input/curl: wrap CURLM* in new class CurlMulti

Makefile.am

@@ -1277,6 +1277,7 @@ libinput_a_SOURCES += \
 	src/input/IcyInputStream.cxx src/input/IcyInputStream.hxx \
 	src/input/plugins/CurlInputPlugin.cxx src/input/plugins/CurlInputPlugin.hxx \
 	src/lib/curl/Easy.hxx \
+	src/lib/curl/Multi.hxx \
 	src/IcyMetaDataParser.cxx src/IcyMetaDataParser.hxx
 endif
 

src/input/plugins/CurlInputPlugin.cxx

@@ -20,6 +20,7 @@
 #include "config.h"
 #include "CurlInputPlugin.hxx"
 #include "lib/curl/Easy.hxx"
+#include "lib/curl/Multi.hxx"
 #include "../AsyncInputStream.hxx"
 #include "../IcyInputStream.hxx"
 #include "../InputPlugin.hxx"
@@ -194,14 +195,10 @@ private:
  * Manager for the global CURLM object.
  */
 class CurlGlobal final : private TimeoutMonitor {
-	CURLM *const multi;
+	CurlMulti multi;
 
 public:
-	CurlGlobal(EventLoop &_loop, CURLM *_multi);
+	explicit CurlGlobal(EventLoop &_loop);
-
-	~CurlGlobal() {
-		curl_multi_cleanup(multi);
-	}
 
 	void Add(CurlInputStream *c);
 	void Remove(CurlInputStream *c);
@@ -214,7 +211,7 @@ public:
 	void ReadInfo();
 
 	void Assign(curl_socket_t fd, CurlSocket &cs) {
-		curl_multi_assign(multi, fd, &cs);
+		curl_multi_assign(multi.Get(), fd, &cs);
 	}
 
 	void SocketAction(curl_socket_t fd, int ev_bitmask);
@@ -230,7 +227,7 @@ public:
 	 */
 	void ResumeSockets() {
 		int running_handles;
-		curl_multi_socket_all(multi, &running_handles);
+		curl_multi_socket_all(multi.Get(), &running_handles);
 	}
 
 private:
@@ -258,15 +255,14 @@ static CurlGlobal *curl_global;
 static constexpr Domain curl_domain("curl");
 static constexpr Domain curlm_domain("curlm");
 
-CurlGlobal::CurlGlobal(EventLoop &_loop, CURLM *_mutex)
+CurlGlobal::CurlGlobal(EventLoop &_loop)
-	:TimeoutMonitor(_loop), multi(_mutex)
+	:TimeoutMonitor(_loop)
 {
-	curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION,
+	multi.SetOption(CURLMOPT_SOCKETFUNCTION, CurlSocket::SocketFunction);
-			  CurlSocket::SocketFunction);
+	multi.SetOption(CURLMOPT_SOCKETDATA, this);
-	curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, this);
 
-	curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, TimerFunction);
+	multi.SetOption(CURLMOPT_TIMERFUNCTION, TimerFunction);
-	curl_multi_setopt(multi, CURLMOPT_TIMERDATA, this);
+	multi.SetOption(CURLMOPT_TIMERDATA, this);
 }
 
 /**
@@ -366,7 +362,7 @@ CurlGlobal::Add(CurlInputStream *c)
 	assert(c != nullptr);
 	assert(c->easy);
 
-	CURLMcode mcode = curl_multi_add_handle(multi, c->easy.Get());
+	CURLMcode mcode = curl_multi_add_handle(multi.Get(), c->easy.Get());
 	if (mcode != CURLM_OK)
 		throw FormatRuntimeError("curl_multi_add_handle() failed: %s",
 					 curl_multi_strerror(mcode));
@@ -394,7 +390,7 @@ input_curl_easy_add_indirect(CurlInputStream *c)
 inline void
 CurlGlobal::Remove(CurlInputStream *c)
 {
-	curl_multi_remove_handle(multi, c->easy.Get());
+	curl_multi_remove_handle(multi.Get(), c->easy.Get());
 }
 
 void
@@ -467,7 +463,7 @@ void
 CurlGlobal::SocketAction(curl_socket_t fd, int ev_bitmask)
 {
 	int running_handles;
-	CURLMcode mcode = curl_multi_socket_action(multi, fd, ev_bitmask,
+	CURLMcode mcode = curl_multi_socket_action(multi.Get(), fd, ev_bitmask,
 						   &running_handles);
 	if (mcode != CURLM_OK)
 		FormatError(curlm_domain,
@@ -490,7 +486,7 @@ CurlGlobal::ReadInfo()
 	CURLMsg *msg;
 	int msgs_in_queue;
 
-	while ((msg = curl_multi_info_read(multi,
+	while ((msg = curl_multi_info_read(multi.Get(),
 					   &msgs_in_queue)) != nullptr) {
 		if (msg->msg == CURLMSG_DONE)
 			input_curl_handle_done(msg->easy_handle, msg->data.result);
@@ -501,7 +497,7 @@ int
 CurlGlobal::TimerFunction(gcc_unused CURLM *_global, long timeout_ms, void *userp)
 {
 	auto &global = *(CurlGlobal *)userp;
-	assert(_global == global.multi);
+	assert(_global == global.multi.Get());
 
 	if (timeout_ms < 0) {
 		global.Cancel();
@@ -566,14 +562,14 @@ input_curl_init(const ConfigBlock &block)
 	verify_peer = block.GetBlockValue("verify_peer", true);
 	verify_host = block.GetBlockValue("verify_host", true);
 
-	CURLM *global = curl_multi_init();
+	try {
-	if (global == nullptr) {
+		curl_global = new CurlGlobal(io_thread_get());
+	} catch (const std::runtime_error &e) {
+		LogError(e);
 		curl_slist_free_all(http_200_aliases);
 		curl_global_cleanup();
 		throw PluginUnavailable("curl_multi_init() failed");
 	}
-
-	curl_global = new CurlGlobal(io_thread_get(), global);
 }
 
 static void

src/lib/curl/Multi.hxx

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2016 Max Kellermann <max@duempel.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef CURL_MULTI_HXX
+#define CURL_MULTI_HXX
+
+#include <curl/curl.h>
+
+#include <utility>
+#include <stdexcept>
+#include <cstddef>
+
+/**
+ * An OO wrapper for a "CURLM*" (a libCURL "multi" handle).
+ */
+class CurlMulti {
+	CURLM *handle = nullptr;
+
+public:
+	/**
+	 * Allocate a new CURLM*.
+	 *
+	 * Throws std::runtime_error on error.
+	 */
+	CurlMulti()
+		:handle(curl_multi_init())
+	{
+		if (handle == nullptr)
+			throw std::runtime_error("curl_multi_init() failed");
+	}
+
+	/**
+	 * Create an empty instance.
+	 */
+	CurlMulti(std::nullptr_t):handle(nullptr) {}
+
+	CurlMulti(CurlMulti &&src):handle(std::exchange(src.handle, nullptr)) {}
+
+	~CurlMulti() {
+		if (handle != nullptr)
+			curl_multi_cleanup(handle);
+	}
+
+	operator bool() const {
+		return handle != nullptr;
+	}
+
+	CurlMulti &operator=(CurlMulti &&src) {
+		std::swap(handle, src.handle);
+		return *this;
+	}
+
+	CURL *Get() {
+		return handle;
+	}
+
+	template<typename T>
+	void SetOption(CURLMoption option, T value) {
+		auto code = curl_multi_setopt(handle, option, value);
+		if (code != CURLM_OK)
+			throw std::runtime_error(curl_multi_strerror(code));
+	}
+};
+
+#endif