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
|
// $Id: Mutex.cpp 91633 2010-09-07 14:27:13Z johnnyw $
#include "ace/config-lite.h"
#if defined (ACE_HAS_THREADS)
#include "ace/Synch.h"
#include "ace/Guard_T.h"
class LogMessage
{
public:
enum { CRITICAL, NORMAL};
virtual ~LogMessage ()
{
}
virtual int priority (void)
{
return NORMAL;
}
};
class CriticalLogMessage : public LogMessage
{
virtual int priority (void)
{
return LogMessage::CRITICAL;
}
};
// Listing 1 code/ch14
typedef ACE_Thread_Mutex MUTEX;
class Logger
{
public:
void log (LogMessage *msg)
{
ACE_GUARD (MUTEX, mon, mutex_);
if (msg->priority () == LogMessage::CRITICAL)
logCritical (msg);
}
void logCritical (LogMessage *)
{
// Acquires the same mutex as log()!
ACE_GUARD(MUTEX, mon, mutex_);
}
private:
MUTEX mutex_;
};
static Logger logger;
int ACE_TMAIN (int, ACE_TCHAR *[])
{
CriticalLogMessage cm;
logger.log(&cm); // Will cause deadlock.
return 0;
}
// Listing 1
#else
#include "ace/OS_main.h"
#include "ace/OS_NS_stdio.h"
int ACE_TMAIN (int, ACE_TCHAR *[])
{
ACE_OS::puts (ACE_TEXT ("This example requires threads."));
return 0;
}
#endif /* ACE_HAS_THREADS */
|
