* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
- * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
- * E-mail:
- * <brain@chatspike.net>
- * <Craig@chatspike.net>
+ * InspIRCd: (C) 2002-2007 InspIRCd Development Team
+ * See: http://www.inspircd.org/wiki/index.php/Credits
*
- * Written by Craig Edwards, Craig McLure, and others.
* This program is free but copyrighted software; see
* the file COPYING for details.
*
* ---------------------------------------------------
-*/
+ */
#ifndef __SOCKETENGINE__
#define __SOCKETENGINE__
#include <string>
#include <map>
#include "inspircd_config.h"
-#include "globals.h"
-#include "inspircd.h"
-
-/**
- * Each of these values represents a socket
- * type in our reference table (the reference
- * table itself is only accessible to
- * socketengine.cpp)
+#include "base.h"
+
+/** Types of event an EventHandler may receive.
+ * EVENT_READ is a readable file descriptor,
+ * and EVENT_WRITE is a writeable file descriptor.
+ * EVENT_ERROR can always occur, and indicates
+ * a write error or read error on the socket,
+ * e.g. EOF condition or broken pipe.
*/
-const char X_EMPTY_SLOT = 0;
-const char X_LISTEN = 1;
-const char X_ESTAB_CLIENT = 2;
-const char X_ESTAB_MODULE = 3;
-const char X_ESTAB_DNS = 4;
-const char X_ESTAB_CLASSDNS = 5;
-
-/**
- * To indicate that a socket is readable, we
- * mask its top bit with this X_READBIT value.
- * The socket engine can handle two types of
- * socket, readable and writeable (error sockets
- * are dealt with when read() and write() return
- * negative or zero values).
+enum EventType
+{
+ EVENT_READ = 0,
+ EVENT_WRITE = 1,
+ EVENT_ERROR = 2
+};
+
+class InspIRCd;
+
+/** This class is a basic I/O handler class.
+ * Any object which wishes to receive basic I/O events
+ * from the socketengine must derive from this class and
+ * implement the HandleEvent() method. The derived class
+ * must then be added to SocketEngine using the method
+ * SocketEngine::AddFd(), after which point the derived
+ * class will receive events to its HandleEvent() method.
+ * The derived class should also implement one of Readable()
+ * and Writeable(). In the current implementation, only
+ * Readable() is used. If this returns true, the socketengine
+ * inserts a readable socket. If it is false, the socketengine
+ * inserts a writeable socket. The derived class should never
+ * change the value this function returns without first
+ * deleting the socket from the socket engine. The only
+ * requirement beyond this for an event handler is that it
+ * must have a file descriptor. What this file descriptor
+ * is actually attached to is completely up to you.
*/
-const char X_READBIT = 0x80;
+class CoreExport EventHandler : public Extensible
+{
+ protected:
+ /** File descriptor.
+ * All events which can be handled
+ * must have a file descriptor.
+ * This allows you to add events for
+ * sockets, fifo's, pipes, and various
+ * other forms of IPC.
+ */
+ int fd;
+ public:
+ /** Get the current file descriptor
+ * @return The file descriptor of this handler
+ */
+ int GetFd();
+
+ /** Set a new file desciptor
+ * @param FD The new file descriptor. Do not
+ * call this method without first deleting the
+ * object from the SocketEngine if you have
+ * added it to a SocketEngine instance.
+ */
+ void SetFd(int FD);
+
+ /** Constructor
+ */
+ EventHandler() {}
+
+ /** Destructor
+ */
+ virtual ~EventHandler() {}
+
+ /** Override this function to indicate readability.
+ * @return This should return true if the function
+ * wishes to receive EVENT_READ events. Do not change
+ * what this function returns while the event handler
+ * is still added to a SocketEngine instance!
+ * If this function is unimplemented, the base class
+ * will return true.
+ *
+ * NOTE: You cannot set both Readable() and
+ * Writeable() to true. If you wish to receive
+ * a write event for your object, you must call
+ * SocketEngine::WantWrite() instead. This will
+ * trigger your objects next EVENT_WRITE type event.
+ */
+ virtual bool Readable();
+
+ /** Override this function to indicate writeability.
+ * @return This should return true if the function
+ * wishes to receive EVENT_WRITE events. Do not change
+ * what this function returns while the event handler
+ * is still added to a SocketEngine instance!
+ * If this function is unimplemented, the base class
+ * will return false.
+ *
+ * NOTE: You cannot set both Readable() and
+ * Writeable() to true. If you wish to receive
+ * a write event for your object, you must call
+ * SocketEngine::WantWrite() instead. This will
+ * trigger your objects next EVENT_WRITE type event.
+ */
+ virtual bool Writeable();
-/**
+ /** Process an I/O event.
+ * You MUST implement this function in your derived
+ * class, and it will be called whenever read or write
+ * events are received, depending on what your functions
+ * Readable() and Writeable() returns and wether you
+ * previously made a call to SocketEngine::WantWrite().
+ * @param et either one of EVENT_READ for read events,
+ * and EVENT_WRITE for write events.
+ */
+ virtual void HandleEvent(EventType et, int errornum = 0) = 0;
+
+#ifdef WINDOWS
+
+ /** "Fake" file descriptor. This is windows-specific.
+ */
+ int m_internalFd;
+
+ /** Pointer to read event. We delete this so the buffer can't be used
+ * after the socket is deleted, and so it doesn't leak memory
+ */
+ void * m_readEvent;
+ void * m_writeEvent;
+ void * m_acceptEvent;
+
+#endif
+};
+
+/** Provides basic file-descriptor-based I/O support.
