pylibmount: add debug messages

Signed-off-by: Karel Zak <kzak@redhat.com>

libmount/python/context.c

@@ -1224,6 +1224,8 @@ void Context_AddModuleObject(PyObject *mod)
 	if (PyType_Ready(&ContextType) < 0)
 		return;
 
+	DBG(CXT, pymnt_debug("add to module"));
+
 	Py_INCREF(&ContextType);
 	PyModule_AddObject(mod, "Context", (PyObject *)&ContextType);
 }

libmount/python/fs.c

@@ -571,9 +571,10 @@ static PyMethodDef Fs_methods[] = {
 	{NULL}
 };
 
-static void Fs_dealloc(FsObject *self)
+static void Fs_destructor(FsObject *self)
 {
-	fprintf(stderr, "KZAK: [%p] delalocate\n", self->fs);
+	DBG(FS, pymnt_debug_h(self->fs, "destrutor py-obj: %p, py-refcnt=%d",
+				self, (int) ((PyObject *) self)->ob_refcnt));
 	mnt_unref_fs(self->fs);
 	self->ob_type->tp_free((PyObject*)self);
 }
@@ -583,8 +584,10 @@ static PyObject *Fs_new(PyTypeObject *type, PyObject *args __attribute__((unused
 {
 	FsObject *self = (FsObject*)type->tp_alloc(type, 0);
 
-	if (self)
+	if (self) {
 		self->fs = NULL;
+		DBG(FS, pymnt_debug_h(self, "new"));
+	}
 	return (PyObject *) self;
 }
 
@@ -606,6 +609,9 @@ static int Fs_init(FsObject *self, PyObject *args, PyObject *kwds)
 		PyErr_SetString(PyExc_TypeError, "Invalid type");
 		return -1;
 	}
+
+	DBG(FS, pymnt_debug_h(self, "init"));
+
 	if (self->fs)
 		mnt_unref_fs(self->fs);
 
@@ -701,6 +707,8 @@ PyObject *PyObjectResultFs(struct libmnt_fs *fs)
 	result = mnt_fs_get_userdata(fs);
 	if (result) {
 		Py_INCREF(result);
+		DBG(FS, pymnt_debug_h(fs, "result py-obj %p: already exists, py-refcnt=%d",
+				result, (int) ((PyObject *) result)->ob_refcnt));
 		return (PyObject *) result;
 	}
 
@@ -717,6 +725,8 @@ PyObject *PyObjectResultFs(struct libmnt_fs *fs)
 	Py_INCREF(result);
 	mnt_ref_fs(fs);
 
+	DBG(FS, pymnt_debug_h(fs, "result py-obj %p new, py-refcnt=%d",
+				result, (int) ((PyObject *) result)->ob_refcnt));
 	result->fs = fs;
 	mnt_fs_set_userdata(fs, result);
 	return (PyObject *) result;
@@ -734,10 +744,13 @@ static PyObject *Fs_copy_fs(FsObject *self, PyObject *args, PyObject *kwds)
 	if (PyObject_TypeCheck(dest, &FsType)) {	/* existing object passed as argument */
 		if (!mnt_copy_fs(((FsObject *)dest)->fs, self->fs))
 			return NULL;
+		DBG(FS, pymnt_debug_h(dest, "copy data"));
 		return (PyObject *)dest;
 
 	} else if (dest == Py_None) {			/* create new object */
 		FsObject *result = PyObject_New(FsObject, &FsType);
+
+		DBG(FS, pymnt_debug_h(result, "new copy"));
 		result->fs = mnt_copy_fs(NULL, self->fs);
 		mnt_fs_set_userdata(result->fs, result);	/* keep a pointer to encapsulating object */
 		return (PyObject *)result;
@@ -754,7 +767,7 @@ PyTypeObject FsType = {
 	"libmount.Fs", /*tp_name*/
 	sizeof(FsObject), /*tp_basicsize*/
 	0, /*tp_itemsize*/
-	(destructor)Fs_dealloc, /*tp_dealloc*/
+	(destructor)Fs_destructor, /*tp_dealloc*/
 	0, /*tp_print*/
 	0, /*tp_getattr*/
 	0, /*tp_setattr*/
@@ -795,6 +808,7 @@ void FS_AddModuleObject(PyObject *mod)
 	if (PyType_Ready(&FsType) < 0)
 		return;
 
