sr_driver_list() now takes a context pointer.

This requires sr_hw_cleanup_all() and sanity_check_all_drivers()
to also take a context.

The (runtime) generation of the driver list now happens in sr_init()
and sr_driver_list() always returns that pre-generated list. This fixes
a segfault when (correctly) invoking multiple sr_init() and sr_exit()
calls with different contexts (caught by the unit tests).

This fixes bug #565.

bindings/cxx/classes.cpp

@@ -77,7 +77,7 @@ Context::Context() :
 {
 	check(sr_init(&_structure));
 
-	struct sr_dev_driver **driver_list = sr_driver_list();
+	struct sr_dev_driver **driver_list = sr_driver_list(_structure);
 	if (driver_list)
 		for (int i = 0; driver_list[i]; i++)
 			_drivers[driver_list[i]->name] =

include/libsigrok/proto.h

@@ -79,7 +79,7 @@ SR_API int sr_dev_inst_channel_add(struct sr_dev_inst *sdi, int index, int type,
 
 /*--- hwdriver.c ------------------------------------------------------------*/
 
-SR_API struct sr_dev_driver **sr_driver_list(void);
+SR_API struct sr_dev_driver **sr_driver_list(const struct sr_context *ctx);
 SR_API int sr_driver_init(struct sr_context *ctx,
 		struct sr_dev_driver *driver);
 SR_API GSList *sr_driver_scan(struct sr_dev_driver *driver, GSList *options);

src/backend.c

@@ -122,18 +122,24 @@
 /**
  * Sanity-check all libsigrok drivers.
  *
+ * @param[in] ctx Pointer to a libsigrok context struct. Must not be NULL.
+ *
  * @retval SR_OK All drivers are OK
  * @retval SR_ERR One or more drivers have issues.
+ * @retval SR_ERR_ARG Invalid argument.
  */
-static int sanity_check_all_drivers(void)
+static int sanity_check_all_drivers(const struct sr_context *ctx)
 {
 	int i, errors, ret = SR_OK;
 	struct sr_dev_driver **drivers;
 	const char *d;
 
+	if (!ctx)
+		return SR_ERR_ARG;
+
 	sr_spew("Sanity-checking all drivers.");
 
-	drivers = sr_driver_list();
+	drivers = sr_driver_list(ctx);
 	for (i = 0; drivers[i]; i++) {
 		errors = 0;
 
@@ -375,13 +381,25 @@ SR_API int sr_init(struct sr_context **ctx)
 {
 	int ret = SR_ERR;
 	struct sr_context *context;
+	struct sr_dev_driver ***lists, **drivers;
+	GArray *array;
 
 	if (!ctx) {
 		sr_err("%s(): libsigrok context was NULL.", __func__);
 		return SR_ERR;
 	}
 
-	if (sanity_check_all_drivers() < 0) {
+	context = g_malloc0(sizeof(struct sr_context));
+
+	/* Generate ctx->driver_list at runtime. */
+	array = g_array_new(TRUE, FALSE, sizeof(struct sr_dev_driver *));
+	for (lists = drivers_lists; *lists; lists++)
+		for (drivers = *lists; *drivers; drivers++)
+			g_array_append_val(array, *drivers);
+	context->driver_list = (struct sr_dev_driver **)array->data;
+	g_array_free(array, FALSE);
+
+	if (sanity_check_all_drivers(context) < 0) {
 		sr_err("Internal driver error(s), aborting.");
 		return ret;
 	}
@@ -401,9 +419,6 @@ SR_API int sr_init(struct sr_context **ctx)
 		return ret;
 	}
 
-	/* + 1 to handle when struct sr_context has no members. */
-	context = g_malloc0(sizeof(struct sr_context) + 1);
-
 #ifdef HAVE_LIBUSB_1_0
 	ret = libusb_init(&context->libusb_ctx);
 	if (LIBUSB_SUCCESS != ret) {
@@ -439,13 +454,13 @@ SR_API int sr_exit(struct sr_context *ctx)
 		return SR_ERR;
 	}
 
-	sr_hw_cleanup_all();
+	sr_hw_cleanup_all(ctx);
 
