Hi !
I may have found something that replaces finalizers. I followed Andy and
Amirouche advices and used guardians, as in guile-sqlite3.
The idea here is to create a guardian per pointer-type to finalize. A
pumper function that operates on this guardian is also created. This
pumper function knows the git_libgit2_xxx function to call to free the
pointers stored in guardians.
Finally, all pumpers are registered into a hook that is run before
shutting down.
I tried it on "repository" pointers but it can be easily extended to the
other finalizers.
WDYT ?
Thanks,
Mathieu
>From 84bd5aa7f1c5bd01c721d475f8fdfad5533c71b5 Mon Sep 17 00:00:00 2001
From: Mathieu Othacehe <m.othac...@gmail.com>
Date: Mon, 19 Jun 2017 17:48:08 +0200
Subject: [PATCH] Replace pointer finalizer by guardians.
* git/bindings.scm (%pumpers-hook): New exported variable,
(define-element-guardian): New exported macro.
* git/repository.scm (%repository-free): Remove and replace by a call
to define-element-guardian macro.
(pointer->repository): Do not set a pointer finalizer and add the
pointer to the guardian generated by define-element-guardian
instead.
---
git/bindings.scm | 37 ++++++++++++++++++++++++++++++++++---
git/repository.scm | 4 ++--
2 files changed, 36 insertions(+), 5 deletions(-)
diff --git a/git/bindings.scm b/git/bindings.scm
index 189369e..29eab73 100644
--- a/git/bindings.scm
+++ b/git/bindings.scm
@@ -30,7 +30,9 @@
make-buffer
free-buffer
buffer-content
- buffer-content/string))
+ buffer-content/string
+ %pumpers-hook
+ define-element-guardian))
;; DRAFT!
@@ -207,8 +209,37 @@
(define libgit2-opts
(libgit2->procedure int "git_libgit2_init" `(,int)))
-(define-public libgit2-shutdown
- (libgit2->procedure int "git_libgit2_shutdown" '()))
+(define %pumpers-hook (make-hook))
+
+(define-syntax define-element-guardian
+ (lambda (x)
+ (define-syntax-rule (id ctx parts ...)
+ "Assemble PARTS into a raw (unhygienic) identifier."
+ (datum->syntax ctx (symbol-append (syntax->datum parts) ...)))
+ (syntax-case x ()
+ ((_ element finalizer hook)
+ (with-syntax
+ ((finalizer-name (id #'element #'element #'-free))
+ (guardian-name (id #'element #'element #'-guardian))
+ (pumper-name (id #'element #'pump- #'element #'-guardian)))
+ #'(begin
+ (define finalizer-name
+ (let ((proc (libgit2->procedure void finalizer '(*))))
+ (lambda (pointer)
+ (proc pointer))))
+ (define guardian-name (make-guardian))
+ (define (pumper-name)
+ (let ((pointer (guardian-name)))
+ (when pointer
+ (finalizer-name pointer)
+ (pumper-name))))
+ (add-hook! hook pumper-name)))))))
+
+(define-public (libgit2-shutdown)
+ ;; Before shutting down, try to finalize pointers kept in guardians.
+ (run-hook %pumpers-hook)
+ (let ((proc (libgit2->procedure int "git_libgit2_shutdown" '())))
+ (proc)))
(define libgit2-version
(let ((proc (libgit2->procedure void "git_libgit2_version" '(* * *))))
diff --git a/git/repository.scm b/git/repository.scm
index f82dff4..646dbe4 100644
--- a/git/repository.scm
+++ b/git/repository.scm
@@ -89,10 +89,10 @@
;; FIXME: https://libgit2.github.com/libgit2/#HEAD/group/repository/git_repository_fetchhead_foreach
-(define %repository-free (dynamic-func "git_repository_free" libgit2))
+(define-element-guardian repository "git_repository_free" %pumpers-hook)
(define (pointer->repository! pointer)
- (set-pointer-finalizer! pointer %repository-free)
+ (repository-guardian pointer)
(pointer->repository pointer))
(define repository-get-namespace
--
2.1.4
