From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sat, 6 Apr 2013 14:58:54 +0000 (+0200)
Subject: Implement epoll main loop in Server, and parse header.
X-Git-Tag: 1.0.0~219
X-Git-Url: https://git.sesse.net/?p=cubemap;a=commitdiff_plain;h=cfe0df3728d8155fb03688f6db69e00971e23685

Implement epoll main loop in Server, and parse header.
---

diff --git a/Makefile b/Makefile
index c80ab9d..78ec5a6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,9 @@
 CC=gcc
 CXX=g++
 CXXFLAGS=-Wall -O2 -g
-LDLIBS=-lcurl
+LDLIBS=-lcurl -lpthread
 
-OBJS=cubemap.o server.o mutexlock.o
+OBJS=cubemap.o server.o mutexlock.o input.o
 
 all: cubemap
 
diff --git a/server.cpp b/server.cpp
index 31e5c0a..25da16c 100644
--- a/server.cpp
+++ b/server.cpp
@@ -47,9 +47,26 @@ void *Server::do_work_thunk(void *arg)
 void Server::do_work()
 {
 	for ( ;; ) {
-		MutexLock lock(&mutex);
-		printf("server thread running\n");
-		sleep(1);
+		int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
+
+		MutexLock lock(&mutex);  // We release the mutex between iterations.
+		if (nfds == -1) {
+			perror("epoll_wait");
+			exit(1);
+		}
+		
+		for (int i = 0; i < nfds; ++i) {
+			int fd = events[i].data.fd;
+			assert(clients.count(fd) != 0);
+			Client *client = &clients[fd];
+
+			if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
+				close_client(client);
+				continue;
+			}
+
+			process_client(client);
+		}
 	}
 }
 	
@@ -57,6 +74,8 @@ void Server::add_client(int sock)
 {
 	MutexLock lock(&mutex);
 	Client new_client;
+	new_client.sock = sock;
+	new_client.client_request.reserve(1024);
 	new_client.state = Client::READING_REQUEST;
 	new_client.header_bytes_sent = 0;
 	new_client.bytes_sent = 0;
@@ -65,7 +84,7 @@ void Server::add_client(int sock)
 
 	// Start listening on data from this socket.
 	epoll_event ev;
-	ev.events = EPOLLIN;
+	ev.events = EPOLLIN | EPOLLRDHUP;
 	ev.data.fd = sock;
 	if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
 		perror("epoll_ctl(EPOLL_CTL_ADD)");
@@ -88,3 +107,80 @@ void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 {
 	// TODO
 }
+	
+void Server::process_client(Client *client)
+{
+	switch (client->state) {
+	case Client::READING_REQUEST: {
+		// Try to read more of the request.
+		char buf[1024];
+		int ret = read(client->sock, buf, sizeof(buf));
+		if (ret == -1) {
+			perror("read");
+			close_client(client);
+			return;
+		}
+		if (ret == 0) {
+			// No data? This really means that we were triggered for something else than
+			// POLLIN (which suggests a logic error in epoll).
+			fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
+			close_client(client);
+			return;
+		}
+
+		// Guard against overlong requests gobbling up all of our space.
+		if (client->client_request.size() + ret > MAX_CLIENT_REQUEST) {
+			fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
+			close_client(client);
+			return;
+		}	
+
+		// See if we have \r\n\r\n anywhere in the request. We start three bytes
+		// before what we just appended, in case we just got the final character.
+		size_t existing_req_bytes = client->client_request.size();
+		client->client_request.append(string(buf, buf + ret));
+	
+		size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
+		const char *ptr = reinterpret_cast<char *>(
+			memmem(client->client_request.data() + start_at, client->client_request.size() - start_at,
+			       "\r\n\r\n", 4));
+		if (ptr == NULL) {
+			// OK, we don't have the entire header yet. Fine; we'll get it later.
+			return;
+		}
+
+		if (ptr != client->client_request.data() + client->client_request.size() - 4) {
+			fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
+			close_client(client);
+			return;
+		}
+
+		client->state = Client::SENDING_HEADER;
+
+		epoll_event ev;
+		ev.events = EPOLLOUT | EPOLLRDHUP;
+		ev.data.fd = client->sock;
+
+		if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
+			perror("epoll_ctl(EPOLL_CTL_MOD)");
+			exit(1);
+		}
+		break;
+	}
+	default:
+		// TODO
+		assert(false);
+	}
+}
+	
+void Server::close_client(Client *client)
+{
+	if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
+		perror("epoll_ctl(EPOLL_CTL_DEL)");
+		exit(1);
+	}
+	
+	// Bye-bye!
+	close(client->sock);
+	clients.erase(client->sock);
+}
diff --git a/server.h b/server.h
index d8b9064..c44b81e 100644
--- a/server.h
+++ b/server.h
@@ -6,9 +6,16 @@
 #include <string>
 #include <map>
 
+#define NUM_SERVERS 4
 #define BACKLOG_SIZE 1048576
+#define EPOLL_MAX_EVENTS 8192
+#define EPOLL_TIMEOUT_MS 20
+#define MAX_CLIENT_REQUEST 16384
 
 struct Client {
+	// The file descriptor associated with this socket.
+	int sock;
+
 	enum State { READING_REQUEST, SENDING_HEADER, SENDING_DATA };
 	State state;
 
@@ -53,6 +60,9 @@ public:
 	void add_data(const std::string &stream_id, const char *data, size_t bytes);
 
 private:
+	void process_client(Client *client);
+	void close_client(Client *client);
+
 	pthread_mutex_t mutex;
 
 	// Map from stream ID to stream.
@@ -61,7 +71,9 @@ private:
 	// Map from file descriptor to client.
 	std::map<int, Client> clients;
 
+	// Used for epoll implementation (obviously).
 	int epoll_fd;
+	epoll_event events[EPOLL_MAX_EVENTS];
 
 	// Recover the this pointer, and call do_work().
 	static void *do_work_thunk(void *arg);