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Diffstat (limited to 'trunk/ACE/ace/Reactor_Impl.h')
| -rw-r--r-- | trunk/ACE/ace/Reactor_Impl.h | 569 |
1 files changed, 569 insertions, 0 deletions
diff --git a/trunk/ACE/ace/Reactor_Impl.h b/trunk/ACE/ace/Reactor_Impl.h new file mode 100644 index 00000000000..47800975214 --- /dev/null +++ b/trunk/ACE/ace/Reactor_Impl.h @@ -0,0 +1,569 @@ +// -*- C++ -*- + +//============================================================================= +/** + * @file Reactor_Impl.h + * + * $Id$ + * + * @author Irfan Pyarali + */ +//============================================================================= + + +#ifndef ACE_REACTOR_IMPL_H +#define ACE_REACTOR_IMPL_H +#include /**/ "ace/pre.h" + +// Timer Queue is a complicated template class. A simple forward +// declaration will not work +#include "ace/Timer_Queuefwd.h" + +#if !defined (ACE_LACKS_PRAGMA_ONCE) +# pragma once +#endif /* ACE_LACKS_PRAGMA_ONCE */ + +// Event_Handler.h contains the definition of ACE_Reactor_Mask +#include "ace/Event_Handler.h" +#include "ace/Countdown_Time.h" + +ACE_BEGIN_VERSIONED_NAMESPACE_DECL + +// Forward decls +class ACE_Handle_Set; +class ACE_Reactor_Impl; +class ACE_Sig_Action; +class ACE_Sig_Handler; +class ACE_Sig_Set; + +/** + * @class ACE_Reactor_Notify + * + * @internal This class is for ACE internal use only. + * + * @brief Abstract class for unblocking an <ACE_Reactor_Impl> from its + * event loop. + */ +class ACE_Export ACE_Reactor_Notify : public ACE_Event_Handler +{ +public: + // = Initialization and termination methods. + virtual int open (ACE_Reactor_Impl *, + ACE_Timer_Queue *timer_queue = 0, + int disable_notify = 0) = 0; + virtual int close (void) = 0; + + /** + * Called by a thread when it wants to unblock the <Reactor_Impl>. + * This wakeups the <Reactor_Impl> if currently blocked. Pass over + * both the <Event_Handler> *and* the <mask> to allow the caller to + * dictate which <Event_Handler> method the <Reactor_Impl> will + * invoke. The <ACE_Time_Value> indicates how long to blocking + * trying to notify the <Reactor_Impl>. If <timeout> == 0, the + * caller will block until action is possible, else will wait until + * the relative time specified in *<timeout> elapses). + */ + virtual int notify (ACE_Event_Handler *eh = 0, + ACE_Reactor_Mask mask = ACE_Event_Handler::EXCEPT_MASK, + ACE_Time_Value *timeout = 0) = 0; + + /// Handles pending threads (if any) that are waiting to unblock the + /// <Reactor_Impl>. + virtual int dispatch_notifications (int &number_of_active_handles, + ACE_Handle_Set &rd_mask) = 0; + + /// Returns the ACE_HANDLE of the notify pipe on which the reactor + /// is listening for notifications so that other threads can unblock + /// the <Reactor_Impl> + virtual ACE_HANDLE notify_handle (void) = 0; + + /// Verify whether the buffer has dispatchable info or not. + virtual int is_dispatchable (ACE_Notification_Buffer &buffer)= 0; + + /// Handle one of the notify call on the <handle>. This could be + /// because of a thread trying to unblock the <Reactor_Impl> + virtual int dispatch_notify (ACE_Notification_Buffer &buffer) = 0; + + /// Read one of the notify call on the <handle> into the + /// <buffer>. This could be because of a thread trying to unblock + /// the <Reactor_Impl> + virtual int read_notify_pipe (ACE_HANDLE handle, + ACE_Notification_Buffer &buffer) = 0; + /** + * Set the maximum number of times that the <handle_input> method + * will iterate and dispatch the <ACE_Event_Handlers> that are + * passed in via the notify queue before breaking out of the event + * loop. By default, this is set to -1, which means "iterate until + * the queue is empty." Setting this to a value like "1 or 2" will + * increase "fairness" (and thus prevent starvation) at the expense + * of slightly higher dispatching overhead. + */ + virtual void max_notify_iterations (int) = 0; + + /** + * Get the maximum number of times that the <handle_input> method + * will iterate and dispatch the <ACE_Event_Handlers> that are + * passed in via the notify queue before breaking out of its event + * loop. + */ + virtual int max_notify_iterations (void) = 0; + + /** + * Purge any notifications pending in this reactor for the specified + * ACE_Event_Handler object. Returns the number of notifications + * purged. Returns -1 on error. + */ + virtual int purge_pending_notifications (ACE_Event_Handler * = 0, + ACE_Reactor_Mask = ACE_Event_Handler::ALL_EVENTS_MASK) = 0; + + /// Dump the state of an object. + virtual void dump (void) const = 0; +}; + +/** + * @class ACE_Reactor_Impl + * + * @brief An abstract class for implementing the Reactor Pattern. + */ +class ACE_Export ACE_Reactor_Impl +{ +public: + /// Close down and release all resources. + virtual ~ACE_Reactor_Impl (void); + + /// Initialization. + virtual int open (size_t size, + int restart = 0, + ACE_Sig_Handler * = 0, + ACE_Timer_Queue * = 0, + int disable_notify_pipe = 0, + ACE_Reactor_Notify * = 0) = 0; + + /** + * Returns 0, if the size of the current message has been put in + * <size> Returns -1, if not. ACE_HANDLE allows the reactor to + * check if the caller is valid. + */ + virtual int current_info (ACE_HANDLE, size_t & /* size */) = 0; + + /// Use a user specified signal handler instead. + virtual int set_sig_handler (ACE_Sig_Handler *signal_handler) = 0; + + /// Set a user-specified timer queue. + virtual int timer_queue (ACE_Timer_Queue *tq) = 0; + + /// Return the current ACE_Timer_Queue. + virtual ACE_Timer_Queue *timer_queue (void) const = 0; + + /// Close down and release all resources. + virtual int close (void) = 0; + + // = Event loop drivers. + /** + * Returns non-zero if there are I/O events "ready" for dispatching, + * but does not actually dispatch the event handlers. By default, + * don't block while checking this, i.e., "poll". + */ + virtual int work_pending (const ACE_Time_Value &max_wait_time = ACE_Time_Value::zero) = 0; + + /** + * This event loop driver blocks for up to <max_wait_time> before + * returning. It will return earlier if events occur. Note that + * <max_wait_time> can be 0, in which case this method blocks + * indefinitely until events occur. + * + * <max_wait_time> is decremented to reflect how much time this call + * took. For instance, if a time value of 3 seconds is passed to + * handle_events and an event occurs after 2 seconds, + * <max_wait_time> will equal 1 second. This can be used if an + * application wishes to handle events for some fixed amount of + * time. + * + * Returns the total number of ACE_Event_Handlers that were + * dispatched, 0 if the <max_wait_time> elapsed without dispatching + * any handlers, or -1 if an error occurs. + * + * The only difference between <alertable_handle_events> and + * <handle_events> is that in the alertable case, the eventloop will + * return when the system queues an I/O completion routine or an + * Asynchronous Procedure Call. + */ + virtual int handle_events (ACE_Time_Value *max_wait_time = 0) = 0; + virtual int alertable_handle_events (ACE_Time_Value *max_wait_time = 0) = 0; + + /** + * This method is just like the one above, except the + * <max_wait_time> value is a reference and can therefore never be + * NULL. + * + * The only difference between <alertable_handle_events> and + * <handle_events> is that in the alertable case, the eventloop will + * return when the system queues an I/O completion routine or an + * Asynchronous Procedure Call. + */ + virtual int handle_events (ACE_Time_Value &max_wait_time) = 0; + virtual int alertable_handle_events (ACE_Time_Value &max_wait_time) = 0; + + // = Event handling control. + + /** + * Return the status of Reactor. If this function returns 0, the reactor is + * actively handling events. If it returns non-zero, <handling_events> and + * <handle_alertable_events> return -1 immediately. + */ + virtual int deactivated (void) = 0; + + /** + * Control whether the Reactor will handle any more incoming events or not. + * If <do_stop> == 1, the Reactor will be disabled. By