#include <babeltrace/plugin/plugin-internal.h>
#include <babeltrace/graph/component-class-internal.h>
#include <babeltrace/types.h>
+#include <babeltrace/list-internal.h>
#include <string.h>
#include <stdlib.h>
#include <glib.h>
#include <gmodule.h>
-#define NATIVE_PLUGIN_SUFFIX ".so"
+#define NATIVE_PLUGIN_SUFFIX "." G_MODULE_SUFFIX
#define NATIVE_PLUGIN_SUFFIX_LEN sizeof(NATIVE_PLUGIN_SUFFIX)
#define LIBTOOL_PLUGIN_SUFFIX ".la"
#define LIBTOOL_PLUGIN_SUFFIX_LEN sizeof(LIBTOOL_PLUGIN_SUFFIX)
#define PLUGIN_SUFFIX_LEN max_t(size_t, sizeof(NATIVE_PLUGIN_SUFFIX), \
sizeof(LIBTOOL_PLUGIN_SUFFIX))
-#define SECTION_BEGIN(_name) (&(__start_##_name))
-#define SECTION_END(_name) (&(__stop_##_name))
-#define SECTION_ELEMENT_COUNT(_name) (SECTION_END(_name) - SECTION_BEGIN(_name))
-
-#define DECLARE_SECTION(_type, _name) \
- extern _type __start_##_name __attribute((weak)); \
- extern _type __stop_##_name __attribute((weak))
-
-DECLARE_SECTION(struct __bt_plugin_descriptor const *, __bt_plugin_descriptors);
-DECLARE_SECTION(struct __bt_plugin_descriptor_attribute const *, __bt_plugin_descriptor_attributes);
-DECLARE_SECTION(struct __bt_plugin_component_class_descriptor const *, __bt_plugin_component_class_descriptors);
-DECLARE_SECTION(struct __bt_plugin_component_class_descriptor_attribute const *, __bt_plugin_component_class_descriptor_attributes);
+BT_PLUGIN_MODULE();
/*
- * This hash table, global to the library, maps component class pointers
- * to shared library handles.
+ * This list, global to the library, keeps all component classes that
+ * have a reference to their shared library handles. It allows iteration
+ * on all component classes still present when the destructor executes
+ * to release the shared library handle references they might still have.
*
- * The keys (component classes) are NOT owned by this hash table, whereas
- * the values (shared library handles) are owned by this hash table.
- *
- * The keys are the component classes created with
+ * The list items are the component classes created with
* bt_plugin_add_component_class(). They keep the shared library handle
* object created by their plugin alive so that the plugin's code is
* not discarded when it could still be in use by living components
* created from those component classes:
*
- * [component] --ref-> [component class] --through this HT-> [shlib handle]
- *
- * This hash table exists for two reasons:
+ * [component] --ref-> [component class]-> [shlib handle]
*
- * 1. To allow this application:
+ * It allows this use-case:
*
* my_plugins = bt_plugin_create_all_from_file("/path/to/my-plugin.so");
* // instantiate components from a plugin's component classes
* // put plugins and free my_plugins here
* // user code of instantiated components still exists
*
- * 2. To decouple the plugin subsystem from the component subsystem:
- * while plugins objects need to know component class objects, the
- * opposite is not necessary, thus it makes no sense for a component
- * class to keep a reference to the plugin object from which it was
- * created.
- *
- * An entry is removed from this HT when a component class is destroyed
- * thanks to a custom destroy listener. When the entry is removed, the
- * GLib function calls the value destroy notifier of the HT, which is
- * bt_put(). This decreases the reference count of the mapped shared
- * library handle. Assuming the original plugin object which contained
- * some component classes is put first, when the last component class is
- * removed from this HT, the shared library handle object's reference
- * count falls to zero and the shared library is finally closed.
