input/Plugin: migrate open() from class Error to C++ exceptions

src/input/AsyncInputStream.cxx

@@ -81,6 +81,7 @@ AsyncInputStream::Resume()
 
 	if (paused) {
 		paused = false;
+
 		DoResume();
 	}
 }
@@ -264,7 +265,12 @@ AsyncInputStream::DeferredResume()
 {
 	const ScopeLock protect(mutex);
 
-	Resume();
+	try {
+		Resume();
+	} catch (...) {
+		postponed_exception = std::current_exception();
+		cond.broadcast();
+	}
 }
 
 void
@@ -274,10 +280,16 @@ AsyncInputStream::DeferredSeek()
 	if (seek_state != SeekState::SCHEDULED)
 		return;
 
-	Resume();
+	try {
+		Resume();
 
-	seek_state = SeekState::PENDING;
-	buffer.Clear();
-	paused = false;
-	DoSeek(seek_offset);
+		seek_state = SeekState::PENDING;
+		buffer.Clear();
+		paused = false;
+
+		DoSeek(seek_offset);
+	} catch (...) {
+		postponed_exception = std::current_exception();
+		cond.broadcast();
+	}
 }

src/input/InputPlugin.hxx

@@ -36,7 +36,6 @@
 
 struct ConfigBlock;
 class InputStream;
-class Error;
 struct Tag;
 
 struct InputPlugin {
@@ -58,9 +57,11 @@ struct InputPlugin {
 	 */
 	void (*finish)();
 
+	/**
+	 * Throws std::runtime_error on error.
+	 */
 	InputStream *(*open)(const char *uri,
-			     Mutex &mutex, Cond &cond,
-			     Error &error);
+			     Mutex &mutex, Cond &cond);
 };
 
 #endif

src/input/InputStream.hxx

@@ -115,16 +115,17 @@ public:
 	 * Opens a new input stream.  You may not access it until the "ready"
 	 * flag is set.
 	 *
+	 * Throws std::runtime_error on error.
+	 *
 	 * @param mutex a mutex that is used to protect this object; must be
 	 * locked before calling any of the public methods
 	 * @param cond a cond that gets signalled when the state of
 	 * this object changes; may be nullptr if the caller doesn't want to get
 	 * notifications
-	 * @return an #InputStream object on success, nullptr on error
+	 * @return an #InputStream object on success
 	 */
 	gcc_nonnull_all
-	static InputStreamPtr Open(const char *uri, Mutex &mutex, Cond &cond,
-				   Error &error);
+	static InputStreamPtr Open(const char *uri, Mutex &mutex, Cond &cond);
 
 	/**
 	 * Just like Open(), but waits for the stream to become ready.
@@ -132,8 +133,7 @@ public:
 	 */
 	gcc_nonnull_all
 	static InputStreamPtr OpenReady(const char *uri,
-					Mutex &mutex, Cond &cond,
-					Error &error);
+					Mutex &mutex, Cond &cond);
 
 	/**
 	 * The absolute URI which was used to open this stream.

src/input/LocalOpen.cxx

@@ -27,7 +27,7 @@
 #endif
 
 #include "fs/Path.hxx"
-#include "util/Error.hxx"
+#include "system/Error.hxx"
 
 #include <assert.h>
 
@@ -36,20 +36,24 @@
 #endif
 
 InputStreamPtr
-OpenLocalInputStream(Path path, Mutex &mutex, Cond &cond, Error &error)
+OpenLocalInputStream(Path path, Mutex &mutex, Cond &cond)
 {
-	assert(!error.IsDefined());
+	InputStreamPtr is;
 
-	InputStreamPtr is(OpenFileInputStream(path, mutex, cond, error));
 #ifdef ENABLE_ARCHIVE
-	if (is == nullptr && error.IsDomain(errno_domain) &&
-	    error.GetCode() == ENOTDIR) {
-		/* ENOTDIR means this may be a path inside an archive
-		   file */
-		Error error2;
-		is.reset(OpenArchiveInputStream(path, mutex, cond, error2));
-		if (is == nullptr && error2.IsDefined())
-			error = std::move(error2);
+	try {
+#endif
+		is = OpenFileInputStream(path, mutex, cond);
+#ifdef ENABLE_ARCHIVE
+	} catch (const std::system_error &e) {
+		if (IsPathNotFound(e)) {
+			/* ENOTDIR means this may be a path inside an archive
+			   file */
+			is = OpenArchiveInputStream(path, mutex, cond);
+			if (!is)
+				throw;
+		} else
+			throw;
 	}
 #endif
 

src/input/LocalOpen.hxx

@@ -26,13 +26,14 @@
 class Path;
 class Mutex;
 class Cond;
-class Error;
 
