAVE_C_ATOMICS], 1, [Define to 1 if your C compiler provides __atomic operations.]), AC_MSG_RESULT(no) ) +if test -z $ax_cv_have_c_atomics$ax_cv_have_gcc_atomics; then + AC_MSG_ERROR([*** Atomic operations are not supported by your compiler.]) +fi + # glibc, AFAIK, is the only C library that makes printing a NULL to a string safe. AC_MSG_CHECKING([if your system printf is NULL-safe.]) AC_RUN_IFELSE( @@ -1413,9 +1419,6 @@ AST_C_DEFINE_CHECK([RTLD_NOLOAD], [RTLD_NOLOAD], [dlfcn.h]) AST_C_DEFINE_CHECK([IP_MTU_DISCOVER], [IP_MTU_DISCOVER], [netinet/in.h]) -AC_CHECK_HEADER([libkern/OSAtomic.h], - [AC_DEFINE_UNQUOTED([HAVE_OSX_ATOMICS], 1, [Define to 1 if OSX atomic operations are supported.])]) - AC_CHECK_SIZEOF([int]) AC_CHECK_SIZEOF([long]) AC_CHECK_SIZEOF([long long]) diff --git a/include/asterisk/autoconfig.h.in b/include/asterisk/autoconfig.h.in index 18f9d4e75e..b95d52693f 100644 --- a/include/asterisk/autoconfig.h.in +++ b/include/asterisk/autoconfig.h.in @@ -603,9 +603,6 @@ /* Define to 1 if you have the Open Sound System library. */ #undef HAVE_OSS -/* Define to 1 if OSX atomic operations are supported. */ -#undef HAVE_OSX_ATOMICS - /* Define to 1 if your system defines the file flag O_EVTONLY in fcntl.h */ #undef HAVE_O_EVTONLY diff --git a/include/asterisk/lock.h b/include/asterisk/lock.h index d912b56d32..c3dd691a81 100644 --- a/include/asterisk/lock.h +++ b/include/asterisk/lock.h @@ -617,107 +617,39 @@ static void __attribute__((destructor)) fini_##rwlock(void) \ #define pthread_create __use_ast_pthread_create_instead__ #endif -/* - * Support for atomic instructions. - * For platforms that have it, use the native cpu instruction to - * implement them. For other platforms, resort to a 'slow' version - * (defined in utils.c) that protects the atomic instruction with - * a single lock. - * The slow versions is always available, for testing purposes, - * as ast_atomic_fetchadd_int_slow() - */ - -int ast_atomic_fetchadd_int_slow(volatile int *p, int v); +/* Support for atomic instructions. */ #include "asterisk/inline_api.h" -#if defined(HAVE_OSX_ATOMICS) -#include "libkern/OSAtomic.h" +#if defined(HAVE_C_ATOMICS) +#define ast_atomic_fetch_add(p, v, memorder) __atomic_fetch_add(p, v, memorder) +#define ast_atomic_sub_fetch(p, v, memorder) __atomic_sub_fetch(p, v, memorder) +#elif defined(HAVE_GCC_ATOMICS) +#define ast_atomic_fetch_add(p, v, memorder) __sync_fetch_and_add(p, v) +#define ast_atomic_sub_fetch(p, v, memorder) __sync_sub_and_fetch(p, v) +#else +#error "Atomics not available." #endif -/*! \brief Atomically add v to *p and return * the previous value of *p. +/*! + * \brief Atomically add v to *p and return the previous value of *p. + * * This can be used to handle reference counts, and the return value * can be used to generate unique identifiers. */ - -#if defined(HAVE_C_ATOMICS) AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), { - return __atomic_fetch_add(p, v, __ATOMIC_RELAXED); + return ast_atomic_fetch_add(p, v, __ATOMIC_RELAXED); }) -#elif defined(HAVE_GCC_ATOMICS) -AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), -{ - return __sync_fetch_and_add(p, v); -}) -#elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 4) -AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), -{ - return OSAtomicAdd32(v, (int32_t *) p) - v; -}) -#elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 8) -AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), -{ - return OSAtomicAdd64(v, (int64_t *) p) - v; -}) -#elif defined (__i386__) || defined(__x86_64__) -#ifdef sun -AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), -{ - __asm __volatile ( - " lock; xaddl %0, %1 ; " - : "+r" (v), /* 0 (result) */ - "=m" (*p) /* 1 */ - : "m" (*p)); /* 2 */ - return (v); -}) -#else /* ifndef sun */ -AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), -{ - __asm __volatile ( - " lock xaddl %0, %1 ; " - : "+r" (v), /* 0 (result) */ - "=m" (*p) /* 1 */ - : "m" (*p)); /* 2 */ - return (v); -}) -#endif -#else /* low performance version in utils.c */ -AST_INLINE_API(int ast_atomic_fetchadd_int(volatile int *p, int v), -{ - return ast_atomic_fetchadd_int_slow(p, v); -}) -#endif -/*! \brief decrement *p by 1 and return true if the variable has reached 0. +/*! + * \brief decrement *p by 1 and return true if the variable has reached 0. + * * Useful e.g. to check if a refcount has reached 0. */ -#if defined(HAVE_C_ATOMICS) -AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), -{ - return __atomic_sub_fetch(p, 1, __ATOMIC_RELAXED) == 0; -}) -#elif defined(HAVE_GCC_ATOMICS) -AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), -{ - return __sync_sub_and_fetch(p, 1) == 0; -}) -#elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 4) -AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), -{ - return OSAtomicAdd32( -1, (int32_t *) p) == 0; -}) -#elif defined(HAVE_OSX_ATOMICS) && (SIZEOF_INT == 8) -AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), -{ - return OSAtomicAdd64( -1, (int64_t *) p) == 0; -}) -#else AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p), { - int a = ast_atomic_fetchadd_int(p, -1); - return a == 1; /* true if the value is 0 now (so it was 1 previously) */ + return ast_atomic_sub_fetch(p, 1, __ATOMIC_RELAXED) == 0; }) -#endif #endif /* _ASTERISK_LOCK_H */ diff --git a/main/utils.c b/main/utils.c index 85228c183f..7f74f40be9 100644 --- a/main/utils.c +++ b/main/utils.c @@ -1985,18 +1985,6 @@ char *ast_to_camel_case_delim(const char *s, const char *delim) return res; } -AST_MUTEX_DEFINE_STATIC(fetchadd_m); /* used for all fetc&add ops */ - -int ast_atomic_fetchadd_int_slow(volatile int *p, int v) -{ - int ret; - ast_mutex_lock(&fetchadd_m); - ret = *p; - *p += v; - ast_mutex_unlock(&fetchadd_m); - return ret; -} - /*! \brief * get values from config variables. */ diff --git a/utils/check_expr.c b/utils/check_expr.c index e15705e1b8..1e4b9d1756 100644 --- a/utils/check_expr.c +++ b/utils/check_expr.c @@ -143,13 +143,6 @@ int check_eval(char *buffer, char *error_report); void parse_file(const char *fname); int ast_add_profile(const char *x, uint64_t scale) { return 0;} -int ast_atomic_fetchadd_int_slow(volatile int *p, int v) -{ - int ret; - ret = *p; - *p += v; - return ret; -} char *find_var(const char *varname) /* the list should be pretty short, if there's any list at all */ {