+ * An entry is removed from this list when a component class is
+ * destroyed thanks to a custom destroy listener. When the entry is
+ * removed, the entry is removed from the list, and we release the
+ * reference on the shlib handle. Assuming the original plugin object
+ * which contained some component classes is put first, when the last
+ * component class is removed from this list, the shared library handle
+ * object's reference count falls to zero and the shared library is
+ * finally closed.
*/
+
static
-GHashTable *comp_classes_to_shlib_handles;
-
-__attribute__((constructor)) static
-void init_comp_classes_to_shlib_handles(void) {
- comp_classes_to_shlib_handles = g_hash_table_new_full(g_direct_hash,
- g_direct_equal, NULL, bt_put);
- assert(comp_classes_to_shlib_handles);
- BT_LOGD_STR("Initialized component class to shared library handle hash table.");
-}
+BT_LIST_HEAD(component_class_list);
__attribute__((destructor)) static
-void fini_comp_classes_to_shlib_handles(void) {
- if (comp_classes_to_shlib_handles) {
- g_hash_table_destroy(comp_classes_to_shlib_handles);
- BT_LOGD_STR("Destroyed component class to shared library handle hash table.");
+void fini_comp_class_list(void)
+{
+ struct bt_component_class *comp_class, *tmp;
+
+ bt_list_for_each_entry_safe(comp_class, tmp, &component_class_list, node) {
+ bt_list_del(&comp_class->node);
+ BT_PUT(comp_class->so_handle);
}
+ BT_LOGD_STR("Released references from all component classes to shared library handles.");
}
static
goto error;
}
- shared_lib_handle->module = g_module_open(path, 0);
+ shared_lib_handle->module = g_module_open(path, G_MODULE_BIND_LOCAL);
if (!shared_lib_handle->module) {
/*
* DEBUG-level logging because we're only _trying_ to
const struct __bt_plugin_descriptor_attribute *cur_attr =
*cur_attr_ptr;
+ if (cur_attr == NULL) {
+ continue;
+ }
+
if (cur_attr->plugin_descriptor != descriptor) {
continue;
}
*cur_cc_descr_ptr;
struct comp_class_full_descriptor full_descriptor = {0};
+ if (cur_cc_descr == NULL) {
+ continue;
+ }
+
if (cur_cc_descr->plugin_descriptor != descriptor) {
continue;
}
const struct __bt_plugin_component_class_descriptor_attribute *cur_cc_descr_attr =
*cur_cc_descr_attr_ptr;
+ if (cur_cc_descr_attr == NULL) {
+ continue;
+ }
+
if (cur_cc_descr_attr->comp_class_descriptor->plugin_descriptor !=
descriptor) {
continue;
*
* This will call back
* bt_plugin_so_on_add_component_class() so that we can
- * add a mapping in comp_classes_to_shlib_handles when
+ * add a mapping in the component class list when
* we know the component class is successfully added.
*/
status = bt_plugin_add_component_class(plugin,
return plugin;
}
+static
+size_t count_non_null_items_in_section(const void *begin, const void *end)
+{
+ size_t count = 0;
+ const int * const *begin_int = (const int * const *) begin;
+ const int * const *end_int = (const int * const *) end;
+ const int * const *iter;
+
+ for (iter = begin_int; iter != end_int; iter++) {
+ if (*iter) {
+ count++;
+ }
+ }
+
+ return count;
+}
+
static
struct bt_plugin_set *bt_plugin_so_create_all_from_sections(
struct bt_plugin_so_shared_lib_handle *shared_lib_handle,
size_t i;
struct bt_plugin_set *plugin_set = NULL;
- descriptor_count = descriptors_end - descriptors_begin;
- attrs_count = attrs_end - attrs_begin;
- cc_descriptors_count = cc_descriptors_end - cc_descriptors_begin;
