ACE_Process_Manager Class Reference

Manages a group of processes. More...

#include <Process_Manager.h>

Inheritance diagram for ACE_Process_Manager:

[legend]Collaboration diagram for ACE_Process_Manager:

[legend]List of all members.

Utility methods
int	register_handler (ACE_Event_Handler *event_handler, pid_t pid=ACE_INVALID_PID)
int	remove (pid_t pid)
size_t	managed (void) const
	Return the number of managed processes.
int	set_scheduler (const ACE_Sched_Params &params, pid_t pid)
int	set_scheduler_all (const ACE_Sched_Params &params)
void	dump (void) const
	Dump the state of an object.
	ACE_ALLOC_HOOK_DECLARE
	Declare the dynamic allocation hooks.
Public Types
	DEFAULT_SIZE = 100
enum	{ DEFAULT_SIZE = 100 }
Public Member Functions
Initialization and termination methods
	ACE_Process_Manager (size_t size=ACE_Process_Manager::DEFAULT_SIZE, ACE_Reactor *reactor=0)
int	open (size_t size=ACE_Process_Manager::DEFAULT_SIZE, ACE_Reactor *r=0)
int	close (void)
	Release all resources. Do not wait for processes to exit.
virtual	~ACE_Process_Manager (void)
Process creation methods
pid_t	spawn (ACE_Process *proc, ACE_Process_Options &options, ACE_Event_Handler *event_handler=0)
pid_t	spawn (ACE_Process_Options &options, ACE_Event_Handler *event_handler=0)
int	spawn_n (size_t n, ACE_Process_Options &options, pid_t *child_pids=0, ACE_Event_Handler *event_Handler=0)
Process synchronization operations
int	terminate (pid_t pid)
int	terminate (pid_t pid, int sig)
int	wait (const ACE_Time_Value &timeout=ACE_Time_Value::max_time)
pid_t	wait (pid_t pid, const ACE_Time_Value &timeout, ACE_exitcode *status=0)
pid_t	wait (pid_t pid, ACE_exitcode *status=0)
int	reap (pid_t pid=-1, ACE_exitcode *stat_loc=0, int options=WNOHANG)
Static Public Member Functions
Singleton access and control
static ACE_Process_Manager *	instance (void)
	Get pointer to a process-wide ACE_Process_Manager.
static ACE_Process_Manager *	instance (ACE_Process_Manager *)
static void	close_singleton (void)
	Delete the dynamically allocated singleton.
static void	cleanup (void *instance, void *arg)
Protected Member Functions
virtual int	handle_input (ACE_HANDLE proc)
	Collect one (or more, on unix) process exit status.
virtual int	handle_signal (int signum, siginfo_t *=0, ucontext_t *=0)
Private Member Functions
int	resize (size_t)
	Resize the pool of Process_Descriptors.
ssize_t	find_proc (pid_t process_id)
int	insert_proc (ACE_Process *process, ACE_Event_Handler *event_handler=0)
int	append_proc (ACE_Process *process, ACE_Event_Handler *event_handler=0)
int	remove_proc (size_t n)
int	notify_proc_handler (size_t n, ACE_exitcode status)
Private Attributes
Process_Descriptor *	process_table_
	Vector that describes process state within the Process_Manager.
size_t	max_process_table_size_
size_t	current_count_
	Current number of processes we are managing.
ACE_Event_Handler *	default_exit_handler_
Static Private Attributes
static ACE_Process_Manager *	instance_ = 0
	Singleton pointer.
static bool	delete_instance_ = false
Friends
class	ACE_Process_Control
Classes
struct	Process_Descriptor
	Information describing each process that's controlled by an ACE_Process_Manager. More...

---

Detailed Description

Manages a group of processes.

This class allows applications to control groups of processes, similar to how the ACE_Thread_Manager controls groups of threads. Naturally, it doesn't work at all on platforms, such as VxWorks or pSoS, that don't support process. There are two main ways of using ACE_Process_Manager, depending on how involved you wish to be with the termination of managed processes. If you want processes to simply go away when they're finished, register the ACE_Process_Manager with an ACE_Reactor that can handle notifications of child process exit:

 ACE_Process_Manager mgr;
 // ...
 mgr.open (100, ACE_Reactor::instance ());

In this usage scenario, the ACE_Process_Manager will clean up after any processes that it spawns. (On Unix, this means executing a wait(2) to collect the exit status and avoid zombie processes; on Win32, it means closing the process and thread HANDLEs that are created when CreateProcess is called.)

Note:

When you register a ACE_Process_Manager with a ACE_Reactor, the reactor's notification pipe is used to help reap the available process exit statuses. Therefore, you must not use a reactor whose notify pipe has been disabled. Here's the sequence of steps used to reap the exit statuses in this case:

1. The ACE_Process_Manager registers a signal handler for SIGCHLD.
2. The SIGCHLD handler, when invoked, uses the ACE_Reactor's notify() method to inform the ACE_Reactor to wake up.
3. The ACE_Reactor calls the ACE_Process_Manager's handle_input() method; this happens synchronously, not in signal context.
4. The handle_input() method collects all available exit statuses.

If, on the other hand you want to wait "in line" to handle the terminated process cleanup code, call one of the wait functions whenever there might be managed processes that have exited.

Note that in either case, ACE_Process_Manager allows you to register an ACE_Event_Handler to be called when a specific spawned process exits, or when any process without a specific ACE_Event_Handler exits. When a process exits, the appropriate ACE_Event_Handler's handle_input() method is called; the ACE_HANDLE passed is either the process's HANDLE (on Win32), or its pid cast to an ACE_HANDLE (on POSIX). It is also possible to call the wait() functions even when the ACE_Process_Manager is registered with a reactor.

