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/* -*- C++ -*- */
// $Id$
// ============================================================================
//
// = LIBRARY
// ace
//
// = FILENAME
// Reactor.h
//
// = AUTHOR
// Doug Schmidt
//
// ============================================================================
#if !defined (ACE_REACTOR_H)
#define ACE_REACTOR_H
#include "ace/Handle_Set.h"
#include "ace/Timer_Queue.h"
#include "ace/Signal.h"
#include "ace/Thread.h"
#include "ace/Token.h"
#include "ace/Pipe.h"
#include "ace/SOCK_Stream.h"
// Add useful typedefs to simplify the following code.
typedef void (ACE_Handle_Set::*ACE_FDS_PTMF) (ACE_HANDLE);
typedef int (ACE_Event_Handler::*ACE_EH_PTMF) (ACE_HANDLE);
// Forward declaration.
class ACE_Reactor;
#if defined (ACE_MT_SAFE)
// The following two classes have to be moved out here to keep the SGI
// C++ compiler happy (it doesn't like nested classes).
class ACE_Export ACE_Notification_Handler : public ACE_Event_Handler
// = TITLE
// Callback and unblock the ACE_Reactor if it's sleeping.
//
// = DESCRIPTION
// This implementation is necessary for cases where the Reactor
// is being run in a multi-threaded program. In this case, we
// need a special trick to unblock select() or poll() when
// updates occur in somewhere other than the main ACE_Reactor
// thread. All we do is write data to a pipe or socket that the
// ACE_Reactor is listening on.
{
public:
// = Initialization and termination methods.
int open (ACE_Reactor *);
int close (void);
int handle_notifications (ACE_Handle_Set &rmask);
// Handles pending threads (if any) that are waiting to unblock the
// Reactor.
ssize_t notify (ACE_Event_Handler * = 0,
ACE_Reactor_Mask = ACE_Event_Handler::EXCEPT_MASK);
// Called by a thread when it wants to unblock the Reactor.
virtual int handle_input (ACE_HANDLE handle);
// Called back by the Reactor when a thread wants to unblock us.
void dump (void) const;
// Dump the state of an object.
ACE_ALLOC_HOOK_DECLARE;
// Declare the dynamic allocation hooks.
private:
ACE_Reactor *reactor_;
// Keep a back pointer to the Reactor.
ACE_Pipe notification_pipe_;
// Contains the HANDLE the Reactor is listening on, as well as the
// HANDLE that threads wanting the attention of the Reactor will
// write to.
};
#if defined (ACE_REACTOR_HAS_DEADLOCK_DETECTION)
#include "ace/Local_Tokens.h"
typedef ACE_Local_Mutex ACE_REACTOR_MUTEX;
#else
typedef ACE_Token ACE_REACTOR_MUTEX;
#endif /* ACE_REACTOR_HAS_DEADLOCK_DETECTION */
class ACE_Export ACE_Reactor_Token : public ACE_REACTOR_MUTEX
// = TITLE
// Used as a synchronization mechanism to coordinate concurrent
// access to a Reactor object.
{
public:
ACE_Reactor_Token (ACE_Reactor &r);
virtual void sleep_hook (void);
// Called just before the ACE_Event_Handler goes to sleep.
void dump (void) const;
// Dump the state of an object.
ACE_ALLOC_HOOK_DECLARE;
// Declare the dynamic allocation hooks.
private:
ACE_Reactor &reactor_;
};
#endif /* ACE_MT_SAFE */
class ACE_Export ACE_Handler_Repository
{
// = TITLE
// Used to map ACE_HANDLEs onto the appropriate ACE_Event_Handler *.
//
// = DESCRIPTION
// This class is necessary to shield differences between UNIX
// and WIN32. In UNIX, ACE_HANDLE is an int, whereas in WIN32
// it's a void *. This class hides all these details from the
// bulk of the Reactor code.
public:
friend class ACE_Handler_Repository_Iterator;
// = Initialization and termination methods.
ACE_Handler_Repository (void);
// Default "do-nothing" constructor.
int open (size_t size);
// Initialize a repository of the appropriate <size>.
int close (ACE_Reactor *);
// Destroy the handler and cleanup the Reactor.
// = Search structure operations.
ACE_Event_Handler *find (ACE_HANDLE);
// Return the <ACE_Event_Handler *> associated with <ACE_HANDLE>.
int bind (ACE_HANDLE, ACE_Event_Handler *);
// Bind the <ACE_Event_Handler *> to the <ACE_HANDLE>.
int unbind (ACE_HANDLE, ACE_Handle_Set &rd_mask,
ACE_Handle_Set &wr_mask, ACE_Handle_Set &ex_mask);
// Remove the binding of <ACE_HANDLE>.
