[stable-3.14] Fix stuttering and freezing of client while computing sync state changes (macOS VFS)

src/gui/macOS/fileproviderxpc.h

@@ -12,8 +12,9 @@
  * for more details.
  */
 
 #include <QObject>
 #include <QHash>
+#include <QDateTime>
 
 #include "accountstate.h"
 
@@ -34,7 +35,7 @@
 public:
     explicit FileProviderXPC(QObject *parent = nullptr);
 
-    [[nodiscard]] bool fileProviderExtReachable(const QString &extensionAccountId) const;
+    [[nodiscard]] bool fileProviderExtReachable(const QString &extensionAccountId);
 
     // Returns enabled and set state of fast enumeration for the given extension
     [[nodiscard]] std::optional<std::pair<bool, bool>> fastEnumerationStateForExtension(const QString &extensionAccountId) const;
@@ -53,6 +54,7 @@
 
 private:
     QHash<QString, void*> _clientCommServices;
+    QHash<QString, QDateTime> _unreachableAccountExtensions;
 };
 
 } // namespace OCC::Mac

src/gui/macOS/fileproviderxpc_mac.mm

@@ -21,7 +21,8 @@
 #include "gui/macOS/fileproviderxpc_mac_utils.h"
 
 namespace {
-    constexpr int64_t semaphoreWaitDelta = 3000000000; // 3 seconds
+    constexpr int64_t semaphoreWaitDelta = 1000000000; // 1 seconds
+    constexpr auto reachableRetryTimeout = 300; // seconds
 }
 
 namespace OCC::Mac {
@@ -143,19 +144,34 @@
     }
 }
 
-bool FileProviderXPC::fileProviderExtReachable(const QString &extensionAccountId) const
+bool FileProviderXPC::fileProviderExtReachable(const QString &extensionAccountId)
 {
+    const auto lastUnreachableTime = _unreachableAccountExtensions.value(extensionAccountId);
+    if (lastUnreachableTime.isValid() && lastUnreachableTime.secsTo(QDateTime::currentDateTime()) < ::reachableRetryTimeout) {
+        qCInfo(lcFileProviderXPC) << "File provider extension was unreachable less than a minute ago. "
+                                  << "Not checking again";
+        return false;
+    }
+
     const auto service = (NSObject<ClientCommunicationProtocol> *)_clientCommServices.value(extensionAccountId);
     if (service == nil) {
         return false;
     }
+
     __block auto response = false;
     dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
     [service getExtensionAccountIdWithCompletionHandler:^(NSString *const, NSError *const) {
         response = true;
         dispatch_semaphore_signal(semaphore);
     }];
     dispatch_semaphore_wait(semaphore, dispatch_time(DISPATCH_TIME_NOW, semaphoreWaitDelta));
+
+    if (response) {
+        _unreachableAccountExtensions.remove(extensionAccountId);
+    } else {
+        qCWarning(lcFileProviderXPC) << "Could not reach file provider extension.";
+        _unreachableAccountExtensions.insert(extensionAccountId, QDateTime::currentDateTime());
+    }
     return response;
 }