From 2eb37622418a5c9f31a9d728a99bc621d3157ab0 Mon Sep 17 00:00:00 2001 From: Philip Withnall Date: Sat, 21 Sep 2019 17:34:37 +0200 Subject: [PATCH] gatomic: Use new __atomic_*() intrinsics for all atomic operations Previously we used the old `__sync_fetch_*()` intrinsics for some of the atomic operations, such as `g_atomic_int_compare_and_exchange()`. When available, use the new `__atomic_*()` intrinsics for those instead. As with the rest of our use of `__atomic_*()` intrinsics, we use the `__ATOMIC_SEQ_CST` memory model. If people want to use a less restrictive memory model to get better performance in certain situations, they can use the compiler intrinsics directly themselves. `g_atomic_*()` aim to be as fast as possible while remaining general purpose. Tested using: ``` meson test --repeat 1000 atomic atomic-test ``` Signed-off-by: Philip Withnall Fixes: #1750 --- glib/gatomic.h | 90 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 88 insertions(+), 2 deletions(-) diff --git a/glib/gatomic.h b/glib/gatomic.h index 61a99adf2..712553e69 100644 --- a/glib/gatomic.h +++ b/glib/gatomic.h @@ -118,6 +118,92 @@ G_END_DECLS __atomic_store ((gpointer *)(atomic), &gaps_temp, __ATOMIC_SEQ_CST); \ })) +#define g_atomic_int_inc(atomic) \ + (G_GNUC_EXTENSION ({ \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ + (void) (0 ? *(atomic) ^ *(atomic) : 1); \ + (void) __atomic_fetch_add ((atomic), 1, __ATOMIC_SEQ_CST); \ + })) +#define g_atomic_int_dec_and_test(atomic) \ + (G_GNUC_EXTENSION ({ \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ + (void) (0 ? *(atomic) ^ *(atomic) : 1); \ + __atomic_fetch_sub ((atomic), 1, __ATOMIC_SEQ_CST) == 1; \ + })) +#define g_atomic_int_compare_and_exchange(atomic, oldval, newval) \ + (G_GNUC_EXTENSION ({ \ + gint gaicae_oldval = (oldval); \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ + (void) (0 ? *(atomic) ^ (newval) ^ (oldval) : 1); \ + __atomic_compare_exchange_n ((atomic), &gaicae_oldval, (newval), FALSE, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ? TRUE : FALSE; \ + })) +#define g_atomic_int_add(atomic, val) \ + (G_GNUC_EXTENSION ({ \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ + (void) (0 ? *(atomic) ^ (val) : 1); \ + (gint) __atomic_fetch_add ((atomic), (val), __ATOMIC_SEQ_CST); \ + })) +#define g_atomic_int_and(atomic, val) \ + (G_GNUC_EXTENSION ({ \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ + (void) (0 ? *(atomic) ^ (val) : 1); \ + (guint) __atomic_fetch_and ((atomic), (val), __ATOMIC_SEQ_CST); \ + })) +#define g_atomic_int_or(atomic, val) \ + (G_GNUC_EXTENSION ({ \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ + (void) (0 ? *(atomic) ^ (val) : 1); \ + (guint) __atomic_fetch_or ((atomic), (val), __ATOMIC_SEQ_CST); \ + })) +#define g_atomic_int_xor(atomic, val) \ + (G_GNUC_EXTENSION ({ \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ + (void) (0 ? *(atomic) ^ (val) : 1); \ + (guint) __atomic_fetch_xor ((atomic), (val), __ATOMIC_SEQ_CST); \ + })) + +#define g_atomic_pointer_compare_and_exchange(atomic, oldval, newval) \ + (G_GNUC_EXTENSION ({ \ + __typeof__ ((oldval)) gapcae_oldval = (oldval); \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer)); \ + (void) (0 ? (gpointer) *(atomic) : NULL); \ + __atomic_compare_exchange_n ((atomic), &gapcae_oldval, (newval), FALSE, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ? TRUE : FALSE; \ + })) +#define g_atomic_pointer_add(atomic, val) \ + (G_GNUC_EXTENSION ({ \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer)); \ + (void) (0 ? (gpointer) *(atomic) : NULL); \ + (void) (0 ? (val) ^ (val) : 1); \ + (gssize) __atomic_fetch_add ((atomic), (val), __ATOMIC_SEQ_CST); \ + })) +#define g_atomic_pointer_and(atomic, val) \ + (G_GNUC_EXTENSION ({ \ + volatile gsize *gapa_atomic = (volatile gsize *) (atomic); \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer)); \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gsize)); \ + (void) (0 ? (gpointer) *(atomic) : NULL); \ + (void) (0 ? (val) ^ (val) : 1); \ + (gsize) __atomic_fetch_and (gapa_atomic, (val), __ATOMIC_SEQ_CST); \ + })) +#define g_atomic_pointer_or(atomic, val) \ + (G_GNUC_EXTENSION ({ \ + volatile gsize *gapo_atomic = (volatile gsize *) (atomic); \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer)); \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gsize)); \ + (void) (0 ? (gpointer) *(atomic) : NULL); \ + (void) (0 ? (val) ^ (val) : 1); \ + (gsize) __atomic_fetch_or (gapo_atomic, (val), __ATOMIC_SEQ_CST); \ + })) +#define g_atomic_pointer_xor(atomic, val) \ + (G_GNUC_EXTENSION ({ \ + volatile gsize *gapx_atomic = (volatile gsize *) (atomic); \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer)); \ + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gsize)); \ + (void) (0 ? (gpointer) *(atomic) : NULL); \ + (void) (0 ? (val) ^ (val) : 1); \ + (gsize) __atomic_fetch_xor (gapx_atomic, (val), __ATOMIC_SEQ_CST); \ + })) + #else /* defined(__ATOMIC_SEQ_CST) */ /* We want to achieve __ATOMIC_SEQ_CST semantics here. See @@ -184,8 +270,6 @@ G_END_DECLS *(atomic) = (__typeof__ (*(atomic))) (gsize) (newval); \ })) -#endif /* !defined(__ATOMIC_SEQ_CST) */ - #define g_atomic_int_inc(atomic) \ (G_GNUC_EXTENSION ({ \ G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ @@ -264,6 +348,8 @@ G_END_DECLS (gsize) __sync_fetch_and_xor ((atomic), (val)); \ })) +#endif /* !defined(__ATOMIC_SEQ_CST) */ + #else /* defined(G_ATOMIC_LOCK_FREE) && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) */ #define g_atomic_int_get(atomic) \