1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
#include "vtkConditionVariable.h"
#include "vtkMultiThreader.h"
#include <stdlib.h>
// For vtkSleep
#include "vtkWindows.h"
#include <ctype.h>
#include <time.h>
// Cross platform sleep
inline void vtkSleep( double duration )
{
// sleep according to OS
#ifdef _WIN32
Sleep( (int)( 1000 * duration ) );
#elif defined(__FreeBSD__) || defined(__linux__) || defined(sgi) || defined(__APPLE__)
struct timespec sleep_time, dummy;
sleep_time.tv_sec = static_cast<int>( duration );
sleep_time.tv_nsec = static_cast<int>( 1000000000 * ( duration - sleep_time.tv_sec ) );
nanosleep( &sleep_time, &dummy );
#else
(void)duration;
#warning Missing sleep implementation
#endif
}
typedef struct {
vtkMutexLock* Lock;
vtkConditionVariable* Condition;
int Done;
int NumberOfWorkers;
} vtkThreadUserData;
VTK_THREAD_RETURN_TYPE vtkTestCondVarThread( void* arg )
{
int threadId = static_cast<vtkMultiThreader::ThreadInfo*>(arg)->ThreadID;
int threadCount = static_cast<vtkMultiThreader::ThreadInfo*>(arg)->NumberOfThreads;
vtkThreadUserData* td = static_cast<vtkThreadUserData*>(
static_cast<vtkMultiThreader::ThreadInfo*>(arg)->UserData );
if ( td )
{
if ( threadId == 0 )
{
td->Done = 0;
td->Lock->Lock();
cout << "Thread " << ( threadId + 1 ) << " of " << threadCount << " initializing.\n";
cout.flush();
td->Lock->Unlock();
int i;
for ( i = 0; i < 2 * threadCount; ++ i )
{
td->Lock->Lock();
cout << "Signaling (count " << i << ")...\n";
cout.flush();
td->Lock->Unlock();
td->Condition->Signal();
//sleep( 1 );
}
i = 0;
do
{
td->Lock->Lock();
td->Done = 1;
cout << "Broadcasting...\n";
cout.flush();
td->Lock->Unlock();
td->Condition->Broadcast();
vtkSleep( 0.2 ); // 0.2 s between broadcasts
}
while ( td->NumberOfWorkers > 0 && ( i ++ < 1000 ) );
if ( i >= 1000 )
{
exit( 2 );
}
}
else
{
// Wait for thread 0 to initialize... Ugly but effective
while ( td->Done < 0 )
{
vtkSleep( 0.2 ); // 0.2 s between checking
}
// Wait for the condition and then note we were signaled.
// This part looks like a Hansen Monitor:
// ref: http://www.cs.utexas.edu/users/lorenzo/corsi/cs372h/07S/notes/Lecture12.pdf (page 2/5), code on Tradeoff slide.
td->Lock->Lock();
while ( td->Done <= 0 )
{
cout << " Thread " << ( threadId + 1 ) << " waiting.\n";
cout.flush();
// Wait() performs an Unlock internally.
td->Condition->Wait( td->Lock );
// Once Wait() returns, the lock is locked again.
cout << " Thread " << ( threadId + 1 ) << " responded.\n";
cout.flush();
}
-- td->NumberOfWorkers;
td->Lock->Unlock();
}
td->Lock->Lock();
cout << " Thread " << ( threadId + 1 ) << " of " << threadCount << " exiting.\n";
cout.flush();
td->Lock->Unlock();
}
else
{
cout << "No thread data!\n";
cout << " Thread " << ( threadId + 1 ) << " of " << threadCount << " exiting.\n";
-- td->NumberOfWorkers;
cout.flush();
}
return VTK_THREAD_RETURN_VALUE;
}
int TestConditionVariable( int, char*[] )
{
vtkMultiThreader* threader = vtkMultiThreader::New();
int numThreads = threader->GetNumberOfThreads();
vtkThreadUserData data;
data.Lock = vtkMutexLock::New();
data.Condition = vtkConditionVariable::New();
data.Done = -1;
data.NumberOfWorkers = numThreads - 1;
threader->SetNumberOfThreads( numThreads );
threader->SetSingleMethod( vtkTestCondVarThread, &data );
threader->SingleMethodExecute();
cout << "Done with threader.\n";
cout.flush();
vtkIndent indent;
indent = indent.GetNextIndent();
data.Condition->PrintSelf( cout, indent );
data.Lock->Delete();
data.Condition->Delete();
threader->Delete();
return 0;
}
|