+	DBG(FS, pymnt_debug("add to module"));
 	Py_INCREF(&FsType);
 	PyModule_AddObject(mod, "Fs", (PyObject *)&FsType);
 }

libmount/python/pylibmount.c

@@ -22,6 +22,8 @@
 
 /* Libmount-specific Exception class */
 PyObject *LibmountError;
+int pylibmount_debug_mask;
+
 
 PyObject *UL_IncRef(void *killme)
 {
@@ -130,9 +132,27 @@ PyMODINIT_FUNC initpylibmount(void)
 
 	if (!m)
 		return;
+	/*
+	 * init debug stuff
+	 */
+	if (!(pylibmount_debug_mask & PYMNT_DEBUG_INIT)) {
+		char *str = getenv("PYLIBMOUNT_DEBUG");
 
-	/*mnt_init_debug(0xffff);*/
+		pylibmount_debug_mask = 0;
+		if (str)
+			pylibmount_debug_mask = strtoul(str, 0, 0);
 
+		pylibmount_debug_mask |= PYMNT_DEBUG_INIT;
+	}
+
+	if (pylibmount_debug_mask && pylibmount_debug_mask != PYMNT_DEBUG_INIT)
+		DBG(INIT, pymnt_debug("library debug mask: 0x%04x",
+					pylibmount_debug_mask));
+	mnt_init_debug(0);
+
+	/*
+	 * Add module objects
+	 */
 	LibmountError = PyErr_NewException("libmount.Error", NULL, NULL);
 	Py_INCREF(LibmountError);
 	PyModule_AddObject(m, "Error", (PyObject *)LibmountError);

libmount/python/pylibmount.h

@@ -6,6 +6,54 @@
 
 #include "libmount.h"
 
+#define CONFIG_PYLIBMOUNT_DEBUG
+
+#define PYMNT_DEBUG_INIT	(1 << 1)
+#define PYMNT_DEBUG_TAB		(1 << 2)
+#define PYMNT_DEBUG_FS		(1 << 3)
+#define PYMNT_DEBUG_CXT		(1 << 4)
+
+#ifdef CONFIG_PYLIBMOUNT_DEBUG
+# include <stdio.h>
+# include <stdarg.h>
+
+# define DBG(m, x)	do { \
+				if ((PYMNT_DEBUG_ ## m) & pylibmount_debug_mask) { \
+					fprintf(stderr, "%d: pylibmount: %6s: ", getpid(), # m); \
+					x; \
+				} \
+			} while (0)
+
+extern int pylibmount_debug_mask;
+
+static inline void __attribute__ ((__format__ (__printf__, 1, 2)))
+pymnt_debug(const char *mesg, ...)
+{
+	va_list ap;
+	va_start(ap, mesg);
+	vfprintf(stderr, mesg, ap);
+	va_end(ap);
+	fputc('\n', stderr);
+}
+
+static inline void __attribute__ ((__format__ (__printf__, 2, 3)))
+pymnt_debug_h(void *handler, const char *mesg, ...)
+{
+	va_list ap;
+
+	if (handler)
+		fprintf(stderr, "[%p]: ", handler);
+	va_start(ap, mesg);
+	vfprintf(stderr, mesg, ap);
+	va_end(ap);
+	fputc('\n', stderr);
+}
+
+#else /* !CONFIG_PYLIBMOUNT_DEBUG */
+# define DBG(m,x) do { ; } while (0)
+#endif
+
+
 #define NODEL_ATTR	"This attribute cannot be deleted"
 #define CONSTRUCT_ERR	"Error during object construction"
 #define ARG_ERR		"Invalid number or type of arguments"

libmount/python/tab.c

@@ -546,19 +546,27 @@ void Table_unref(struct libmnt_table *tab)
 	if (!tab)
 		return;
 
+	DBG(TAB, pymnt_debug_h(tab, "un-referencing filesystems"));
+
 	iter = mnt_new_iter(MNT_ITER_BACKWARD);
 
