search for: free_callback

...tor index c52200b..d6b9352 100755 --- a/generator/generator +++ b/generator/generator @@ -3284,6 +3284,7 @@ let generate_lib_libnbd_syms () = pr "LIBNBD_%d.%d {\n" major minor; pr " global:\n"; if (major, minor) = (1, 0) then ( + pr " nbd_add_free_callback;\n"; pr " nbd_create;\n"; pr " nbd_close;\n"; pr " nbd_get_errno;\n"; @@ -3581,6 +3582,13 @@ let generate_include_libnbd_h () = pr "extern int nbd_get_errno (void);\n"; pr "#define LIBNBD_HAVE_NBD_GET_ERRNO...

...DATA, &error) == -1) cmd->error = error ? error : EPROTO; - if (cmd->cb.fn.chunk.free) - cmd->cb.fn.chunk.free (cmd->cb.fn.chunk.user_data); - cmd->cb.fn.chunk.callback = NULL; /* because we've freed it */ + FREE_CALLBACK (cmd->cb.fn.chunk); } SET_NEXT_STATE (%^FINISH_COMMAND); diff --git a/generator/states-reply-structured.c b/generator/states-reply-structured.c index 7c4d63e..62ae3ad 100644 --- a/generator/states-reply-structured.c +++ b/generator/states-reply-structured.c @@ -307,11 +307,8 @@...

...pointers to buffers > +passed to C<nbd_aio_pread>, C<nbd_aio_pwrite>, etc., > +and pointers to the C<user_data> for callbacks. If you > +want to know when it is safe to free these objects then > +you can register a free callback using: > + > + typedef void (*nbd_free_callback) (void *ptr, void *user_data); > + int nbd_add_free_callback (struct nbd_handle *h, > + void *ptr, > + nbd_free_callback cb, > + void *user_data); Do we want to insist on a user_data argument? Libvirt, fo...

....) \ (cb).callback ((cb).user_data, ##__VA_ARGS__) -/* Free a callback. - * - * Note this works for any type of callback because the basic layout - * of the struct is the same for all of them. Therefore casting cb to - * nbd_completion_callback does not change the effective code. - */ -#define FREE_CALLBACK(cb) \ - do { \ - nbd_completion_callback *_cb = (nbd_completion_callback *)&(cb); \ - if (_cb->callback != NULL && _cb->free != NULL) \ -...

On Mon, Aug 12, 2019 at 11:29:10AM -0500, Eric Blake wrote: > On 8/12/19 11:08 AM, Richard W.M. Jones wrote: > > + typedef void (*nbd_free_callback) (void *ptr, void *user_data); > > + int nbd_add_free_callback (struct nbd_handle *h, > > + void *ptr, > > + nbd_free_callback cb, > > + void *user_data); > > Do we want to insist on a us...

...ing anyway) and 57150880. I didn't see this one before implementing an alternate version here: https://www.redhat.com/archives/libguestfs/2019-August/msg00251.html https://www.redhat.com/archives/libguestfs/2019-August/msg00253.html They're fairly similar, but I didn't get rid of the FREE_CALLBACK macro for reasons which are clearer later in the series. Rich. > --- > lib/internal.h | 14 -------------- > generator/states-reply-simple.c | 1 - > generator/states-reply-structured.c | 20 +------------------- > generator/states-reply.c | 1...

When retiring a command test for a free_callback associated with their buffer. If there is one call it. This allows language bindings to use this mechanism to automatically decrement a reference to the persistent buffer (note: this patch does not implement this). The vast majority of this change is simply passing around the handle so we have i...

On 8/12/19 1:13 PM, Richard W.M. Jones wrote: > On Mon, Aug 12, 2019 at 11:29:10AM -0500, Eric Blake wrote: >> On 8/12/19 11:08 AM, Richard W.M. Jones wrote: >>> + typedef void (*nbd_free_callback) (void *ptr, void *user_data); >>> + int nbd_add_free_callback (struct nbd_handle *h, >>> + void *ptr, >>> + nbd_free_callback cb, >>> + void *user_data); >> >> Do we wan...

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.