Note:

Be aware that the wait functions are "sloppy" on Unix, because there's no good way to wait for a subset of the children of a process. The wait functions may end up collecting the exit status of a process that's not managed by the ACE_Process_Manager whose wait() you invoked. It's best to only use a single ACE_Process_Manager, and to create all subprocesses by calling that manager's spawn() method.

Definition at line 98 of file Process_Manager.h.

---

Member Enumeration Documentation

anonymous enum

Enumerator:

DEFAULT_SIZE

Definition at line 103 of file Process_Manager.h.

  {
    DEFAULT_SIZE = 100
  };

---

Constructor & Destructor Documentation

ACE_Process_Manager::ACE_Process_Manager	(	size_t	size = ACE_Process_Manager::DEFAULT_SIZE,
		ACE_Reactor *	reactor = 0
	)

Initialize an ACE_Process_Manager with a table containing up to size processes. This table resizes itself automatically as needed. If a reactor is provided, this ACE_Process_Manager uses it to notify an application when a process it controls exits. By default, however, we don't use an ACE_Reactor.

Definition at line 245 of file Process_Manager.cpp.

References ACE_ERROR, ACE_TEXT, ACE_TRACE, and LM_ERROR.

  : ACE_Event_Handler (),
    process_table_ (0),
    max_process_table_size_ (0),
    current_count_ (0),
    default_exit_handler_ (0)
#if defined (ACE_HAS_THREADS)
  , lock_ ()
#endif /* ACE_HAS_THREADS */
{
  ACE_TRACE ("ACE_Process_Manager::ACE_Process_Manager");

  if (this->open (size,
                  r) == -1)
    ACE_ERROR ((LM_ERROR,
                ACE_TEXT ("%p\n"),
                ACE_TEXT ("ACE_Process_Manager")));
}

ACE_Process_Manager::~ACE_Process_Manager

(

void

)

[virtual]

Destructor releases all resources and does not wait for processes to exit.

Definition at line 300 of file Process_Manager.cpp.

References ACE_TRACE, and close().

{
  ACE_TRACE ("ACE_Process_Manager::~ACE_Process_Manager");
  this->close ();
}

---

Member Function Documentation

int ACE_Process_Manager::append_proc	(	ACE_Process *	process,
		ACE_Event_Handler *	event_handler = 0
	)			[private]

Append information about a process, i.e., its <process_id> in the process_table_. Each entry is added at the end, growing the table if necessary. Register event_handler to be called back when the process exits.

Definition at line 496 of file Process_Manager.cpp.

References ACE_TRACE, current_count_, DEFAULT_SIZE, ACE_Process_Manager::Process_Descriptor::exit_notify_, ACE_Process::gethandle(), max_process_table_size_, ACE_Process_Manager::Process_Descriptor::process_, process_table_, ACE_Event_Handler::reactor(), and ACE_Reactor::register_handler().

Referenced by insert_proc().

{
  ACE_TRACE ("ACE_Process_Manager::append_proc");

  // Try to resize the array to twice its existing size (or the DEFAULT_SIZE,
  // if there are no array entries) if we run out of space...
  if (this->current_count_ >= this->max_process_table_size_)
    {
      size_t new_size = this->max_process_table_size_ * 2;
      if (new_size == 0)
        new_size = ACE_Process_Manager::DEFAULT_SIZE;
      if (this->resize (new_size) == -1)
        return -1;
    }

  Process_Descriptor &proc_desc =
    this->process_table_[this->current_count_];

  proc_desc.process_ = proc;
  proc_desc.exit_notify_ = event_handler;

#if defined (ACE_WIN32)
  // If we have a Reactor, then we're supposed to reap Processes
  // automagically.  Get a handle to this new Process and tell the
  // Reactor we're interested in <handling_input> on it.
  ACE_Reactor * const r = this->reactor ();
  if (r != 0)
    r->register_handler (this, proc->gethandle ());
#endif /* ACE_WIN32 */

  ++this->current_count_;
  return 0;
}

ACE_BEGIN_VERSIONED_NAMESPACE_DECL void ACE_Process_Manager::cleanup	(	void *	instance,
		void *	arg
	)			[static]

Cleanup method, used by the ACE_Object_Manager to destroy the singleton.

Definition at line 38 of file Process_Manager.cpp.

References close_singleton().

Referenced by instance().

{
  ACE_Process_Manager::close_singleton ();
}

int ACE_Process_Manager::close

(

void

)

Release all resources. Do not wait for processes to exit.

Definition at line 268 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_TRACE, current_count_, default_exit_handler_, ACE_Event_Handler::handle_close(), max_process_table_size_, process_table_, ACE_Event_Handler::reactor(), ACE_Reactor::remove_handler(), remove_proc(), and SIGCHLD.

Referenced by ~ACE_Process_Manager().

{
  ACE_TRACE ("ACE_Process_Manager::close");

  if (this->reactor () != 0)
    {
#if !defined (ACE_WIN32) && !defined (ACE_LACKS_UNIX_SIGNALS)
      this->reactor ()->remove_handler (SIGCHLD, (ACE_Sig_Action *) 0);
#endif /*  !ACE_WIN32  */
      this->reactor (0);
    }

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));

  if (this->process_table_ != 0)
    {
      while (this->current_count_ > 0)
        this->remove_proc (0);

      delete [] this->process_table_;
      this->process_table_ = 0;
      this->max_process_table_size_ = 0;
      this->current_count_ = 0;
    }

  if (this->default_exit_handler_ != 0)
      this->default_exit_handler_->handle_close (ACE_INVALID_HANDLE,0);
  this->default_exit_handler_ = 0;

  return 0;
}

void ACE_Process_Manager::close_singleton

(

void

)

[static]

Delete the dynamically allocated singleton.

Definition at line 176 of file Process_Manager.cpp.

