diff options
author | Jonathon Anderson <jma14@rice.edu> | 2019-08-25 10:01:51 -0500 |
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committer | Mark Wielaard <mark@klomp.org> | 2019-10-22 18:27:30 +0200 |
commit | 77b66a71adaff5b445c3a5bb43b6d5742265df14 (patch) | |
tree | 4b8d792ba9969be78236b5d0dd2add05649ad048 /lib | |
parent | 47780c9e4cbd312da6d93c9d70c554d34d83dd05 (diff) | |
download | elfutils-77b66a71adaff5b445c3a5bb43b6d5742265df14.tar.gz |
Add some supporting framework for C11-style atomics.
Uses the stdatomic.h provided by FreeBSD when GCC doesn't (ie. GCC < 4.9)
Signed-off-by: Jonathon Anderson <jma14@rice.edu>
Signed-off-by: Srđan Milaković <sm108@rice.edu>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/ChangeLog | 6 | ||||
-rw-r--r-- | lib/Makefile.am | 3 | ||||
-rw-r--r-- | lib/atomics.h | 37 | ||||
-rw-r--r-- | lib/stdatomic-fbsd.h | 442 |
4 files changed, 487 insertions, 1 deletions
diff --git a/lib/ChangeLog b/lib/ChangeLog index 7381860c..3799c3aa 100644 --- a/lib/ChangeLog +++ b/lib/ChangeLog @@ -1,3 +1,9 @@ +2019-08-25 Jonathon Anderson <jma14@rice.edu> + + * stdatomic-fbsd.h: New file, taken from FreeBSD. + * atomics.h: New file. + * Makefile.am (noinst_HEADERS): Added *.h above. + 2019-05-03 Rosen Penev <rosenp@gmail.com> * color.c (parse_opt): Cast program_invocation_short_name to char *. diff --git a/lib/Makefile.am b/lib/Makefile.am index 36d21a07..3086cf06 100644 --- a/lib/Makefile.am +++ b/lib/Makefile.am @@ -38,7 +38,8 @@ libeu_a_SOURCES = xstrdup.c xstrndup.c xmalloc.c next_prime.c \ color.c printversion.c noinst_HEADERS = fixedsizehash.h libeu.h system.h dynamicsizehash.h list.h \ - eu-config.h color.h printversion.h bpf.h + eu-config.h color.h printversion.h bpf.h \ + atomics.h stdatomic-fbsd.h EXTRA_DIST = dynamicsizehash.c if !GPROF diff --git a/lib/atomics.h b/lib/atomics.h new file mode 100644 index 00000000..ffd12f87 --- /dev/null +++ b/lib/atomics.h @@ -0,0 +1,37 @@ +/* Conditional wrapper header for C11-style atomics. + Copyright (C) 2019-2019 Red Hat, Inc. + This file is part of elfutils. + + This file is free software; you can redistribute it and/or modify + it under the terms of either + + * 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 + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at + your option) any later version + + or both in parallel, as here. + + elfutils 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 + General Public License for more details. + + You should have received copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see <http://www.gnu.org/licenses/>. */ + +#include "config.h" + +#if HAVE_STDATOMIC_H +/* If possible, use the compiler's preferred atomics. */ +# include <stdatomic.h> +#else +/* Otherwise, try to use the builtins provided by this compiler. */ +# include "stdatomic-fbsd.h" +#endif /* HAVE_STDATOMIC_H */ diff --git a/lib/stdatomic-fbsd.h b/lib/stdatomic-fbsd.h new file mode 100644 index 00000000..49626662 --- /dev/null +++ b/lib/stdatomic-fbsd.h @@ -0,0 +1,442 @@ +/*- + * Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org> + * David Chisnall <theraven@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#ifndef _STDATOMIC_H_ +#define _STDATOMIC_H_ + +#include <stddef.h> +#include <stdint.h> + +#if !defined(__has_feature) +#define __has_feature(x) 0 +#endif +#if !defined(__has_builtin) +#define __has_builtin(x) 0 +#endif +#if !defined(__GNUC_PREREQ__) +#if defined(__GNUC__) && defined(__GNUC_MINOR__) +#define __GNUC_PREREQ__(maj, min) \ + ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) +#else +#define __GNUC_PREREQ__(maj, min) 0 +#endif +#endif + +#if !defined(__CLANG_ATOMICS) && !defined(__GNUC_ATOMICS) +#if __has_feature(c_atomic) +#define __CLANG_ATOMICS +#elif __GNUC_PREREQ__(4, 7) +#define __GNUC_ATOMICS +#elif !defined(__GNUC__) +#error "stdatomic.h does not support your compiler" +#endif +#endif + +/* + * language independent type to represent a Boolean value + */ + +typedef int __Bool; + +/* + * 7.17.1 Atomic lock-free macros. + */ + +#ifdef __GCC_ATOMIC_BOOL_LOCK_FREE +#define ATOMIC_BOOL_LOCK_FREE __GCC_ATOMIC_BOOL_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_CHAR_LOCK_FREE +#define ATOMIC_CHAR_LOCK_FREE __GCC_ATOMIC_CHAR_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_CHAR16_T_LOCK_FREE +#define ATOMIC_CHAR16_T_LOCK_FREE __GCC_ATOMIC_CHAR16_T_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_CHAR32_T_LOCK_FREE +#define ATOMIC_CHAR32_T_LOCK_FREE __GCC_ATOMIC_CHAR32_T_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_WCHAR_T_LOCK_FREE +#define ATOMIC_WCHAR_T_LOCK_FREE __GCC_ATOMIC_WCHAR_T_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_SHORT_LOCK_FREE +#define ATOMIC_SHORT_LOCK_FREE __GCC_ATOMIC_SHORT_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_INT_LOCK_FREE +#define ATOMIC_INT_LOCK_FREE __GCC_ATOMIC_INT_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_LONG_LOCK_FREE +#define ATOMIC_LONG_LOCK_FREE __GCC_ATOMIC_LONG_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_LLONG_LOCK_FREE +#define ATOMIC_LLONG_LOCK_FREE __GCC_ATOMIC_LLONG_LOCK_FREE +#endif +#ifdef __GCC_ATOMIC_POINTER_LOCK_FREE +#define ATOMIC_POINTER_LOCK_FREE __GCC_ATOMIC_POINTER_LOCK_FREE +#endif + +#if !defined(__CLANG_ATOMICS) +#define _Atomic(T) struct { volatile __typeof__(T) __val; } +#endif + +/* + * 7.17.2 Initialization. + */ + +#if defined(__CLANG_ATOMICS) +#define ATOMIC_VAR_INIT(value) (value) +#define atomic_init(obj, value) __c11_atomic_init(obj, value) +#else +#define ATOMIC_VAR_INIT(value) { .__val = (value) } +#define atomic_init(obj, value) ((void)((obj)->__val = (value))) +#endif + +/* + * Clang and recent GCC both provide predefined macros for the memory + * orderings. If we are using a compiler that doesn't define them, use the + * clang values - these will be ignored in the fallback path. + */ + +#ifndef __ATOMIC_RELAXED +#define __ATOMIC_RELAXED 0 +#endif +#ifndef __ATOMIC_CONSUME +#define __ATOMIC_CONSUME 1 +#endif +#ifndef __ATOMIC_ACQUIRE +#define __ATOMIC_ACQUIRE 2 +#endif +#ifndef __ATOMIC_RELEASE +#define __ATOMIC_RELEASE 3 +#endif +#ifndef __ATOMIC_ACQ_REL +#define __ATOMIC_ACQ_REL 4 +#endif +#ifndef __ATOMIC_SEQ_CST +#define __ATOMIC_SEQ_CST 5 +#endif + +/* + * 7.17.3 Order and consistency. + * + * The memory_order_* constants that denote the barrier behaviour of the + * atomic operations. + */ + +typedef enum { + memory_order_relaxed = __ATOMIC_RELAXED, + memory_order_consume = __ATOMIC_CONSUME, + memory_order_acquire = __ATOMIC_ACQUIRE, + memory_order_release = __ATOMIC_RELEASE, + memory_order_acq_rel = __ATOMIC_ACQ_REL, + memory_order_seq_cst = __ATOMIC_SEQ_CST +} memory_order; + +/* + * 7.17.4 Fences. + */ + +//#define __unused + +//static __inline void +//atomic_thread_fence(memory_order __order __unused) +//{ +// +//#ifdef __CLANG_ATOMICS +// __c11_atomic_thread_fence(__order); +//#elif defined(__GNUC_ATOMICS) +// __atomic_thread_fence(__order); +//#else +// __sync_synchronize(); +//#endif +//} +// +//static __inline void +//atomic_signal_fence(memory_order __order __unused) +//{ +// +//#ifdef __CLANG_ATOMICS +// __c11_atomic_signal_fence(__order); +//#elif defined(__GNUC_ATOMICS) +// __atomic_signal_fence(__order); +//#else +// __asm volatile ("" ::: "memory"); +//#endif +//} + +//#undef __unused + +/* + * 7.17.5 Lock-free property. + */ + +#if defined(_KERNEL) +/* Atomics in kernelspace are always lock-free. */ +#define atomic_is_lock_free(obj) \ + ((void)(obj), (__Bool)1) +#elif defined(__CLANG_ATOMICS) +#define atomic_is_lock_free(obj) \ + __atomic_is_lock_free(sizeof(*(obj)), obj) +#elif defined(__GNUC_ATOMICS) +#define atomic_is_lock_free(obj) \ + __atomic_is_lock_free(sizeof((obj)->__val), &(obj)->__val) +#else +#define atomic_is_lock_free(obj) \ + ((void)(obj), sizeof((obj)->__val) <= sizeof(void *)) +#endif + +/* + * 7.17.6 Atomic integer types. + */ + +typedef _Atomic(__Bool) atomic_bool; +typedef _Atomic(char) atomic_char; +typedef _Atomic(signed char) atomic_schar; +typedef _Atomic(unsigned char) atomic_uchar; +typedef _Atomic(short) atomic_short; +typedef _Atomic(unsigned short) atomic_ushort; +typedef _Atomic(int) atomic_int; +typedef _Atomic(unsigned int) atomic_uint; +typedef _Atomic(long) atomic_long; +typedef _Atomic(unsigned long) atomic_ulong; +typedef _Atomic(long long) atomic_llong; +typedef _Atomic(unsigned long long) atomic_ullong; +#if 0 +typedef _Atomic(char16_t) atomic_char16_t; +typedef _Atomic(char32_t) atomic_char32_t; +#endif +typedef _Atomic(wchar_t) atomic_wchar_t; +typedef _Atomic(int_least8_t) atomic_int_least8_t; +typedef _Atomic(uint_least8_t) atomic_uint_least8_t; +typedef _Atomic(int_least16_t) atomic_int_least16_t; +typedef _Atomic(uint_least16_t) atomic_uint_least16_t; +typedef _Atomic(int_least32_t) atomic_int_least32_t; +typedef _Atomic(uint_least32_t) atomic_uint_least32_t; +typedef _Atomic(int_least64_t) atomic_int_least64_t; +typedef _Atomic(uint_least64_t) atomic_uint_least64_t; +typedef _Atomic(int_fast8_t) atomic_int_fast8_t; +typedef _Atomic(uint_fast8_t) atomic_uint_fast8_t; +typedef _Atomic(int_fast16_t) atomic_int_fast16_t; +typedef _Atomic(uint_fast16_t) atomic_uint_fast16_t; +typedef _Atomic(int_fast32_t) atomic_int_fast32_t; +typedef _Atomic(uint_fast32_t) atomic_uint_fast32_t; +typedef _Atomic(int_fast64_t) atomic_int_fast64_t; +typedef _Atomic(uint_fast64_t) atomic_uint_fast64_t; +typedef _Atomic(intptr_t) atomic_intptr_t; +typedef _Atomic(uintptr_t) atomic_uintptr_t; +typedef _Atomic(size_t) atomic_size_t; +typedef _Atomic(ptrdiff_t) atomic_ptrdiff_t; +typedef _Atomic(intmax_t) atomic_intmax_t; +typedef _Atomic(uintmax_t) atomic_uintmax_t; + +/* + * 7.17.7 Operations on atomic types. + */ + +/* + * Compiler-specific operations. + */ + +#if defined(__CLANG_ATOMICS) +#define atomic_compare_exchange_strong_explicit(object, expected, \ + desired, success, failure) \ + __c11_atomic_compare_exchange_strong(object, expected, desired, \ + success, failure) +#define atomic_compare_exchange_weak_explicit(object, expected, \ + desired, success, failure) \ + __c11_atomic_compare_exchange_weak(object, expected, desired, \ + success, failure) +#define atomic_exchange_explicit(object, desired, order) \ + __c11_atomic_exchange(object, desired, order) +#define