From: Tyler Retzlaff [mailto:roret...@linux.microsoft.com]
Sent: Wednesday, 8 February 2023 22.44
Introduce atomics abstraction that permits optional use of standard C11
atomics when meson is provided the new enable_stdatomics=true option.
Signed-off-by: Tyler Retzlaff <roret...@linux.microsoft.com>
---
Looks good. A few minor suggestions about implementation only.
With or without suggested modifications,
Acked-by: Morten Brørup <m...@smartsharesystems.com>
config/meson.build | 11 ++++
lib/eal/arm/include/rte_atomic_32.h | 6 ++-
lib/eal/arm/include/rte_atomic_64.h | 6 ++-
lib/eal/include/generic/rte_atomic.h | 96
+++++++++++++++++++++++++++++++++-
lib/eal/loongarch/include/rte_atomic.h | 6 ++-
lib/eal/ppc/include/rte_atomic.h | 6 ++-
lib/eal/riscv/include/rte_atomic.h | 6 ++-
lib/eal/x86/include/rte_atomic.h | 8 ++-
meson_options.txt | 2 +
9 files changed, 139 insertions(+), 8 deletions(-)
diff --git a/config/meson.build b/config/meson.build
index 26f3168..25dd628 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -255,6 +255,17 @@ endif
# add -include rte_config to cflags
add_project_arguments('-include', 'rte_config.h', language: 'c')
+stdc_atomics_enabled = get_option('enable_stdatomics')
+dpdk_conf.set('RTE_STDC_ATOMICS', stdc_atomics_enabled)
+
+if stdc_atomics_enabled
+if cc.get_id() == 'gcc' or cc.get_id() == 'clang'
+ add_project_arguments('-std=gnu11', language: 'c')
+else
+ add_project_arguments('-std=c11', language: 'c')
+endif
+endif
+
# enable extra warnings and disable any unwanted warnings
# -Wall is added by default at warning level 1, and -Wextra
# at warning level 2 (DPDK default)
diff --git a/lib/eal/arm/include/rte_atomic_32.h
b/lib/eal/arm/include/rte_atomic_32.h
index c00ab78..7088a12 100644
--- a/lib/eal/arm/include/rte_atomic_32.h
+++ b/lib/eal/arm/include/rte_atomic_32.h
@@ -34,9 +34,13 @@
#define rte_io_rmb() rte_rmb()
static __rte_always_inline void
-rte_atomic_thread_fence(int memorder)
+rte_atomic_thread_fence(rte_memory_order memorder)
{
+#ifdef RTE_STDC_ATOMICS
+ atomic_thread_fence(memorder);
+#else
__atomic_thread_fence(memorder);
+#endif
}
#ifdef __cplusplus
diff --git a/lib/eal/arm/include/rte_atomic_64.h
b/lib/eal/arm/include/rte_atomic_64.h
index 6047911..7f02c57 100644
--- a/lib/eal/arm/include/rte_atomic_64.h
+++ b/lib/eal/arm/include/rte_atomic_64.h
@@ -38,9 +38,13 @@
#define rte_io_rmb() rte_rmb()
static __rte_always_inline void
-rte_atomic_thread_fence(int memorder)
+rte_atomic_thread_fence(rte_memory_order memorder)
{
+#ifdef RTE_STDC_ATOMICS
+ atomic_thread_fence(memorder);
+#else
__atomic_thread_fence(memorder);
+#endif
}
/*------------------------ 128 bit atomic operations -----------------
--------*/
diff --git a/lib/eal/include/generic/rte_atomic.h
b/lib/eal/include/generic/rte_atomic.h
index f5c49a9..392d928 100644
--- a/lib/eal/include/generic/rte_atomic.h
+++ b/lib/eal/include/generic/rte_atomic.h
@@ -110,6 +110,100 @@
#endif /* __DOXYGEN__ */
+#ifdef RTE_STDC_ATOMICS
+
+#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L ||
defined(__STDC_NO_ATOMICS__)
+#error compiler does not support C11 standard atomics
+#else
+#include <stdatomic.h>
+#endif
+
+#define __rte_atomic _Atomic
+
+typedef int rte_memory_order;
I would prefer enum for rte_memory_order:
typedef enum {
rte_memory_order_relaxed = memory_order_relaxed,
rte_memory_order_consume = memory_order_consume,
rte_memory_order_acquire = memory_order_acquire,
rte_memory_order_release = memory_order_release,
rte_memory_order_acq_rel = memory_order_acq_rel,
rte_memory_order_seq_cst = memory_order_seq_cst
} rte_memory_order;
+
+#define rte_memory_order_relaxed memory_order_relaxed
