similar to: [PATCH libnbd] generator: Add Mutable type to the generator.

[RFC because generated OCaml code needs the same treatment, but I ran out of time to play with that. At least 'make -C python check' passes, although coverage is not complete yet, as there is no python/t/5XX-pread-structured-callback.py...] [Also RFC because I'm not sure if the use of a record type for 'callback' is the best approach or most idiomatic OCaml - but hey, it

A Closure is a list of (usually one, but can be more) closures. In C there is also a singe ‘void *user_data’ parameter which is passed by the caller into the function and through as the first parameter of each callback invocation. By grouping the previously separate Opaque and Callback* parameters together we can avoid the awkward situation where we have to scan through the argument list to try

If we accept that callbacks will never handle the full range of parameters then we can simplify the generator quite a bit by using a special type for closure args vs normal method args. This removes many asserts and quite a bit of unreachable code (eg. Python code for handling ArrayAndLen in normal methods that was never used). The output of the generator after this commit should be identical.

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 +- examples/strict-structured-reads.c | 2 +- generator/generator | 760

Posting now that I got something to compile (at the expense of breaking OCaml bindings), but I'm open to ideas on how to improve it. Eric Blake (2): generator: Tweak print_c_arg_list to take alternate first arg RFC: generator: Handle shared callbacks in Python generator/generator | 556 ++++++++++++++++++++++---------------------- 1 file changed, 280 insertions(+), 276 deletions(-) --

An upcoming patch to add callbacks for aio completion notification wants to expose Int64 as a callback parameter. It's time to wire that up. --- generator/generator | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/generator/generator b/generator/generator index 45a030f..c5988e2 100755 --- a/generator/generator +++ b/generator/generator @@ -3508,7

An upcoming patch to add callbacks during structured reads wants to expose Int as a callback parameter. It's time to wire that up. --- generator/generator | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/generator/generator b/generator/generator index e1a97a5..2d1a4e5 100755 --- a/generator/generator +++ b/generator/generator @@ -3260,7 +3260,8

Time to wire up user access to react to structured reads as the chunks come in, exposing the framework added in the last patch. I chose to use an int for the callback status rather than an enum for ease of wiring things up to the various language bindings. Still, it required quite a few tweaks to the generator to support an Int type in a callback. It's easy to test callback behavior for

On Mon, Jun 17, 2019 at 07:07:56PM -0500, Eric Blake wrote: > diff --git a/generator/generator b/generator/generator > index 2614689..ce77f17 100755 > --- a/generator/generator > +++ b/generator/generator > @@ -1305,7 +1305,72 @@ Issue a read command to the NBD server for the range starting > at C<offset> and ending at C<offset> + C<count> - 1. NBD > can

--- docs/libnbd.pod | 73 +++++++++++++++++++++++++++++++++++++++++++++ generator/generator | 52 +++++++++++++++++++++++++++----- lib/handle.c | 32 ++++++++++++++++++++ lib/internal.h | 7 +++++ lib/socket.c | 22 +++++++++++--- podwrapper.pl.in | 3 +- 6 files changed, 177 insertions(+), 12 deletions(-) diff --git a/docs/libnbd.pod b/docs/libnbd.pod index

This is a bitmask so using an unsigned type is slightly safer. This is not an ABI change since the types are compatible. Thanks: Eric Blake. --- examples/strict-structured-reads.c | 2 +- generator/generator | 67 ++++++++++++++++-------------- interop/structured-read.c | 2 +- lib/internal.h | 2 +- tests/oldstyle.c | 2 +- 5

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.

Exploration of what it would take to treat the nbd_pread_callback status parameter as a language-appropriate enum rather than a bare integer. While I've identified a rough set of the places to change, I have not actually got it working with Python or OCaml bindings. --- Posting this more for an idea of whether we want to pursue it further. I have no hard feelings if we decide to ditch it;

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 Mon, Jun 17, 2019 at 08:39:43PM -0500, Eric Blake wrote: > Exploration of what it would take to treat the nbd_pread_callback > status parameter as a language-appropriate enum rather than a bare > integer. While I've identified a rough set of the places to change, I > have not actually got it working with Python or OCaml bindings. > --- > > Posting this more for an

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.

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

On 6/25/19 12:11 PM, Richard W.M. Jones wrote: > Mutable (Int n) => int *n > > This can currently only be used for callback arguments of type int > (not for other types, nor for any ordinary function arguments), but it > could be implemented more generally in future. > --- > generator/generator | 75 +++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 63

In libguestfs generator we have the concept of optargs which is different from plain arguments. These are mapped to optional arguments in languages that support them such as Python. This commit adds a new concept of optargs. At the moment it is simply limited to handling the optional (in some bindings) flags parameter which is used to handle the NBD_CMD_FLAG_* flags. If present, the old Flags