Mercurial > pub > ImplabNet

comparison Implab/Parallels/SharedLock.cs @ 129:471f596b2603 v2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added SharedLock to synchronization routines
author cin
date Thu, 29 Jan 2015 18:31:06 +0300
parents
children 671f60cd0250
comparison
equal deleted inserted replaced
128:6241bff0cd64 129:471f596b2603
1 using System;
2 using System.Threading;
3 using System.Diagnostics;
4
5 namespace Implab.Parallels {
6 /// <summary>
7 /// Implements a lightweight mechanism to aquire a shared or an exclusive lock.
8 /// </summary>
9 public class SharedLock {
10 readonly object m_lock = new object();
11 int m_locks;
12 bool m_exclusive;
13
14 public bool LockExclusive(int timeout) {
15 lock (m_lock) {
16 if (m_locks > 0 && !Monitor.Wait(m_lock, timeout))
17 return false;
18 m_exclusive = true;
19 m_locks = 1;
20 }
21 }
22
23 public void LockExclusive() {
24 LockExclusive(-1);
25 }
26
27 public bool LockShared(int timeout) {
28 lock (m_lock) {
29 if (!m_exclusive) {
30 m_locks++;
31 return true;
32 }
33
34 if (m_lock == 0) {
35 m_exclusive = false;
36 m_locks = 1;
37 return true;
38 }
39
40 if (Monitor.Wait(m_lock, timeout)) {
41 Debug.Assert(m_locks == 0);
42 m_locks = 1;
43 m_exclusive = false;
44 return true;
45 }
46 return false;
47 }
48 }
49
50 public void LockShared() {
51 LockShared(-1);
52 }
53
54 public void ReleaseShared() {
55 lock (m_lock) {
56 if (m_exclusive || m_locks <= 0)
57 throw new InvalidOperationException();
58 m_locks--;
59 if (m_locks == 0)
60 Monitor.PulseAll(m_lock);
61 }
62 }
63
64 public void ReleaseExclusive() {
65 lock (m_lock) {
66 if (!m_exclusive && m_locks != 1)
67 throw new InvalidOperationException();
68 m_locks = 0;
69 Monitor.PulseAll(m_lock);
70 }
71 }
72
73 }
74 }
75