From 1491b33007e84be0a0a74354e89deca8a21ed198 Mon Sep 17 00:00:00 2001
From: Vinayak hariharmath <[email protected]>
Date: Tue, 19 Jan 2021 15:39:35 +0530
Subject: [PATCH 572/584] locks: remove unused conditional switch to spin_lock
 code

use of spin_locks is depend on the variable use_spinlocks
but the same is commented in the current code base through
https://review.gluster.org/#/c/glusterfs/+/14763/. So it is
of no use to have conditional switching to spin_lock or
mutex. Removing the dead code as part of the patch

Backport of:
> Upstream-patch: https://github.com/gluster/glusterfs/pull/2007
> Fixes: #1996
> Change-Id: Ib005dd86969ce33d3409164ef3e1011bb3169129
> Signed-off-by: Vinayakswami Hariharmath <[email protected]>

BUG: 1925425
Change-Id: Ib005dd86969ce33d3409164ef3e1011bb3169129
Signed-off-by: Vinayakswami Hariharmath <[email protected]>
Reviewed-on: https://code.engineering.redhat.com/gerrit/c/rhs-glusterfs/+/244965
Tested-by: RHGS Build Bot <[email protected]>
Reviewed-by: Sunil Kumar Heggodu Gopala Acharya <[email protected]>
---
 configure.ac                         |  7 -----
 libglusterfs/src/Makefile.am         |  2 +-
 libglusterfs/src/common-utils.c      |  5 ----
 libglusterfs/src/glusterfs/locking.h | 51 ------------------------------------
 libglusterfs/src/locking.c           | 27 -------------------
 5 files changed, 1 insertion(+), 91 deletions(-)
 delete mode 100644 libglusterfs/src/locking.c

diff --git a/configure.ac b/configure.ac
index 6138a59..3d99f6a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -585,13 +585,6 @@ AC_CHECK_HEADERS([linux/falloc.h])
 
 AC_CHECK_HEADERS([linux/oom.h], AC_DEFINE(HAVE_LINUX_OOM_H, 1, [have linux/oom.h]))
 
-dnl Mac OS X does not have spinlocks
-AC_CHECK_FUNC([pthread_spin_init], [have_spinlock=yes])
-if test "x${have_spinlock}" = "xyes"; then
-   AC_DEFINE(HAVE_SPINLOCK, 1, [define if found spinlock])
-fi
-AC_SUBST(HAVE_SPINLOCK)
-
 dnl some os may not have GNU defined strnlen function
 AC_CHECK_FUNC([strnlen], [have_strnlen=yes])
 if test "x${have_strnlen}" = "xyes"; then
diff --git a/libglusterfs/src/Makefile.am b/libglusterfs/src/Makefile.am
index 970f4b7..830a0c3 100644
--- a/libglusterfs/src/Makefile.am
+++ b/libglusterfs/src/Makefile.am
@@ -35,7 +35,7 @@ libglusterfs_la_SOURCES = dict.c xlator.c logging.c \
 	strfd.c parse-utils.c $(CONTRIBDIR)/mount/mntent.c \
 	$(CONTRIBDIR)/libexecinfo/execinfo.c quota-common-utils.c rot-buffs.c \
 	$(CONTRIBDIR)/timer-wheel/timer-wheel.c \
-	$(CONTRIBDIR)/timer-wheel/find_last_bit.c default-args.c locking.c \
+	$(CONTRIBDIR)/timer-wheel/find_last_bit.c default-args.c \
 	$(CONTRIBDIR)/xxhash/xxhash.c \
 	compound-fop-utils.c throttle-tbf.c monitoring.c
 
diff --git a/libglusterfs/src/common-utils.c b/libglusterfs/src/common-utils.c
index d351b93..c2dfe28 100644
--- a/libglusterfs/src/common-utils.c
+++ b/libglusterfs/src/common-utils.c
@@ -860,11 +860,6 @@ gf_dump_config_flags()
     gf_msg_plain_nomem(GF_LOG_ALERT, "setfsid 1");
 #endif
 