References ACE_GUARD, ACE_TRACE, delete_instance_, and instance_.

Referenced by cleanup().

{
  ACE_TRACE ("ACE_Process_Manager::close_singleton");

  ACE_MT (ACE_GUARD (ACE_Recursive_Thread_Mutex, ace_mon,
                     *ACE_Static_Object_Lock::instance ()));

  if (ACE_Process_Manager::delete_instance_)
    {
      delete ACE_Process_Manager::instance_;
      ACE_Process_Manager::instance_ = 0;
      ACE_Process_Manager::delete_instance_ = false;
    }
}

void ACE_Process_Manager::dump

(

void

)

const

Dump the state of an object.

Definition at line 84 of file Process_Manager.cpp.

References ACE_BEGIN_DUMP, ACE_DEBUG, ACE_END_DUMP, ACE_TEXT, ACE_TRACE, current_count_, and LM_DEBUG.

{
#if defined (ACE_HAS_DUMP)
  ACE_TRACE ("ACE_Process_Manager::dump");

  ACE_DEBUG ((LM_DEBUG, ACE_BEGIN_DUMP, this));

  ACE_DEBUG ((LM_DEBUG,  ACE_TEXT ("\nmax_process_table_size_ = %d"), this->max_process_table_size_));
  ACE_DEBUG ((LM_DEBUG,  ACE_TEXT ("\ncurrent_count_ = %d"), this->current_count_));

  for (size_t i = 0; i < this->current_count_; i++)
    this->process_table_[i].dump ();

  ACE_DEBUG ((LM_DEBUG, ACE_END_DUMP));
#endif /* ACE_HAS_DUMP */
}

ssize_t ACE_Process_Manager::find_proc

(

pid_t

process_id

)

[private]

Locate the index of the table slot occupied by process_id. Returns -1 if process_id is not in the process_table_

Definition at line 684 of file Process_Manager.cpp.

References ACE_TRACE, and current_count_.

Referenced by handle_signal(), register_handler(), remove(), set_scheduler(), terminate(), and wait().

{
  ACE_TRACE ("ACE_Process_Manager::find_proc");

  for (size_t i = 0; i < this->current_count_; ++i)
    if (pid == this->process_table_[i].process_->getpid ())
      return i;

  return -1;
}

int ACE_Process_Manager::handle_input

(

ACE_HANDLE

proc

)

[protected, virtual]

Collect one (or more, on unix) process exit status.

Reimplemented from ACE_Event_Handler.

Definition at line 315 of file Process_Manager.cpp.

References ACE_INVALID_PID, ACE_TRACE, wait(), and ACE_Time_Value::zero.

{
  ACE_TRACE ("ACE_Process_Manager::handle_input");

   pid_t pid;

   do
     pid = this->wait (0,
                       ACE_Time_Value::zero);
   while (pid != 0 && pid != ACE_INVALID_PID);

  return 0;
}

int ACE_Process_Manager::handle_signal	(	int	signum,
		siginfo_t *	= 0,
		ucontext_t *	= 0
	)			[protected, virtual]

On Unix, this routine is called asynchronously when a SIGCHLD is received. We just tweak the reactor so that it'll call back our <handle_input> function, which allows us to handle Process exits synchronously.

On Win32, this routine is called synchronously, and is passed the HANDLE of the Process that exited, so we can do all our work here

Reimplemented from ACE_Event_Handler.

Definition at line 340 of file Process_Manager.cpp.

References ACE_ERROR_RETURN, ACE_GUARD_RETURN, ACE_INVALID_PID, ACE_TEXT, find_proc(), ACE_Process::getpid(), LM_ERROR, ACE_Reactor::notify(), notify_proc_handler(), ACE_Process_Manager::Process_Descriptor::process_, process_table_, ACE_Event_Handler::reactor(), ACE_Event_Handler::READ_MASK, remove_proc(), and siginfo_t::si_handle_.

{
#if defined (ACE_WIN32)
  ACE_HANDLE proc = si->si_handle_;
  ACE_exitcode status = 0;
  BOOL result = ::GetExitCodeProcess (proc,
                                      &status);
  if (result)
    {
      if (status != STILL_ACTIVE)
        {
          {
            ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, lock_, -1));

            ssize_t const i = this->find_proc (proc);
            if (i == -1)
              return -1;
#if 0
            pid_t pid = i != -1
              ? process_table_[i].process_->getpid ()
              : ACE_INVALID_PID;
#endif
            this->notify_proc_handler (i, status);
            this->remove_proc (i);
          }
          return -1; // remove this HANDLE/Event_Handler combination
        }
      else
        ACE_ERROR_RETURN ((LM_ERROR,
                           ACE_TEXT ("Process still active")
                           ACE_TEXT (" -- shouldn't have been called yet!\n")),
                          0); // return 0 : stay registered
    }
  else
    {
      // <GetExitCodeProcess> failed.
      ACE_ERROR_RETURN ((LM_ERROR,
                         ACE_TEXT ("GetExitCodeProcess failed")),
                        -1); // return -1: unregister
    }
#else /* !ACE_WIN32 */
  ACE_UNUSED_ARG (si);
  return reactor ()->notify (this, ACE_Event_Handler::READ_MASK);
#endif /* !ACE_WIN32 */
}

int ACE_Process_Manager::insert_proc	(	ACE_Process *	process,
		ACE_Event_Handler *	event_handler = 0
	)			[private]

Insert a process in the table (checks for duplicates). Omitting the process handle won't work on Win32... Register event_handler to be called back when the process exits.

Definition at line 535 of file Process_Manager.cpp.

References ACE_TRACE, append_proc(), and ACE_Process::getpid().

