Use the new callback system instead of add_update_callback() & co.

src/common.cc

@@ -59,6 +59,8 @@
 #include "openbsd.h"
 #endif
 
+#include "update-cb.hh"
+
 /* folds a string over top of itself, like so:
  *
  * if start is "blah", and you call it with count = 1, the result will be "lah"
@@ -245,134 +247,11 @@ void format_seconds_short(char *buf, unsigned int n, long seconds)
 	}
 }
 
-/* Linked list containing the functions to call upon each update interval.
- * Populated while initialising text objects in construct_text_object(). */
-struct update_cb {
-	struct update_cb *next;
-	int (*func)(void);
-	pthread_t thread;
-	sem_t start_wait, end_wait;
-	update_cb() : next(NULL), func(NULL) {}
-
-    /* set to 1 when starting the thread
-	 * set to 0 to request thread termination */
-	volatile char running;
-};
-
-static struct update_cb update_cb_head;
-
-static void *run_update_callback(void *);
-
-static int threading_started = 0;
-
-/* Register an update callback. Don't allow duplicates, to minimise side
- * effects and overhead. */
-void add_update_callback(int (*func)(void))
-{
-	struct update_cb *uc = &update_cb_head;
-
-	if (!func)
-		return;
-
-	while (uc->next) {
-		if (uc->next->func == func)
-			return;
-		uc = uc->next;
-	}
-
-	uc->next = new update_cb;
-	uc = uc->next;
-
-	memset(uc, 0, sizeof(struct update_cb));
-	uc->func = func;
-	sem_init(&uc->start_wait, 0, 0);
-	sem_init(&uc->end_wait, 0, 0);
-
-	if (threading_started) {
-		if (!uc->running) {
-			uc->running = 1;
-			pthread_create(&uc->thread, NULL, &run_update_callback, uc);
-		}
-	}
-}
-
-/* Free the list element uc and all decendants recursively. */
-static void __free_update_callbacks(struct update_cb *uc)
-{
-	if (uc->next)
-		__free_update_callbacks(uc->next);
-
-	if (uc->running) {
-		/* send cancellation request, then trigger and join the thread */
-		uc->running = 0;
-		sem_post(&uc->start_wait);
-	}
-	if (uc->thread && pthread_join(uc->thread, NULL)) {
-		NORM_ERR("Error destroying thread");
-	}
-
-	/* finally destroy the semaphores */
-	sem_destroy(&uc->start_wait);
-	sem_destroy(&uc->end_wait);
-
-	delete uc;
-}
-
-/* Free the whole list of update callbacks. */
-void free_update_callbacks(void)
-{
-	if (update_cb_head.next)
-		__free_update_callbacks(update_cb_head.next);
-	update_cb_head.next = NULL;
-}
-
-/* We cannot start threads before we forked to background, because the threads
- * would remain in the wrong process. Because of that, add_update_callback()
- * doesn't create threads before start_update_threading() is called.
- * start_update_threading() starts all threads previously registered, and sets a
- * flag so that future threads are automagically started by
- * add_update_callback().
- * This text is almost longer than the actual code.
- */
-void start_update_threading(void)
-{
-	struct update_cb *uc;
-
-	threading_started = 1;
-
-	for (uc = update_cb_head.next; uc; uc = uc->next) {
-		if (!uc->running) {
-			uc->running = 1;
-			pthread_create(&uc->thread, NULL, &run_update_callback, uc);
-		}
-	}
-}
-
-static void *run_update_callback(void *data)
-{
-	struct update_cb *ucb = static_cast<struct update_cb *>(data);
-
-	if (!ucb || !ucb->func) return(NULL);
-
-	while (1) {
-		if (sem_wait(&ucb->start_wait)) return(NULL);
-		if (ucb->running == 0) return(NULL);
-		if((*ucb->func)()) {
-			ucb->next = ucb;	//this is normally not be possible, so we use it to show that there was a critical error
-			sem_post(&ucb->end_wait);
-			sem_post(&ucb->end_wait);
-			pthread_exit(NULL);
-		}
-		if (sem_post(&ucb->end_wait)) return(NULL);
-	}
-}
-
 conky::simple_config_setting<bool> no_buffers("no_buffers", true, true);
 
 void update_stuff(void)
 {
 	int i;
-	struct update_cb *uc;
 
 	/* clear speeds and up status in case device was removed and doesn't get
 	 * updated */
@@ -390,21 +269,7 @@ void update_stuff(void)
 
 	prepare_update();
 
-	for (uc = update_cb_head.next; uc; uc = uc->next) {
+	conky::run_all_callbacks();
-		if (sem_post(&uc->start_wait)) {
-			NORM_ERR("Semaphore error");
-		}
-	}
-	/* need to synchronise here, otherwise locking is needed (as data
-	 * would be printed with some update callbacks still running) */
-	for (uc = update_cb_head.next; uc; uc = uc->next) {
-		sem_wait(&uc->end_wait);
-		if(uc == uc->next) {
-			pthread_join(uc->thread, NULL);
-			delete uc;
-			exit(EXIT_FAILURE);
-		}
-	}
 