 /**
  * Open a "local" file.  This is a wrapper for the input plugins
  * "file" and "archive".
+ *
+ * Throws std::runtime_error on error.
  */
 InputStreamPtr
-OpenLocalInputStream(Path path, Mutex &mutex, Cond &cond, Error &error);
+OpenLocalInputStream(Path path, Mutex &mutex, Cond &cond);
 
 #endif

src/input/Open.cxx

@@ -28,51 +28,51 @@
 #include "fs/AllocatedPath.hxx"
 #include "util/Error.hxx"
 
+#include <stdexcept>
+
 InputStreamPtr
 InputStream::Open(const char *url,
-		  Mutex &mutex, Cond &cond,
-		  Error &error)
+		  Mutex &mutex, Cond &cond)
 {
 	if (PathTraitsUTF8::IsAbsolute(url)) {
+		Error error;
 		const auto path = AllocatedPath::FromUTF8(url, error);
 		if (path.IsNull())
-			return nullptr;
+			throw std::runtime_error(error.GetMessage());
 
-		return OpenLocalInputStream(path,
-					    mutex, cond, error);
+		return OpenLocalInputStream(path, mutex, cond);
 	}
 
 	input_plugins_for_each_enabled(plugin) {
 		InputStream *is;
 
-		is = plugin->open(url, mutex, cond, error);
+		is = plugin->open(url, mutex, cond);
 		if (is != nullptr) {
 			is = input_rewind_open(is);
 
 			return InputStreamPtr(is);
-		} else if (error.IsDefined())
-			return nullptr;
+		}
 	}
 
-	error.Set(input_domain, "Unrecognized URI");
-	return nullptr;
+	throw std::runtime_error("Unrecognized URI");
 }
 
 InputStreamPtr
 InputStream::OpenReady(const char *uri,
-		       Mutex &mutex, Cond &cond,
-		       Error &error)
+		       Mutex &mutex, Cond &cond)
 {
-	auto is = Open(uri, mutex, cond, error);
-	if (is == nullptr)
-		return nullptr;
+	auto is = Open(uri, mutex, cond);
 
 	bool success;
 
 	{
 		const ScopeLock protect(mutex);
 		is->WaitReady();
+
+		Error error;
 		success = is->Check(error);
+		if (!success)
+			throw std::runtime_error(error.GetMessage());
 	}
 
 	if (!success)

src/input/plugins/AlsaInputPlugin.cxx

@@ -30,6 +30,7 @@
 #include "../AsyncInputStream.hxx"
 #include "util/Domain.hxx"
 #include "util/Error.hxx"
+#include "util/RuntimeError.hxx"
 #include "util/StringCompare.hxx"
 #include "util/ReusableArray.hxx"
 #include "util/ScopeExit.hxx"
@@ -102,8 +103,7 @@ public:
 		snd_pcm_close(capture_handle);
 	}
 
-	static InputStream *Create(const char *uri, Mutex &mutex, Cond &cond,
-				   Error &error);
+	static InputStream *Create(const char *uri, Mutex &mutex, Cond &cond);
 
 protected:
 	/* virtual methods from AsyncInputStream */
@@ -120,8 +120,7 @@ protected:
 
 private:
 	static snd_pcm_t *OpenDevice(const char *device, int rate,
-				     snd_pcm_format_t format, int channels,
-				     Error &error);
+				     snd_pcm_format_t format, int channels);
 
 	void Pause() {
 		AsyncInputStream::Pause();
@@ -143,8 +142,7 @@ private:
 };
 
 inline InputStream *
-AlsaInputStream::Create(const char *uri, Mutex &mutex, Cond &cond,
-			Error &error)
+AlsaInputStream::Create(const char *uri, Mutex &mutex, Cond &cond)
 {
 	const char *device = StringAfterPrefix(uri, "alsa://");
 	if (device == nullptr)
@@ -160,10 +158,7 @@ AlsaInputStream::Create(const char *uri, Mutex &mutex, Cond &cond,
 	snd_pcm_format_t format = default_format;
 	int channels = default_channels;
 
-	snd_pcm_t *handle = OpenDevice(device, rate, format, channels,
-				       error);
-	if (handle == nullptr)
-		return nullptr;
+	snd_pcm_t *handle = OpenDevice(device, rate, format, channels);
 
 	int frame_size = snd_pcm_format_width(format) / 8 * channels;
 	return new AlsaInputStream(io_thread_get(),
@@ -242,47 +237,40 @@ AlsaInputStream::Recover(int err)
 	return err;
 }
 
