diff options
| -rw-r--r-- | libglusterfs/src/Makefile.am | 2 | ||||
| -rw-r--r-- | libglusterfs/src/locking.c | 28 | ||||
| -rw-r--r-- | libglusterfs/src/locking.h | 59 |
3 files changed, 79 insertions, 10 deletions
diff --git a/libglusterfs/src/Makefile.am b/libglusterfs/src/Makefile.am index e0acc3c4e58..39ae9e05091 100644 --- a/libglusterfs/src/Makefile.am +++ b/libglusterfs/src/Makefile.am @@ -31,7 +31,7 @@ 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 tw.c default-args.c + $(CONTRIBDIR)/timer-wheel/find_last_bit.c tw.c default-args.c locking.c nodist_libglusterfs_la_SOURCES = y.tab.c graph.lex.c defaults.c nodist_libglusterfs_la_HEADERS = y.tab.h diff --git a/libglusterfs/src/locking.c b/libglusterfs/src/locking.c new file mode 100644 index 00000000000..d3b9754ef76 --- /dev/null +++ b/libglusterfs/src/locking.c @@ -0,0 +1,28 @@ +/* + 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 "locking.h" + +int use_spinlocks = 0; + +static void __attribute__((constructor)) +gf_lock_setup (void) +{ + use_spinlocks = (sysconf(_SC_NPROCESSORS_ONLN) > 1); +} + +#endif diff --git a/libglusterfs/src/locking.h b/libglusterfs/src/locking.h index 24edf9aed44..71b6a286e6c 100644 --- a/libglusterfs/src/locking.h +++ b/libglusterfs/src/locking.h @@ -12,7 +12,8 @@ #define _LOCKING_H #include <pthread.h> -#ifdef GF_DARWIN_HOST_OS + +#if defined (GF_DARWIN_HOST_OS) #include <libkern/OSAtomic.h> #define pthread_spinlock_t OSSpinLock #define pthread_spin_lock(l) OSSpinLockLock(l) @@ -21,23 +22,63 @@ #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))) -#if HAVE_SPINLOCK -#define LOCK_INIT(x) pthread_spin_init (x, 0) -#define LOCK(x) pthread_spin_lock (x) -#define TRY_LOCK(x) pthread_spin_trylock (x) -#define UNLOCK(x) pthread_spin_unlock (x) -#define LOCK_DESTROY(x) pthread_spin_destroy (x) +#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 -typedef pthread_spinlock_t gf_lock_t; #else + +typedef pthread_mutex_t gf_lock_t; + #define LOCK_INIT(x) pthread_mutex_init (x, 0) #define LOCK(x) pthread_mutex_lock (x) #define TRY_LOCK(x) pthread_mutex_trylock (x) #define UNLOCK(x) pthread_mutex_unlock (x) #define LOCK_DESTROY(x) pthread_mutex_destroy (x) -typedef pthread_mutex_t gf_lock_t; #endif /* HAVE_SPINLOCK */ |