ceph/src/include/Spinlock.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2013 Inktank
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  * @author Sage Weil <sage@inktank.com>
  14  */
  15
  16 #ifndef CEPH_SPINLOCK_H
  17 #define CEPH_SPINLOCK_H
  18
  19 #include "acconfig.h"
  20
  21 #include <pthread.h>
  22
  23 typedef struct {
  24 #ifdef HAVE_PTHREAD_SPINLOCK
  25   pthread_spinlock_t lock;
  26 #else
  27   pthread_mutex_t lock;
  28 #endif
  29 } ceph_spinlock_t;
  30
  31 #ifdef HAVE_PTHREAD_SPINLOCK
  32
  33 static inline int ceph_spin_init(ceph_spinlock_t *l)
  34 {
  35   return pthread_spin_init(&l->lock, PTHREAD_PROCESS_PRIVATE);
  36 }
  37
  38 static inline int ceph_spin_destroy(ceph_spinlock_t *l)
  39 {
  40   return pthread_spin_destroy(&l->lock);
  41 }
  42
  43 static inline int ceph_spin_lock(ceph_spinlock_t *l)
  44 {
  45   return pthread_spin_lock(&l->lock);
  46 }
  47
  48 static inline int ceph_spin_unlock(ceph_spinlock_t *l)
  49 {
  50   return pthread_spin_unlock(&l->lock);
  51 }
  52
  53 #else /* !HAVE_PTHREAD_SPINLOCK */
  54
  55 static inline int ceph_spin_init(ceph_spinlock_t *l)
  56 {
  57   return pthread_mutex_init(&l->lock, NULL);
  58 }
  59
  60 static inline int ceph_spin_destroy(ceph_spinlock_t *l)
  61 {
  62   return pthread_mutex_destroy(&l->lock);
  63 }
  64
  65 static inline int ceph_spin_lock(ceph_spinlock_t *l)
  66 {
  67   return pthread_mutex_lock(&l->lock);
  68 }
  69
  70 static inline int ceph_spin_unlock(ceph_spinlock_t *l)
  71 {
  72   return pthread_mutex_unlock(&l->lock);
  73 }
  74
  75 #endif
  76
  77 class Spinlock {
  78   mutable ceph_spinlock_t _lock;
  79
  80 public:
  81   Spinlock() {
  82     ceph_spin_init(&_lock);
  83   }
  84   ~Spinlock() {
  85     ceph_spin_destroy(&_lock);
  86   }
  87
  88   // don't allow copying.
  89   void operator=(Spinlock& s);
  90   Spinlock(const Spinlock& s);
  91
  92   /// acquire spinlock
  93   void lock() const {
  94     ceph_spin_lock(&_lock);
  95   }
  96   /// release spinlock
  97   void unlock() const {
  98     ceph_spin_unlock(&_lock);
  99   }
 100
 101   class Locker {
 102     const Spinlock& spinlock;
 103   public:
 104     Locker(const Spinlock& s) : spinlock(s) {
 105       spinlock.lock();
 106     }
 107     ~Locker() {
 108       spinlock.unlock();
 109     }
 110   };
 111 };
 112
 113 #endif