feat: epoll tags

runtime/include/epoll_tag.h

@@ -0,0 +1,9 @@
+#pragma once
+
+enum epoll_tag
+{
+	EPOLL_TAG_INVALID              = 0,
+	EPOLL_TAG_TENANT_SERVER_SOCKET = 1,
+	EPOLL_TAG_METRICS_SERVER_SOCKET,
+	EPOLL_TAG_HTTP_SESSION_CLIENT_SOCKET,
+};

runtime/include/http_session.h

@@ -9,17 +9,18 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
-#include "tcp_session.h"
 #include "debuglog.h"
-#include "http_request.h"
+#include "epoll_tag.h"
 #include "http_parser.h"
 #include "http_parser_settings.h"
+#include "http_request.h"
+#include "http_route_total.h"
+#include "http_session_perf_log.h"
 #include "http_total.h"
 #include "route.h"
-#include "http_route_total.h"
+#include "tcp_session.h"
 #include "tenant.h"
 #include "vec.h"
-#include "http_session_perf_log.h"
 
 #define HTTP_SESSION_DEFAULT_REQUEST_RESPONSE_SIZE (PAGE_SIZE)
 #define HTTP_SESSION_RESPONSE_HEADER_CAPACITY      256
@@ -45,6 +46,7 @@ enum http_session_state
 };
 
 struct http_session {
+	enum epoll_tag          tag;
 	enum http_session_state state;
 	struct sockaddr         client_address; /* client requesting connection! */
 	int                     socket;
@@ -93,6 +95,7 @@ http_session_init(struct http_session *session, int socket_descriptor, const str
 	assert(socket_descriptor >= 0);
 	assert(socket_address != NULL);
 
+	session->tag                       = EPOLL_TAG_HTTP_SESSION_CLIENT_SOCKET;
 	session->tenant                    = tenant;
 	session->route                     = NULL;
 	session->socket                    = socket_descriptor;

runtime/include/metrics_server.h

@@ -1,8 +1,16 @@
 #pragma once
 
+#include "epoll_tag.h"
 #include "tcp_server.h"
 
-extern struct tcp_server metrics_server;
+struct metrics_server {
+	enum epoll_tag    tag;
+	struct tcp_server tcp;
+	pthread_attr_t    thread_settings;
+};
+
+
+extern struct metrics_server metrics_server;
 
 void metrics_server_init();
 void metrics_server_thread_spawn(int client_socket);

runtime/include/tenant.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "epoll_tag.h"
 #include "http_router.h"
 #include "map.h"
 #include "module_database.h"
@@ -32,6 +33,7 @@ struct tenant_global_request_queue {
 };
 
 struct tenant {
+	enum epoll_tag         tag; /* Tag must be first member */
 	char                  *name;
 	struct tcp_server      tcp_server;
 	http_router_t          router;

runtime/include/tenant_functions.h

@@ -87,6 +87,7 @@ tenant_alloc(struct tenant_config *config)
 	struct tenant *tenant = (struct tenant *)calloc(1, sizeof(struct tenant));
 
 	/* Move name */
+	tenant->tag  = EPOLL_TAG_TENANT_SERVER_SOCKET;
 	tenant->name = config->name;
 	config->name = NULL;
 

runtime/src/listener_thread.c

@@ -145,7 +145,7 @@ listener_thread_register_metrics_server()
 	struct epoll_event accept_evt;
 	accept_evt.data.ptr = (void *)&metrics_server;
 	accept_evt.events   = EPOLLIN;
-	rc = epoll_ctl(listener_thread_epoll_file_descriptor, EPOLL_CTL_ADD, metrics_server.socket_descriptor,
+	rc = epoll_ctl(listener_thread_epoll_file_descriptor, EPOLL_CTL_ADD, metrics_server.tcp.socket_descriptor,
 	               &accept_evt);
 
 	return rc;
@@ -355,7 +355,7 @@ on_metrics_server_epoll_event(struct epoll_event *evt)
 	/* Accept as many clients requests as possible, returning when we would have blocked */
 	while (true) {
 		/* We accept the client connection with blocking semantics because we spawn ephemeral worker threads */
-		int client_socket = accept4(metrics_server.socket_descriptor, (struct sockaddr *)&client_address,
+		int client_socket = accept4(metrics_server.tcp.socket_descriptor, (struct sockaddr *)&client_address,
 		                            &address_length, 0);
 		if (unlikely(client_socket < 0)) {
 			if (errno == EWOULDBLOCK || errno == EAGAIN) return;
@@ -433,12 +433,20 @@ listener_thread_main(void *dummy)
 		for (int i = 0; i < descriptor_count; i++) {
 			panic_on_epoll_error(&epoll_events[i]);
 
