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Reference Guide
TAtomicCountPthread.h
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1 // @(#)root/thread:$Id$
2 // Author: Fons Rademakers 14/11/06
3 
4 /*************************************************************************
5  * Copyright (C) 1995-2006, Rene Brun and Fons Rademakers. *
6  * All rights reserved. *
7  * *
8  * For the licensing terms see $ROOTSYS/LICENSE. *
9  * For the list of contributors see $ROOTSYS/README/CREDITS. *
10  *************************************************************************/
11 
12 #ifndef ROOT_TAtomicCountPthread
13 #define ROOT_TAtomicCountPthread
14 
15 //////////////////////////////////////////////////////////////////////////
16 // //
17 // TAtomicCountPthread //
18 // //
19 // Class providing atomic operations on a long. Setting, getting, //
20 // incrementing and decrementing are atomic, thread safe, operations. //
21 // //
22 // This implementation uses pthread mutexes for locking. This clearly //
23 // is less efficient than the version using asm locking instructions //
24 // as in TAtomicCountGcc.h, but better than nothing. //
25 // //
26 // ATTENTION: Don't use this file directly, it is included by //
27 // TAtomicCount.h. //
28 // //
29 //////////////////////////////////////////////////////////////////////////
30 
31 #include <pthread.h>
32 
33 #include "RtypesCore.h"
34 
35 class TAtomicCount {
36 private:
37  Long_t fCnt; // counter
38  mutable pthread_mutex_t fMutex; // mutex used to lock counter
39 
40  TAtomicCount(const TAtomicCount &); // not implemented
41  TAtomicCount &operator=(const TAtomicCount &); // not implemented
42 
43  class LockGuard {
44  private:
45  pthread_mutex_t &fM; // mutex to be guarded
46  public:
47  LockGuard(pthread_mutex_t &m): fM(m) { pthread_mutex_lock(&fM); }
48  ~LockGuard() { pthread_mutex_unlock(&fM); }
49  };
50 
51 public:
52  explicit TAtomicCount(Long_t v): fCnt(v) {
53  pthread_mutex_init(&fMutex, 0);
54  }
55 
56  ~TAtomicCount() { pthread_mutex_destroy(&fMutex); }
57 
58  void operator++() {
59  LockGuard lock(fMutex);
60  ++fCnt;
61  }
62 
64  LockGuard lock(fMutex);
65  return --fCnt;
66  }
67 
68  operator long() const {
69  LockGuard lock(fMutex);
70  return fCnt;
71  }
72 
73  void Set(Long_t v) {
74  LockGuard lock(fMutex);
75  fCnt = v;
76  }
77 
78  Long_t Get() const {
79  LockGuard lock(fMutex);
80  return fCnt;
81  }
82  };
83 
84 #endif
Long_t Get() const
pthread_mutex_t fMutex
SVector< double, 2 > v
Definition: Dict.h:5
TMarker * m
Definition: textangle.C:8
void Set(Long_t v)
TAtomicCount(Long_t v)
long Long_t
Definition: RtypesCore.h:50
TAtomicCount & operator=(const TAtomicCount &)
TAtomicCount(const TAtomicCount &)
LockGuard(pthread_mutex_t &m)