-static bool
+static void
 ConfigureCapture(snd_pcm_t *capture_handle,
-		 int rate, snd_pcm_format_t format, int channels,
-		 Error &error)
+		 int rate, snd_pcm_format_t format, int channels)
 {
 	int err;
 
 	snd_pcm_hw_params_t *hw_params;
-	if ((err = snd_pcm_hw_params_malloc(&hw_params)) < 0) {
-		error.Format(alsa_input_domain, "Cannot allocate hardware parameter structure (%s)", snd_strerror(err));
-		return false;
-	}
+	if ((err = snd_pcm_hw_params_malloc(&hw_params)) < 0)
+		throw FormatRuntimeError("Cannot allocate hardware parameter structure (%s)",
+					 snd_strerror(err));
 
 	AtScopeExit(hw_params) {
 		snd_pcm_hw_params_free(hw_params);
 	};
 
-	if ((err = snd_pcm_hw_params_any(capture_handle, hw_params)) < 0) {
-		error.Format(alsa_input_domain, "Cannot initialize hardware parameter structure (%s)", snd_strerror(err));
-		return false;
-	}
+	if ((err = snd_pcm_hw_params_any(capture_handle, hw_params)) < 0)
+		throw FormatRuntimeError("Cannot initialize hardware parameter structure (%s)",
+					 snd_strerror(err));
 
-	if ((err = snd_pcm_hw_params_set_access(capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
-		error.Format(alsa_input_domain, "Cannot set access type (%s)", snd_strerror (err));
-		return false;
-	}
+	if ((err = snd_pcm_hw_params_set_access(capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0)
+		throw FormatRuntimeError("Cannot set access type (%s)",
+					 snd_strerror(err));
 
-	if ((err = snd_pcm_hw_params_set_format(capture_handle, hw_params, format)) < 0) {
-		error.Format(alsa_input_domain, "Cannot set sample format (%s)", snd_strerror (err));
-		return false;
-	}
+	if ((err = snd_pcm_hw_params_set_format(capture_handle, hw_params, format)) < 0)
+		throw FormatRuntimeError("Cannot set sample format (%s)",
+					 snd_strerror(err));
 
-	if ((err = snd_pcm_hw_params_set_channels(capture_handle, hw_params, channels)) < 0) {
-		error.Format(alsa_input_domain, "Cannot set channels (%s)", snd_strerror (err));
-		return false;
-	}
+	if ((err = snd_pcm_hw_params_set_channels(capture_handle, hw_params, channels)) < 0)
+		throw FormatRuntimeError("Cannot set channels (%s)",
+					 snd_strerror(err));
 
-	if ((err = snd_pcm_hw_params_set_rate(capture_handle, hw_params, rate, 0)) < 0) {
-		error.Format(alsa_input_domain, "Cannot set sample rate (%s)", snd_strerror (err));
-		return false;
-	}
+	if ((err = snd_pcm_hw_params_set_rate(capture_handle, hw_params, rate, 0)) < 0)
+		throw FormatRuntimeError("Cannot set sample rate (%s)",
+					 snd_strerror(err));
 
 	/* period needs to be big enough so that poll() doesn't fire too often,
 	 * but small enough that buffer overruns don't occur if Read() is not
@@ -293,17 +281,13 @@ ConfigureCapture(snd_pcm_t *capture_handle,
 	snd_pcm_uframes_t period = read_buffer_size * 2;
 	int direction = -1;
 	if ((err = snd_pcm_hw_params_set_period_size_near(capture_handle, hw_params,
-							  &period, &direction)) < 0) {
-		error.Format(alsa_input_domain, "Cannot set period size (%s)",
-			     snd_strerror(err));
-		return false;
-	}
+							  &period, &direction)) < 0)
+		throw FormatRuntimeError("Cannot set period size (%s)",
+					 snd_strerror(err));
 
-	if ((err = snd_pcm_hw_params(capture_handle, hw_params)) < 0) {
-		error.Format(alsa_input_domain, "Cannot set parameters (%s)",
-			     snd_strerror(err));
-		return false;
-	}
+	if ((err = snd_pcm_hw_params(capture_handle, hw_params)) < 0)
+		throw FormatRuntimeError("Cannot set parameters (%s)",
+					 snd_strerror(err));
 
 	snd_pcm_sw_params_t *sw_params;
 
@@ -315,37 +299,31 @@ ConfigureCapture(snd_pcm_t *capture_handle,
 	};
 
 	if ((err = snd_pcm_sw_params_set_start_threshold(capture_handle, sw_params,
-							 period)) < 0)  {
-		error.Format(alsa_input_domain,
-			     "unable to set start threshold (%s)", snd_strerror(err));
-		return false;
-	}
+							 period)) < 0)
+		throw FormatRuntimeError("unable to set start threshold (%s)",
+					 snd_strerror(err));
 