{
  ACE_TRACE ("ACE_Process_Manager::insert_proc");

  // Check for duplicates and bail out if they're already
  // registered...
  if (this->find_proc (proc->getpid ()) != -1)
    return -1;

  return this->append_proc (proc, event_handler);
}

ACE_Process_Manager * ACE_Process_Manager::instance

(

ACE_Process_Manager *

)

[static]

Set pointer to a process-wide ACE_Process_Manager and return existing pointer.

Definition at line 147 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_TRACE, ACE_Object_Manager::at_exit(), cleanup(), delete_instance_, and instance_.

{
  ACE_TRACE ("ACE_Process_Manager::instance");
  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon,
                            *ACE_Static_Object_Lock::instance (), 0));

  ACE_Process_Manager *t = ACE_Process_Manager::instance_;
  // We can't safely delete it since we don't know who created it!
  ACE_Process_Manager::delete_instance_ = false;

  // Register with the Object_Manager so that the wrapper to
  // delete the proactor will be called when Object_Manager is
  // being terminated.

#if defined ACE_HAS_SIG_C_FUNC
  ACE_Object_Manager::at_exit (ACE_Process_Manager::instance_,
                                ACE_Process_Manager_cleanup,
                                0);
#else
  ACE_Object_Manager::at_exit (ACE_Process_Manager::instance_,
                                ACE_Process_Manager::cleanup,
                                0);
#endif /* ACE_HAS_SIG_C_FUNC */

  ACE_Process_Manager::instance_ = tm;
  return t;
}

ACE_Process_Manager * ACE_Process_Manager::instance

(

void

)

[static]

Get pointer to a process-wide ACE_Process_Manager.

Definition at line 109 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_NEW_RETURN, ACE_TRACE, ACE_Object_Manager::at_exit(), cleanup(), delete_instance_, and instance_.

{
  ACE_TRACE ("ACE_Process_Manager::instance");

  if (ACE_Process_Manager::instance_ == 0)
    {
      // Perform Double-Checked Locking Optimization.
      ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon,
                                *ACE_Static_Object_Lock::instance (), 0));

      if (ACE_Process_Manager::instance_ == 0)
        {
          ACE_NEW_RETURN (ACE_Process_Manager::instance_,
                          ACE_Process_Manager,
                          0);
          ACE_Process_Manager::delete_instance_ = true;

          // Register with the Object_Manager so that the wrapper to
          // delete the proactor will be called when Object_Manager is
          // being terminated.

#if defined ACE_HAS_SIG_C_FUNC
          ACE_Object_Manager::at_exit (ACE_Process_Manager::instance_,
                                       ACE_Process_Manager_cleanup,
                                       0);
#else
          ACE_Object_Manager::at_exit (ACE_Process_Manager::instance_,
                                       ACE_Process_Manager::cleanup,
                                       0);
#endif /* ACE_HAS_SIG_C_FUNC */

        }
    }

  return ACE_Process_Manager::instance_;
}

ACE_BEGIN_VERSIONED_NAMESPACE_DECL ACE_INLINE size_t ACE_Process_Manager::managed

(

void

)

const

Return the number of managed processes.

Definition at line 8 of file Process_Manager.inl.

References current_count_.

{
  return current_count_;
}

int ACE_Process_Manager::notify_proc_handler	(	size_t	n,
		ACE_exitcode	status
	)			[private]

If there's a specific handler for the Process at index n in the table, or there's a default handler, call it.

Definition at line 983 of file Process_Manager.cpp.

References ACE_DEBUG, ACE_TEXT, default_exit_handler_, ACE_Process::exit_code(), ACE_Process_Manager::Process_Descriptor::exit_notify_, ACE_Event_Handler::handle_exit(), LM_DEBUG, ACE_Process_Manager::Process_Descriptor::process_, and process_table_.

Referenced by handle_signal(), and wait().

{
  if (i < this->current_count_)
    {
      Process_Descriptor &proc_desc =
        this->process_table_[i];

      proc_desc.process_->exit_code (exit_code);

      if (proc_desc.exit_notify_ != 0)
        proc_desc.exit_notify_->handle_exit (proc_desc.process_);
      else if (this->default_exit_handler_ != 0
               && this->default_exit_handler_->handle_exit (proc_desc.process_) < 0)
        {
          this->default_exit_handler_->handle_close
            (ACE_INVALID_HANDLE,
             0);
          this->default_exit_handler_ = 0;
        }
      return 1;
    }
  else
    {
      ACE_DEBUG ((LM_DEBUG,
                  ACE_TEXT ("(%P:%t|%T) ACE_Process_Manager::notify_proc_handler:")
                  ACE_TEXT (" unknown/unmanaged process reaped\n")));
      return 0;
    }
}

int ACE_Process_Manager::open	(	size_t	size = ACE_Process_Manager::DEFAULT_SIZE,
		ACE_Reactor *	r = 0
	)

Initialize an ACE_Process_Manager with a table containing up to size processes. This table resizes itself automatically as needed. If a reactor is provided, this ACE_Process_Manager uses it to notify an application when a process it controls exits. By default, however, we don't use an ACE_Reactor.

Definition at line 222 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_TRACE, ACE_Event_Handler::reactor(), resize(), and SIGCHLD.

{
  ACE_TRACE ("ACE_Process_Manager::open");

  if (r)
    {
      this->reactor (r);
#if !defined (ACE_WIN32) && !defined (ACE_LACKS_UNIX_SIGNALS)
      // Register signal handler object.
      if (r->register_handler (SIGCHLD, this) == -1)
        return -1;
#endif /* !defined(ACE_WIN32) */
    }

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));

  if (this->max_process_table_size_ < size)
    this->resize (size);
  return 0;
}

int ACE_Process_Manager::reap	(	pid_t	pid = -1,
		ACE_exitcode *	stat_loc = 0,
		int	options = WNOHANG
	)

Deprecated:

Reap the result of a single process by calling ACE_OS::waitpid(), therefore, this method is not portable to Windows. If the child is successfully reaped, remove() is called automatically. Use one of the wait() methods instead of this method.

