Adding upstream version 15.5.upstream/15.5

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

1 files changed, 401 insertions, 0 deletions

diff --git a/src/include/port/atomics/generic.h b/src/include/port/atomics/generic.h
new file mode 100644
index 0000000..a1f2456
--- /dev/null
+++ b/src/include/port/atomics/generic.h
@@ -0,0 +1,401 @@
+/*-------------------------------------------------------------------------
+ *
+ * generic.h
+ *	  Implement higher level operations based on some lower level atomic
+ *	  operations.
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/port/atomics/generic.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/* intentionally no include guards, should only be included by atomics.h */
+#ifndef INSIDE_ATOMICS_H
+#	error "should be included via atomics.h"
+#endif
+
+/*
+ * If read or write barriers are undefined, we upgrade them to full memory
+ * barriers.
+ */
+#if !defined(pg_read_barrier_impl)
+#	define pg_read_barrier_impl pg_memory_barrier_impl
+#endif
+#if !defined(pg_write_barrier_impl)
+#	define pg_write_barrier_impl pg_memory_barrier_impl
+#endif
+
+#ifndef PG_HAVE_SPIN_DELAY
+#define PG_HAVE_SPIN_DELAY
+#define pg_spin_delay_impl()	((void)0)
+#endif
+
+
+/* provide fallback */
+#if !defined(PG_HAVE_ATOMIC_FLAG_SUPPORT) && defined(PG_HAVE_ATOMIC_U32_SUPPORT)
+#define PG_HAVE_ATOMIC_FLAG_SUPPORT
+typedef pg_atomic_uint32 pg_atomic_flag;
+#endif
+
+#ifndef PG_HAVE_ATOMIC_READ_U32
+#define PG_HAVE_ATOMIC_READ_U32
+static inline uint32
+pg_atomic_read_u32_impl(volatile pg_atomic_uint32 *ptr)
+{
+	return ptr->value;
+}
+#endif
+
+#ifndef PG_HAVE_ATOMIC_WRITE_U32
+#define PG_HAVE_ATOMIC_WRITE_U32
+static inline void
+pg_atomic_write_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 val)
+{
+	ptr->value = val;
+}
+#endif
+
+#ifndef PG_HAVE_ATOMIC_UNLOCKED_WRITE_U32
+#define PG_HAVE_ATOMIC_UNLOCKED_WRITE_U32
+static inline void
+pg_atomic_unlocked_write_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 val)
+{
+	ptr->value = val;
+}
+#endif
+
+/*
+ * provide fallback for test_and_set using atomic_exchange if available
+ */
+#if !defined(PG_HAVE_ATOMIC_TEST_SET_FLAG) && defined(PG_HAVE_ATOMIC_EXCHANGE_U32)
+
+#define PG_HAVE_ATOMIC_INIT_FLAG
+static inline void
+pg_atomic_init_flag_impl(volatile pg_atomic_flag *ptr)
+{
+	pg_atomic_write_u32_impl(ptr, 0);
+}
+
+#define PG_HAVE_ATOMIC_TEST_SET_FLAG
+static inline bool
+pg_atomic_test_set_flag_impl(volatile pg_atomic_flag *ptr)
+{
+	return pg_atomic_exchange_u32_impl(ptr, &value, 1) == 0;
+}
+
+#define PG_HAVE_ATOMIC_UNLOCKED_TEST_FLAG
+static inline bool
+pg_atomic_unlocked_test_flag_impl(volatile pg_atomic_flag *ptr)
+{
+	return pg_atomic_read_u32_impl(ptr) == 0;
+}
+
+
+#define PG_HAVE_ATOMIC_CLEAR_FLAG
+static inline void
+pg_atomic_clear_flag_impl(volatile pg_atomic_flag *ptr)
+{
+	/* XXX: release semantics suffice? */
+	pg_memory_barrier_impl();
+	pg_atomic_write_u32_impl(ptr, 0);
+}
+
+/*
+ * provide fallback for test_and_set using atomic_compare_exchange if
+ * available.
+ */
+#elif !defined(PG_HAVE_ATOMIC_TEST_SET_FLAG) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U32)
+
+#define PG_HAVE_ATOMIC_INIT_FLAG
+static inline void
+pg_atomic_init_flag_impl(volatile pg_atomic_flag *ptr)
+{
+	pg_atomic_write_u32_impl(ptr, 0);
+}
+
+#define PG_HAVE_ATOMIC_TEST_SET_FLAG
+static inline bool
+pg_atomic_test_set_flag_impl(volatile pg_atomic_flag *ptr)
+{
+	uint32 value = 0;
+	return pg_atomic_compare_exchange_u32_impl(ptr, &value, 1);
+}
+
+#define PG_HAVE_ATOMIC_UNLOCKED_TEST_FLAG
+static inline bool
+pg_atomic_unlocked_test_flag_impl(volatile pg_atomic_flag *ptr)
+{
+	return pg_atomic_read_u32_impl(ptr) == 0;
+}
+
+#define PG_HAVE_ATOMIC_CLEAR_FLAG
+static inline void
+pg_atomic_clear_flag_impl(volatile pg_atomic_flag *ptr)
+{
+	/*
+	 * Use a memory barrier + plain write if we have a native memory
+	 * barrier. But don't do so if memory barriers use spinlocks - that'd lead
+	 * to circularity if flags are used to implement spinlocks.
