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// $Id$
// ============================================================================
//
// = LIBRARY
// tests
//
// = FILENAME
// Process_Mutex_Test.cpp
//
// = DESCRIPTION
// Tests an <ACE_Process_Mutex> shared between multiple child processes.
//
// = AUTHOR
// Irfan Pyarali <irfan@cs.wustl.edu>
//
// ============================================================================
#include "test_config.h"
#include "ace/Mutex.h"
#include "ace/Process.h"
#include "ace/Process_Mutex.h"
#include "ace/Get_Opt.h"
#include "ace/ACE.h"
#include "ace/OS_NS_stdio.h"
#include "ace/OS_NS_string.h"
#include "ace/OS_NS_fcntl.h"
#include "ace/os_include/os_dirent.h"
ACE_RCSID(tests, Process_Mutex_Test, "$Id$")
static int release_mutex = 1;
static int child_process = 0;
static const ACE_TCHAR *mutex_name = ACE_DEFAULT_MUTEX;
#if defined (__Lynx__)
static const u_int n_processes = 4;
#else /* ! __Lynx__ */
static const u_int n_processes = ACE_MAX_PROCESSES;
#endif /* ! __Lynx__ */
// Explain usage and exit.
static void
print_usage_and_die (void)
{
ACE_DEBUG ((LM_DEBUG,
ACE_TEXT ("usage: %n [-d (don't release mutex)] ")
ACE_TEXT ("[-c (child process)] [-n mutex name]\n")));
ACE_OS::exit (1);
}
// Parse the command-line arguments and set options.
static void
parse_args (int argc, ACE_TCHAR *argv[])
{
ACE_Get_Opt get_opt (argc, argv, ACE_TEXT("dcn:"));
int c;
while ((c = get_opt ()) != -1)
switch (c)
{
case 'd':
release_mutex = 0;
break;
case 'c':
child_process = 1;
break;
case 'n':
mutex_name = get_opt.opt_arg ();
break;
default:
print_usage_and_die ();
break;
}
}
static void
acquire_release (void)
{
ACE_Process_Mutex mutex (mutex_name);
// Make sure the constructor succeeded
ACE_ASSERT (ACE_LOG_MSG->op_status () == 0);
// To see if we really are the only holder of the mutex below,
// we'll try to create a file with exclusive access. If the file
// already exists, we're not the only one holding the mutex.
ACE_TCHAR mutex_check[MAXPATHLEN+1];
ACE_OS::strncpy (mutex_check, mutex_name, MAXPATHLEN);
ACE_OS::strncat (mutex_check, ACE_TEXT ("_checker"), MAXPATHLEN);
// Grab the lock
int mutex_acq = mutex.acquire ();
ACE_ASSERT (mutex_acq == 0);
ACE_DEBUG ((LM_DEBUG,
ACE_TEXT ("(%P) Mutex acquired %s\n"),
mutex_name));
ACE_HANDLE checker_handle = ACE_OS::open (mutex_check, O_CREAT | O_EXCL);
if (checker_handle == ACE_INVALID_HANDLE)
{
ACE_ASSERT (errno != EEXIST);
ACE_DEBUG ((LM_WARNING, ACE_TEXT ("(%P): %p\n"),
ACE_TEXT ("checker file open")));
}
else
ACE_OS::close (checker_handle);
ACE_DEBUG ((LM_DEBUG,
ACE_TEXT ("(%P) Working....\n")));
// Do some "work", i.e., just sleep for a couple of seconds.
ACE_OS::sleep (2);
// Free up the check file for the next acquirer.
ACE_OS::unlink (mutex_check);
// Check if we need to release the mutex
if (release_mutex == 1)
{
ACE_DEBUG ((LM_DEBUG,
ACE_TEXT ("(%P) Releasing the mutex %s\n"),
mutex_name));
int mutex_release = mutex.release ();
ACE_ASSERT (mutex_release == 0);
}
}
int
run_main (int argc, ACE_TCHAR *argv[])
{
parse_args (argc, argv);
// Child process code.
if (child_process)
{
ACE_TCHAR lognm[MAXPATHLEN];
int mypid (ACE_OS::getpid ());
ACE_OS::sprintf(lognm, ACE_TEXT ("Process_Mutex_Test-child-%d"), mypid);
ACE_START_TEST (lognm);
acquire_release ();
ACE_END_LOG;
}
else
{
ACE_START_TEST (ACE_TEXT ("Process_Mutex_Test"));
# if !defined( ACE_HAS_SYSV_IPC) || defined( ACE_USES_MUTEX_FOR_PROCESS_MUTEX )
// When Process_Mutex is pthreads based, then the owner of mutex destroys it
// in destructor. This may disturb the other processes which still uses the
// mutex. It is safer then to hold the mutex in main process, and destroy it after
// children finish. This is temporary solution, and in future pthread base
// Process_Mutex shall control the destruction of mutex better.
ACE_Process_Mutex mutex( mutex_name );
# endif
#if !defined (ACE_WIN32) && defined (ACE_USES_WCHAR)
static const ACE_TCHAR* format = ACE_TEXT ("%ls -c -n %ls%ls");
#else
static const ACE_TCHAR* format = ACE_TEXT ("%s -c -n %s%s");
#endif /* !ACE_WIN32 && ACE_USES_WCHAR */
ACE_Process_Options options;
options.command_line (format, argc > 0 ? argv[0] : ACE_TEXT ("Process_Mutex_Test"), mutex_name,
release_mutex == 0 ? ACE_TEXT (" -d") : ACE_TEXT (""));
// Spawn <n_processes> child processes that will contend for the
// lock.
ACE_Process children[n_processes];
size_t i;
for (i = 0;
i < n_processes;
i++)
{
// Spawn the child process.
if (children[i].spawn (options) == -1)
{
ACE_ERROR_RETURN ((LM_ERROR,
ACE_TEXT ("spawn of client %d failed\n"),
i),
-1);
}
else
{
ACE_DEBUG ((LM_DEBUG,
ACE_TEXT ("Parent spawned child process with pid = %d.\n"),
children[i].getpid ()));
}
// Give the newly spawned child process a chance to start...
// David Levine thinks this sleep() is required because
// calling ::waitpid () before a fork'ed child has actually
// been created may be a problem on some platforms. It's
// not enough for fork() to have returned to the parent.
ACE_OS::sleep (1);
}
for (i = 0; i < n_processes; i++)
{
ACE_exitcode child_status;
// Wait for the child processes we created to exit.
int wait_result = children[i].wait (&child_status);
ACE_ASSERT (wait_result != -1);
if (child_status == 0)
ACE_DEBUG ((LM_DEBUG,
ACE_TEXT ("Child %d finished ok\n"),
children[i].getpid ()));
else
ACE_ERROR ((LM_ERROR,
ACE_TEXT ("Child %d finished with status %d\n"),
children[i].getpid (), child_status));
}
ACE_END_TEST;
}
return 0;
}
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