+#define rte_memory_order_consume memory_order_consume
+#define rte_memory_order_acquire memory_order_acquire
+#define rte_memory_order_release memory_order_release
+#define rte_memory_order_acq_rel memory_order_acq_rel
+#define rte_memory_order_seq_cst memory_order_seq_cst
+
+#define rte_atomic_store_explicit(obj, desired, order) \
+ atomic_store_explicit(obj, desired, order)
+
+#define rte_atomic_load_explicit(obj, order) \
+ atomic_load_explicit(obj, order)
+
+#define rte_atomic_exchange_explicit(obj, desired, order) \
+ atomic_exchange_explicit(obj, desired, order)
+
+#define rte_atomic_compare_exchange_strong_explicit(obj, expected,
desired, success, fail) \
+ atomic_compare_exchange_strong_explicit(obj, expected, desired,
success, fail)
+
+#define rte_atomic_compare_exchange_weak_explicit(obj, expected,
desired, success, fail) \
+ atomic_compare_exchange_weak_explicit(obj, expected, desired,
success, fail)
+
+#define rte_atomic_fetch_add_explicit(obj, arg, order) \
+ atomic_fetch_add_explicit(obj, arg, order)
+
+#define rte_atomic_fetch_sub_explicit(obj, arg, order) \
+ atomic_fetch_sub_explicit(obj, arg, order)
+
+#define rte_atomic_fetch_or_explicit(obj, arg, order) \
+ atomic_fetch_or_explicit(obj, arg, order)
+
+#define rte_atomic_fetch_xor_explicit(obj, arg, order) \
+ atomic_fetch_xor_explicit(obj, arg, order)
+
+#define rte_atomic_fetch_and_explicit(obj, arg, order) \
+ atomic_fetch_and_explicit(obj, arg, order)
+
+#else
+
+#define __rte_atomic
+
+typedef int rte_memory_order;
+
+#define rte_memory_order_relaxed __ATOMIC_RELAXED
+#define rte_memory_order_consume __ATOMIC_CONSUME
+#define rte_memory_order_acquire __ATOMIC_ACQUIRE
+#define rte_memory_order_release __ATOMIC_RELEASE
+#define rte_memory_order_acq_rel __ATOMIC_ACQ_REL
+#define rte_memory_order_seq_cst __ATOMIC_SEQ_CST
Prefer enum for rte_memory_order:
typedef enum {
rte_memory_order_relaxed = __ATOMIC_RELAXED,
rte_memory_order_consume = __ATOMIC_CONSUME,
rte_memory_order_acquire = __ATOMIC_ACQUIRE,
rte_memory_order_release = __ATOMIC_RELEASE,
rte_memory_order_acq_rel = __ATOMIC_ACQ_REL,
rte_memory_order_seq_cst = __ATOMIC_SEQ_CST
} rte_memory_order;
+
+#define rte_atomic_store_explicit(obj, desired, order) \
+ __atomic_store_n(obj, desired, order)
+
+#define rte_atomic_load_explicit(obj, order) \
+ __atomic_load_n(obj, order)
+
+#define rte_atomic_exchange_explicit(obj, desired, order) \
+ __atomic_exchange_n(obj, desired, order)
+
+#define rte_atomic_compare_exchange_strong_explicit(obj, expected,
desired, success, fail) \
+ __atomic_compare_exchange_n(obj, expected, desired, 0, success,
fail)
The type of the "weak" parameter to __atomic_compare_exchange_n() is bool, not int, so
use "false" instead of 0. There is probably no practical difference, so I'll leave it up
to you.
You might need to include <stdbool.h> for this... I haven't checked.
+
+#define rte_atomic_compare_exchange_weak_explicit(obj, expected,
desired, success, fail) \
+ __atomic_compare_exchange_n(obj, expected, desired, 1, success,
fail)
Same as above: Use "true" instead of 1.
+
+#define rte_atomic_fetch_add_explicit(obj, arg, order) \
+ __atomic_fetch_add(obj, arg, order)
+
+#define rte_atomic_fetch_sub_explicit(obj, arg, order) \
+ __atomic_fetch_sub(obj, arg, order)
+
+#define rte_atomic_fetch_or_explicit(obj, arg, order) \
+ __atomic_fetch_or(obj, arg, order)
+
+#define rte_atomic_fetch_xor_explicit(obj, arg, order) \
+ __atomic_fetch_xor(obj, arg, order)
+
+#define rte_atomic_fetch_and_explicit(obj, arg, order) \
+ __atomic_fetch_and(obj, arg, order)
+
+#endif
+
/**
* Compiler barrier.