 #ifdef HAVE_LIBUSB_1_0
 	libusb_exit(ctx->libusb_ctx);
 #endif
 
-	g_free(sr_driver_list());
+	g_free(sr_driver_list(ctx));
 	g_free(ctx);
 
 	return SR_OK;

src/hwdriver.c

@@ -31,8 +31,6 @@
 #define LOG_PREFIX "hwdriver"
 /** @endcond */
 
-extern SR_PRIV struct sr_dev_driver **drivers_lists[];
-
 /**
  * @file
  *
@@ -259,27 +257,20 @@ SR_PRIV int sr_variant_type_check(uint32_t key, GVariant *value)
 /**
  * Return the list of supported hardware drivers.
  *
- * @return Pointer to the NULL-terminated list of hardware driver pointers.
+ * @param[in] ctx Pointer to a libsigrok context struct. Must not be NULL.
  *
- * @since 0.1.0
+ * @retval NULL The ctx argument was NULL, or there are no supported drivers.
+ * @retval Other Pointer to the NULL-terminated list of hardware drivers.
+ *               The user should NOT g_free() this list, sr_exit() will do that.
+ *
+ * @since 0.4.0
  */
-SR_API struct sr_dev_driver **sr_driver_list(void)
+SR_API struct sr_dev_driver **sr_driver_list(const struct sr_context *ctx)
 {
-	static struct sr_dev_driver **combined_list = NULL;
+	if (!ctx)
-	struct sr_dev_driver ***lists, **drivers;
+		return NULL;
-	GArray *array;
 
-	if (combined_list)
+	return ctx->driver_list;
-		return combined_list;
-
-	array = g_array_new(TRUE, FALSE, sizeof(struct sr_dev_driver *));
-	for (lists = drivers_lists; *lists; lists++)
-		for (drivers = *lists; *drivers; drivers++)
-			g_array_append_val(array, *drivers);
-	combined_list = (struct sr_dev_driver **)array->data;
-	g_array_free(array, FALSE);
-
-	return combined_list;
 }
 
 /**
@@ -418,14 +409,22 @@ SR_API GSList *sr_driver_scan(struct sr_dev_driver *driver, GSList *options)
 	return l;
 }
 
-/** Call driver cleanup function for all drivers.
+/**
- *  @private */
+ * Call driver cleanup function for all drivers.
-SR_PRIV void sr_hw_cleanup_all(void)
+ *
+ * @param[in] ctx Pointer to a libsigrok context struct. Must not be NULL.
+ *
+ * @private
+ */
+SR_PRIV void sr_hw_cleanup_all(const struct sr_context *ctx)
 {
 	int i;
 	struct sr_dev_driver **drivers;
 
-	drivers = sr_driver_list();
+	if (!ctx)
+		return;
+
+	drivers = sr_driver_list(ctx);
 	for (i = 0; drivers[i]; i++) {
 		if (drivers[i]->cleanup)
 			drivers[i]->cleanup(drivers[i]);

src/libsigrok-internal.h

@@ -174,6 +174,7 @@
 #endif
 
 struct sr_context {
+	struct sr_dev_driver **driver_list;
 #ifdef HAVE_LIBUSB_1_0
 	libusb_context *libusb_ctx;
 	gboolean usb_source_present;
@@ -645,9 +646,11 @@ SR_PRIV void sr_usbtmc_dev_inst_free(struct sr_usbtmc_dev_inst *usbtmc);
 
 /*--- hwdriver.c ------------------------------------------------------------*/
 
+extern SR_PRIV struct sr_dev_driver **drivers_lists[];
+
 SR_PRIV const GVariantType *sr_variant_type_get(int datatype);
 SR_PRIV int sr_variant_type_check(uint32_t key, GVariant *data);
-SR_PRIV void sr_hw_cleanup_all(void);
+SR_PRIV void sr_hw_cleanup_all(const struct sr_context *ctx);
 SR_PRIV struct sr_config *sr_config_new(uint32_t key, GVariant *data);
 SR_PRIV void sr_config_free(struct sr_config *src);
 SR_PRIV int sr_source_remove(int fd);

tests/driver_all.c

@@ -28,7 +28,7 @@ START_TEST(test_driver_available)
 {
 	struct sr_dev_driver **drivers;
 
-	drivers = sr_driver_list();
+	drivers = sr_driver_list(srtest_ctx);
 	fail_unless(drivers != NULL, "No drivers found.");
 }
 END_TEST

tests/lib.c

@@ -50,7 +50,7 @@ struct sr_dev_driver *srtest_driver_get(const char *drivername)
 	struct sr_dev_driver **drivers, *driver = NULL;
 	int i;
 
-	drivers = sr_driver_list();
+	drivers = sr_driver_list(srtest_ctx);
 	fail_unless(drivers != NULL, "No drivers found.");
 
 	for (i = 0; drivers[i]; i++) {
@@ -79,7 +79,7 @@ void srtest_driver_init_all(struct sr_context *sr_ctx)
 	struct sr_dev_driver **drivers, *driver;
 	int i, ret;
 
-	drivers = sr_driver_list();
+	drivers = sr_driver_list(srtest_ctx);
 	fail_unless(drivers != NULL, "No drivers found.");
 
 	for (i = 0; drivers[i]; i++) {