From: Michael Tremer <michael.tremer@ipfire.org>
Date: Mon, 9 May 2022 08:42:02 +0000 (+0000)
Subject: pakfire: Add function to reset all callbacks
X-Git-Tag: 0.9.28~813
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d122626c91aa93488bc47b94d6d6ec7ec8fb4d95;p=pakfire.git

pakfire: Add function to reset all callbacks

When we call pakfire from Python, we will pass some callbacks which we
will hold a reference to. If those are being freed but Pakfire isn't we
might call the freed callback.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/_pakfire/pakfire.c b/src/_pakfire/pakfire.c
index bb6ab635f..108fa4511 100644
--- a/src/_pakfire/pakfire.c
+++ b/src/_pakfire/pakfire.c
@@ -252,22 +252,17 @@ static int Pakfire_init(PakfireObject* self, PyObject* args, PyObject* kwds) {
 }
 
 static void Pakfire_dealloc(PakfireObject* self) {
-	if (self->pakfire)
-		pakfire_unref(self->pakfire);
+	if (self->pakfire) {
+		// Drop references to all callbacks
+		pakfire_reset_all_callbacks(self->pakfire);
 
-#if 0
-	/*
-		It might happen, that the Pakfire python object is deallocated but the
-		actual struct pakfire object isn't yet. However, it might still happen
-		that the logging function is called which will try to call the logging
-		callback which has already been deallocated.
+		pakfire_unref(self->pakfire);
+	}
 
-		TODO This has to move into struct pakfire or something similar.
-	*/
+	// Free callbacks
 	Py_XDECREF(self->callbacks.log);
 	Py_XDECREF(self->callbacks.status);
 	Py_XDECREF(self->callbacks.progress);
-#endif
 
 	Py_TYPE(self)->tp_free((PyObject *)self);
 }
diff --git a/src/libpakfire/include/pakfire/pakfire.h b/src/libpakfire/include/pakfire/pakfire.h
index 0f33b7084..2261d9f42 100644
--- a/src/libpakfire/include/pakfire/pakfire.h
+++ b/src/libpakfire/include/pakfire/pakfire.h
@@ -71,6 +71,7 @@ int pakfire_create(struct pakfire** pakfire, const char* path, const char* arch,
 
 struct pakfire* pakfire_ref(struct pakfire* pakfire);
 struct pakfire* pakfire_unref(struct pakfire* pakfire);
+void pakfire_reset_all_callbacks(struct pakfire* pakfire);
 
 const char* pakfire_get_path(struct pakfire* pakfire);
 
diff --git a/src/libpakfire/libpakfire.sym b/src/libpakfire/libpakfire.sym
index c87b7b539..174821203 100644
--- a/src/libpakfire/libpakfire.sym
+++ b/src/libpakfire/libpakfire.sym
@@ -39,6 +39,7 @@ global:
 	pakfire_list_keys;
 	pakfire_ref;
 	pakfire_refresh;
+	pakfire_reset_all_callbacks;
 	pakfire_search;
 	pakfire_sync;
 	pakfire_unref;
diff --git a/src/libpakfire/pakfire.c b/src/libpakfire/pakfire.c
index 576f2adda..7aea65260 100644
--- a/src/libpakfire/pakfire.c
+++ b/src/libpakfire/pakfire.c
@@ -879,6 +879,9 @@ PAKFIRE_EXPORT int pakfire_create(struct pakfire** pakfire, const char* path,
 	p->nrefs = 1;
 	p->flags = flags;
 
+	// Initialize callbacks
+	pakfire_reset_all_callbacks(p);
+
 	// Copy callbacks
 	if (callbacks) {
 		if (callbacks->data)
@@ -894,10 +897,6 @@ PAKFIRE_EXPORT int pakfire_create(struct pakfire** pakfire, const char* path,
 			p->callbacks.progress = callbacks->progress;
 	}
 
-	// Log to syslog by default
-	if (!p->callbacks.log)
-		p->callbacks.log = pakfire_log_syslog;
-
 	// Set architecture
 	pakfire_string_set(p->arch, arch);
 
@@ -1065,6 +1064,24 @@ PAKFIRE_EXPORT struct pakfire* pakfire_unref(struct pakfire* pakfire) {
 	return NULL;
 }
 
+/*
+	Drops all callbacks.
+
+	This is useful when Pakfire is being called from Python and we cannot
+	determine the order when things are being freed.
+*/
+PAKFIRE_EXPORT void pakfire_reset_all_callbacks(struct pakfire* pakfire) {
+	pakfire->callbacks.data = NULL;
+
+	// Reset callbacks
+	pakfire->callbacks.status = NULL;
+	pakfire->callbacks.progress = NULL;
+	pakfire->callbacks.speed = NULL;
+
+	// Log to syslog by default
+	pakfire->callbacks.log = pakfire_log_syslog;
+}
+
 int pakfire_has_flag(struct pakfire* pakfire, int flag) {
 	return pakfire->flags & flag;
 }