-	if ((err = snd_pcm_sw_params(capture_handle, sw_params)) < 0) {
-		error.Format(alsa_input_domain,
-			     "unable to install sw params (%s)", snd_strerror(err));
-		return false;
-	}
-
-	return true;
+	if ((err = snd_pcm_sw_params(capture_handle, sw_params)) < 0)
+		throw FormatRuntimeError("unable to install sw params (%s)",
+					 snd_strerror(err));
 }
 
 inline snd_pcm_t *
 AlsaInputStream::OpenDevice(const char *device,
-			    int rate, snd_pcm_format_t format, int channels,
-			    Error &error)
+			    int rate, snd_pcm_format_t format, int channels)
 {
 	snd_pcm_t *capture_handle;
 	int err;
 	if ((err = snd_pcm_open(&capture_handle, device,
-				SND_PCM_STREAM_CAPTURE, 0)) < 0) {
-		error.Format(alsa_input_domain, "Failed to open device: %s (%s)", device, snd_strerror(err));
-		return nullptr;
-	}
+				SND_PCM_STREAM_CAPTURE, 0)) < 0)
+		throw FormatRuntimeError("Failed to open device: %s (%s)",
+					 device, snd_strerror(err));
 
-	if (!ConfigureCapture(capture_handle, rate, format, channels, error)) {
+	try {
+		ConfigureCapture(capture_handle, rate, format, channels);
+	} catch (...) {
 		snd_pcm_close(capture_handle);
-		return nullptr;
+		throw;
 	}
 
 	snd_pcm_prepare(capture_handle);
@@ -356,9 +334,9 @@ AlsaInputStream::OpenDevice(const char *device,
 /*#########################  Plugin Functions  ##############################*/
 
 static InputStream *
-alsa_input_open(const char *uri, Mutex &mutex, Cond &cond, Error &error)
+alsa_input_open(const char *uri, Mutex &mutex, Cond &cond)
 {
-	return AlsaInputStream::Create(uri, mutex, cond, error);
+	return AlsaInputStream::Create(uri, mutex, cond);
 }
 
 const struct InputPlugin input_plugin_alsa = {

src/input/plugins/ArchiveInputPlugin.cxx

@@ -25,14 +25,18 @@
 #include "archive/ArchivePlugin.hxx"
 #include "archive/ArchiveFile.hxx"
 #include "../InputPlugin.hxx"
+#include "../InputStream.hxx"
 #include "fs/Path.hxx"
 #include "Log.hxx"
 #include "util/ScopeExit.hxx"
+#include "util/Error.hxx"
+
+#include <stdexcept>
 
 #include <stdlib.h>
 
-InputStream *
-OpenArchiveInputStream(Path path, Mutex &mutex, Cond &cond, Error &error)
+InputStreamPtr
+OpenArchiveInputStream(Path path, Mutex &mutex, Cond &cond)
 {
 	const ArchivePlugin *arplug;
 
@@ -57,22 +61,21 @@ OpenArchiveInputStream(Path path, Mutex &mutex, Cond &cond, Error &error)
 		return nullptr;
 	}
 
+	Error error;
 	auto file = archive_file_open(arplug, Path::FromFS(archive), error);
-	if (file == nullptr) {
-		return nullptr;
-	}
+	if (file == nullptr)
+		throw std::runtime_error(error.GetMessage());
 
 	AtScopeExit(file) {
 		file->Close();
 	};
 
-	return file->OpenStream(filename, mutex, cond, error);
+	return InputStreamPtr(file->OpenStream(filename, mutex, cond));
 }
 
 static InputStream *
 input_archive_open(gcc_unused const char *filename,
-		gcc_unused Mutex &mutex, gcc_unused Cond &cond,
-		gcc_unused Error &error)
+		   gcc_unused Mutex &mutex, gcc_unused Cond &cond)
 {
 	/* dummy method; use OpenArchiveInputStream() instead */
 

src/input/plugins/ArchiveInputPlugin.hxx

@@ -20,15 +20,15 @@
 #ifndef MPD_INPUT_ARCHIVE_HXX
 #define MPD_INPUT_ARCHIVE_HXX
 
-class InputStream;
+#include "input/Ptr.hxx"
+
 class Path;
 class Mutex;
 class Cond;
-class Error;
 
 extern const struct InputPlugin input_plugin_archive;
 
-InputStream *
-OpenArchiveInputStream(Path path, Mutex &mutex, Cond &cond, Error &error);
+InputStreamPtr
+OpenArchiveInputStream(Path path, Mutex &mutex, Cond &cond);
 