- cc_descr_attrs_count = cc_descr_attrs_end - cc_descr_attrs_begin;
+ descriptor_count = count_non_null_items_in_section(descriptors_begin, descriptors_end);
+ attrs_count = count_non_null_items_in_section(attrs_begin, attrs_end);
+ cc_descriptors_count = count_non_null_items_in_section(cc_descriptors_begin, cc_descriptors_end);
+ cc_descr_attrs_count = count_non_null_items_in_section(cc_descr_attrs_begin, cc_descr_attrs_end);
BT_LOGD("Creating all SO plugins from sections: "
"plugin-path=\"%s\", "
goto error;
}
- for (i = 0; i < descriptor_count; i++) {
+ for (i = 0; i < descriptors_end - descriptors_begin; i++) {
enum bt_plugin_status status;
const struct __bt_plugin_descriptor *descriptor =
descriptors_begin[i];
struct bt_plugin *plugin;
+ if (descriptor == NULL) {
+ continue;
+ }
+
BT_LOGD("Creating plugin object for plugin: "
"name=\"%s\", abi-major=%d, abi-minor=%d",
descriptor->name, descriptor->major, descriptor->minor);
BT_LOGD_STR("Creating all SO plugins from built-in plugins.");
plugin_set = bt_plugin_so_create_all_from_sections(shared_lib_handle,
- SECTION_BEGIN(__bt_plugin_descriptors),
- SECTION_END(__bt_plugin_descriptors),
- SECTION_BEGIN(__bt_plugin_descriptor_attributes),
- SECTION_END(__bt_plugin_descriptor_attributes),
- SECTION_BEGIN(__bt_plugin_component_class_descriptors),
- SECTION_END(__bt_plugin_component_class_descriptors),
- SECTION_BEGIN(__bt_plugin_component_class_descriptor_attributes),
- SECTION_END(__bt_plugin_component_class_descriptor_attributes));
+ __bt_get_begin_section_plugin_descriptors(),
+ __bt_get_end_section_plugin_descriptors(),
+ __bt_get_begin_section_plugin_descriptor_attributes(),
+ __bt_get_end_section_plugin_descriptor_attributes(),
+ __bt_get_begin_section_component_class_descriptors(),
+ __bt_get_end_section_component_class_descriptors(),
+ __bt_get_begin_section_component_class_descriptor_attributes(),
+ __bt_get_end_section_component_class_descriptor_attributes());
end:
BT_PUT(shared_lib_handle);
struct __bt_plugin_component_class_descriptor const * const *cc_descriptors_end = NULL;
struct __bt_plugin_component_class_descriptor_attribute const * const *cc_descr_attrs_begin = NULL;
struct __bt_plugin_component_class_descriptor_attribute const * const *cc_descr_attrs_end = NULL;
+ struct __bt_plugin_descriptor const * const *(*get_begin_section_plugin_descriptors)(void);
+ struct __bt_plugin_descriptor const * const *(*get_end_section_plugin_descriptors)(void);
+ struct __bt_plugin_descriptor_attribute const * const *(*get_begin_section_plugin_descriptor_attributes)(void);
+ struct __bt_plugin_descriptor_attribute const * const *(*get_end_section_plugin_descriptor_attributes)(void);
+ struct __bt_plugin_component_class_descriptor const * const *(*get_begin_section_component_class_descriptors)(void);
+ struct __bt_plugin_component_class_descriptor const * const *(*get_end_section_component_class_descriptors)(void);
+ struct __bt_plugin_component_class_descriptor_attribute const * const *(*get_begin_section_component_class_descriptor_attributes)(void);
+ struct __bt_plugin_component_class_descriptor_attribute const * const *(*get_end_section_component_class_descriptor_attributes)(void);
bt_bool is_libtool_wrapper = BT_FALSE, is_shared_object = BT_FALSE;
struct bt_plugin_so_shared_lib_handle *shared_lib_handle = NULL;
goto end;
}