// Performs sanity checking on the ACE_HANDLE.
int invalid_handle (ACE_HANDLE);
size_t max_handlep1 (void);
// Maximum ACE_HANDLE value, plus 1.
void dump (void) const;
// Dump the state of an object.
ACE_ALLOC_HOOK_DECLARE;
// Declare the dynamic allocation hooks.
private:
ssize_t max_size_;
// Maximum number of handles.
#if defined (ACE_WIN32)
ssize_t cur_size_;
// The highest currently active handle, plus 1.
// = This structure maps <HANDLES> to <Event_Handlers>.
struct ACE_NT_EH_Record
{
ACE_HANDLE handle_;
ACE_Event_Handler *event_handler_;
};
ACE_NT_EH_Record *event_handlers_;
// The NT version implements this via a dynamically allocated
// array of <ACE_NT_EH_Record *>. Since NT implements ACE_HANDLE
// as a void * we can't directly index into this array. Therefore,
// we just do a linear search (for now). Next, we'll modify
// things to use hashing or something faster...
#else
ACE_HANDLE max_handlep1_;
// The highest currently active handle, plus 1.
ACE_Event_Handler **event_handlers_;
// The UNIX version implements this via a dynamically allocated
// array of <ACE_Event_Handler *> that is indexed directly using
// the ACE_HANDLE value.
#endif /* ACE_WIN32 */
};
class ACE_Export ACE_Handler_Repository_Iterator
{
public:
// = Initialization method.
ACE_Handler_Repository_Iterator (const ACE_Handler_Repository &s);
// = Iteration methods.
int next (ACE_Event_Handler *&next_item);
// Pass back the <next_item> that hasn't been seen in the Set.
// Returns 0 when all items have been seen, else 1.
int advance (void);
// Move forward by one element in the set.
void dump (void) const;
// Dump the state of an object.
ACE_ALLOC_HOOK_DECLARE;
// Declare the dynamic allocation hooks.
private:
const ACE_Handler_Repository &rep_;
// Reference to the Handler_Repository we are iterating over.
ssize_t current_;
// Pointer to the current iteration level.
};
class ACE_Export ACE_Reactor
// = TITLE
// An object oriented event demultiplexor and event handler
// dispatcher.
//
// = DESCRIPTION
// The ACE_Reactor is an object-oriented event demultiplexor
// and event handler dispatcher. The sources of events that the
// ACE_Reactor waits for and dispatches includes I/O events,
// signals, and timer events.
{
public:
enum
{
DEFAULT_SIZE = ACE_DEFAULT_REACTOR_SIZE,
// Default size of the Reactor's handle table.
// = Operations on the "ready" mask and the "dispatch" mask.
GET_MASK = 1,
// Retrieve current value of the the "ready" mask or the "dispatch" mask.
SET_MASK = 2,
// Set value of bits to new mask (changes the entire mask).
ADD_MASK = 3,
// Bitwise "or" the value into the mask (only changes enabled bits).
CLR_MASK = 4
// Bitwise "and" the negation of the value out of the mask (only changes enabled bits).
};
// = Initialization and termination methods.
ACE_Reactor (ACE_Sig_Handler * = 0);
// Initialize the new ACE_Reactor with the default size.
ACE_Reactor (size_t size,
int restart = 0,
ACE_Sig_Handler * = 0);
// Initialize the new ACE_Reactor of size <size>.
virtual int open (size_t size = DEFAULT_SIZE,
int restart = 0,
ACE_Sig_Handler * = 0);
// Initialize the new ACE_Reactor of size <size>.
virtual void close (void);
// Close down the reactor and release all of its resources.
virtual ~ACE_Reactor (void);
// Close down the reactor and release all of its resources.