 #endif

src/input/plugins/CdioParanoiaInputPlugin.cxx

@@ -127,7 +127,7 @@ struct cdio_uri {
 };
 
 static bool
-parse_cdio_uri(struct cdio_uri *dest, const char *src, Error &error)
+parse_cdio_uri(struct cdio_uri *dest, const char *src)
 {
 	if (!StringStartsWith(src, "cdda://"))
 		return false;
@@ -160,10 +160,8 @@ parse_cdio_uri(struct cdio_uri *dest, const char *src, Error &error)
 
 	char *endptr;
 	dest->track = strtoul(track, &endptr, 10);
-	if (*endptr != 0) {
-		error.Set(cdio_domain, "Malformed track number");
-		return false;
-	}
+	if (*endptr != 0)
+		throw std::runtime_error("Malformed track number");
 
 	if (endptr == track)
 		/* play the whole CD */
@@ -187,35 +185,28 @@ cdio_detect_device(void)
 
 static InputStream *
 input_cdio_open(const char *uri,
-		Mutex &mutex, Cond &cond,
-		Error &error)
+		Mutex &mutex, Cond &cond)
 {
 	struct cdio_uri parsed_uri;
-	if (!parse_cdio_uri(&parsed_uri, uri, error))
+	if (!parse_cdio_uri(&parsed_uri, uri))
 		return nullptr;
 
 	/* get list of CD's supporting CD-DA */
 	const AllocatedPath device = parsed_uri.device[0] != 0
 		? AllocatedPath::FromFS(parsed_uri.device)
 		: cdio_detect_device();
-	if (device.IsNull()) {
-		error.Set(cdio_domain,
-			  "Unable find or access a CD-ROM drive with an audio CD in it.");
-		return nullptr;
-	}
+	if (device.IsNull())
+		throw std::runtime_error("Unable find or access a CD-ROM drive with an audio CD in it.");
 
 	/* Found such a CD-ROM with a CD-DA loaded. Use the first drive in the list. */
 	const auto cdio = cdio_open(device.c_str(), DRIVER_UNKNOWN);
-	if (cdio == nullptr) {
-		error.Set(cdio_domain, "Failed to open CD drive");
-		return nullptr;
-	}
+	if (cdio == nullptr)
+		throw std::runtime_error("Failed to open CD drive");
 
 	const auto drv = cdio_cddap_identify_cdio(cdio, 1, nullptr);
 	if (drv == nullptr) {
-		error.Set(cdio_domain, "Unable to identify audio CD disc.");
 		cdio_destroy(cdio);
-		return nullptr;
+		throw std::runtime_error("Unable to identify audio CD disc.");
 	}
 
 	cdda_verbose_set(drv, CDDA_MESSAGE_FORGETIT, CDDA_MESSAGE_FORGETIT);
@@ -223,12 +214,12 @@ input_cdio_open(const char *uri,
 	if (0 != cdio_cddap_open(drv)) {
 		cdio_cddap_close_no_free_cdio(drv);
 		cdio_destroy(cdio);
-		error.Set(cdio_domain, "Unable to open disc.");
-		return nullptr;
+		throw std::runtime_error("Unable to open disc.");
 	}
 
 	bool reverse_endian;
-	switch (data_bigendianp(drv)) {
+	const int be = data_bigendianp(drv);
+	switch (be) {
 	case -1:
 		LogDebug(cdio_domain, "drive returns unknown audio data");
 		reverse_endian = default_reverse_endian;
@@ -245,11 +236,10 @@ input_cdio_open(const char *uri,
 		break;
 
 	default:
-		error.Format(cdio_domain, "Drive returns unknown data type %d",
-			     data_bigendianp(drv));
 		cdio_cddap_close_no_free_cdio(drv);
 		cdio_destroy(cdio);
-		return nullptr;
+		throw FormatRuntimeError("Drive returns unknown data type %d",
+					 be);
 	}
 
 	lsn_t lsn_from, lsn_to;

src/input/plugins/CurlInputPlugin.cxx

@@ -32,6 +32,7 @@
 #include "util/ASCII.hxx"
 #include "util/StringUtil.hxx"
 #include "util/NumberParser.hxx"
+#include "util/RuntimeError.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
 #include "Log.hxx"
@@ -78,17 +79,18 @@ struct CurlInputStream final : public AsyncInputStream {
 				  CURL_MAX_BUFFERED,
 				  CURL_RESUME_AT),
 		 request_headers(nullptr),
-		 icy(new IcyInputStream(this)) {}
+		 icy(new IcyInputStream(this)) {
+		InitEasy();
+	}
 
 	~CurlInputStream();
 
 	CurlInputStream(const CurlInputStream &) = delete;
 	CurlInputStream &operator=(const CurlInputStream &) = delete;
 
-	static InputStream *Open(const char *url, Mutex &mutex, Cond &cond,
-				 Error &error);
+	static InputStream *Open(const char *url, Mutex &mutex, Cond &cond);
 
