From 4030a9fb2eb699361c58d71878e97b282647319a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20M=C3=A4kel=C3=A4?= <marko.makela@mariadb.com>
Date: Fri, 18 Feb 2022 15:13:56 +0200
Subject: [PATCH] MDEV-26476: Implement futex for FreeBSD, DragonFly BSD

---
 storage/innobase/include/rw_lock.h | 16 ++++++++++++----
 storage/innobase/sync/srw_lock.cc  | 13 ++++++++++++-
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/storage/innobase/include/rw_lock.h b/storage/innobase/include/rw_lock.h
index a9099d10670..70607b979c1 100644
--- a/storage/innobase/include/rw_lock.h
+++ b/storage/innobase/include/rw_lock.h
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 2020, 2021, MariaDB Corporation.
+Copyright (c) 2020, 2022, MariaDB Corporation.
 
 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
@@ -20,9 +20,17 @@ this program; if not, write to the Free Software Foundation, Inc.,
 #include <atomic>
 #include "my_dbug.h"
 
-#if !(defined __linux__ || defined __OpenBSD__ || defined _WIN32)
-# define SUX_LOCK_GENERIC
-#elif 0 // defined SAFE_MUTEX
+#if defined __linux__
+/* futex(2): FUTEX_WAIT_PRIVATE, FUTEX_WAKE_PRIVATE */
+#elif defined __OpenBSD__ || defined __FreeBSD__ || defined __DragonFly__
+/* system calls similar to Linux futex(2) */
+#elif defined _WIN32
+/* SRWLOCK as well as WaitOnAddress(), WakeByAddressSingle() */
+#else
+# define SUX_LOCK_GENERIC /* fall back to generic synchronization primitives */
+#endif
+
+#if !defined SUX_LOCK_GENERIC && 0 /* defined SAFE_MUTEX */
 # define SUX_LOCK_GENERIC /* Use dummy implementation for debugging purposes */
 #endif
 
diff --git a/storage/innobase/sync/srw_lock.cc b/storage/innobase/sync/srw_lock.cc
index 71414e8ddb2..f406b04712a 100644
--- a/storage/innobase/sync/srw_lock.cc
+++ b/storage/innobase/sync/srw_lock.cc
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 2020, 2021, MariaDB Corporation.
+Copyright (c) 2020, 2022, MariaDB Corporation.
 
 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
@@ -339,6 +339,17 @@ void ssux_lock_impl<spinloop>::wake() { WakeByAddressSingle(&readers); }
 #   include <sys/futex.h>
 #   define SRW_FUTEX(a,op,n) \
     futex((volatile uint32_t*) a, FUTEX_ ## op, n, nullptr, nullptr)
+#  elif defined __FreeBSD__
+#   include <sys/types.h>
+#   include <sys/umtx.h>
+#   define FUTEX_WAKE UMTX_OP_WAKE_PRIVATE
+#   define FUTEX_WAIT UMTX_OP_WAIT_UINT_PRIVATE
+#   define SRW_FUTEX(a,op,n) _umtx_op(a, FUTEX_ ## op, n, nullptr, nullptr)
+#  elif defined __DragonFly__
+#   include <unistd.h>
+#   define FUTEX_WAKE(a,n) umtx_wakeup(a,n)
+#   define FUTEX_WAIT(a,n) umtx_sleep(a,n,0)
+#   define SRW_FUTEX(a,op,n) FUTEX_ ## op((volatile int*) a, int(n))
 #  else
 #   error "no futex support"
 #  endif