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// $Id$
#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 */
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