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# Proposed

## <a name="futex">Futex</a>

Add a futex kernel trap to GNU Mach.
This can be useful for nicer locking
primitives, including inter-process primitives. `vm_allocate` can be used as an
example in the `gnumach` source tree for how to add a kernel trap. 


### [[!GNU_Savannah_task 6231]]

### Patches on bug-hurd

### IRC, freenode, #hurd, 2014-01-20

    <teythoon> braunr: i meant to ask about the futex stuff
    <teythoon> what do you mean when you talk about the interface ?
    <teythoon> i imagined something like this
    <braunr> more precisely ?
    <teythoon> for shared futexes, do not use a pointer, but a right
      referencing a memory object, and the offset ?
    <braunr> why not a pointer ?
    <braunr> well, an address
    <teythoon> that's how it's currently done, right ?
    <teythoon> in marins prototype i mean
    <braunr> yes
    <braunr> it's a task/address pair
    <teythoon> so the only concern is the access in the kernel ?
    <braunr> hum not only no
    <braunr> or yes, but there are multiple ways to access
    <teythoon> i meant to say this, for me, it would be very helpful if you
      were more explicit when you describe how you picture something
    <braunr> i thought i did it clearly
    <braunr> i even agree with what roland describes
    <braunr> which looks even clearer
    <braunr> also, i said i didn't picture it completely
    <braunr> :)
    <braunr> i didn't want to work on that, only review
    <teythoon> sure, but what might be clear to you is most likely not that
      clear to me
    <braunr> ok