* The actual socketengine class presents the
* same interface on all operating systems, but
* its private members and internal behaviour
* have to be aware of which SocketEngine derived
* class they are using.
*/
-class SocketEngine : public Extensible
+class CoreExport SocketEngine : public Extensible
{
protected:
- int EngineHandle; /* Handle to the socket engine if needed */
- int CurrentSetSize; /* Current number of descriptors in the engine */
- char ref[MAX_DESCRIPTORS]; /* Reference table */
+ /** Owner/Creator
+ */
+ InspIRCd* ServerInstance;
+ /** Handle to socket engine, where needed.
+ */
+ int EngineHandle;
+ /** Current number of descriptors in the engine
+ */
+ int CurrentSetSize;
+ /** Reference table, contains all current handlers
+ */
+ EventHandler* ref[MAX_DESCRIPTORS];
public:
- /** Constructor
+ /** Constructor.
* The constructor transparently initializes
* the socket engine which the ircd is using.
* Please note that if there is a catastrophic
* failure (for example, you try and enable
* epoll on a 2.4 linux kernel) then this
* function may bail back to the shell.
+ * @param Instance The creator/owner of this object
*/
- SocketEngine();
+ SocketEngine(InspIRCd* Instance);
- /** Destructor
+ /** Destructor.
* The destructor transparently tidies up
* any resources used by the socket engine.
*/
virtual ~SocketEngine();
- /** Add a file descriptor to the engine
+ /** Add an EventHandler object to the engine.
* Use AddFd to add a file descriptor to the
* engine and have the socket engine monitor
- * it. You must provide a type (see the consts
- * in socketengine.h) and a boolean flag to
- * indicate wether to watch this fd for read
- * or write events (there is currently no
- * need for support of both).
- */
- virtual bool AddFd(int fd, bool readable, char type);
-
- /** Returns the type value for this file descriptor
- * This function masks off the X_READBIT value
- * so that the type of the socket can be obtained.
- * The core uses this to decide where to dispatch
- * the event to. Please note that some engines
- * such as select() have an upper limit of 1024
- * descriptors which may be active at any one time,
- * where others such as kqueue have no practical
- * limits at all.
- */
- char GetType(int fd);
+ * it. You must provide an object derived from
+ * EventHandler which implements HandleEvent()
+ * and optionally Readable() and Writeable().
+ * @param eh An event handling object to add
+ */
+ virtual bool AddFd(EventHandler* eh);
+
+ /** If you call this function and pass it an
+ * event handler, that event handler will
+ * receive the next available write event,
+ * even if the socket is a readable socket only.
+ * Developers should avoid constantly keeping
+ * an eventhandler in the writeable state,
+ * as this will consume large amounts of
+ * CPU time.
+ * @param eh An event handler which wants to
+ * receive the next writeability event.
+ */
+ virtual void WantWrite(EventHandler* eh);
/** Returns the maximum number of file descriptors
* you may store in the socket engine at any one time.
+ * @return The maximum fd value
*/
virtual int GetMaxFds();
/** Returns the number of file descriptor slots
* which are available for storing fds.
+ * @return The number of remaining fd's
*/
virtual int GetRemainingFds();
- /** Delete a file descriptor from the engine
- * This function call deletes a file descriptor
+ /** Delete an event handler from the engine.
+ * This function call deletes an EventHandler
* from the engine, returning true if it succeeded
- * and false if it failed.
+ * and false if it failed. This does not free the
+ * EventHandler pointer using delete, if this is
+ * required you must do this yourself.
+ * Note on forcing deletes. DO NOT DO THIS! This is
+ * extremely dangerous and will most likely render the
+ * socketengine dead. This was added only for handling
+ * very rare cases where broken 3rd party libs destroys
+ * the OS socket beyond our control. If you can't explain
+ * in minute details why forcing is absolutely necessary
+ * then you don't need it. That was a NO!
+ * @param eh The event handler object to remove
+ * @param force *DANGEROUS* See method description!
+ * @return True if the event handler was removed
+ */
+ virtual bool DelFd(EventHandler* eh, bool force = false);
+
+ /** Returns true if a file descriptor exists in
+ * the socket engine's list.
+ * @param fd The event handler to look for
+ * @return True if this fd has an event handler
*/
- virtual bool DelFd(int fd);
+ virtual bool HasFd(int fd);
- /** Returns true if a socket exists in the socket
- * engine's list.
+ /** Returns the EventHandler attached to a specific fd.
+ * If the fd isnt in the socketengine, returns NULL.
+ * @param fd The event handler to look for
+ * @return A pointer to the event handler, or NULL
*/
- bool HasFd(int fd);
+ virtual EventHandler* GetRef(int fd);
- /** Waits for an event.
+ /** Waits for events and dispatches them to handlers.
* Please note that this doesnt wait long, only
- * a couple of milliseconds. It returns a list
- * of active file descriptors in the vector
- * fdlist which the core may then act upon.
+ * a couple of milliseconds. It returns the number of
+ * events which occured during this call.
+ * This method will dispatch events to their handlers
+ * by calling their EventHandler::HandleEvent()
+ * methods with the neccessary EventType value.
+ * @return The number of events which have occured.
*/
- virtual int Wait(int* fdlist);
+ virtual int DispatchEvents();
- /** Returns the socket engines name
+ /** Returns the socket engines name.
* This returns the name of the engine for use
* in /VERSION responses.
+ * @return The socket engine name
*/
virtual std::string GetName();
};