+	 */
+#ifndef PG_HAVE_MEMORY_BARRIER_EMULATION
+	/* XXX: release semantics suffice? */
+	pg_memory_barrier_impl();
+	pg_atomic_write_u32_impl(ptr, 0);
+#else
+	uint32 value = 1;
+	pg_atomic_compare_exchange_u32_impl(ptr, &value, 0);
+#endif
+}
+
+#elif !defined(PG_HAVE_ATOMIC_TEST_SET_FLAG)
+#	error "No pg_atomic_test_and_set provided"
+#endif /* !defined(PG_HAVE_ATOMIC_TEST_SET_FLAG) */
+
+
+#ifndef PG_HAVE_ATOMIC_INIT_U32
+#define PG_HAVE_ATOMIC_INIT_U32
+static inline void
+pg_atomic_init_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 val_)
+{
+	ptr->value = val_;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_EXCHANGE_U32) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U32)
+#define PG_HAVE_ATOMIC_EXCHANGE_U32
+static inline uint32
+pg_atomic_exchange_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 xchg_)
+{
+	uint32 old;
+	old = ptr->value;			/* ok if read is not atomic */
+	while (!pg_atomic_compare_exchange_u32_impl(ptr, &old, xchg_))
+		/* skip */;
+	return old;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_FETCH_ADD_U32) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U32)
+#define PG_HAVE_ATOMIC_FETCH_ADD_U32
+static inline uint32
+pg_atomic_fetch_add_u32_impl(volatile pg_atomic_uint32 *ptr, int32 add_)
+{
+	uint32 old;
+	old = ptr->value;			/* ok if read is not atomic */
+	while (!pg_atomic_compare_exchange_u32_impl(ptr, &old, old + add_))
+		/* skip */;
+	return old;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_FETCH_SUB_U32) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U32)
+#define PG_HAVE_ATOMIC_FETCH_SUB_U32
+static inline uint32
+pg_atomic_fetch_sub_u32_impl(volatile pg_atomic_uint32 *ptr, int32 sub_)
+{
+	return pg_atomic_fetch_add_u32_impl(ptr, -sub_);
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_FETCH_AND_U32) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U32)
+#define PG_HAVE_ATOMIC_FETCH_AND_U32
+static inline uint32
+pg_atomic_fetch_and_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 and_)
+{
+	uint32 old;
+	old = ptr->value;			/* ok if read is not atomic */
+	while (!pg_atomic_compare_exchange_u32_impl(ptr, &old, old & and_))
+		/* skip */;
+	return old;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_FETCH_OR_U32) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U32)
+#define PG_HAVE_ATOMIC_FETCH_OR_U32
+static inline uint32
+pg_atomic_fetch_or_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 or_)
+{
+	uint32 old;
+	old = ptr->value;			/* ok if read is not atomic */
+	while (!pg_atomic_compare_exchange_u32_impl(ptr, &old, old | or_))
+		/* skip */;
+	return old;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_ADD_FETCH_U32) && defined(PG_HAVE_ATOMIC_FETCH_ADD_U32)
+#define PG_HAVE_ATOMIC_ADD_FETCH_U32
+static inline uint32
+pg_atomic_add_fetch_u32_impl(volatile pg_atomic_uint32 *ptr, int32 add_)
+{
+	return pg_atomic_fetch_add_u32_impl(ptr, add_) + add_;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_SUB_FETCH_U32) && defined(PG_HAVE_ATOMIC_FETCH_SUB_U32)
+#define PG_HAVE_ATOMIC_SUB_FETCH_U32
+static inline uint32
+pg_atomic_sub_fetch_u32_impl(volatile pg_atomic_uint32 *ptr, int32 sub_)
+{
+	return pg_atomic_fetch_sub_u32_impl(ptr, sub_) - sub_;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_EXCHANGE_U64) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U64)
+#define PG_HAVE_ATOMIC_EXCHANGE_U64
+static inline uint64
+pg_atomic_exchange_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 xchg_)
+{
+	uint64 old;
+	old = ptr->value;			/* ok if read is not atomic */
+	while (!pg_atomic_compare_exchange_u64_impl(ptr, &old, xchg_))
+		/* skip */;
+	return old;
+}
+#endif
+
+#ifndef PG_HAVE_ATOMIC_WRITE_U64
+#define PG_HAVE_ATOMIC_WRITE_U64
+
+#if defined(PG_HAVE_8BYTE_SINGLE_COPY_ATOMICITY) && \
+	!defined(PG_HAVE_ATOMIC_U64_SIMULATION)
+
+static inline void
+pg_atomic_write_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 val)
+{
+	/*
+	 * On this platform aligned 64bit writes are guaranteed to be atomic,
+	 * except if using the fallback implementation, where can't guarantee the
+	 * required alignment.