default, a reactor + * is in active state and can be deactivated/reactived as wish. + */ + virtual void deactivate (int do_stop) = 0; + + // = Register and remove Handlers. + + /// Register <event_handler> with <mask>. The I/O handle will always + /// come from <get_handle> on the <event_handler>. + virtual int register_handler (ACE_Event_Handler *event_handler, + ACE_Reactor_Mask mask) = 0; + + /// Register <event_handler> with <mask>. The I/O handle is provided + /// through the <io_handle> parameter. + virtual int register_handler (ACE_HANDLE io_handle, + ACE_Event_Handler *event_handler, + ACE_Reactor_Mask mask) = 0; + +#if defined (ACE_WIN32) + + // Originally this interface was available for all platforms, but + // because ACE_HANDLE is an int on non-Win32 platforms, compilers + // are not able to tell the difference between + // register_handler(ACE_Event_Handler*,ACE_Reactor_Mask) and + // register_handler(ACE_Event_Handler*,ACE_HANDLE). Therefore, we + // have restricted this method to Win32 only. + + /** + * Register an <event_handler> that will be notified when + * <event_handle> is signaled. Since no event mask is passed + * through this interface, it is assumed that the <event_handle> + * being passed in is an event handle and not an I/O handle. + */ + virtual int register_handler (ACE_Event_Handler *event_handler, + ACE_HANDLE event_handle = ACE_INVALID_HANDLE) = 0; + +#endif /* ACE_WIN32 */ + + /** + * Register an <event_handler> that will be notified when + * <event_handle> is signaled. <mask> specifies the network events + * that the <event_handler> is interested in. + */ + virtual int register_handler (ACE_HANDLE event_handle, + ACE_HANDLE io_handle, + ACE_Event_Handler *event_handler, + ACE_Reactor_Mask mask) = 0; + + /// Register <event_handler> with all the <handles> in the <Handle_Set>. + virtual int register_handler (const ACE_Handle_Set &handles, + ACE_Event_Handler *event_handler, + ACE_Reactor_Mask mask) = 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 (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) = 0; + + /// Registers <new_sh> to handle a set of signals <sigset> using the + /// <new_disp>. + virtual int register_handler (const ACE_Sig_Set &sigset, + ACE_Event_Handler *new_sh, + ACE_Sig_Action *new_disp = 0) = 0; + + /** + * Removes <event_handler>. Note that the I/O handle will be + * obtained using <get_handle> method of <event_handler> . If + * <mask> == <ACE_Event_Handler::DONT_CALL> then the <handle_close> + * method of the <event_handler> is not invoked. + */ + virtual int remove_handler (ACE_Event_Handler *event_handler, + ACE_Reactor_Mask mask) = 0; + + /** + * Removes <handle>. If <mask> == <ACE_Event_Handler::DONT_CALL> + * then the <handle_close> method of the associated <event_handler> + * is not invoked. + */ + virtual int remove_handler (ACE_HANDLE handle, + ACE_Reactor_Mask mask) = 0; + + /** + * Removes all handles in <handle_set>. If <mask> == + * <ACE_Event_Handler::DONT_CALL> then the <handle_close> method of + * the associated <event_handler>s is not invoked. + */ + virtual int remove_handler (const ACE_Handle_Set &handle_set, + ACE_Reactor_Mask mask) = 0; + + /** + * Remove the ACE_Event_Handler currently associated with <signum>. + * 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 (int signum, + ACE_Sig_Action *new_disp, + ACE_Sig_Action *old_disp = 0, + int sigkey = -1) = 0; + + /// Calls <remove_handler> for every signal in <sigset>. + virtual int remove_handler (const ACE_Sig_Set &sigset) = 0; + + // = Suspend and resume Handlers. + + /// Suspend <event_handler> temporarily. Use + /// <ACE_Event_Handler::get_handle> to get the handle. + virtual int suspend_handler (ACE_Event_Handler *event_handler) = 0; + + /// Suspend <handle> temporarily. + virtual int suspend_handler (ACE_HANDLE handle) = 0; + + /// Suspend all <handles> in handle set temporarily. + virtual int suspend_handler (const ACE_Handle_Set &handles) = 0; + + /// Suspend all <handles> temporarily. + virtual