// = Timer management.
virtual int schedule_timer (ACE_Event_Handler *,
const void *arg,
const ACE_Time_Value &delta,
const ACE_Time_Value &interval = ACE_Time_Value::zero);
// Schedule an <event_handler> that will expire after <delay> amount
// of time. If it expires then <arg> is passed in as the value to
// the <event_handler>'s <handle_timeout> callback method. If
// <interval> is != to <ACE_Time_Value::zero> then it is used to
// reschedule the <event_handler> automatically. This method
// returns a timer handle that uniquely identifies the
// <event_handler> in an internal list. This timer handle can be
// used to cancel an <event_handler> before it expires. The
// cancellation ensures that timer_ids are unique up to values of
// greater than 2 billion timers. As long as timers don't stay
// around longer than this there should be no problems with
// accidentally deleting the wrong timer.
virtual int cancel_timer (ACE_Event_Handler *event_handler);
// Cancel all <event_handlers> that match the address of
// <event_handler>.
virtual int cancel_timer (int timer_id, const void **arg = 0);
// Cancel the single <ACE_Event_Handler> that matches the <timer_id>
// value (which was returned from the <schedule> method). If arg is
// non-NULL then it will be set to point to the ``magic cookie''
// argument passed in when the <Event_Handler> was registered. This
// makes it possible to free up the memory and avoid memory leaks.
// = Event loop drivers.
virtual int handle_events (ACE_Time_Value *how_long = 0);
// Main event loop driver that blocks for <how_long> before
// returning (will return earlier if I/O or signal events occur).
// Note that <how_long> can be 0, in which case this method blocks
// until I/O events or signals occur.
virtual int handle_events (ACE_Time_Value &how_long);
// Main event loop driver that blocks for <how_long> before
// returning (will return earlier if I/O or signal events occur).
// = Register and remove Handlers.
virtual int register_handler (ACE_Event_Handler *eh,
ACE_Reactor_Mask mask);
// Register an Event_Handler <eh> with a particular <mask>. Note
// that the Reactor will call eh->get_handle() to extract the
// underlying I/O handle).
virtual int register_handler (ACE_HANDLE handle,
ACE_Event_Handler *eh,
ACE_Reactor_Mask mask);
// Register an Event_Handler <eh> with a particular <mask>. Note
// that since the <handle> is given the Reactor will *not* call
// eh->get_handle() to extract the underlying I/O handle).
virtual int register_handler (const ACE_Handle_Set &handles,
ACE_Event_Handler *eh,
ACE_Reactor_Mask mask);
// Register <eh> with all the <handles> in the <Handle_Set>.
virtual int register_handler (int signum,
ACE_Event_Handler *new_sh,
ACE_Sig_Action *new_disp = 0,
ACE_Event_Handler **old_sh = 0,
ACE_Sig_Action *old_disp = 0);
// Register <new_sh> to handle the signal <signum> using the
// <new_disp>. Returns the <old_sh> that was previously registered
// (if any), along with the <old_disp> of the signal handler.
virtual int register_handler (const ACE_Sig_Set &sigset,
ACE_Event_Handler *new_sh,
ACE_Sig_Action *new_disp = 0);
// Registers <new_sh> to handle a set of signals <sigset> using the
// <new_disp>.
virtual int remove_handler (ACE_Event_Handler *eh,
ACE_Reactor_Mask mask);
// Removes the <mask> binding of <eh> from the Reactor. If there
// are no more bindings for this <eh> then it is removed from the
// Reactor. Note that the Reactor will call eh->get_handle() to
// extract the underlying I/O handle.
virtual int remove_handler (ACE_HANDLE handle,
ACE_Reactor_Mask);
// Removes the <mask> bind of <Event_Handler> whose handle is
// <handle> from the Reactor. If there are no more bindings for
// this <eh> then it is removed from the Reactor.
virtual int remove_handler (const ACE_Handle_Set &handle_set,
ACE_Reactor_Mask);
// Removes all the <mask> bindings for handles in the <handle_set>
// bind of <Event_Handler>. If there are no more bindings for any
// of these handlers then they are removed from the Reactor.
virtual int remove_handler (int signum,
ACE_Sig_Action *new_disp,
ACE_Sig_Action *old_disp = 0,
int sigkey = -1);
// Remove the ACE_Event_Handler currently associated with <signum>.
// <sigkey> is ignored in this implementation since there is only
// one instance of a signal handler. Install the new disposition
// (if given) and return the previous disposition (if desired by the
// caller). Returns 0 on success and -1 if <signum> is invalid.
virtual int remove_handler (const ACE_Sig_Set &sigset);
// Calls <remove_handler> for every signal in <sigset>.
// = Suspend and resume Handlers.
virtual int suspend_handler (ACE_Event_Handler *eh);
// Temporarily suspend the <Event_Handler> associated with <eh>.
virtual int suspend_handler (ACE_HANDLE handle);
// Temporarily suspend the <Event_Handler> associated with <handle>.
virtual int resume_handler (ACE_Event_Handler *eh);
// Resume a temporarily suspend <Event_Handler> associated with
// <eh>.
virtual int resume_handler (ACE_HANDLE handle);
// Resume a temporarily suspended <Event_Handler> associated with
// <handle>.
virtual int suspend_handlers (void);
// Suspend all the <Event_Handlers> in the Reactor.
virtual int resume_handlers (void);
// Resume all the <Event_Handlers> in the Reactor.
