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// $Id$
// Illustrates the use of the ACE_SV_Semaphore_Complex class and the
// ACE_Malloc class using the ACE_Shared_Memory_Pool (which uses
// System V shared memory). Note that it doesn't matter whether the
// parent or the child creates the semaphore since Semaphore_Complex
// will correctly serialize the intialization of the mutex and synch
// objects.
#include "ace/Malloc.h"
#include "ace/SV_Semaphore_Complex.h"
#if defined (ACE_HAS_SYSV_IPC)
// Shared memory allocator (note that this chews up the
// ACE_DEFAULT_SEM_KEY).
static ACE_Malloc<ACE_SHARED_MEMORY_POOL, ACE_SV_Semaphore_Simple> allocator;
const int SEM_KEY_1 = ACE_DEFAULT_SEM_KEY + 1;
const int SEM_KEY_2 = ACE_DEFAULT_SEM_KEY + 2;
const int SHMSZ = 27;
static int
parent (char *shm)
{
char *s = shm;
ACE_SV_Semaphore_Complex mutex (SEM_KEY_1, ACE_SV_Semaphore_Complex::ACE_CREATE, 0);
ACE_SV_Semaphore_Complex synch (SEM_KEY_2, ACE_SV_Semaphore_Complex::ACE_CREATE, 0);
for (char c = 'a'; c <= 'z'; c++)
*s++ = c;
*s = '\0';
if (mutex.release () == -1)
ACE_ERROR ((LM_ERROR, "%p", "parent mutex.release"));
else if (synch.acquire () == -1)
ACE_ERROR ((LM_ERROR, "%p", "parent synch.acquire"));
if (allocator.remove () == -1)
ACE_ERROR ((LM_ERROR, "%p\n", "allocator.remove"));
if (mutex.remove () == -1)
ACE_ERROR ((LM_ERROR, "%p\n", "mutex.remove"));
if (synch.remove () == -1)
ACE_ERROR ((LM_ERROR, "%p\n", "synch.remove"));
return 0;
}
static int
child (char *shm)
{
ACE_SV_Semaphore_Complex mutex (SEM_KEY_1, ACE_SV_Semaphore_Complex::ACE_CREATE, 0);
ACE_SV_Semaphore_Complex synch (SEM_KEY_2, ACE_SV_Semaphore_Complex::ACE_CREATE, 0);
while (mutex.tryacquire () == -1)
if (errno == EAGAIN)
ACE_DEBUG ((LM_DEBUG, "spinning in child!\n"));
else
ACE_ERROR_RETURN ((LM_ERROR, "child mutex.tryacquire"), 1);
for (char *s = (char *) shm; *s != '\0'; s++)
ACE_DEBUG ((LM_DEBUG, "%c", *s));
ACE_DEBUG ((LM_DEBUG, "\n"));
if (synch.release () == -1)
ACE_ERROR_RETURN ((LM_ERROR, "child synch.release"), 1);
return 0;
}
int
main (void)
{
char *shm = (char *) allocator.malloc (27);
switch (ACE_OS::fork ())
{
case -1:
ACE_ERROR_RETURN ((LM_ERROR, "fork failed\n"), -1);
/* NOTREACHED */
case 0:
// Child.
return child (shm);
default:
return parent (shm);
}
}
#else
int main (void)
{
ACE_ERROR ((LM_ERROR,
"SYSV IPC is not supported on this platform\n"));
return 0;
}
#endif /* ACE_HAS_SYSV_IPC */
#if defined (ACE_TEMPLATES_REQUIRE_SPECIALIZATION)
template class ACE_Malloc<ACE_SHARED_MEMORY_POOL, ACE_SV_Semaphore_Simple>;
#endif /* ACE_TEMPLATES_REQUIRE_SPECIALIZATION */
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