Definition at line 965 of file Process_Manager.cpp.

References ACE_BIT_ENABLED, ACE_TRACE, ACE_Time_Value::max_time, wait(), WNOHANG, and ACE_Time_Value::zero.

{
  ACE_TRACE ("ACE_Process_Manager::reap");

  return this->wait (pid,
                     (ACE_BIT_ENABLED (options, WNOHANG)
                      ? ACE_Time_Value::zero
                      : ACE_Time_Value::max_time),
                     stat_loc);
}

int ACE_Process_Manager::register_handler	(	ACE_Event_Handler *	event_handler,
		pid_t	pid = ACE_INVALID_PID
	)

Register an event handler to be called back when the specified process exits. If pid == ACE_INVALID_PID this handler is called when any process with no specific handler exits.

Warning:

In multithreaded applications, there is a race condition if a process exits between the time it is spawned and when its handler is registered. To avoid this, register the handler at the time the process is spawned.

Definition at line 389 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_INVALID_PID, default_exit_handler_, ACE_Process_Manager::Process_Descriptor::exit_notify_, find_proc(), ACE_Event_Handler::handle_close(), and process_table_.

{
  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));

  if (pid == ACE_INVALID_PID)
    {
      if (this->default_exit_handler_ != 0)
        this->default_exit_handler_->handle_close (ACE_INVALID_HANDLE, 0);
      this->default_exit_handler_ = eh;
      return 0;
    }

  ssize_t const i = this->find_proc (pid);

  if (i == -1)
    {
      errno = EINVAL;
      return -1;
    }

  Process_Descriptor &proc_desc = this->process_table_[i];

  if (proc_desc.exit_notify_ != 0)
    proc_desc.exit_notify_->handle_close (ACE_INVALID_HANDLE, 0);
  proc_desc.exit_notify_ = eh;
  return 0;
}

int ACE_Process_Manager::remove

(

pid_t

pid

)

Remove process pid from the ACE_Process_Manager's internal records. This is called automatically by the reap() method after it successfully reaps a process. It's also possible to call this method directly from a signal handler, but don't call both reap() and remove()!

Definition at line 551 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_TRACE, find_proc(), and remove_proc().

Referenced by wait().

{
  ACE_TRACE ("ACE_Process_Manager::remove");

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));

  ssize_t const i = this->find_proc (pid);

  if (i != -1)
    return this->remove_proc (i);

  // set "process not found" error
  return -1;
}

int ACE_Process_Manager::remove_proc

(

size_t

n

)

[private]

Actually removes the process at index n from the table. This method must be called with locks held.

Definition at line 569 of file Process_Manager.cpp.

References ACE_TRACE, current_count_, ACE_Event_Handler::DONT_CALL, ACE_Process_Manager::Process_Descriptor::exit_notify_, ACE_Event_Handler::handle_close(), ACE_Process_Manager::Process_Descriptor::process_, process_table_, ACE_Event_Handler::reactor(), ACE_Reactor::remove_handler(), and ACE_Process::unmanage().

Referenced by close(), handle_signal(), remove(), and wait().

{
  ACE_TRACE ("ACE_Process_Manager::remove_proc");

  // If there's an exit_notify_ <Event_Handler> for this pid, call its
  // <handle_close> method.

  if (this->process_table_[i].exit_notify_ != 0)
    {
      this->process_table_[i].exit_notify_->handle_close
        (this->process_table_[i].process_->gethandle(),
         0);
      this->process_table_[i].exit_notify_ = 0;
    }

#if defined (ACE_WIN32)
  ACE_Reactor * const r = this->reactor ();
  if (r != 0)
    r->remove_handler (this->process_table_[i].process_->gethandle (),
                       ACE_Event_Handler::DONT_CALL);
#endif /* ACE_WIN32 */

  this->process_table_[i].process_->unmanage ();

  this->process_table_[i].process_ = 0;

  this->current_count_--;

  if (this->current_count_ > 0)
    // Compact the table by moving the last item into the slot vacated
    // by the index being removed (this is a structure assignment).
    this->process_table_[i] =
      this->process_table_[this->current_count_];

  return 0;
}

int ACE_Process_Manager::resize

(

size_t

)

[private]

Resize the pool of Process_Descriptors.

Definition at line 192 of file Process_Manager.cpp.

References ACE_NEW_RETURN, ACE_TRACE, current_count_, and max_process_table_size_.

Referenced by open().

{
  ACE_TRACE ("ACE_Process_Manager::resize");

  if (size <= this->max_process_table_size_)
    return 0;

  Process_Descriptor *temp = 0;

  ACE_NEW_RETURN (temp,
                  Process_Descriptor[size],
                  -1);

  for (size_t i = 0;
       i < this->current_count_;
       i++)
    // Structure assignment.
    temp[i] = this->process_table_[i];

  this->max_process_table_size_ = size;

  delete [] this->process_table_;

  this->process_table_ = temp;
  return 0;
}

int ACE_Process_Manager::set_scheduler	(	const ACE_Sched_Params &	params,
		pid_t	pid
	)

Sets the scheduling parameters for process identified by pid by passing params, pid to ACE_OS::sched_params().

Return values:

0

on success, -1 on failure, and ACE_INVALID_PID when the specified pid is not managed by this ACE_Process_Manager.

Definition at line 644 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_INVALID_PID, ACE_TRACE, find_proc(), and ACE_OS::sched_params().