// = Misc. Handler operations.
virtual int handler (ACE_HANDLE handle,
ACE_Reactor_Mask mask,
ACE_Event_Handler **eh = 0);
// Check to see if <handle> is associated with a valid Event_Handler
// bound to <mask>. Return the <eh> associated with this <handler>
// if <eh> != 0.
virtual int handler (int signum,
ACE_Event_Handler ** = 0);
// Check to see if <signum> is associated with a valid Event_Handler
// bound to a signal. Return the <eh> associated with this
// <handler> if <eh> != 0.
// = High-level Event_Handler scheduling operations
virtual int schedule_wakeup (ACE_Event_Handler *eh,
ACE_Reactor_Mask mask);
// ADD the dispatch MASK "bit" bound with the <eh> and the <mask>.
virtual int schedule_wakeup (ACE_HANDLE handle,
ACE_Reactor_Mask mask);
// ADD the dispatch MASK "bit" bound with the <handle> and the <mask>.
virtual int cancel_wakeup (ACE_Event_Handler *eh,
ACE_Reactor_Mask mask);
// CLR the dispatch MASK "bit" bound with the <eh> and the <mask>.
virtual int cancel_wakeup (ACE_HANDLE handle,
ACE_Reactor_Mask mask);
// CLR the dispatch MASK "bit" bound with the <handle> and the <mask>.
// = Low-level dispatch mask manipulation methods.
virtual int mask_ops (ACE_Event_Handler *eh,
ACE_Reactor_Mask mask,
int ops);
// GET/SET/ADD/CLR the dispatch MASK "bit" bound with the <eh> and
// <mask>.
virtual int mask_ops (ACE_HANDLE handle,
ACE_Reactor_Mask mask,
int ops);
// GET/SET/ADD/CLR the dispatch MASK "bit" bound with the <handle>
// and <mask>.
// = Ready bit manipulation methods.
virtual int ready_ops (ACE_Event_Handler *eh,
ACE_Reactor_Mask mask,
int ops);
// GET/SET/ADD/CLR the ready "bit" bound with the <eh> and <mask>.
virtual int ready_ops (ACE_HANDLE handle,
ACE_Reactor_Mask,
int ops);
// GET/SET/ADD/CLR the ready "bit" bound with the <handle> and <mask>.
virtual int notify (ACE_Event_Handler * = 0,
ACE_Reactor_Mask = ACE_Event_Handler::EXCEPT_MASK);
// Wakeup ACE_Reactor if currently blocked in select()/poll(). Pass
// over both the Event_Handler *and* the mask in order to allow the
// caller to dictate which Event_Handler method the receiver
// invokes.
// = Get/set position that the main ACE_Reactor thread is requeued
// in the list of waiters during a notify() callback.
void requeue_position (int);
int requeue_position (void);
// = Get/set the current "owner" of the thread (i.e., the only
// thread that can perform a handle_events()).
void owner (ACE_thread_t n_id, ACE_thread_t *o_id = 0);
// Set the new owner of the thread and return the old owner.
int owner (ACE_thread_t *);
// Return the current owner of the thread.
void dump (void) const;
// Dump the state of an object.
ACE_ALLOC_HOOK_DECLARE;
// Declare the dynamic allocation hooks.
protected:
// = Internal methods that do the actual work (most of these
// assume that locks are held).
virtual int attach (ACE_HANDLE handle,
ACE_Event_Handler *eh,
ACE_Reactor_Mask mask);
// Do the work of actually binding the <handle> and <eh> with the
// <mask>.
virtual int detach (ACE_HANDLE handle,
ACE_Reactor_Mask);
// Do the work of actually unbinding the <handle> and <eh> with the
// <mask>.
virtual int suspend (ACE_HANDLE handle);
// Suspend the <Event_Handler> associated with <handle>
virtual int resume (ACE_HANDLE handle);
// Resume the <Event_Handler> associated with <handle>
virtual int remove_handlers (const ACE_Handle_Set &handles,
ACE_Reactor_Mask);
// Remove a set of <handles>.
virtual int register_handlers (const ACE_Handle_Set &handles,
ACE_Event_Handler *handler,
ACE_Reactor_Mask mask);
// Register a set of <handles>.