 	/* XXX: move the following into the update_meminfo() functions? */
 	if (no_buffers.get(*state)) {

src/common.h

@@ -38,10 +38,6 @@ char* readfile(const char* filename, int* total_read, char showerror);
 
 void print_to_bytes(struct text_object *, char *, int);
 
-void add_update_callback(int (*func)(void));
-void free_update_callbacks(void);
-void start_update_threading(void);
-
 void strfold(char *start, int count);
 int check_mount(struct text_object *);
 void prepare_update(void);

src/conky.cc

@@ -2593,7 +2593,7 @@ void clean_up_without_threads(void *memtofree1, void* memtofree2)
 
 void clean_up(void *memtofree1, void* memtofree2)
 {
-	free_update_callbacks();
+	/* free_update_callbacks(); XXX: some new equivalent of this? */
 	clean_up_without_threads(memtofree1, memtofree2);
 }
 
@@ -2994,8 +2994,6 @@ void initialisation(int argc, char **argv) {
 		}
 	}
 
-	start_update_threading();
-
 	text_buffer = (char*)malloc(max_user_text.get(*state));
 	memset(text_buffer, 0, max_user_text.get(*state));
 	tmpstring1 = (char*)malloc(text_buffer_size.get(*state));

src/core.cc

@@ -244,6 +244,14 @@ void stock_parse_arg(struct text_object *obj, const char *arg)
 }
 #endif /* BUILD_CURL */
 
+legacy_cb_handle *create_cb_handle(int (*fn)())
+{
+	if(fn)
+		return new legacy_cb_handle(conky::register_cb<legacy_cb>(1, fn));
+	else
+		return NULL;
+}
+
 /* construct_text_object() creates a new text_object */
 struct text_object *construct_text_object(char *s, const char *arg, long
 		line, void **ifblock_opaque, void *free_at_crash)
@@ -255,7 +263,7 @@ struct text_object *construct_text_object(char *s, const char *arg, long
 
 /* helper defines for internal use only */
 #define __OBJ_HEAD(a, n) if (!strcmp(s, #a)) { \
-	add_update_callback(n);
+	obj->cb_handle = create_cb_handle(n);
 #define __OBJ_IF obj_be_ifblock_if(ifblock_opaque, obj)
 #define __OBJ_ARG(...) if (!arg) { free(s); CRIT_ERR(obj, free_at_crash, __VA_ARGS__); }
 
@@ -852,7 +860,7 @@ struct text_object *construct_text_object(char *s, const char *arg, long
 #ifdef __linux__
 			determine_longstat_file();
 #endif
-			add_update_callback(&update_top);
+			obj->cb_handle = create_cb_handle(update_top);
 		} else {
 			free(obj);
 			return NULL;
@@ -2016,6 +2024,7 @@ void free_text_objects(struct text_object *root)
 			free_text_objects(obj->sub);
 			free_and_zero(obj->sub);
 			free_and_zero(obj->special_data);
+			delete obj->cb_handle;
 
 			free(obj);
 		}

src/text_object.h

@@ -32,6 +32,7 @@
 #include <stdint.h>		/* uint8_t */
 #include "config.h"		/* for the defines */
 #include "specials.h"		/* enum special_types */
+#include "update-cb.hh"
 
 /* text object callbacks */
 struct obj_cb {
@@ -74,6 +75,20 @@ void gen_print_nothing(struct text_object *, char *, int);
  * used by the $text object */
 void gen_print_obj_data_s(struct text_object *, char *, int);
 
+class legacy_cb: public conky::callback<void *, int (*)()> {
+    typedef conky::callback<void *, int (*)()> Base;
+
+protected:
+    virtual void work()
+    { std::get<0>(tuple)(); }
+
+public:
+    legacy_cb(uint32_t period, int (*fn)())
+        : Base(period, true, Base::Tuple(fn))
+    {}
+};
+typedef conky::callback_handle<legacy_cb> legacy_cb_handle;
+
 struct text_object {
 	struct text_object *next, *prev;	/* doubly linked list of text objects */
 	struct text_object *sub;		/* for objects parsing text into objects */
@@ -93,6 +108,8 @@ struct text_object {
 	struct obj_cb callbacks;
 	bool parse;	//if this true then data.s should still be parsed
 	bool thread;	//if this true then data.s should be set by a seperate thread
+
+        legacy_cb_handle *cb_handle;
 };
 
 /* text object list helpers */

src/top.cc

@@ -383,6 +383,9 @@ static void process_find_top(struct process **cpu, struct process **mem,
 
 int update_top(void)
 {
+	// XXX: this was a separate callback. and it should be again, as soon as it's possible
+	update_meminfo();
+
 	process_find_top(info.cpu, info.memu, info.time
 #ifdef BUILD_IOSTATS
 					 , info.io
@@ -568,7 +571,6 @@ int parse_top_args(const char *s, const char *arg, struct text_object *obj)
 			obj->callbacks.print = &print_top_pid;
 		} else if (strcmp(buf, "mem") == EQUAL) {
 			obj->callbacks.print = &print_top_mem;
-			add_update_callback(&update_meminfo);
 		} else if (strcmp(buf, "time") == EQUAL) {
 			obj->callbacks.print = &print_top_time;
 		} else if (strcmp(buf, "mem_res") == EQUAL) {