-	bool InitEasy(Error &error);
+	void InitEasy();
 
 	/**
 	 * Frees the current "libcurl easy" handle, and everything
@@ -201,7 +203,7 @@ public:
 		curl_multi_cleanup(multi);
 	}
 
-	bool Add(CurlInputStream *c, Error &error);
+	void Add(CurlInputStream *c);
 	void Remove(CurlInputStream *c);
 
 	/**
@@ -355,41 +357,39 @@ CurlSocket::OnSocketReady(unsigned flags)
 
 /**
  * Runs in the I/O thread.  No lock needed.
+ *
+ * Throws std::runtime_error on error.
  */
-inline bool
-CurlMulti::Add(CurlInputStream *c, Error &error)
+inline void
+CurlMulti::Add(CurlInputStream *c)
 {
 	assert(io_thread_inside());
 	assert(c != nullptr);
 	assert(c->easy != nullptr);
 
 	CURLMcode mcode = curl_multi_add_handle(multi, c->easy);
-	if (mcode != CURLM_OK) {
-		error.Format(curlm_domain, mcode,
-			     "curl_multi_add_handle() failed: %s",
-			     curl_multi_strerror(mcode));
-		return false;
-	}
+	if (mcode != CURLM_OK)
+		throw FormatRuntimeError("curl_multi_add_handle() failed: %s",
+					 curl_multi_strerror(mcode));
 
 	InvalidateSockets();
-	return true;
 }
 
 /**
  * Call input_curl_easy_add() in the I/O thread.  May be called from
  * any thread.  Caller must not hold a mutex.
+ *
+ * Throws std::runtime_error on error.
  */
-static bool
-input_curl_easy_add_indirect(CurlInputStream *c, Error &error)
+static void
+input_curl_easy_add_indirect(CurlInputStream *c)
 {
 	assert(c != nullptr);
 	assert(c->easy != nullptr);
 
-	bool result;
-	BlockingCall(io_thread_get(), [c, &error, &result](){
-			result = curl_multi->Add(c, error);
+	BlockingCall(io_thread_get(), [c](){
+			curl_multi->Add(c);
 		});
-	return result;
 }
 
 inline void
@@ -727,14 +727,12 @@ input_curl_writefunction(void *ptr, size_t size, size_t nmemb, void *stream)
 	return c.DataReceived(ptr, size);
 }
 
-bool
-CurlInputStream::InitEasy(Error &error)
+void
+CurlInputStream::InitEasy()
 {
 	easy = curl_easy_init();
-	if (easy == nullptr) {
-		error.Set(curl_domain, "curl_easy_init() failed");
-		return false;
-	}
+	if (easy == nullptr)
+		throw std::runtime_error("curl_easy_init() failed");
 
 	curl_easy_setopt(easy, CURLOPT_PRIVATE, (void *)this);
 	curl_easy_setopt(easy, CURLOPT_USERAGENT,
@@ -773,19 +771,14 @@ CurlInputStream::InitEasy(Error &error)
 	curl_easy_setopt(easy, CURLOPT_SSL_VERIFYHOST, verify_host ? 2l : 0l);
 
 	CURLcode code = curl_easy_setopt(easy, CURLOPT_URL, GetURI());
-	if (code != CURLE_OK) {
-		error.Format(curl_domain, code,
-			     "curl_easy_setopt() failed: %s",
-			     curl_easy_strerror(code));
-		return false;
-	}
+	if (code != CURLE_OK)
+		throw FormatRuntimeError("curl_easy_setopt() failed: %s",
+					 curl_easy_strerror(code));
 
 	request_headers = nullptr;
 	request_headers = curl_slist_append(request_headers,
 					       "Icy-Metadata: 1");
 	curl_easy_setopt(easy, CURLOPT_HTTPHEADER, request_headers);
-
-	return true;
 }
 
 void
@@ -809,11 +802,11 @@ CurlInputStream::DoSeek(offset_type new_offset)
 		return;
 	}
 
-	Error error;
-	if (!InitEasy(postponed_error)) {
+	try {
+		InitEasy();
+	} catch (...) {
 		mutex.lock();
-		PostponeError(std::move(error));
-		return;
+		throw;
 	}
 
 	/* send the "Range" header */
@@ -823,10 +816,11 @@ CurlInputStream::DoSeek(offset_type new_offset)
 		curl_easy_setopt(easy, CURLOPT_RANGE, range);
 	}
 