virtual int handler_i (ACE_HANDLE handle,
ACE_Reactor_Mask,
ACE_Event_Handler ** = 0);
// Implement the public <handler> method.
virtual int handler_i (int signum, ACE_Event_Handler ** = 0);
// Implement the public <handler> method.
virtual int any_ready (void) const;
virtual int handle_error (void);
// Take corrective action when errors occur.
virtual int check_handles (void);
// Make sure the handles are all valid.
virtual int bit_ops (ACE_HANDLE handle,
ACE_Reactor_Mask mask,
ACE_Handle_Set &rd,
ACE_Handle_Set &wr,
ACE_Handle_Set &ex,
int ops);
// Allow manipulation of the dispatch mask and ready ops mask.
virtual int fill_in_ready (ACE_Handle_Set &,
ACE_Handle_Set &,
ACE_Handle_Set &);
// Check if there are any bits enabled in the ready_ops set.
virtual int wait_for_multiple_events (ACE_Handle_Set &,
ACE_Handle_Set &,
ACE_Handle_Set &,
ACE_Time_Value *);
// Wait for events to occur.
virtual void dispatch (int,
ACE_Handle_Set &,
ACE_Handle_Set &,
ACE_Handle_Set &);
// Dispatch timers and I/O event handlers once events have occurred.
virtual void notify_handle (ACE_HANDLE handle,
ACE_Reactor_Mask mask,
ACE_Handle_Set &,
ACE_Event_Handler *eh,
ACE_EH_PTMF callback);
// Notify the appropriate <callback> in the context of the <eh>
// associated with <handle> that a particular event has occurred.
ACE_Timer_Queue *timer_queue_;
// Defined as a pointer to allow overriding by derived classes...
ACE_Handler_Repository handler_rep_;
// Pointer to an array of <ACE_Event_Handler *>s used to keep track
// of the user-defined callbacks.
ACE_Sig_Handler *signal_handler_;
// Handle signals without requiring global/static variables.
int delete_signal_handler_;
// Keeps track of whether we should delete the signal handler.
// = Track which handles we are interested
// for various types of (reading, writing, and exception) events.
// The following three <Handle_Sets> are waited for by poll() or
// select().
ACE_Handle_Set rd_handle_mask_;
ACE_Handle_Set wr_handle_mask_;
ACE_Handle_Set ex_handle_mask_;
// = Keep track of events that we'd like to have dispatched
// *without* requiring poll() or select() to wait...
ACE_Handle_Set rd_handle_mask_ready_;
ACE_Handle_Set wr_handle_mask_ready_;
ACE_Handle_Set ex_handle_mask_ready_;
int restart_;
// Restart automatically when interrupted
int requeue_position_;
// Position that the main ACE_Reactor thread is requeued in the list
// of waiters during a notify() callback. If this value == -1 we
// are requeued at the end of the list. Else if it's 0 then we are
// requeued at the front of the list. Else if it's > 1 then that
// indicates the number of waiters to skip over.
int initialized_;
// True if we've been initialized yet...
ACE_thread_t owner_;
// The original thread that created this Reactor.
#if defined (ACE_MT_SAFE)
ACE_Notification_Handler notification_handler_;
// Callback object that unblocks the ACE_Reactor if it's sleeping.
ACE_Reactor_Token token_;
// Synchronization token for the MT_SAFE ACE_Reactor.
void renew (void);
// Enqueue ourselves into the list of waiting threads at the
// appropriate point specified by <requeue_position_>.
friend class ACE_Notification_Handler;
#endif /* ACE_MT_SAFE */
friend class ACE_Handler_Repository;
#if defined (ACE_USE_POLL)
// = Convert to and from the select() to poll() types.
pollfd *handle_sets_to_poll_fds (ACE_HANDLE &width);
void poll_fds_to_handle_sets (ACE_HANDLE width,
ACE_Handle_Set &,
ACE_Handle_Set &,
ACE_Handle_Set &,
int nfound);
pollfd *poll_h_;
// Pointer to the array of pollfd handles for poll() version.
#endif /* ACE_USE_POLL */
private:
ACE_Time_Value timer_skew_;
// Adjusts for skew that occurs in certain OS timers (e.g.,
// Solaris).
// Deny access since member-wise won't work...
ACE_Reactor (const ACE_Reactor &);
ACE_Reactor &operator = (const ACE_Reactor &);
};
#include "ace/Reactor.i"
#endif /* ACE_REACTOR_H */
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