initial code repo

[stor4nfv.git] / src / ceph / src / common / Mutex.h

diff --git a/src/ceph/src/common/Mutex.h b/src/ceph/src/common/Mutex.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MUTEX_H
+#define CEPH_MUTEX_H
+
+#include "include/assert.h"
+#include "lockdep.h"
+#include "common/ceph_context.h"
+
+#include <pthread.h>
+
+using namespace ceph;
+
+class PerfCounters;
+
+enum {
+  l_mutex_first = 999082,
+  l_mutex_wait,
+  l_mutex_last
+};
+
+class Mutex {
+private:
+  std::string name;
+  int id;
+  bool recursive;
+  bool lockdep;
+  bool backtrace;  // gather backtrace on lock acquisition
+
+  pthread_mutex_t _m;
+  int nlock;
+  pthread_t locked_by;
+  CephContext *cct;
+  PerfCounters *logger;
+
+  // don't allow copying.
+  void operator=(const Mutex &M);
+  Mutex(const Mutex &M);
+
+  void _register() {
+    id = lockdep_register(name.c_str());
+  }
+  void _will_lock() { // about to lock
+    id = lockdep_will_lock(name.c_str(), id, backtrace);
+  }
+  void _locked() {    // just locked
+    id = lockdep_locked(name.c_str(), id, backtrace);
+  }
+  void _will_unlock() {  // about to unlock
+    id = lockdep_will_unlock(name.c_str(), id);
+  }
+
+public:
+  Mutex(const std::string &n, bool r = false, bool ld=true, bool bt=false,
+       CephContext *cct = 0);
+  ~Mutex();
+  bool is_locked() const {
+    return (nlock > 0);
+  }
+  bool is_locked_by_me() const {
+    return nlock > 0 && locked_by == pthread_self();
+  }
+
+  bool TryLock() {
+    int r = pthread_mutex_trylock(&_m);
+    if (r == 0) {
+      if (lockdep && g_lockdep) _locked();
+      _post_lock();
+    }
+    return r == 0;
+  }
+
+  void Lock(bool no_lockdep=false);
+
+  void _post_lock() {
+    if (!recursive) {
+      assert(nlock == 0);
+      locked_by = pthread_self();
+    };
+    nlock++;
+  }
+
+  void _pre_unlock() {
+    assert(nlock > 0);
+    --nlock;
+    if (!recursive) {
+      assert(locked_by == pthread_self());
+      locked_by = 0;
+      assert(nlock == 0);
+    }
+  }
+  void Unlock();
+
+  friend class Cond;
+
+
+public:
+  class Locker {
+    Mutex &mutex;
+
+  public:
+    explicit Locker(Mutex& m) : mutex(m) {
+      mutex.Lock();
+    }
+    ~Locker() {
+      mutex.Unlock();
+    }
+  };
+};
+
+
+#endif