Adding upstream version 3.4.0.upstream/3.4.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 73 insertions, 0 deletions

diff --git a/src/contrib/atomic.h b/src/contrib/atomic.h
new file mode 100644
index 0000000..b8dace1
--- /dev/null
+++ b/src/contrib/atomic.h
@@ -0,0 +1,73 @@
+/*  Copyright (C) 2024 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/*!
+ * \brief C11 atomic operations with fallbacks.
+ */
+
+#pragma once
+
+#ifdef HAVE_C11_ATOMIC           /* C11 */
+ #define KNOT_HAVE_ATOMIC
+
+ #include <stdatomic.h>
+
+ #define ATOMIC_SET(dst, val)  atomic_store_explicit(&(dst), (val), memory_order_relaxed)
+ #define ATOMIC_GET(src)       atomic_load_explicit(&(src), memory_order_relaxed)
+ #define ATOMIC_ADD(dst, val)  (void)atomic_fetch_add_explicit(&(dst), (val), memory_order_relaxed)
+ #define ATOMIC_SUB(dst, val)  (void)atomic_fetch_sub_explicit(&(dst), (val), memory_order_relaxed)
+ #define ATOMIC_XCHG(dst, val) atomic_exchange_explicit(&(dst), (val), memory_order_relaxed)
+
+ typedef atomic_uint_fast16_t knot_atomic_uint16_t;
+ typedef atomic_uint_fast64_t knot_atomic_uint64_t;
+ typedef atomic_size_t knot_atomic_size_t;
+ typedef _Atomic (void *) knot_atomic_ptr_t;
+ typedef atomic_bool knot_atomic_bool;
+#elif defined(HAVE_GCC_ATOMIC)   /* GCC __atomic */
+ #define KNOT_HAVE_ATOMIC
+
+ #include <stdint.h>
+ #include <stdbool.h>
+
+ #define ATOMIC_SET(dst, val)  __atomic_store_n(&(dst), (val), __ATOMIC_RELAXED)
+ #define ATOMIC_GET(src)       __atomic_load_n(&(src), __ATOMIC_RELAXED)
+ #define ATOMIC_ADD(dst, val)  __atomic_add_fetch(&(dst), (val), __ATOMIC_RELAXED)
+ #define ATOMIC_SUB(dst, val)  __atomic_sub_fetch(&(dst), (val), __ATOMIC_RELAXED)
+ #define ATOMIC_XCHG(dst, val) __atomic_exchange_n(&(dst), (val), __ATOMIC_RELAXED)
+
+ typedef uint16_t knot_atomic_uint16_t;
+ typedef uint64_t knot_atomic_uint64_t;
+ typedef size_t knot_atomic_size_t;
+ typedef void* knot_atomic_ptr_t;
+ typedef bool knot_atomic_bool;
+#else                            /* Fallback, non-atomic. */
+ #warning "Atomic operations not availabe, using unreliable replacement."
+
+ #include <stdint.h>
+ #include <stdbool.h>
+
+ #define ATOMIC_SET(dst, val)  ((dst) = (val))
+ #define ATOMIC_GET(src)       (src)
+ #define ATOMIC_ADD(dst, val)  ((dst) += (val))
+ #define ATOMIC_SUB(dst, val)  ((dst) -= (val))
+ #define ATOMIC_XCHG(dst, val) ({ __typeof__ (dst) _z = (dst); (dst) = (val); _z; })
+
+ typedef uint16_t knot_atomic_uint16_t;
+ typedef uint64_t knot_atomic_uint64_t;
+ typedef size_t knot_atomic_size_t;
+ typedef void* knot_atomic_ptr_t;
+ typedef bool knot_atomic_bool;
+#endif