atomic_fetch_add_explicit(object, operand, order) \ + __c11_atomic_fetch_add(object, operand, order) +#define atomic_fetch_and_explicit(object, operand, order) \ + __c11_atomic_fetch_and(object, operand, order) +#define atomic_fetch_or_explicit(object, operand, order) \ + __c11_atomic_fetch_or(object, operand, order) +#define atomic_fetch_sub_explicit(object, operand, order) \ + __c11_atomic_fetch_sub(object, operand, order) +#define atomic_fetch_xor_explicit(object, operand, order) \ + __c11_atomic_fetch_xor(object, operand, order) +#define atomic_load_explicit(object, order) \ + __c11_atomic_load(object, order) +#define atomic_store_explicit(object, desired, order) \ + __c11_atomic_store(object, desired, order) +#elif defined(__GNUC_ATOMICS) +#define atomic_compare_exchange_strong_explicit(object, expected, \ + desired, success, failure) \ + __atomic_compare_exchange_n(&(object)->__val, expected, \ + desired, 0, success, failure) +#define atomic_compare_exchange_weak_explicit(object, expected, \ + desired, success, failure) \ + __atomic_compare_exchange_n(&(object)->__val, expected, \ + desired, 1, success, failure) +#define atomic_exchange_explicit(object, desired, order) \ + __atomic_exchange_n(&(object)->__val, desired, order) +#define atomic_fetch_add_explicit(object, operand, order) \ + __atomic_fetch_add(&(object)->__val, operand, order) +#define atomic_fetch_and_explicit(object, operand, order) \ + __atomic_fetch_and(&(object)->__val, operand, order) +#define atomic_fetch_or_explicit(object, operand, order) \ + __atomic_fetch_or(&(object)->__val, operand, order) +#define atomic_fetch_sub_explicit(object, operand, order) \ + __atomic_fetch_sub(&(object)->__val, operand, order) +#define atomic_fetch_xor_explicit(object, operand, order) \ + __atomic_fetch_xor(&(object)->__val, operand, order) +#define atomic_load_explicit(object, order) \ + __atomic_load_n(&(object)->__val, order) +#define atomic_store_explicit(object, desired, order) \ + __atomic_store_n(&(object)->__val, desired, order) +#else +#define __atomic_apply_stride(object, operand) \ + (((__typeof__((object)->__val))0) + (operand)) +#define atomic_compare_exchange_strong_explicit(object, expected, \ + desired, success, failure) __extension__ ({ \ + __typeof__(expected) __ep = (expected); \ + __typeof__(*__ep) __e = *__ep; \ + (void)(success); (void)(failure); \ + (__Bool)((*__ep = __sync_val_compare_and_swap(&(object)->__val, \ + __e, desired)) == __e); \ +}) +#define atomic_compare_exchange_weak_explicit(object, expected, \ + desired, success, failure) \ + atomic_compare_exchange_strong_explicit(object, expected, \ + desired, success, failure) +#if __has_builtin(__sync_swap) +/* Clang provides a full-barrier atomic exchange - use it if available. */ +#define atomic_exchange_explicit(object, desired, order) \ + ((void)(order), __sync_swap(&(object)->__val, desired)) +#else +/* + * __sync_lock_test_and_set() is only an acquire barrier in theory (although in + * practice it is usually a full barrier) so we need an explicit barrier before + * it. + */ +#define atomic_exchange_explicit(object, desired, order) \ +__extension__ ({ \ + __typeof__(object) __o = (object); \ + __typeof__(desired) __d = (desired); \ + (void)(order); \ + __sync_synchronize(); \ + __sync_lock_test_and_set(&(__o)->__val, __d); \ +}) +#endif +#define atomic_fetch_add_explicit(object, operand, order) \ + ((void)(order), __sync_fetch_and_add(&(object)->__val, \ + __atomic_apply_stride(object, operand))) +#define atomic_fetch_and_explicit(object, operand, order) \ + ((void)(order), __sync_fetch_and_and(&(object)->__val, operand)) +#define atomic_fetch_or_explicit(object, operand, order) \ + ((void)(order), __sync_fetch_and_or(&(object)->__val, operand)) +#define atomic_fetch_sub_explicit(object, operand, order) \ + ((void)(order), __sync_fetch_and_sub(&(object)->__val, \ + __atomic_apply_stride(object, operand))) +#define atomic_fetch_xor_explicit(object, operand, order) \ + ((void)(order), __sync_fetch_and_xor(&(object)->__val, operand)) +#define atomic_load_explicit(object, order) \ + ((void)(order), __sync_fetch_and_add(&(object)->__val, 0)) +#define atomic_store_explicit(object, desired, order) \ + ((void)atomic_exchange_explicit(object, desired, order)) +#endif + +/* + * Convenience functions. + * + * Don't provide these in kernel space. In kernel space, we should be + * disciplined enough to always provide explicit barriers. + */ + +#ifndef _KERNEL +#define atomic_compare_exchange_strong(object, expected, desired) \ + atomic_compare_exchange_strong_explicit(object, expected, \ + desired, memory_order_seq_cst, memory_order_seq_cst) +#define atomic_compare_exchange_weak(object, expected, desired) \ + atomic_compare_exchange_weak_explicit(object, expected, \ + desired, memory_order_seq_cst, memory_order_seq_cst) +#define atomic_exchange(object, desired) \ + atomic_exchange_explicit(object, desired, memory_order_seq_cst) +#define atomic_fetch_add(object, operand) \ + atomic_fetch_add_explicit(object, operand, memory_order_seq_cst) +#define atomic_fetch_and(object, operand) \ + atomic_fetch_and_explicit(object, operand, memory_order_seq_cst) +#define atomic_fetch_or(object, operand) \ + atomic_fetch_or_explicit(object, operand, memory_order_seq_cst) +#define atomic_fetch_sub(object, operand) \ + atomic_fetch_sub_explicit(object, operand, memory_order_seq_cst) +#define atomic_fetch_xor(object, operand) \ + atomic_fetch_xor_explicit(object, operand, memory_order_seq_cst) +#define atomic_load(object) \ + atomic_load_explicit(object, memory_order_seq_cst) +#define atomic_store(object, desired) \ + atomic_store_explicit(object, desired, memory_order_seq_cst) +#endif /* !_KERNEL */ + +/* + * 7.17.8 Atomic flag type and operations. + * + * XXX: Assume atomic_bool can be used as an atomic_flag. Is there some + * kind of compiler built-in type we could use? + */ + +typedef struct { + atomic_bool __flag; +} atomic_flag; + +#define ATOMIC_FLAG_INIT { ATOMIC_VAR_INIT(0) } + +static __inline __Bool +atomic_flag_test_and_set_explicit(volatile atomic_flag *__object, + memory_order __order) +{ + return (atomic_exchange_explicit(&__object->__flag, 1, __order)); +} + +static __inline void +atomic_flag_clear_explicit(volatile atomic_flag *__object, memory_order __order) +{ + + atomic_store_explicit(&__object->__flag, 0, __order); +} + +#ifndef _KERNEL +static __inline __Bool +atomic_flag_test_and_set(volatile atomic_flag *__object) +{ + + return (atomic_flag_test_and_set_explicit(__object, + memory_order_seq_cst)); +} + +static __inline void +atomic_flag_clear(volatile atomic_flag *__object) +{ + + atomic_flag_clear_explicit(__object, memory_order_seq_cst); +} +#endif /* !_KERNEL */ + +#endif /* !_STDATOMIC_H_ */
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