Files
esp-idf/examples/build_system/cmake/plugins/components/plugins/plugins.c

72 lines
2.4 KiB
C

/*
* SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Unlicense OR CC0-1.0
*/
#include <stdio.h>
#include <string.h>
#include <sys/queue.h>
#include "plugins_api.h"
/**
* Demonstration of dynamic registration (self-registration):
*
* - example_plugin_register function is called from "constructor" functions of each plugin.
* Information about the plugin is passed inside 'example_plugin_desc_t' structure.
* This function adds each plugin description into linked list (s_plugins_list).
*
* - example_plugins_greet function iterates over the linked list.
*/
struct plugin_record {
example_plugin_desc_t plugin_desc;
LIST_ENTRY(plugin_record) list_entry;
};
static LIST_HEAD(plugins_list, plugin_record) s_plugins_list = LIST_HEAD_INITIALIZER(s_plugins_list);
void example_plugin_register(const example_plugin_desc_t* plugin_desc)
{
struct plugin_record *record = (struct plugin_record *) malloc(sizeof(struct plugin_record));
if (record == NULL) {
abort();
}
memcpy(&record->plugin_desc, plugin_desc, sizeof(*plugin_desc));
struct plugin_record *head = LIST_FIRST(&s_plugins_list);
if (head == NULL) {
LIST_INSERT_HEAD(&s_plugins_list, record, list_entry);
} else {
LIST_INSERT_BEFORE(head, record, list_entry);
}
printf("Successfully registered plugin '%s'\n", plugin_desc->name);
}
void example_plugins_greet(const char* arg)
{
struct plugin_record *it;
LIST_FOREACH(it, &s_plugins_list, list_entry) {
printf("Calling greet function of plugin '%s'...\n", it->plugin_desc.name);
(*it->plugin_desc.greet)(arg);
printf("Done with greet function of plugin '%s'.\n", it->plugin_desc.name);
}
}
/**
* Demonstration of static registration.
* Symbols '_plugins_array_start' and '_plugins_array_end' mark the beginning and end
* of the array where 'example_plugin_desc_t' structures are placed by the linker.
* The names of these variables are determined by linker.lf in 'plugins' component,
* look for 'SURROUND(plugins_array)'.
*/
void example_plugins_list(void)
{
printf("List of plugins:\n");
extern const example_plugin_desc_t _plugins_array_start;
extern const example_plugin_desc_t _plugins_array_end;
for (const example_plugin_desc_t* it = &_plugins_array_start; it != &_plugins_array_end; ++it) {
printf("- Plugin '%s', function greet=%p\n", it->name, it->greet);
}
}