int suspend_handlers (void) = 0; + + /// Resume <event_handler>. Use <ACE_Event_Handler::get_handle> to + /// get the handle. + virtual int resume_handler (ACE_Event_Handler *event_handler) = 0; + + /// Resume <handle>. + virtual int resume_handler (ACE_HANDLE handle) = 0; + + /// Resume all <handles> in handle set. + virtual int resume_handler (const ACE_Handle_Set &handles) = 0; + + /// Resume all <handles>. + virtual int resume_handlers (void) = 0; + + /// Does the reactor allow the application to resume the handle on + /// its own ie. can it pass on the control of handle resumption to + /// the application + virtual int resumable_handler (void) = 0; + + /// Return 1 if we any event associations were made by the reactor + /// for the handles that it waits on, 0 otherwise. + virtual int uses_event_associations (void) = 0; + + // If we need to reset handles returned from accept/connect. + + // = Timer management. + + /** + * Schedule an ACE_Event_Handler that will expire after an amount + * of time. The return value of this method, a timer_id value, + * uniquely identifies the event_handler in the ACE_Reactor's + * internal list of timers. + * This timer_id value can be used to cancel the timer + * with the cancel_timer() call. + * + * @see cancel_timer() + * @see reset_timer_interval() + * + * @param event_handler event handler to schedule on reactor + * @param arg argument passed to the handle_timeout() method of event_handler + * @param delay time interval after which the timer will expire + * @param interval time interval after which the timer will be automatically rescheduled + * @return -1 on failure, a timer_id value on success + */ + virtual long schedule_timer (ACE_Event_Handler *event_handler, + const void *arg, + const ACE_Time_Value &delay, + const ACE_Time_Value &interval = ACE_Time_Value::zero) = 0; + + /** + * Resets the interval of the timer represented by <timer_id> to + * <interval>, which is specified in relative time to the current + * <gettimeofday>. If <interval> is equal to + * <ACE_Time_Value::zero>, the timer will become a non-rescheduling + * timer. Returns 0 if successful, -1 if not. + */ + virtual int reset_timer_interval (long timer_id, + const ACE_Time_Value &interval) = 0; + + /// Cancel all Event_Handlers that match the address of + /// <event_handler>. Returns number of handlers cancelled. + virtual int cancel_timer (ACE_Event_Handler *event_handler, + int dont_call_handle_close = 1) = 0; + + /** + * Cancel the single 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. + * Returns 1 if cancellation succeeded and 0 if the <timer_id> + * wasn't found. + */ + virtual int cancel_timer (long timer_id, + const void **arg = 0, + int dont_call_handle_close = 1) = 0; + + // = High-level Event_Handler scheduling operations + + /// Add <masks_to_be_added> to the <event_handler>'s entry. + /// <event_handler> must already have been registered. + virtual int schedule_wakeup (ACE_Event_Handler *event_handler, + ACE_Reactor_Mask masks_to_be_added) = 0; + + /// Add <masks_to_be_added> to the <handle>'s entry. <event_handler> + /// associated with <handle> must already have been registered. + virtual int schedule_wakeup (ACE_HANDLE handle, + ACE_Reactor_Mask masks_to_be_added) = 0; + + /// Clear <masks_to_be_cleared> from the <event_handler>'s entry. + virtual int cancel_wakeup (ACE_Event_Handler *event_handler, + ACE_Reactor_Mask masks_to_be_cleared) = 0; + + /// Clear <masks_to_be_cleared> from the <handle>'s entry. + virtual int cancel_wakeup (ACE_HANDLE handle, + ACE_Reactor_Mask masks_to_be_cleared) = 0; + + // = Notification methods. + + /** + * Notify <event_handler> of <mask> event. The <ACE_Time_Value> + * indicates how long to blocking trying to notify. If <timeout> == + * 0, the caller will block until action is possible, else will wait + * until the relative time specified in <timeout> elapses). + */ + virtual int notify (ACE_Event_Handler *event_handler = 0, + ACE_Reactor_Mask mask = ACE_Event_Handler::EXCEPT_MASK, + ACE_Time_Value * = 0) = 0; + + /** + * Set the maximum number of times that ACE_Reactor_Impl will + * iterate and dispatch the <ACE_Event_Handlers> that are passed in + * via the notify queue before breaking out of its + * <ACE_Message_Queue::dequeue> loop. By default, this is set to + * -1, which means "iterate until the queue is empty." Setting this + * to a value like "1 or 2" will increase "fairness" (and thus + * prevent starvation) at the expense of slightly higher dispatching + * overhead. + */ + virtual void max_notify_iterations (int) = 0; + + /** + * Get the maximum number of times that the ACE_Reactor_Impl will + * iterate and dispatch the <ACE_Event_Handlers> that are passed in + * via the notify queue before breaking out of its + * <ACE_Message_Queue::dequeue> loop. + */ + virtual int max_notify_iterations (void) = 0; + + /** + * Purge any notifications pending in this reactor for the specified + * ACE_Event_Handler object. Returns the number of notifications + * purged. Returns -1 on error. + */ + virtual int purge_pending_notifications (ACE_Event_Handler * = 0, + ACE_Reactor_Mask = ACE_Event_Handler::ALL_EVENTS_MASK) = 0; + + /** + * Return the Event_Handler associated with <handle>. Return 0 if + * <handle> is not registered. + */ + virtual ACE_Event_Handler *find_handler (ACE_HANDLE handle) = 0; + + /** + * Check to see if <handle> is associated with a valid Event_Handler + * bound to <mask>. Return the <event_handler> associated with this + * <handler> if <event_handler> != 0. + */ + virtual int handler (ACE_HANDLE handle, + ACE_Reactor_Mask mask, + ACE_Event_Handler **event_handler = 0) = 0; + + /** + * Check to see if <signum> is associated with a valid Event_Handler + * bound to a signal. Return the <event_handler> associated with + * this <handler> if <event_handler> != 0. + */ + virtual int handler (int signum, + ACE_Event_Handler ** = 0) = 0; + + /// Returns true if Reactor has been successfully initialized, else + /// false. + virtual bool initialized (void) = 0; + + /// Returns the current size of the Reactor's internal descriptor + /// table. + virtual size_t size (void) const = 0; + + /// Returns a reference to the Reactor's internal lock. + virtual ACE_Lock &lock (void) = 0; + + /// Wake up all threads in waiting in the event loop + virtual void wakeup_all_threads (void) = 0; + + /// Transfers ownership of Reactor_Impl to the <new_owner>. + virtual int owner (ACE_thread_t new_owner, ACE_thread_t *old_owner = 0) = 0; + + /// Return the ID of the "owner" thread. + virtual int owner (ACE_thread_t *owner) = 0; + + /// Get the existing restart value. + virtual int restart (void) = 0; + + /// Set a new value for restart and return the original value. + virtual int restart (int r) = 0; + + /// Set position of the owner thread. + virtual void requeue_position (int) = 0; + + /// Get position of the owner thread. + virtual int requeue_position (void) = 0; + + // = Low-level wait_set mask manipulation methods. + + /// GET/SET/ADD/CLR the dispatch mask "bit" bound with the + /// <event_handler> and <mask>. + virtual int mask_ops (ACE_Event_Handler *event_handler, + ACE_Reactor_Mask mask, + int ops) = 0; + + /// GET/SET/ADD/CLR the dispatch MASK "bit" bound with the <handle> + /// and <mask>. + virtual int mask_ops (ACE_HANDLE handle, + ACE_Reactor_Mask mask, + int ops) = 0; + + // = Low-level ready_set mask manipulation methods. + /// GET/SET/ADD/CLR the ready "bit" bound with the <event_handler> + /// and <mask>. + virtual int ready_ops (ACE_Event_Handler *event_handler, + ACE_Reactor_Mask mask, + int ops) = 0; + + /// GET/SET/ADD/CLR the ready "bit" bound with the <handle> and <mask>. + virtual int ready_ops (ACE_HANDLE handle, + ACE_Reactor_Mask, + int ops) = 0; + + /// Dump the state of an object. + virtual void dump (void) const = 0; + + /// Declare the dynamic allocation hooks. + ACE_ALLOC_HOOK_DECLARE; +}; + +ACE_END_VERSIONED_NAMESPACE_DECL + +#include /**/ "ace/post.h" +#endif /* ACE_REACTOR_IMPL_H */ |