Merge #9517: [refactor] Switched httpserver.cpp to use RAII wrapped libevents.

1ae86ec Changed event RAII helper functions to inline to deal with duplicate symbol linker errors. (Karl-Johan Alm)
fd369d2 Switched httpserver.cpp to use RAII wrapped libevents. (Kalle Alm)

Tree-SHA512: 877e431f211024d42a3b0800e860e02833398611433e8393f8d5d4970f47f4bd670b900443678c067fec110c087aaab7dc1981ccbf17f6057676fdbbda89aed9

Author: laanwj

src/httpserver.cpp

@@ -21,13 +21,13 @@
 #include <signal.h>
 #include <future>
 
-#include <event2/event.h>
-#include <event2/http.h>
 #include <event2/thread.h>
 #include <event2/buffer.h>
 #include <event2/util.h>
 #include <event2/keyvalq_struct.h>
 
+#include "support/events.h"
+
 #ifdef EVENT__HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #ifdef _XOPEN_SOURCE_EXTENDED
@@ -367,9 +367,6 @@ static void libevent_log_cb(int severity, const char *msg)
 
 bool InitHTTPServer()
 {
-    struct evhttp* http = 0;
-    struct event_base* base = 0;
-
     if (!InitHTTPAllowList())
         return false;
 
@@ -395,17 +392,13 @@ bool InitHTTPServer()
     evthread_use_pthreads();
 #endif
 
-    base = event_base_new(); // XXX RAII
-    if (!base) {
-        LogPrintf("Couldn't create an event_base: exiting\n");
-        return false;
-    }
+    raii_event_base base_ctr = obtain_event_base();
 
     /* Create a new evhttp object to handle requests. */
-    http = evhttp_new(base); // XXX RAII
+    raii_evhttp http_ctr = obtain_evhttp(base_ctr.get());
+    struct evhttp* http = http_ctr.get();
     if (!http) {
         LogPrintf("couldn't create evhttp. Exiting.\n");
-        event_base_free(base);
         return false;
     }
 
@@ -416,8 +409,6 @@ bool InitHTTPServer()
 
     if (!HTTPBindAddresses(http)) {
         LogPrintf("Unable to bind any endpoint for RPC server\n");
-        evhttp_free(http);
-        event_base_free(base);
         return false;
     }
 
@@ -426,8 +417,9 @@ bool InitHTTPServer()
     LogPrintf("HTTP: creating work queue of depth %d\n", workQueueDepth);
 
     workQueue = new WorkQueue<HTTPClosure>(workQueueDepth);
-    eventBase = base;
-    eventHTTP = http;
+    // tranfer ownership to eventBase/HTTP via .release()
+    eventBase = base_ctr.release();
+    eventHTTP = http_ctr.release();
     return true;
 }
 

src/support/events.h

@@ -27,26 +27,26 @@ MAKE_RAII(evhttp);
 MAKE_RAII(evhttp_request);
 MAKE_RAII(evhttp_connection);
 
-raii_event_base obtain_event_base() {
+inline raii_event_base obtain_event_base() {
     auto result = raii_event_base(event_base_new());
     if (!result.get())
         throw std::runtime_error("cannot create event_base");
     return result;
 }
 
-raii_event obtain_event(struct event_base* base, evutil_socket_t s, short events, event_callback_fn cb, void* arg) {
+inline raii_event obtain_event(struct event_base* base, evutil_socket_t s, short events, event_callback_fn cb, void* arg) {
     return raii_event(event_new(base, s, events, cb, arg));
 }
 
-raii_evhttp obtain_evhttp(struct event_base* base) {
+inline raii_evhttp obtain_evhttp(struct event_base* base) {
     return raii_evhttp(evhttp_new(base));
 }
 
-raii_evhttp_request obtain_evhttp_request(void(*cb)(struct evhttp_request *, void *), void *arg) {
+inline raii_evhttp_request obtain_evhttp_request(void(*cb)(struct evhttp_request *, void *), void *arg) {
     return raii_evhttp_request(evhttp_request_new(cb, arg));
 }
 
-raii_evhttp_connection obtain_evhttp_connection_base(struct event_base* base, std::string host, uint16_t port) {
+inline raii_evhttp_connection obtain_evhttp_connection_base(struct event_base* base, std::string host, uint16_t port) {
     auto result = raii_evhttp_connection(evhttp_connection_base_new(base, NULL, host.c_str(), port));
     if (!result.get())
         throw std::runtime_error("create connection failed");