Crate winmmf_ffi 

An FFI interface for WinMMF

The recommended way of working with this interface is to call open (or new) and then immediately read with an explicit count of 0. Reuse the pointer provided for all subsequent reads by calling read_buf, and then freeing it with free_result, most likely with other teardown and exit steps for your program. Alternatively, you could just bring your own pointers. Just make sure they’re all valid.

If the lifetime for any MMFs should be &'static or longer than the execution context (e.g. you only open MMFs created by a system service), it’s possible to leave cleanup to the OS. No guarantees are made if or when that happens, other than that cleanup will be done between program exit and system shutdown. If nobody is using the MMF anymore, and all relevant programs have finished their main function (regardless of exit status), the system should free up lingering handles with no active processes before erroring on the resource limit getting hit.

During the lifetime of your program, if you decide to close any MMFs, they will be ejected from the inner collection. Should you need to reopen one, and you’re sure other handles to it yet live in the system, you can open it anew and your data should be there unchanged. Should you forget to free a pointer, use free_raw at your own risk.

If you need to use several MMFs at once in your code, you can. Beware that tracking their indices is entirely at your own risk though. Should you know which indices you need, and do you plan to use the same one for extended periods of time, then select one for use with select_default.

Enums

ValidNamespaces

Namespaces as an enum, to unambiguously represent relevant information.

Functions

close

Close the MMF

free_raw^⚠

You had better know how big that thing is.

free_result^⚠

Free a pointer used for reading from an MMF by its index number.

init

Initialize the inner object to hold MMF instances.

new

Create a new MMF and push it into the list, returning the new index or an error indicator.

open

Open an existing MMF and push it into the list, returning its index or an error indicator.

open_ro

Convenience function to open a read-only MMF and get an index back to read from it.

read

Read count bytes or all contents from the MMF and give back a pointer to the data.

read_buf^⚠

Read count bytes from the MMF into the provided buffer.

select_default

Selects a different default mmf for all operations.

write^⚠

Expose writing data as well. Slightly less complex for FFI purposes than reading.