{
  ACE_TRACE ("ACE_Process_Manager::set_scheduler");

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex,
                            ace_mon, this->lock_, -1));

  // Check to see if the process identified by the given pid is managed by
  // this instance of ACE_Process_Manager.
  ssize_t const i = this->find_proc (pid);

  if (i == -1)
    // set "no such process" error
    return ACE_INVALID_PID;

  return ACE_OS::sched_params (params, pid);
}

int ACE_Process_Manager::set_scheduler_all

(

const ACE_Sched_Params &

params

)

Sets the scheduling parameters for all the processes managed by this ACE_Process_Manager by passing params to ACE_OS::sched_params().

Return values:

0

on success, -1 on failure.

Definition at line 664 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_TRACE, current_count_, and ACE_OS::sched_params().

{
  ACE_TRACE ("ACE_Process_Manager::set_scheduler_all");

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex,
                            ace_mon, this->lock_, -1));

  for (size_t i = 0; i < this->current_count_; ++i)
    {
      pid_t const pid = this->process_table_[i].process_->getpid ();
      if (ACE_OS::sched_params (params, pid) != 0)
        return -1;
    }
  return 0;
}

pid_t ACE_Process_Manager::spawn	(	ACE_Process_Options &	options,
		ACE_Event_Handler *	event_handler = 0
	)

Create a new process with the specified options. Register event_handler to be called back when the process exits.

On success, returns the process id of the child that was created. On failure, returns ACE_INVALID_PID.

Definition at line 421 of file Process_Manager.cpp.

References ACE_INVALID_PID, ACE_NEW_RETURN, and spawn().

{
  ACE_Process *process = 0;
  ACE_NEW_RETURN (process,
                  ACE_Managed_Process,
                  ACE_INVALID_PID);

  pid_t const pid = spawn (process, options, event_handler);
  if (pid == ACE_INVALID_PID || pid == 0)
    delete process;

  return pid;
}

pid_t ACE_Process_Manager::spawn	(	ACE_Process *	proc,
		ACE_Process_Options &	options,
		ACE_Event_Handler *	event_handler = 0
	)

Create a new process with specified options. Register event_handler to be called back when the process exits.

On success, returns the process id of the child that was created. On failure, returns ACE_INVALID_PID.

Definition at line 439 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_INVALID_PID, ACE_TRACE, and ACE_Process::spawn().

Referenced by spawn().

{
  ACE_TRACE ("ACE_Process_Manager::spawn");

  pid_t const pid = process->spawn (options);

  // Only include the pid in the parent's table.
  if (pid == ACE_INVALID_PID || pid == 0)
    return pid;

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex,
                            ace_mon, this->lock_, -1));

  if (this->append_proc (process, event_handler) == -1)
    // bad news: spawned, but not registered in table.
    return ACE_INVALID_PID;

  return pid;
}

int ACE_Process_Manager::spawn_n	(	size_t	n,
		ACE_Process_Options &	options,
		pid_t *	child_pids = 0,
		ACE_Event_Handler *	event_Handler = 0
	)

Create n new processes with the same options. If child_pids is non-0 it is expected to be an array of at least n pid_t, which are filled in with the process IDs of the spawned processes. Register event_handler to be called back when each process exits. Returns 0 on success and -1 on failure.

Definition at line 464 of file Process_Manager.cpp.

References ACE_INVALID_PID, and ACE_TRACE.

{
  ACE_TRACE ("ACE_Process_Manager::spawn_n");

  if (child_pids != 0)
    for (size_t i = 0;
         i < n;
         ++i)
      child_pids[i] = ACE_INVALID_PID;

  for (size_t i = 0;
       i < n;
       i++)
    {
      pid_t const pid = this->spawn (options, event_handler);
      if (pid == ACE_INVALID_PID || pid == 0)
        // We're in the child or something's gone wrong.
        return pid;
      else if (child_pids != 0)
        child_pids[i] = pid;
    }

  return 0;
}

int ACE_Process_Manager::terminate	(	pid_t	pid,
		int	sig
	)

Sends the specified signal to the specified process.

Note:

This only works on platforms that have signal capability. In particular, it doesn't work on Windows.

Return values:

0

on success and -1 on failure.

Definition at line 625 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_TRACE, find_proc(), and ACE_OS::kill().

{
  ACE_TRACE ("ACE_Process_Manager::terminate");

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));

  // Check for duplicates and bail out if they're already
  // registered...
  ssize_t const i = this->find_proc (pid);

  if (i == -1)
    // set "no such process" error
    return -1;

  return ACE_OS::kill (pid, sig);
}

int ACE_Process_Manager::terminate

(

pid_t

pid

)

Abruptly terminate a single process with id pid using the ACE::terminate_process() method which works on both signal-capable systems and on Windows.

Note:

This call is potentially dangerous to use since the process being terminated may not have a chance to cleanup before it shuts down.

Return values:

0

on success and -1 on failure.

Definition at line 607 of file Process_Manager.cpp.

References ACE_GUARD_RETURN, ACE_TRACE, find_proc(), and ACE::terminate_process().

{
  ACE_TRACE ("ACE_Process_Manager::terminate");

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));

  // Check for duplicates and bail out if they're already
  // registered...
  ssize_t const i = this->find_proc (pid);

  if (i == -1)
    // set "no such process" error
    return -1;

  return ACE::terminate_process (pid);
}

pid_t ACE_Process_Manager::wait	(	pid_t	pid,
		ACE_exitcode *	status = 0
	)

Wait indefinitely for a single, specified process to terminate. If pid is 0, waits for any of the managed processes (but see the note concerning "sloppy process cleanup on unix"). If pid != 0, this method waits for that process only.

Return values:

The

pid of the process which exited, or ACE_INVALID_PID on error.

Definition at line 755 of file Process_Manager.cpp.

References ACE_TRACE, ACE_Time_Value::max_time, and wait().