- if (!g_module_symbol(shared_lib_handle->module, "__start___bt_plugin_descriptors",
- (gpointer *) &descriptors_begin)) {
+ if (g_module_symbol(shared_lib_handle->module, "__bt_get_begin_section_plugin_descriptors",
+ (gpointer *) &get_begin_section_plugin_descriptors)) {
+ descriptors_begin = get_begin_section_plugin_descriptors();
+ } else {
BT_LOGD("Cannot resolve plugin symbol: path=\"%s\", "
"symbol=\"%s\"", path,
- "__start___bt_plugin_descriptors");
+ "__bt_get_begin_section_plugin_descriptors");
goto end;
}
- if (!g_module_symbol(shared_lib_handle->module, "__stop___bt_plugin_descriptors",
- (gpointer *) &descriptors_end)) {
+ if (g_module_symbol(shared_lib_handle->module, "__bt_get_end_section_plugin_descriptors",
+ (gpointer *) &get_end_section_plugin_descriptors)) {
+ descriptors_end = get_end_section_plugin_descriptors();
+ } else {
BT_LOGD("Cannot resolve plugin symbol: path=\"%s\", "
"symbol=\"%s\"", path,
- "__stop___bt_plugin_descriptors");
+ "__bt_get_end_section_plugin_descriptors");
goto end;
}
- if (!g_module_symbol(shared_lib_handle->module, "__start___bt_plugin_descriptor_attributes",
- (gpointer *) &attrs_begin)) {
+ if (g_module_symbol(shared_lib_handle->module, "__bt_get_begin_section_plugin_descriptor_attributes",
+ (gpointer *) &get_begin_section_plugin_descriptor_attributes)) {
+ attrs_begin = get_begin_section_plugin_descriptor_attributes();
+ } else {
BT_LOGD("Cannot resolve plugin symbol: path=\"%s\", "
"symbol=\"%s\"", path,
- "__start___bt_plugin_descriptor_attributes");
+ "__bt_get_begin_section_plugin_descriptor_attributes");
}
- if (!g_module_symbol(shared_lib_handle->module, "__stop___bt_plugin_descriptor_attributes",
- (gpointer *) &attrs_end)) {
+ if (g_module_symbol(shared_lib_handle->module, "__bt_get_end_section_plugin_descriptor_attributes",
+ (gpointer *) &get_end_section_plugin_descriptor_attributes)) {
+ attrs_end = get_end_section_plugin_descriptor_attributes();
+ } else {
BT_LOGD("Cannot resolve plugin symbol: path=\"%s\", "
"symbol=\"%s\"", path,
- "__stop___bt_plugin_descriptor_attributes");
+ "__bt_get_end_section_plugin_descriptor_attributes");
}
if ((!!attrs_begin - !!attrs_end) != 0) {
"path=\"%s\", symbol-start=\"%s\", "
"symbol-end=\"%s\", symbol-start-addr=%p, "
"symbol-end-addr=%p",
- path, "__start___bt_plugin_descriptor_attributes",
- "__stop___bt_plugin_descriptor_attributes",
+ path, "__bt_get_begin_section_plugin_descriptor_attributes",
+ "__bt_get_end_section_plugin_descriptor_attributes",
attrs_begin, attrs_end);
goto end;
}
- if (!g_module_symbol(shared_lib_handle->module, "__start___bt_plugin_component_class_descriptors",
- (gpointer *) &cc_descriptors_begin)) {
+ if (g_module_symbol(shared_lib_handle->module, "__bt_get_begin_section_component_class_descriptors",
+ (gpointer *) &get_begin_section_component_class_descriptors)) {
+ cc_descriptors_begin = get_begin_section_component_class_descriptors();
+ } else {
BT_LOGD("Cannot resolve plugin symbol: path=\"%s\", "
"symbol=\"%s\"", path,
- "__start___bt_plugin_component_class_descriptors");
+ "__bt_get_begin_section_component_class_descriptors");
}
- if (!g_module_symbol(shared_lib_handle->module, "__stop___bt_plugin_component_class_descriptors",
- (gpointer *) &cc_descriptors_end)) {
+ if (g_module_symbol(shared_lib_handle->module, "__bt_get_end_section_component_class_descriptors",
+ (gpointer *) &get_end_section_component_class_descriptors)) {
