Since OCaml 4 the old and confusing caml_enter_blocking_section and caml_leave_blocking_section calls have been replaced with caml_release_runtime_system and caml_acquire_runtime_system (in that order). Use the new names. --- generator/OCaml.ml | 5 +++-- ocaml/guestfs-c.c | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/generator/OCaml.ml b/generator/OCaml.ml index 02d9ee2e91..07ccd26924 100644 --- a/generator/OCaml.ml +++ b/generator/OCaml.ml @@ -429,6 +429,7 @@ and generate_ocaml_c () = #include <caml/memory.h> #include <caml/mlvalues.h> #include <caml/signals.h> +#include <caml/threads.h> #include <guestfs.h> #include \"guestfs-utils.h\" @@ -689,12 +690,12 @@ copy_table (char * const * argv) pr "\n"; if blocking then - pr " caml_enter_blocking_section ();\n"; + pr " caml_release_runtime_system ();\n"; pr " r = %s " c_function; generate_c_call_args ~handle:"g" style; pr ";\n"; if blocking then - pr " caml_leave_blocking_section ();\n"; + pr " caml_acquire_runtime_system ();\n"; (* Free strings if we copied them above. *) List.iter ( diff --git a/ocaml/guestfs-c.c b/ocaml/guestfs-c.c index 3888c94564..8c8aa46096 100644 --- a/ocaml/guestfs-c.c +++ b/ocaml/guestfs-c.c @@ -34,6 +34,7 @@ #include <caml/mlvalues.h> #include <caml/printexc.h> #include <caml/signals.h> +#include <caml/threads.h> #include <caml/unixsupport.h> #include "guestfs-c.h" @@ -395,12 +396,12 @@ event_callback_wrapper (guestfs_h *g, /* Ensure we are holding the GC lock before any GC operations are * possible. (RHBZ#725824) */ - caml_leave_blocking_section (); + caml_acquire_runtime_system (); event_callback_wrapper_locked (g, data, event, event_handle, flags, buf, buf_len, array, array_len); - caml_enter_blocking_section (); + caml_release_runtime_system (); } value -- 2.41.0

When finalizing the handle we call guestfs_close. This function could be long-running (eg. it may have to shut down the qemu subprocess), so release the runtime lock. --- ocaml/guestfs-c.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/ocaml/guestfs-c.c b/ocaml/guestfs-c.c index 8c8aa46096..a1865a726a 100644 --- a/ocaml/guestfs-c.c +++ b/ocaml/guestfs-c.c @@ -77,7 +77,9 @@ guestfs_finalize (value gv) * above, which is why we don't want to delete them before * closing the handle. */ + caml_release_runtime_system (); guestfs_close (g); + caml_acquire_runtime_system (); /* Now unregister the global roots. */ if (roots && len > 0) { -- 2.41.0

Link: https://discuss.ocaml.org/t/ocaml-5-forcing-objects-to-be-collected-and-f... --- ocaml/t/guestfs_065_implicit_close.ml | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/ocaml/t/guestfs_065_implicit_close.ml b/ocaml/t/guestfs_065_implicit_close.ml index f2dfecbd5c..04e511dd8a 100644 --- a/ocaml/t/guestfs_065_implicit_close.ml +++ b/ocaml/t/guestfs_065_implicit_close.ml @@ -16,6 +16,14 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *) +let () = + (* In OCaml 5, Gc.full_major does not actually collect the handle + * for unknown reasons. Skip the test until we can resolve this. + * https://discuss.ocaml.org/t/ocaml-5-forcing-objects-to-be-collected-and-f... + *) + if Sys.ocaml_version >= "5" then + exit 77 + let close_invoked = ref 0 let close _ _ _ _ = -- 2.41.0

On Wed, Jun 28, 2023 at 12:24:17PM +0200, Laszlo Ersek wrote: After further discussion with OCaml upstream I added a few more fixes. These are not actually necessary for OCaml 5 to work but they clean up a few things: https://github.com/libguestfs/libguestfs/commit/27998ecb2feab9460d4b305e3... https://github.com/libguestfs/libguestfs/commit/7d4e9c927e8478662ece204b9... https://github.com/libguestfs/libguestfs/commit/cade0b1aeb828d294a7c4e323... Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html