+	 */
+	AssertPointerAlignment(ptr, 8);
+	ptr->value = val;
+}
+
+#else
+
+static inline void
+pg_atomic_write_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 val)
+{
+	/*
+	 * 64 bit writes aren't safe on all platforms. In the generic
+	 * implementation implement them as an atomic exchange.
+	 */
+	pg_atomic_exchange_u64_impl(ptr, val);
+}
+
+#endif /* PG_HAVE_8BYTE_SINGLE_COPY_ATOMICITY && !PG_HAVE_ATOMIC_U64_SIMULATION */
+#endif /* PG_HAVE_ATOMIC_WRITE_U64 */
+
+#ifndef PG_HAVE_ATOMIC_READ_U64
+#define PG_HAVE_ATOMIC_READ_U64
+
+#if defined(PG_HAVE_8BYTE_SINGLE_COPY_ATOMICITY) && \
+	!defined(PG_HAVE_ATOMIC_U64_SIMULATION)
+
+static inline uint64
+pg_atomic_read_u64_impl(volatile pg_atomic_uint64 *ptr)
+{
+	/*
+	 * On this platform aligned 64-bit reads are guaranteed to be atomic.
+	 */
+	AssertPointerAlignment(ptr, 8);
+	return ptr->value;
+}
+
+#else
+
+static inline uint64
+pg_atomic_read_u64_impl(volatile pg_atomic_uint64 *ptr)
+{
+	uint64 old = 0;
+
+	/*
+	 * 64-bit reads aren't atomic on all platforms. In the generic
+	 * implementation implement them as a compare/exchange with 0. That'll
+	 * fail or succeed, but always return the old value. Possibly might store
+	 * a 0, but only if the previous value also was a 0 - i.e. harmless.
+	 */
+	pg_atomic_compare_exchange_u64_impl(ptr, &old, 0);
+
+	return old;
+}
+#endif /* PG_HAVE_8BYTE_SINGLE_COPY_ATOMICITY && !PG_HAVE_ATOMIC_U64_SIMULATION */
+#endif /* PG_HAVE_ATOMIC_READ_U64 */
+
+#ifndef PG_HAVE_ATOMIC_INIT_U64
+#define PG_HAVE_ATOMIC_INIT_U64
+static inline void
+pg_atomic_init_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 val_)
+{
+	ptr->value = val_;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_FETCH_ADD_U64) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U64)
+#define PG_HAVE_ATOMIC_FETCH_ADD_U64
+static inline uint64
+pg_atomic_fetch_add_u64_impl(volatile pg_atomic_uint64 *ptr, int64 add_)
+{
+	uint64 old;
+	old = ptr->value;			/* ok if read is not atomic */
+	while (!pg_atomic_compare_exchange_u64_impl(ptr, &old, old + add_))
+		/* skip */;
+	return old;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_FETCH_SUB_U64) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U64)
+#define PG_HAVE_ATOMIC_FETCH_SUB_U64
+static inline uint64
+pg_atomic_fetch_sub_u64_impl(volatile pg_atomic_uint64 *ptr, int64 sub_)
+{
+	return pg_atomic_fetch_add_u64_impl(ptr, -sub_);
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_FETCH_AND_U64) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U64)
+#define PG_HAVE_ATOMIC_FETCH_AND_U64
+static inline uint64
+pg_atomic_fetch_and_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 and_)
+{
+	uint64 old;
+	old = ptr->value;			/* ok if read is not atomic */
+	while (!pg_atomic_compare_exchange_u64_impl(ptr, &old, old & and_))
+		/* skip */;
+	return old;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_FETCH_OR_U64) && defined(PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U64)
+#define PG_HAVE_ATOMIC_FETCH_OR_U64
+static inline uint64
+pg_atomic_fetch_or_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 or_)
+{
+	uint64 old;
+	old = ptr->value;			/* ok if read is not atomic */
+	while (!pg_atomic_compare_exchange_u64_impl(ptr, &old, old | or_))
+		/* skip */;
+	return old;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_ADD_FETCH_U64) && defined(PG_HAVE_ATOMIC_FETCH_ADD_U64)
+#define PG_HAVE_ATOMIC_ADD_FETCH_U64
+static inline uint64
+pg_atomic_add_fetch_u64_impl(volatile pg_atomic_uint64 *ptr, int64 add_)
+{
+	return pg_atomic_fetch_add_u64_impl(ptr, add_) + add_;
+}
+#endif
+
+#if !defined(PG_HAVE_ATOMIC_SUB_FETCH_U64) && defined(PG_HAVE_ATOMIC_FETCH_SUB_U64)
+#define PG_HAVE_ATOMIC_SUB_FETCH_U64
+static inline uint64
+pg_atomic_sub_fetch_u64_impl(volatile pg_atomic_uint64 *ptr, int64 sub_)
+{
+	return pg_atomic_fetch_sub_u64_impl(ptr, sub_) - sub_;
+}
+#endif