-	if (!input_curl_easy_add_indirect(this, error)) {
+	try {
+		input_curl_easy_add_indirect(this);
+	} catch (...) {
 		mutex.lock();
-		PostponeError(std::move(error));
-		return;
+		throw;
 	}
 
 	mutex.lock();
@@ -834,27 +828,29 @@ CurlInputStream::DoSeek(offset_type new_offset)
 }
 
 inline InputStream *
-CurlInputStream::Open(const char *url, Mutex &mutex, Cond &cond,
-		      Error &error)
+CurlInputStream::Open(const char *url, Mutex &mutex, Cond &cond)
 {
 	CurlInputStream *c = new CurlInputStream(url, mutex, cond);
-	if (!c->InitEasy(error) || !input_curl_easy_add_indirect(c, error)) {
+
+	try {
+		c->InitEasy();
+		input_curl_easy_add_indirect(c);
+	} catch (...) {
 		delete c;
-		return nullptr;
+		throw;
 	}
 
 	return c->icy;
 }
 
 static InputStream *
-input_curl_open(const char *url, Mutex &mutex, Cond &cond,
-		Error &error)
+input_curl_open(const char *url, Mutex &mutex, Cond &cond)
 {
 	if (memcmp(url, "http://",  7) != 0 &&
 	    memcmp(url, "https://", 8) != 0)
 		return nullptr;
 
-	return CurlInputStream::Open(url, mutex, cond, error);
+	return CurlInputStream::Open(url, mutex, cond);
 }
 
 const struct InputPlugin input_plugin_curl = {

src/input/plugins/FfmpegInputPlugin.cxx

@@ -84,8 +84,7 @@ input_ffmpeg_init(gcc_unused const ConfigBlock &block)
 
 static InputStream *
 input_ffmpeg_open(const char *uri,
-		  Mutex &mutex, Cond &cond,
-		  Error &error)
+		  Mutex &mutex, Cond &cond)
 {
 	if (!StringStartsWith(uri, "gopher://") &&
 	    !StringStartsWith(uri, "rtp://") &&
@@ -97,10 +96,8 @@ input_ffmpeg_open(const char *uri,
 
 	AVIOContext *h;
 	auto result = avio_open(&h, uri, AVIO_FLAG_READ);
-	if (result != 0) {
-		SetFfmpegError(error, result);
-		return nullptr;
-	}
+	if (result != 0)
+		throw MakeFfmpegError(result);
 
 	return new FfmpegInputStream(uri, mutex, cond, h);
 }

src/input/plugins/FileInputPlugin.cxx

@@ -21,18 +21,15 @@
 #include "FileInputPlugin.hxx"
 #include "../InputStream.hxx"
 #include "../InputPlugin.hxx"
-#include "util/Error.hxx"
-#include "util/Domain.hxx"
 #include "fs/Path.hxx"
 #include "fs/FileInfo.hxx"
 #include "fs/io/FileReader.hxx"
 #include "system/FileDescriptor.hxx"
+#include "util/RuntimeError.hxx"
 
 #include <sys/stat.h>
 #include <fcntl.h>
 
-static constexpr Domain file_domain("file");
-
 class FileInputStream final : public InputStream {
 	FileReader reader;
 
@@ -56,38 +53,31 @@ public:
 	bool Seek(offset_type offset, Error &error) override;
 };
 
-InputStream *
+InputStreamPtr
 OpenFileInputStream(Path path,
-		    Mutex &mutex, Cond &cond,
-		    Error &error)
-try {
+		    Mutex &mutex, Cond &cond)
+{
 	FileReader reader(path);
 
 	const FileInfo info = reader.GetFileInfo();
 
-	if (!info.IsRegular()) {
-		error.Format(file_domain, "Not a regular file: %s",
-			     path.c_str());
-		return nullptr;
-	}
+	if (!info.IsRegular())
+		throw FormatRuntimeError("Not a regular file: %s",
+					 path.c_str());
 
 #ifdef POSIX_FADV_SEQUENTIAL
 	posix_fadvise(reader.GetFD().Get(), (off_t)0, info.GetSize(),
 		      POSIX_FADV_SEQUENTIAL);
 #endif
 
-	return new FileInputStream(path.ToUTF8().c_str(),
-				   std::move(reader), info.GetSize(),
-				   mutex, cond);
-} catch (const std::exception &e) {
-	error.Set(std::current_exception());
-	return nullptr;
+	return InputStreamPtr(new FileInputStream(path.ToUTF8().c_str(),
+						  std::move(reader), info.GetSize(),
+						  mutex, cond));
 }
 
 static InputStream *
 input_file_open(gcc_unused const char *filename,
-		gcc_unused Mutex &mutex, gcc_unused Cond &cond,
-		gcc_unused Error &error)
+		gcc_unused Mutex &mutex, gcc_unused Cond &cond)
 {
 	/* dummy method; use OpenFileInputStream() instead */
 

src/input/plugins/FileInputPlugin.hxx

@@ -20,17 +20,16 @@
 #ifndef MPD_INPUT_FILE_HXX
 #define MPD_INPUT_FILE_HXX
 
-class InputStream;
+#include "input/Ptr.hxx"
+
 class Path;
 class Mutex;
 class Cond;
-class Error;
 
 extern const struct InputPlugin input_plugin_file;
 
