Very slow writing speed / Always synchronised writing

[cryptomator]

Very slow writing speed / Always synchronised writing

[overheadhunter]

For the record here is some more information regarding the difference between SYNC and SYNCHRONIZE.

What SYNC means for Java NIO

In the Java world, SYNC is used as a flag during creation of a file handle to request every change to be persisted immediately without caching etc:

Requires that every update to the file's content or metadata be written synchronously to the underlying storage device.

~Source

What SYNCHRONIZE means for Microsoft

In the Microsoft world, the SYNCHRONIZE access right is defined as:

The right to use the object for synchronization. This enables a thread to wait until the object is in the signaled state.

~ Source

This sounds a lot like the wait/notify mechanism in the Java world. I.e. the filehandle can be used as a semaphore.

Each time an I/O operation is started, the operating system sets the file handle to the nonsignaled state. Each time an I/O operation is completed, the operating system sets the file handle to the signaled state.

~ Source

More on this topic can be found here.

How to request uncached write using win32 APIs

What comes closest to the Java SYNC flag is probably FILE_FLAG_WRITE_THROUGH or FILE_FLAG_NO_BUFFERING as defined in the win32 file API.