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
|
// $Id$
// This test program illustrates that the Win32
// <WaitForMultipleObjects> function can be called in multiple
// threads, all of which wait on the same set of HANDLEs. Note that
// the dispatching of the threads should be relatively "fair" (i.e.,
// everyone gets a chance to process the various HANDLEs as they
// become active). Thanks to Ari Erev <Ari_Erev@comverse.com> for
// suggesting this and providing the initial code.
#include "ace/Task.h"
ACE_RCSID(Threads, wfmo, "$Id$")
#if defined (ACE_WIN32)
// Number of threads.
static const int THREAD_COUNT = 5;
// Number of iterations.
static const int MAX_ITERATIONS = 100;
class WFMO_Test : public ACE_Task <ACE_NULL_SYNCH>
{
public:
virtual int open (void *);
virtual int svc (void);
// Use two handles here..
ACE_sema_t sema_handles_[2];
int semaphore_count_;
};
static WFMO_Test wfmo_test;
int
WFMO_Test::open (void *arg)
{
int thread_count = int (arg);
ACE_ASSERT (this->activate (0, thread_count) != -1);
return 0;
}
int
WFMO_Test::svc (void)
{
while(1)
{
int result = ::WaitForMultipleObjects (2, this->sema_handles_,
FALSE, INFINITE);
if (result == WAIT_OBJECT_0)
// Signal the other semaphore just to see if we can get
// another thread to wakeup.
ACE_ASSERT (ACE_OS::sema_post (&sema_handles_[1]) != -1);
else if (result == WAIT_OBJECT_0 + 1)
;
else
{
ACE_DEBUG ((LM_DEBUG, "Error in WaitForMultipleObejcts\n"));
ACE_OS::exit (0);
}
// semaphore_count_ will be displayed by the "main" thread. It's
// value must be 2. Note that although this is a shared
// resource it's not protected via a mutex because the ++
// operation on Intel is atomic.
semaphore_count_++;
ACE_DEBUG ((LM_DEBUG, "(%t) thread has been signaled.\n"));
// Yield this thread so that the other one(s) have a chance to
// run.
ACE_OS::thr_yield ();
}
return 0;
}
int
main (int argc, char *argv[])
{
int thread_count = THREAD_COUNT;
if (argc > 1)
thread_count = ACE_OS::atoi (argv[1]);
wfmo_test.open ((void *) thread_count);
// Initialize the semaphores.
ACE_ASSERT (ACE_OS::sema_init (&wfmo_test.sema_handles_[0], thread_count + 5)
!= -1);
ACE_ASSERT (ACE_OS::sema_init (&wfmo_test.sema_handles_[1], thread_count + 5)
!= -1);
for (int i = 0; i < MAX_ITERATIONS; i++)
{
wfmo_test.semaphore_count_ = 0;
ACE_ASSERT (ACE_OS::sema_post (&wfmo_test.sema_handles_[0]) != -1);
// No real synchronization here. Just sleep enough so that at
// least one (or two threads) run as a result of the semaphore.
ACE_OS::sleep (1);
// Add one for the other thread that was signaled.
ACE_DEBUG ((LM_DEBUG,
"semaphore_count_ = %d (should have been %d).\n",
wfmo_test.semaphore_count_,
2)); // Two semaphores should have been released.
}
ACE_OS::exit (0);
return 0;
}
#else
int
main (int, char *[])
{
ACE_DEBUG ((LM_DEBUG, "this test only runs on Win32\n"));
}
#endif /* ACE_WIN32 */
|