-InputStream *
+InputStreamPtr
 OpenFileInputStream(Path path,
-		    Mutex &mutex, Cond &cond,
-		    Error &error);
+		    Mutex &mutex, Cond &cond);
 
 #endif

src/input/plugins/MmsInputPlugin.cxx

@@ -72,8 +72,7 @@ MmsInputStream::Open(Error &error)
 
 static InputStream *
 input_mms_open(const char *url,
-	       Mutex &mutex, Cond &cond,
-	       gcc_unused Error &error)
+	       Mutex &mutex, Cond &cond)
 {
 	if (!StringStartsWith(url, "mms://") &&
 	    !StringStartsWith(url, "mmsh://") &&

src/input/plugins/NfsInputPlugin.cxx

@@ -57,10 +57,10 @@ public:
 		DeferClose();
 	}
 
-	bool Open(Error &error) {
+	void Open() {
 		assert(!IsReady());
 
-		return NfsFileReader::Open(GetURI(), error);
+		NfsFileReader::Open(GetURI());
 	}
 
 private:
@@ -119,17 +119,10 @@ NfsInputStream::DoResume()
 		reconnect_on_resume = false;
 		reconnecting = true;
 
-		mutex.unlock();
+		ScopeUnlock unlock(mutex);
+
 		NfsFileReader::Close();
-
-		Error error;
-		bool success = NfsFileReader::Open(GetURI(), error);
-		mutex.lock();
-
-		if (!success) {
-			postponed_error = std::move(error);
-			cond.broadcast();
-		}
+		NfsFileReader::Open(GetURI());
 
 		return;
 	}
@@ -229,16 +222,17 @@ input_nfs_finish()
 
 static InputStream *
 input_nfs_open(const char *uri,
-	       Mutex &mutex, Cond &cond,
-	       Error &error)
+	       Mutex &mutex, Cond &cond)
 {
 	if (!StringStartsWith(uri, "nfs://"))
 		return nullptr;
 
 	NfsInputStream *is = new NfsInputStream(uri, mutex, cond);
-	if (!is->Open(error)) {
+	try {
+		is->Open();
+	} catch (...) {
 		delete is;
-		return nullptr;
+		throw;
 	}
 
 	return is;

src/input/plugins/SmbclientInputPlugin.cxx

@@ -24,6 +24,7 @@
 #include "../InputStream.hxx"
 #include "../InputPlugin.hxx"
 #include "PluginUnavailable.hxx"
+#include "system/Error.hxx"
 #include "util/StringCompare.hxx"
 #include "util/Error.hxx"
 
@@ -85,8 +86,7 @@ input_smbclient_init(gcc_unused const ConfigBlock &block)
 
 static InputStream *
 input_smbclient_open(const char *uri,
-		     Mutex &mutex, Cond &cond,
-		     Error &error)
+		     Mutex &mutex, Cond &cond)
 {
 	if (!StringStartsWith(uri, "smb://"))
 		return nullptr;
@@ -94,33 +94,30 @@ input_smbclient_open(const char *uri,
 	const ScopeLock protect(smbclient_mutex);
 
 	SMBCCTX *ctx = smbc_new_context();
-	if (ctx == nullptr) {
-		error.SetErrno("smbc_new_context() failed");
-		return nullptr;
-	}
+	if (ctx == nullptr)
+		throw MakeErrno("smbc_new_context() failed");
 
 	SMBCCTX *ctx2 = smbc_init_context(ctx);
 	if (ctx2 == nullptr) {
-		error.SetErrno("smbc_init_context() failed");
+		int e = errno;
 		smbc_free_context(ctx, 1);
-		return nullptr;
+		throw MakeErrno(e, "smbc_init_context() failed");
 	}
 
 	ctx = ctx2;
 
 	int fd = smbc_open(uri, O_RDONLY, 0);
 	if (fd < 0) {
-		error.SetErrno("smbc_open() failed");
+		int e = errno;
 		smbc_free_context(ctx, 1);
-		return nullptr;
+		throw MakeErrno(e, "smbc_open() failed");
 	}
 
 	struct stat st;
 	if (smbc_fstat(fd, &st) < 0) {
-		error.SetErrno("smbc_fstat() failed");
-		smbc_close(fd);
+		int e = errno;
 		smbc_free_context(ctx, 1);
-		return nullptr;
+		throw MakeErrno(e, "smbc_fstat() failed");
 	}
 
 	return new SmbclientInputStream(uri, mutex, cond, ctx, fd, st);