similar to: [PATCH libnbd v3 0/2] lib: Implement closure lifetimes.

This implements most of what I wrote here: https://www.redhat.com/archives/libguestfs/2019-July/msg00213.html

v1 was here: https://www.redhat.com/archives/libguestfs/2019-July/thread.html#00231 The changes address everything that Eric picked up in his review of the first two patches. I have also added two more patches (4 and 5) which respectively fix docs and change int status -> unsigned status, as discussed. Passes make, check, check-valgrind. Rich.

Patches 1 & 2 are rather complex, but the end result is that we pass closures + user_data + free function in single struct parameters as I described previously in this email: https://www.redhat.com/archives/libguestfs/2019-August/msg00210.html Patch 3 adds a convenient FREE_CALLBACK macro which seems a worthwhile simplification if you buy into 1 & 2. Patch 4 adds another macro which is

As proposed here: https://www.redhat.com/archives/libguestfs/2019-August/msg00130.html I didn't actually read Eric's replies to that yet because I've been concentrating on writing these patches all day. Anyway here they are and I'll look at what Eric said about the proposal next. Rich.

On 7/24/19 7:17 AM, Richard W.M. Jones wrote: > Previously closures had a crude flag which tells if they are > persistent or transient. Transient closures (flag = false) last for > the lifetime of the currently called libnbd function. Persistent > closures had an indefinite lifetime which could last for as long as > the handle. In language bindings handling persistent closures

Patches 1-4 are basically uncontroversial, straightforward refactoring and IMHO we should just push them. Possibly 1-3 should be squashed together, but I posted them separately so they are easier to review. Patches 5 and 6 together implement OClosure. Patch 5 adds the feature and is simple to understand. Patch 6 changes the Closure completion callbacks into OClosure, but because it doesn't

These are some simplifications to the generator. They don't probably make much sense on their own, but they are preparatory to better handling of enums, and or'd lists of flags. Rich.

For example nbd_set_debug takes a callback function. Previously this was defined explicitly inside the function parameters. This commit defines a new public typedef: typedef int (*nbd_debug_callback) (unsigned valid_flag, void *user_data, const char *context, const char *msg); and then uses the typedef like this: extern int nbd_set_debug_callback

On 7/24/19 7:17 AM, Richard W.M. Jones wrote: > Previously closures had a crude flag which tells if they are > persistent or transient. Transient closures (flag = false) last for > the lifetime of the currently called libnbd function. Persistent > closures had an indefinite lifetime which could last for as long as > the handle. In language bindings handling persistent closures

On Mon, Jul 22, 2019 at 10:08:25AM +0100, Richard W.M. Jones wrote: > On Sat, Jul 20, 2019 at 07:38:45AM +0100, Richard W.M. Jones wrote: > > More thoughts on callbacks, etc. following on from: > > https://www.redhat.com/archives/libguestfs/2019-July/thread.html#00184 > > > > Closure lifetimes > > ----------------- Here's a possibly better idea which still

On 7/25/19 8:07 AM, Richard W.M. Jones wrote: > Previously closures had a crude flag which tells if they are > persistent or transient. Transient closures (flag = false) last for > the lifetime of the currently called libnbd function. Persistent > closures had an indefinite lifetime which could last for as long as > the handle. In language bindings handling persistent closures

More thoughts on callbacks, etc. following on from: https://www.redhat.com/archives/libguestfs/2019-July/thread.html#00184 Closure lifetimes ----------------- Closures could have a lifetime if we had a little bit of support from the C library. We would generate (from C only): nbd_set_free_<fn>_<closure> (nbd, free_closure); which calls free_closure (user_data) as soon as the

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to

As before, but this one has working Python bindings. OCaml still TBD. Rich.

On 7/24/19 11:54 AM, Richard W.M. Jones wrote: > Previously closures had a crude flag which tells if they are > persistent or transient. Transient closures (flag = false) last for > the lifetime of the currently called libnbd function. Persistent > closures had an indefinite lifetime which could last for as long as > the handle. In language bindings handling persistent closures

Previously closures had a crude flag which tells if they are persistent or transient. Transient closures (flag = false) last for the lifetime of the currently called libnbd function. Persistent closures had an indefinite lifetime which could last for as long as the handle. In language bindings handling persistent closures was wasteful as we needed to register a "close callback" to

On 7/24/19 7:17 AM, Richard W.M. Jones wrote: > In preparation for closure lifetimes, split up the Closure so it no > longer describes a list of closures, but a single callback. > > This changes the API because functions which take 2 or more closures > now pass a separate user_data for each one. > --- > docs/libnbd.pod | 3 +- >

This is a combination of these two earlier series: https://www.redhat.com/archives/libguestfs/2019-August/msg00235.html https://www.redhat.com/archives/libguestfs/2019-August/msg00240.html plus changes to allow .callback = NULL / .free != NULL, and to reduce the complexity of freeing callbacks. Although it's rather long there's nothing complex here. We might consider squashing some

Basically the same as this patch series, but for Python: https://www.redhat.com/archives/libguestfs/2019-August/msg00235.html plus adding the 590 asynch test at the end. Rich.