Update the wepoll library (#98)

Author: an-tao

License

@@ -1,5 +1,5 @@
 // Trantor - A non-blocking I/O based TCP network library, using C++14/17, 
-// Copyright (c) 2016, Tao An.  All rights reserved.
+// Copyright (c) 2016-2020, Tao An.  All rights reserved.
 // https://github.com/an-tao/trantor
 //
 // Redistribution and use in source and binary forms, with or without

third_party/wepoll/README.md

@@ -0,0 +1,41 @@
+## wepoll
+
+This library is based on [wepoll v1.5.8](https://github.com/piscisaureus/wepoll/commit/0598a791bf9cbbf480793d778930fc635b044980).
+
+An eventfd-like mechanism is added to it. After making the changes, we can wake up `trantor::EventLoop` from the epoll_wait() function.
+
+## Modifications
+
+```shell
+diff wepoll.h Wepoll.h
+53a54
+>     EPOLLEVENT = (int)(1U << 14),
+67a69
+> #define EPOLLEVENT (1U << 14)
+111a114
+>     WEPOLL_EXPORT void epoll_post_signal(HANDLE ephnd, uint64_t event);
+```
+
+```shell
+diff wepoll.c Wepoll.c
+50a51
+>     EPOLLEVENT = (int)(1U << 14),
+64a66
+> #define EPOLLEVENT (1U << 14)
+1262a1265,1271
+>         if (iocp_events[i].lpCompletionKey)
+>         {
+>             struct epoll_event* ev = &epoll_events[epoll_event_count++];
+>             ev->data.u64 = (uint64_t)iocp_events[i].lpCompletionKey;
+>             ev->events = EPOLLEVENT;
+>             continue;
+>         }
+2441a2451,2457
+> void epoll_post_signal(HANDLE port_handle, uint64_t event)
+> {
+>     ULONG_PTR ev;
+>     ev = (ULONG_PTR)event;
+>     PostQueuedCompletionStatus(port_handle, 1, ev, NULL);
+> }
+> 
+```