{
  ACE_TRACE ("ACE_Process_Manager::wait");

  return this->wait (pid,
                     ACE_Time_Value::max_time,
                     status);
}

pid_t ACE_Process_Manager::wait	(	pid_t	pid,
		const ACE_Time_Value &	timeout,
		ACE_exitcode *	status = 0
	)

Wait up to timeout for a single specified process to terminate. If pid is 0, this method waits for any of the managed processes (but see the note concerning "sloppy process cleanup on unix"). If pid != 0, waits for that process only.

Parameters:

	pid	Process ID
	timeout	Relative time to wait for process to terminate
	status	Exit status of terminated process

Return values:

The

pid of the process which exited, 0 if a timeout occurred, or ACE_INVALID_PID on error.

Definition at line 770 of file Process_Manager.cpp.

References ACE_ASSERT, ACE_DEBUG, ACE_ERROR_RETURN, ACE_GUARD_RETURN, ACE_INVALID_PID, ACE_NEW_RETURN, ACE_TEXT, ACE_TRACE, find_proc(), ACE_Process::getpid(), LM_DEBUG, LM_ERROR, ACE_Time_Value::max_time, ACE_Time_Value::msec(), notify_proc_handler(), ACE_Process_Manager::Process_Descriptor::process_, process_table_, ACE_Sig_Action::register_action(), remove(), remove_proc(), SIGCHLD, sigchld_nop(), ACE_OS::sleep(), ACE_Process::wait(), ACE_OS::waitpid(), WNOHANG, and ACE_Time_Value::zero.

{
  ACE_TRACE ("ACE_Process_Manager::wait");

  ACE_exitcode local_stat = 0;
  if (status == 0)
    status = &local_stat;

  *status = 0;

  ssize_t idx = -1;
  ACE_Process *proc = 0;

  {
    // fake context after which the lock is released
    ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));

    if (pid != 0)
      {
        idx = this->find_proc (pid);
        if (idx == -1)
          return ACE_INVALID_PID;
        else
          proc = process_table_[idx].process_;
      }
    // release the lock.
  }
  if (proc != 0)
    pid = proc->wait (timeout, status);
  else
    {
      ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));
      // Wait for any Process spawned by this Process_Manager.
#if defined (ACE_WIN32)
      HANDLE *handles = 0;

      ACE_NEW_RETURN (handles,
                      HANDLE[this->current_count_],
                      ACE_INVALID_PID);

      for (size_t i = 0;
           i < this->current_count_;
           ++i)
        handles[i] =
          process_table_[i].process_->gethandle ();

      DWORD handle_count = static_cast<DWORD> (this->current_count_);
      DWORD result = ::WaitForMultipleObjects (handle_count,
                                               handles,
                                               FALSE,
                                               timeout == ACE_Time_Value::max_time
                                               ? INFINITE
                                               : timeout.msec ());
      if (result == WAIT_FAILED)
        pid = ACE_INVALID_PID;
      else if (result == WAIT_TIMEOUT)
        pid = 0;
      else
        {
          // Green Hills produces a warning that result >=
          // WAIT_OBJECT_0 is a pointless comparison because
          // WAIT_OBJECT_0 is zero and DWORD is unsigned long, so this
          // test is skipped for Green Hills.  Same for mingw.
# if defined (ghs) || defined (__MINGW32__) || (defined (_MSC_VER) && _MSC_VER >= 1300)
          ACE_ASSERT (result < WAIT_OBJECT_0 + this->current_count_);
# else
          ACE_ASSERT (result >= WAIT_OBJECT_0
                      && result < WAIT_OBJECT_0 + this->current_count_);
# endif

          idx = this->find_proc (handles[result - WAIT_OBJECT_0]);

          if (idx != -1)
            {
              pid = process_table_[idx].process_->getpid ();
              result = ::GetExitCodeProcess (handles[result - WAIT_OBJECT_0],
                                             status);
              if (result == 0)
                {
                  // <GetExitCodeProcess> failed!
                  this->remove_proc (idx);
                  pid = ACE_INVALID_PID;
                }
            }
          else
            {
              // uh oh...handle removed from process_table_, even though
              // we're holding a lock!
              delete [] handles;
              ACE_ERROR_RETURN ((LM_ERROR,
                                 ACE_TEXT ("Process removed")
                                 ACE_TEXT (" -- somebody's ignoring the lock!\n")),
                                -1);
            }
        }

      delete [] handles;
#else /* !defined(ACE_WIN32) */
      if (timeout == ACE_Time_Value::max_time)
        pid = ACE_OS::waitpid (-1, status, 0);
      else if (timeout == ACE_Time_Value::zero)
        pid = ACE_OS::waitpid (-1, status, WNOHANG);
      else
        {
# if defined (ACE_LACKS_UNIX_SIGNALS)
          pid = 0;
          ACE_Time_Value sleeptm (1);    // 1 msec
          if (sleeptm > timeout)         // if sleeptime > waittime
            sleeptm = timeout;
          ACE_Time_Value tmo (timeout);  // Need one we can change
          for (ACE_Countdown_Time time_left (&tmo); tmo > ACE_Time_Value::zero ; time_left.update ())
            {
              pid = ACE_OS::waitpid (-1, status, WNOHANG);
              if (pid > 0 || pid == ACE_INVALID_PID)
                break;          // Got a child or an error - all done

              // pid 0, nothing is ready yet, so wait.
              // Do a (very) short sleep (only this thread sleeps).
              ACE_OS::sleep (sleeptm);
            }
# else
          // Force generation of SIGCHLD, even though we don't want to
          // catch it - just need it to interrupt the sleep below.
          // If this object has a reactor set, assume it was given at
          // open(), and there's already a SIGCHLD action set, so no
          // action is needed here.
          ACE_Sig_Action old_action;
          if (this->reactor () == 0)
            {
              ACE_Sig_Action do_sigchld ((ACE_SignalHandler)sigchld_nop);
              do_sigchld.register_action (SIGCHLD, &old_action);
            }

