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-rw-r--r--include/socketengine.h87
1 files changed, 81 insertions, 6 deletions
diff --git a/include/socketengine.h b/include/socketengine.h
index a499b4282..caccd9b3f 100644
--- a/include/socketengine.h
+++ b/include/socketengine.h
@@ -32,37 +32,112 @@
#include <sys/time.h>
#endif
+/**
+ * Each of these values represents a socket
+ * type in our reference table (the reference
+ * table itself is only accessible to
+ * socketengine.cpp)
+ */
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;
+/**
+ * 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).
+ */
const char X_READBIT = 0x80;
+/**
+ * The actual socketengine class presents the
+ * same interface on all operating systems, but
+ * its private members and internal behaviour
+ * should be treated as blackboxed, and vary
+ * from system to system and upon the config
+ * settings chosen by the server admin. The current
+ * version supports select, epoll and kqueue.
+ */
class SocketEngine {
- std::vector<int> fds;
- int EngineHandle;
+ std::vector<int> fds; /* List of file descriptors being monitored */
+ int EngineHandle; /* Handle to the socket engine if needed */
#ifdef USE_SELECT
- fd_set wfdset, rfdset;
+ fd_set wfdset, rfdset; /* Readable and writeable sets for select() */
#endif
#ifdef USE_KQUEUE
- struct kevent ke_list[65535];
- struct timespec ts;
+ struct kevent ke_list[65535]; /* Up to 64k sockets for kqueue */
+ struct timespec ts; /* kqueue delay value */
#endif
#ifdef USE_EPOLL
- struct epoll_event events[65535];
+ struct epoll_event events[65535]; /* Up to 64k sockets for epoll */
#endif
public:
+ /** 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.
+ */
SocketEngine();
+
+ /** Destructor
+ * The destructor transparently tidies up
+ * any resources used by the socket engine.
+ */
~SocketEngine();
+
+ /** Add a file descriptor 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).
+ */
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);
+
+ /** Delete a file descriptor f rom the engine
+ * This function call deletes a file descriptor
+ * from the engine, returning true if it succeeded
+ * and false if it failed.
+ */
bool DelFd(int fd);
+
+ /** Waits for an event.
+ * 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.
+ */
bool Wait(std::vector<int> &fdlist);
+
+ /** Returns the socket engines name
+ * This returns the name of the engine for use
+ * in /VERSION responses.
+ */
std::string GetName();
};