*
@@ -123,7 +217,7 @@
/**
* Synchronization fence between threads based on the specified memory
order.
*/
-static inline void rte_atomic_thread_fence(int memorder);
+static inline void rte_atomic_thread_fence(rte_memory_order memorder);
/*------------------------- 16 bit atomic operations -----------------
--------*/
diff --git a/lib/eal/loongarch/include/rte_atomic.h
b/lib/eal/loongarch/include/rte_atomic.h
index 3c82845..66aa0c8 100644
--- a/lib/eal/loongarch/include/rte_atomic.h
+++ b/lib/eal/loongarch/include/rte_atomic.h
@@ -35,9 +35,13 @@
#define rte_io_rmb() rte_mb()
static __rte_always_inline void
-rte_atomic_thread_fence(int memorder)
+rte_atomic_thread_fence(rte_memory_order memorder)
{
+#ifdef RTE_STDC_ATOMICS
+ atomic_thread_fence(memorder);
+#else
__atomic_thread_fence(memorder);
+#endif
}
#ifdef __cplusplus
diff --git a/lib/eal/ppc/include/rte_atomic.h
b/lib/eal/ppc/include/rte_atomic.h
index 663b4d3..a428a83 100644
--- a/lib/eal/ppc/include/rte_atomic.h
+++ b/lib/eal/ppc/include/rte_atomic.h
@@ -38,9 +38,13 @@
#define rte_io_rmb() rte_rmb()
static __rte_always_inline void
-rte_atomic_thread_fence(int memorder)
+rte_atomic_thread_fence(rte_memory_order memorder)
{
+#ifdef RTE_STDC_ATOMICS
+ atomic_thread_fence(memorder);
+#else
__atomic_thread_fence(memorder);
+#endif
}
/*------------------------- 16 bit atomic operations -----------------
--------*/
diff --git a/lib/eal/riscv/include/rte_atomic.h
b/lib/eal/riscv/include/rte_atomic.h
index 4b4633c..3c203a9 100644
--- a/lib/eal/riscv/include/rte_atomic.h
+++ b/lib/eal/riscv/include/rte_atomic.h
@@ -40,9 +40,13 @@
#define rte_io_rmb() asm volatile("fence ir, ir" : : : "memory")
static __rte_always_inline void
-rte_atomic_thread_fence(int memorder)
+rte_atomic_thread_fence(rte_memory_order memorder)
{
+#ifdef RTE_STDC_ATOMICS
+ atomic_thread_fence(memorder);
+#else
__atomic_thread_fence(memorder);
+#endif
}
#ifdef __cplusplus
diff --git a/lib/eal/x86/include/rte_atomic.h
b/lib/eal/x86/include/rte_atomic.h
index f2ee1a9..02d8b12 100644
--- a/lib/eal/x86/include/rte_atomic.h
+++ b/lib/eal/x86/include/rte_atomic.h
@@ -87,12 +87,16 @@
* used instead.
*/
static __rte_always_inline void
-rte_atomic_thread_fence(int memorder)
+rte_atomic_thread_fence(rte_memory_order memorder)
{
- if (memorder == __ATOMIC_SEQ_CST)
+ if (memorder == rte_memory_order_seq_cst)
rte_smp_mb();
else
+#ifdef RTE_STDC_ATOMICS
+ atomic_thread_fence(memorder);
+#else
__atomic_thread_fence(memorder);
+#endif
}
/*------------------------- 16 bit atomic operations -----------------
--------*/
diff --git a/meson_options.txt b/meson_options.txt
index 0852849..acbcbb8 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -46,6 +46,8 @@ option('mbuf_refcnt_atomic', type: 'boolean', value:
true, description:
'Atomically access the mbuf refcnt.')
option('platform', type: 'string', value: 'native', description:
'Platform to build, either "native", "generic" or a SoC. Please
refer to the Linux build guide for more information.')
+option('enable_stdatomics', type: 'boolean', value: false,
description:
+ 'enable use of standard C11 atomics.')
option('enable_trace_fp', type: 'boolean', value: false, description:
'enable fast path trace points.')
option('tests', type: 'boolean', value: true, description:
--
1.8.3.1