-			if (epoll_events[i].data.ptr == &metrics_server) {
-				on_metrics_server_epoll_event(&epoll_events[i]);
-			} else if (tenant_database_find_by_ptr(epoll_events[i].data.ptr) != NULL) {
+			enum epoll_tag *tag = (enum epoll_tag *)epoll_events[i].data.ptr;
+
+			switch (*tag) {
+			case EPOLL_TAG_TENANT_SERVER_SOCKET:
 				on_tenant_socket_epoll_event(&epoll_events[i]);
-			} else {
+				break;
+			case EPOLL_TAG_HTTP_SESSION_CLIENT_SOCKET:
 				on_client_socket_epoll_event(&epoll_events[i]);
+				break;
+			case EPOLL_TAG_METRICS_SERVER_SOCKET:
+				on_metrics_server_epoll_event(&epoll_events[i]);
+				break;
+			default:
+				panic("Unknown epoll type!");
 			}
 		}
 	}

runtime/src/metrics_server.c

@@ -8,6 +8,7 @@
 #include "debuglog.h"
 #include "http.h"
 #include "http_total.h"
+#include "metrics_server.h"
 #include "proc_stat.h"
 #include "runtime.h"
 #include "sandbox_total.h"
@@ -18,8 +19,7 @@
 #define METRICS_SERVER_CORE_ID 0
 #define METRICS_SERVER_PORT    1776
 
-static pthread_attr_t metrics_server_thread_settings;
-struct tcp_server     metrics_server;
+struct metrics_server metrics_server;
 static void          *metrics_server_handler(void *arg);
 
 extern void metrics_server_route_level_metrics_render(FILE *ostream);
@@ -27,22 +27,23 @@ extern void metrics_server_route_level_metrics_render(FILE *ostream);
 void
 metrics_server_init()
 {
-	tcp_server_init(&metrics_server, METRICS_SERVER_PORT);
-	int rc = tcp_server_listen(&metrics_server);
+	metrics_server.tag = EPOLL_TAG_METRICS_SERVER_SOCKET;
+	tcp_server_init(&metrics_server.tcp, METRICS_SERVER_PORT);
+	int rc = tcp_server_listen(&metrics_server.tcp);
 	assert(rc == 0);
 
 	/* Configure pthread attributes to pin metrics server threads to CPU 0 */
-	pthread_attr_init(&metrics_server_thread_settings);
+	pthread_attr_init(&metrics_server.thread_settings);
 	cpu_set_t cs;
 	CPU_ZERO(&cs);
 	CPU_SET(METRICS_SERVER_CORE_ID, &cs);
-	pthread_attr_setaffinity_np(&metrics_server_thread_settings, sizeof(cpu_set_t), &cs);
+	pthread_attr_setaffinity_np(&metrics_server.thread_settings, sizeof(cpu_set_t), &cs);
 }
 
 int
 metrics_server_close()
 {
-	return tcp_server_close(&metrics_server);
+	return tcp_server_close(&metrics_server.tcp);
 }
 
 void
@@ -65,7 +66,7 @@ metrics_server_thread_spawn(int client_socket)
 
 	/* Fire and forget, so we don't save the thread handles */
 	pthread_t metrics_server_thread;
-	int       rc = pthread_create(&metrics_server_thread, &metrics_server_thread_settings, metrics_server_handler,
+	int       rc = pthread_create(&metrics_server_thread, &metrics_server.thread_settings, metrics_server_handler,
 	                              (void *)(long)client_socket);
 
 	if (rc != 0) {