-/* define if found spinlock */
-#ifdef HAVE_SPINLOCK
-    gf_msg_plain_nomem(GF_LOG_ALERT, "spinlock 1");
-#endif
-
 /* Define to 1 if you have the <sys/epoll.h> header file. */
 #ifdef HAVE_SYS_EPOLL_H
     gf_msg_plain_nomem(GF_LOG_ALERT, "epoll.h 1");
diff --git a/libglusterfs/src/glusterfs/locking.h b/libglusterfs/src/glusterfs/locking.h
index 43cc877..63097bb 100644
--- a/libglusterfs/src/glusterfs/locking.h
+++ b/libglusterfs/src/glusterfs/locking.h
@@ -22,55 +22,6 @@
 #define pthread_spin_init(l, v) (*l = v)
 #endif
 
-#if defined(HAVE_SPINLOCK)
-
-typedef union {
-    pthread_spinlock_t spinlock;
-    pthread_mutex_t mutex;
-} gf_lock_t;
-
-#if !defined(LOCKING_IMPL)
-extern int use_spinlocks;
-
-/*
- * Using a dispatch table would be unpleasant because we're dealing with two
- * different types.  If the dispatch contains direct pointers to pthread_xx
- * or mutex_xxx then we have to hope that every possible union alternative
- * starts at the same address as the union itself.  I'm old enough to remember
- * compilers where this was not the case (for alignment reasons) so I'm a bit
- * paranoid about that.  Also, I don't like casting arguments through "void *"
- * which we'd also have to do to avoid type errors.  The other alternative would
- * be to define actual functions which pick out the right union member, and put
- * those in the dispatch tables.  Now we have a pointer dereference through the
- * dispatch table plus a function call, which is likely to be worse than the
- * branching here from the ?: construct.  If it were a clear win it might be
- * worth the extra complexity, but for now this way seems preferable.
- */
-
-#define LOCK_INIT(x)                                                           \
-    (use_spinlocks ? pthread_spin_init(&((x)->spinlock), 0)                    \
-                   : pthread_mutex_init(&((x)->mutex), 0))
-
-#define LOCK(x)                                                                \
-    (use_spinlocks ? pthread_spin_lock(&((x)->spinlock))                       \
-                   : pthread_mutex_lock(&((x)->mutex)))
-
-#define TRY_LOCK(x)                                                            \
-    (use_spinlocks ? pthread_spin_trylock(&((x)->spinlock))                    \
-                   : pthread_mutex_trylock(&((x)->mutex)))
-
-#define UNLOCK(x)                                                              \
-    (use_spinlocks ? pthread_spin_unlock(&((x)->spinlock))                     \
-                   : pthread_mutex_unlock(&((x)->mutex)))
-
-#define LOCK_DESTROY(x)                                                        \
-    (use_spinlocks ? pthread_spin_destroy(&((x)->spinlock))                    \
-                   : pthread_mutex_destroy(&((x)->mutex)))
-
-#endif
-
-#else
-
 typedef pthread_mutex_t gf_lock_t;
 
 #define LOCK_INIT(x) pthread_mutex_init(x, 0)
@@ -79,6 +30,4 @@ typedef pthread_mutex_t gf_lock_t;
 #define UNLOCK(x) pthread_mutex_unlock(x)
 #define LOCK_DESTROY(x) pthread_mutex_destroy(x)
 
-#endif /* HAVE_SPINLOCK */
-
 #endif /* _LOCKING_H */
diff --git a/libglusterfs/src/locking.c b/libglusterfs/src/locking.c
deleted file mode 100644
index 7577054..0000000
--- a/libglusterfs/src/locking.c
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
-  Copyright (c) 2015 Red Hat, Inc. <http://www.redhat.com>
-  This file is part of GlusterFS.
-
-  This file is licensed to you under your choice of the GNU Lesser
-  General Public License, version 3 or any later version (LGPLv3 or
-  later), or the GNU General Public License, version 2 (GPLv2), in all
-  cases as published by the Free Software Foundation.
-*/
-
-#if defined(HAVE_SPINLOCK)
-/* None of this matters otherwise. */
-
-#include <pthread.h>
-#include <unistd.h>
-
-#define LOCKING_IMPL
-#include "glusterfs/locking.h"
-
-int use_spinlocks = 0;
-
-static void __attribute__((constructor)) gf_lock_setup(void)
-{
-    // use_spinlocks = (sysconf(_SC_NPROCESSORS_ONLN) > 1);
-}
-
-#endif
-- 
1.8.3.1