          ACE_Time_Value tmo (timeout);  // Need one we can change
          for (ACE_Countdown_Time time_left (&tmo); ; time_left.update ())
            {
              pid = ACE_OS::waitpid (-1, status, WNOHANG);
#   if defined (ACE_VXWORKS) && (ACE_VXWORKS >= 0x600)
              if (pid > 0 || (pid == ACE_INVALID_PID && errno != EINTR))
#   else
                if (pid > 0 || pid == ACE_INVALID_PID)
#   endif
                  break;          // Got a child or an error - all done

              // pid 0, nothing is ready yet, so wait.
              // Do a sleep (only this thread sleeps) til something
              // happens. This relies on SIGCHLD interrupting the sleep.
              // If SIGCHLD isn't delivered, we'll need to do something
              // with sigaction to force it.
              if (-1 == ACE_OS::sleep (tmo) && errno == EINTR)
                continue;
              // Timed out
              pid = 0;
              break;
            }

          // Restore the previous SIGCHLD action if it was changed.
          if (this->reactor () == 0)
            old_action.register_action (SIGCHLD);
# endif /* !ACE_LACKS_UNIX_SIGNALS */
        }
#endif /* !defined (ACE_WIN32) */
    }

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->lock_, -1));
  if (pid != ACE_INVALID_PID && pid != 0)
    {
      //we always need to get our id, because we could have been moved in the table meanwhile
      idx = this->find_proc (pid);
      if (idx == -1)
        {
          // oops, reaped an unmanaged process!
          ACE_DEBUG ((LM_DEBUG,
                      ACE_TEXT ("(%P|%t) oops, reaped unmanaged %d\n"),
                      pid));
          return pid;
        }
      else
        proc = process_table_[idx].process_;
      if (proc != 0)
        ACE_ASSERT (pid == proc->getpid ());

      this->notify_proc_handler (idx,
                                 *status);
      this->remove (pid);
    }

  return pid;
}

int ACE_Process_Manager::wait

(

const ACE_Time_Value &

timeout = ACE_Time_Value::max_time

)

Block until there are no more child processes running that were spawned by this ACE_Process_Manager. Unlike the wait() method below, this method does not require a signal handler or use of ACE_OS::sigwait() because it simply blocks synchronously waiting for all the children managed by this ACE_Process_Manager to exit. Note that this does not return any status information about the success or failure of exiting child processes, although any registered exit handlers are called.

Parameters:

timeout

Relative time to wait for processes to terminate.

Return values:

0

on success; -1 on failure.

Definition at line 716 of file Process_Manager.cpp.

References ACE_INVALID_PID, ACE_TRACE, ACE_OS::gettimeofday(), ACE_Time_Value::max_time, and ACE_Time_Value::zero.

Referenced by handle_input(), reap(), and wait().

{
  ACE_TRACE ("ACE_Process_Manager::wait");

  ACE_Time_Value until = timeout;
  ACE_Time_Value remaining = timeout;

  if (until < ACE_Time_Value::max_time)
    until += ACE_OS::gettimeofday ();

  while (this->current_count_ > 0)
    {
      pid_t const pid = this->wait (0, remaining);

      if (pid == ACE_INVALID_PID)       // wait() failed
        return -1;
      else if (pid == 0)     // timeout
        break;

      remaining = until < ACE_Time_Value::max_time
        ? until - ACE_OS::gettimeofday ()
        : ACE_Time_Value::max_time;

      if (remaining <= ACE_Time_Value::zero)
        break;

      // else Process terminated...wait for more...
    }
  return static_cast<int> (this->current_count_);
}

---

Friends And Related Function Documentation

friend class ACE_Process_Control [friend]

Definition at line 101 of file Process_Manager.h.

---

Member Data Documentation

ACE_Process_Manager::ACE_ALLOC_HOOK_DECLARE

Declare the dynamic allocation hooks.

Definition at line 336 of file Process_Manager.h.

size_t ACE_Process_Manager::current_count_ [private]

Current number of processes we are managing.

Definition at line 451 of file Process_Manager.h.

Referenced by append_proc(), close(), dump(), find_proc(), managed(), remove_proc(), resize(), and set_scheduler_all().

ACE_Event_Handler* ACE_Process_Manager::default_exit_handler_ [private]

This event handler is used to notify when a process we control exits.

Definition at line 455 of file Process_Manager.h.

Referenced by close(), notify_proc_handler(), and register_handler().

bool ACE_Process_Manager::delete_instance_ = false [static, private]

Controls whether the <Process_Manager> is deleted when we shut down (we can only delete it safely if we created it!)

Definition at line 462 of file Process_Manager.h.

Referenced by close_singleton(), and instance().

ACE_Process_Manager * ACE_Process_Manager::instance_ = 0 [static, private]

Singleton pointer.

Definition at line 458 of file Process_Manager.h.

Referenced by close_singleton(), and instance().

size_t ACE_Process_Manager::max_process_table_size_ [private]

Maximum number of processes we can manage (should be dynamically allocated).

Definition at line 448 of file Process_Manager.h.

Referenced by append_proc(), close(), and resize().

Process_Descriptor* ACE_Process_Manager::process_table_ [private]

Vector that describes process state within the Process_Manager.

Definition at line 444 of file Process_Manager.h.

Referenced by append_proc(), close(), handle_signal(), notify_proc_handler(), register_handler(), remove_proc(), and wait().

---

The documentation for this class was generated from the following files:

• Process_Manager.h
• Process_Manager.cpp
• Process_Manager.inl

---