 	/* remove pylibmount specific references to the entries */
 	while (mnt_table_next_fs(tab, iter, &fs) == 0)
 		Py_XDECREF(mnt_fs_get_userdata(fs));
 
+	DBG(TAB, pymnt_debug_h(tab, "un-referencing table"));
+
 	mnt_unref_table(tab);
 	mnt_free_iter(iter);
 }
 
 static void Table_destructor(TableObject *self)
 {
+	DBG(TAB, pymnt_debug_h(self->tab, "destrutor py-obj: %p, py-refcnt=%d",
+				self, (int) ((PyObject *) self)->ob_refcnt));
 	Table_unref(self->tab);
+	self->tab = NULL;
+
 	mnt_free_iter(self->iter);
 	Py_XDECREF(self->errcb);
 	self->ob_type->tp_free((PyObject*)self);
@@ -571,6 +579,8 @@ static PyObject *Table_new(PyTypeObject *type,
 	TableObject *self = (TableObject*)type->tp_alloc(type, 0);
 
 	if (self) {
+		DBG(TAB, pymnt_debug_h(self, "new"));
+
 		self->tab = NULL;
 		self->iter = NULL;
 		self->errcb = NULL;
@@ -588,12 +598,15 @@ static int Table_init(TableObject *self, PyObject *args, PyObject *kwds)
 	char *kwlist[] = {"path", "errcb", NULL};
 	PyObject *errcb = NULL;
 	struct stat buf;
+
 	memset (&buf, 0, sizeof(struct stat));
 
 	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|sO",
 					kwlist, &path, &errcb))
 		return -1;
 
+	DBG(TAB, pymnt_debug_h(self, "init"));
+
 	Table_unref(self->tab);
 	self->tab = NULL;
 
@@ -615,6 +628,8 @@ static int Table_init(TableObject *self, PyObject *args, PyObject *kwds)
 	}
 
 	if (path) {
+		DBG(TAB, pymnt_debug_h(self, "init: path defined (%s)", path));
+
 		if (stat(path, &buf)) {
 			/* TODO: weird */
 			PyErr_SetFromErrno(PyExc_RuntimeError);
@@ -624,8 +639,10 @@ static int Table_init(TableObject *self, PyObject *args, PyObject *kwds)
 			self->tab = mnt_new_table_from_file(path);
 		else if (S_ISDIR(buf.st_mode))
 			self->tab = mnt_new_table_from_dir(path);
-	} else
+	} else {
+		DBG(TAB, pymnt_debug_h(self, "init: allocate empty table"));
 		self->tab = mnt_new_table();
+	}
 
 	/* Always set custom handler when using libmount from python */
 	mnt_table_set_parser_errcb(self->tab, pymnt_table_parser_errcb);
@@ -679,6 +696,8 @@ PyObject *PyObjectResultTab(struct libmnt_table *tab)
 	result = mnt_table_get_userdata(tab);
 	if (result) {
 		Py_INCREF(result);
+		DBG(TAB, pymnt_debug_h(tab, "result py-obj %p: already exists, py-refcnt=%d",
+				result, (int) ((PyObject *) result)->ob_refcnt));
 		return (PyObject *) result;
 	}
 
@@ -694,6 +713,9 @@ PyObject *PyObjectResultTab(struct libmnt_table *tab)
 
 	Py_INCREF(result);
 	mnt_ref_table(tab);
+
+	DBG(TAB, pymnt_debug_h(tab, "result py-obj %p new, py-refcnt=%d",
+				result, (int) ((PyObject *) result)->ob_refcnt));
 	result->tab = tab;
 	result->iter = mnt_new_iter(MNT_ITER_FORWARD);
 	mnt_table_set_userdata(result->tab, result);
@@ -767,6 +789,8 @@ void Table_AddModuleObject(PyObject *mod)
 	if (PyType_Ready(&TableType) < 0)
 		return;
 
+	DBG(TAB, pymnt_debug("add to module"));
+
 	Py_INCREF(&TableType);
 	PyModule_AddObject(mod, "Table", (PyObject *)&TableType);
 }