PathBrowser: Abandon a network listing when navigating away

PathBrowser lists on one thread, so going up from the network folder
waited for its listing to finish (up to 8 seconds) before the drive list
showed. Pass GetFilesInDir a cancel flag that PathBrowser sets whenever
the path changes, or on destruction, and check it while waiting.

Also don't probe the drives in the drive list for game folders.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Common/File/DirListing.cpp

@@ -145,10 +145,11 @@ struct NetListing {
 // Network calls can block for a long time (half a minute for the shell's network folder, even after it
 // has found everything), and can't be cancelled. So run them on a thread of their own, and abandon it
 // when the deadline passes, or when it has found something and then gone quiet for a while.
-static bool ListNetworkWithTimeout(const Path &directory, std::function<bool(NetListing &)> func, std::vector<FileInfo> *files) {
+static bool ListNetworkWithTimeout(const Path &directory, std::function<bool(NetListing &)> func, std::vector<FileInfo> *files, const bool *cancel) {
 	// Servers turn up in the network folder after 2 to 6 seconds.
 	constexpr auto timeout = std::chrono::seconds(8);
 	constexpr auto quietTime = std::chrono::seconds(1);
+	constexpr auto cancelPollTime = std::chrono::milliseconds(20);
 	auto listing = std::make_shared<NetListing>();
 	std::thread([listing, func] {
 		SetCurrentThreadName("NetListing");
@@ -166,11 +167,15 @@ static bool ListNetworkWithTimeout(const Path &directory, std::function<bool(Net
 		if (!listing->files.empty()) {
 			wakeup = std::min(deadline, listing->lastAdd + quietTime);
 		}
-		if (std::chrono::steady_clock::now() >= wakeup) {
+		if (cancel && *cancel) {
+			return false;
+		}
+		const auto now = std::chrono::steady_clock::now();
+		if (now >= wakeup) {
 			INFO_LOG(Log::IO, "Stopped waiting for the listing of %s, found %d entries", directory.c_str(), (int)listing->files.size());
 			break;
 		}
-		listing->cond.wait_until(guard, wakeup);
+		listing->cond.wait_until(guard, cancel ? std::min(wakeup, now + cancelPollTime) : wakeup);
 	}
 	files->insert(files->end(), listing->files.begin(), listing->files.end());
 	return listing->success || !listing->files.empty();
@@ -387,7 +392,7 @@ std::vector<File::FileInfo> ApplyFilter(std::vector<File::FileInfo> files, const
 	return files;
 }
 
-bool GetFilesInDir(const Path &directory, std::vector<FileInfo> *files, const char *filter, int flags, std::string_view prefix) {
+bool GetFilesInDir(const Path &directory, std::vector<FileInfo> *files, const char *filter, int flags, std::string_view prefix, const bool *cancel) {
 	if (LOG_IO) {
 		INFO_LOG(Log::IO, "GetFilesInDir '%s' (ext %s, prefix %.*s)", directory.ToVisualString().c_str(), filter, (int)prefix.size(), prefix.data());
 	}
@@ -452,11 +457,11 @@ bool GetFilesInDir(const Path &directory, std::vector<FileInfo> *files, const ch
 		if (server.empty()) {
 			success = ListNetworkWithTimeout(directory, [prefixCopy](NetListing &listing) {
 				return GetNetworkServers(prefixCopy, listing);
-			}, files);
+			}, files, cancel);
 		} else {
 			success = ListNetworkWithTimeout(directory, [directory, server, prefixCopy](NetListing &listing) {
 				return GetUNCServerShares(directory, server, prefixCopy, listing);
-			}, files);
+			}, files, cancel);
 		}
 		std::sort(files->begin(), files->end());
 		return success;

Common/File/DirListing.h

@@ -41,7 +41,8 @@ enum {
 };
 
 // Note: extensionFilter is ignored for directories, so you can recurse.
-bool GetFilesInDir(const Path &directory, std::vector<FileInfo> *files, const char *extensionFilter = nullptr, int flags = 0, std::string_view prefix = std::string_view());
+// cancel is only checked while waiting for a network listing (Windows), which can take seconds.
+bool GetFilesInDir(const Path &directory, std::vector<FileInfo> *files, const char *extensionFilter = nullptr, int flags = 0, std::string_view prefix = std::string_view(), const bool *cancel = nullptr);
 std::vector<File::FileInfo> ApplyFilter(std::vector<File::FileInfo> files, const char *extensionFilter, std::string_view prefix);
 
 #ifdef _WIN32

Common/File/PathBrowser.cpp

@@ -115,6 +115,7 @@ PathBrowser::~PathBrowser() {
 		std::unique_lock<std::mutex> guard(pendingLock_);
 		pendingCancel_ = true;
 		pendingStop_ = true;
+		listingAbort_ = true;
 		pendingCond_.notify_all();
 	}
 	if (pendingThread_.joinable()) {
@@ -136,6 +137,10 @@ void PathBrowser::RestrictToRoot(const Path &root) {
 }
 
 void PathBrowser::HandlePath() {
+	// Asking for the path that's being listed again shouldn't restart it.
+	if (path_ != pendingPath_) {
+		listingAbort_ = true;
+	}
 	if (!path_.empty() && path_.ToString()[0] == '!') {
 		if (pendingActive_) {
 			pendingCancel_ = true;
@@ -171,6 +176,7 @@ void PathBrowser::HandlePath() {
 				break;
 			}
 			lastPath = pendingPath_;
+			listingAbort_ = false;
 			if (lastPath.Type() == PathType::HTTP) {
 				std::string userAgentCopy = userAgent_;
 				guard.unlock();
@@ -184,8 +190,13 @@ void PathBrowser::HandlePath() {
 			} else {
 				guard.unlock();
 				results.clear();
-				bool tempSuccess = File::GetFilesInDir(lastPath, &results, nullptr);
+				bool tempSuccess = File::GetFilesInDir(lastPath, &results, nullptr, 0, std::string_view(), &listingAbort_);
 				guard.lock();
+				if (listingAbort_) {
+					// We navigated away, maybe and back again, in which case this lists it again.
+					lastPath.clear();
+					continue;
+				}
 				success_ = tempSuccess;
 				if (!success_) {
 					WARN_LOG(Log::IO, "PathBrowser: Failed to list directory: %s", lastPath.c_str());

Common/File/PathBrowser.h

@@ -68,6 +68,8 @@ private:
 	bool pendingActive_ = false;
 	bool pendingCancel_ = false;
 	bool pendingStop_ = false;
+	// Abandons a slow listing (network) when the path changes.
+	bool listingAbort_ = false;
 	bool ready_ = false;
 	bool success_ = true;
 };

UI/GameBrowser.cpp

@@ -1133,8 +1133,8 @@ void GameBrowser::Refresh() {
 		path_.GetListing(fileInfo, "iso:cso:chd:pbp:elf:prx:ppdmp:cue:ccd:mds:bin:img:");
 		// PS1 discs: a .bin or .img shows up as its cue sheet or .ccd, when it has one.
 		RemoveDescribedDiscImages(&fileInfo);
-		// Servers aren't games, and probing one that's gone away can take seconds.
-		const bool probeDirs = !path_.GetPath().IsNetworkRoot();
+		// Drives and servers aren't games, and probing a server that's gone away can take seconds.
+		const bool probeDirs = !path_.GetPath().IsRoot() && !path_.GetPath().IsNetworkRoot();
 		for (size_t i = 0; i < fileInfo.size(); i++) {
 			bool isGame = !fileInfo[i].isDirectory;
 			bool isSaveData = false;