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

...enerator/C.ml +++ b/generator/C.ml @@ -553,6 +553,19 @@ let generate_lib_api_c () = print_trace_leave ret; pr "\n" ); + (* Finish any closures not transferred to state machine. *) + List.iter ( + function + | Closure { cbname } -> + pr " FREE_CALLBACK (%s_callback);\n" cbname + | _ -> () + ) args; + List.iter ( + function + | OClosure { cbname } -> + pr " FREE_CALLBACK (%s_callback);\n" cbname + | OFlags _ -> () + ) optargs; if is_locked then ( pr " if (h->public_...

...&error) == -1) + if (CALL_CALLBACK (cmd->cb.fn.chunk, + cmd->data, cmd->count, + cmd->offset, LIBNBD_READ_DATA, + &error) == -1) cmd->error = error ? error : EPROTO; FREE_CALLBACK (cmd->cb.fn.chunk); } diff --git a/generator/states-reply-structured.c b/generator/states-reply-structured.c index 62ae3ad..2e327ce 100644 --- a/generator/states-reply-structured.c +++ b/generator/states-reply-structured.c @@ -301,10 +301,10 @@ * current error rather than any earl...

...) /* Call a callback. */ -#define CALL_CALLBACK(cb, ...) \ - (cb).callback ((cb).user_data, ##__VA_ARGS__) +#define CALL_CALLBACK(cb, ...) \ + ((cb).callback != NULL ? (cb).callback ((cb).user_data, ##__VA_ARGS__) : 0) /* Free a callback. */ -#define FREE_CALLBACK(cb) \ - do { \ - if (CALLBACK_IS_NOT_NULL (cb) && (cb).free != NULL) \ - (cb).free ((cb).user_data); \ - SET_CALLB...

As promised in my earlier thread on libnbd completion callback question. Eric Blake (2): generator: Refactor handling of closures in unlocked functions generator: Free closures on failure docs/libnbd.pod | 2 +- generator/C.ml | 48 +++++++++++------ generator/C.mli | 1 + lib/debug.c | 7 +-- lib/opt.c | 31 ++++++-----

...E (%OPT_META_CONTEXT.START); + return 0; case 0: break; default: diff --git a/lib/opt.c b/lib/opt.c index 6ea8326..2317b72 100644 --- a/lib/opt.c +++ b/lib/opt.c @@ -32,6 +32,8 @@ nbd_internal_free_option (struct nbd_handle *h) { if (h->opt_current == NBD_OPT_LIST) FREE_CALLBACK (h->opt_cb.fn.list); + else if (h->opt_current == NBD_OPT_LIST_META_CONTEXT) + FREE_CALLBACK (h->opt_cb.fn.context); FREE_CALLBACK (h->opt_cb.completion); } @@ -166,6 +168,51 @@ nbd_unlocked_opt_list (struct nbd_handle *h, nbd_list_callback *list) return s.count; } +struct...

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 less obviously useful. Rich.

I'm posting this now, as I'm at the end of a workday and I got things working for manual experimentation. Still to do: - write interop tests for qemu-nbd and nbdkit (including my proposed patch addition of qemu-nbd -A to show qemu:allocation-depth) - figure out if we can make 'nbdinfo --map' use the new API to automatically select all contexts advertised by the server Eric Blake

...) \ > - (cb).callback ((cb).user_data, ##__VA_ARGS__) > +#define CALL_CALLBACK(cb, ...) \ > + ((cb).callback != NULL ? (cb).callback ((cb).user_data, ##__VA_ARGS__) : 0) This one is nice, though. > > /* Free a callback. */ > -#define FREE_CALLBACK(cb) \ > - do { \ > - if (CALLBACK_IS_NOT_NULL (cb) && (cb).free != NULL) \ > - (cb).free ((cb).user_data); \...

...loc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL); if (!io_callbacks) { - err = -ENOMEM; goto free_vqs; } io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL); if (!io_names) { - err = -ENOMEM; goto free_callbacks; } portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), GFP_KERNEL); if (!portdev->in_vqs) { - err = -ENOMEM; goto free_names; } portdev->out_vqs = kmalloc(nr_ports * sizeof...

...loc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL); if (!io_callbacks) { - err = -ENOMEM; goto free_vqs; } io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL); if (!io_names) { - err = -ENOMEM; goto free_callbacks; } portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), GFP_KERNEL); if (!portdev->in_vqs) { - err = -ENOMEM; goto free_names; } portdev->out_vqs = kmalloc(nr_ports * sizeof...