+ cc_descriptors_end = get_end_section_component_class_descriptors();
+ } else {
BT_LOGD("Cannot resolve plugin symbol: path=\"%s\", "
"symbol=\"%s\"", path,
- "__stop___bt_plugin_component_class_descriptors");
+ "__bt_get_end_section_component_class_descriptors");
}
if ((!!cc_descriptors_begin - !!cc_descriptors_end) != 0) {
"path=\"%s\", symbol-start=\"%s\", "
"symbol-end=\"%s\", symbol-start-addr=%p, "
"symbol-end-addr=%p",
- path, "__start___bt_plugin_component_class_descriptors",
- "__stop___bt_plugin_component_class_descriptors",
+ path, "__bt_get_begin_section_component_class_descriptors",
+ "__bt_get_end_section_component_class_descriptors",
cc_descriptors_begin, cc_descriptors_end);
goto end;
}
- if (!g_module_symbol(shared_lib_handle->module, "__start___bt_plugin_component_class_descriptor_attributes",
- (gpointer *) &cc_descr_attrs_begin)) {
+ if (g_module_symbol(shared_lib_handle->module, "__bt_get_begin_section_component_class_descriptor_attributes",
+ (gpointer *) &get_begin_section_component_class_descriptor_attributes)) {
+ cc_descr_attrs_begin = get_begin_section_component_class_descriptor_attributes();
+ } else {
BT_LOGD("Cannot resolve plugin symbol: path=\"%s\", "
"symbol=\"%s\"", path,
- "__start___bt_plugin_component_class_descriptor_attributes");
+ "__bt_get_begin_section_component_class_descriptor_attributes");
}
- if (!g_module_symbol(shared_lib_handle->module, "__stop___bt_plugin_component_class_descriptor_attributes",
- (gpointer *) &cc_descr_attrs_end)) {
+ if (g_module_symbol(shared_lib_handle->module, "__bt_get_end_section_component_class_descriptor_attributes",
+ (gpointer *) &get_end_section_component_class_descriptor_attributes)) {
+ cc_descr_attrs_end = get_end_section_component_class_descriptor_attributes();
+ } else {
BT_LOGD("Cannot resolve plugin symbol: path=\"%s\", "
"symbol=\"%s\"", path,
- "__stop___bt_plugin_component_class_descriptor_attributes");
+ "__bt_get_end_section_component_class_descriptor_attributes");
}
if ((!!cc_descr_attrs_begin - !!cc_descr_attrs_end) != 0) {
"path=\"%s\", symbol-start=\"%s\", "
"symbol-end=\"%s\", symbol-start-addr=%p, "
"symbol-end-addr=%p",
- path, "__start___bt_plugin_component_class_descriptor_attributes",
- "__stop___bt_plugin_component_class_descriptor_attributes",
+ path, "__bt_get_begin_section_component_class_descriptor_attributes",
+ "__bt_get_end_section_component_class_descriptor_attributes",
cc_descr_attrs_begin, cc_descr_attrs_end);
goto end;
}
void plugin_comp_class_destroy_listener(struct bt_component_class *comp_class,
void *data)
{
- gboolean exists = g_hash_table_remove(comp_classes_to_shlib_handles,
- comp_class);
- assert(exists);
- BT_LOGV("Component class destroyed: removed entry from hash table: "
+ bt_list_del(&comp_class->node);
+ BT_PUT(comp_class->so_handle);
+ BT_LOGV("Component class destroyed: removed entry from list: "
"comp-cls-addr=%p", comp_class);
}
assert(plugin->spec_data);
assert(plugin->type == BT_PLUGIN_TYPE_SO);
- /* Map component class pointer to shared lib handle in global HT */
- g_hash_table_insert(comp_classes_to_shlib_handles, comp_class,
- bt_get(spec->shared_lib_handle));
+ bt_list_add(&comp_class->node, &component_class_list);
+ comp_class->so_handle = bt_get(spec->shared_lib_handle);
/* Add our custom destroy listener */
bt_component_class_add_destroy_listener(comp_class,