php code using seamophores, shared memory and related functions

START OF FILE ONE

$shm_id = shmop_open(0xff3, "c", 0644, 100);
echo $shm_id;
echo "
";
$shm_size = shmop_size($shm_id);
echo $shm_size;
$my_string = shmop_read($shm_id, 12, 5);
echo "The data inside shared memory was: ".$my_string."\n";

shmop_delete($shm_id);
shmop_close($shm_id);

END OF FILE 1

START OF FILE 2 semaphores

$MEMSIZE = 128; // size of shared memory to allocate
$SEMKEY = 11; // Semaphore key
$SHMKEY = 51; // Shared memory key

echo "Start.\n";

// Create a semaphore
$sem_id = sem_get($SEMKEY, 1);
if ($sem_id === false)
{
echo "Failed to create semaphore";
exit;
}
else
echo "Created semaphore $sem_id.\n";

// Acquire the semaphore
if (! sem_acquire($sem_id))
{
echo "Failed to acquire semaphore $sem_id.\n";
sem_remove($sem_id);
exit;
}
else
echo "Success acquiring semaphore $sem_id.\n";

// Attach shared memory
$shm_id = shm_attach($SHMKEY, $MEMSIZE);
if ($shm_id === false)
{
echo "Fail to attach shared memory.\n";
sem_remove($sem_id);
exit;
}
else
echo "Success to attach shared memory : $shm_id.\n";

// Write variable 1
if (!shm_put_var($shm_id, 1, "Vikas"))
{
echo "Failed to put var 1 in shared memory $shm_id.\n";

// Clean up nicely
sem_remove($sem_id);
shm_remove($shm_id);
exit;
}
else
echo "Wrote var1 to shared memory.\n";

// Write variable 2
if (!shm_put_var($shm_id, 2, "coral"))
{
echo "Failed to put var 2 on shared memory $shm_id.\n";

// Clean up nicely
sem_remove($sem_id);
shm_remove ($shm_id);
exit;
}
else
echo "Wrote var2 to shared memory.\n";

// Read variable 1
$var1 = shm_get_var($shm_id, 1);
if ($var1 === false)
{
echo "Failed to retreive Var 1 from Shared memory $shm_id, " .
"return value=$var1.\n";
}
else
echo "Read var1=$var1.\n";

// Read variable 1
$var2 = shm_get_var ($shm_id, 2);
if ($var1 === false)
{
echo "Failed to retrive Var 2 from Shared memory $shm_id, " .
"return value=$var2.\n";
}
else
echo "Read var2=$var2.\n";

//sleep (60);

// Release semaphore
if (!sem_release($sem_id))
echo "Failed to release $sem_id semaphore.\n";
else
echo "Semaphore $sem_id released.\n";

// Remove shared memory segment
if (shm_remove ($shm_id))
echo "Shared memory successfully removed.\n";
else
echo "Failed to remove $shm_id shared memory.\n";

// Remove semaphore
if (sem_remove($sem_id))
echo "Semaphore removed successfully.\n";
else
echo "Failed to remove $sem_id semaphore.\n";

echo "End.\n";



END OF FILE2