EFL Threading example 4

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EFL Threading example 4

Now when you want to have a thread do some work, send back results to the mainloop and continue running but the mainloop controls when the thread should stop working, you need some extra flags.

This is an example of how you might use ecore_main_loop_thread_safe_call_async() and pthreads to do this.

EFL Threading example 5

EFL Threading example 6

//Compile with:
//gcc -o efl_thread_4 efl_thread_4.c -g `pkg-config --cflags --libs elementary`
#include <Elementary.h>
#include <pthread.h>
static Evas_Object *win = NULL;
static Evas_Object *rect = NULL;
struct info
{
double x, y;
};
static void my_thread_mainloop_code(void *data);
static pthread_t thread_id;
static pthread_mutex_t th_lock;
static int th_exit = 0;
// BEGIN - code running in my custom pthread instance
//
static void *
my_thread_run(void *arg)
{
double t = 0.0;
// inside the pthread function lets loop forever incrementing a time point
for (;;)
{
struct info *inf = malloc(sizeof(struct info));
int do_exit;
if (inf)
{
inf->x = 200 + (200 * sin(t));
inf->y = 200 + (200 * cos(t));
// now call a function in the mainloop and pass it our allocated
// data that it will free when it gets it
ecore_main_loop_thread_safe_call_async
(my_thread_mainloop_code, inf);
}
// and sleep and loop
usleep(1000);
t += 0.02;
// in case someone has asked us to cancel - then cancel this loop
// co-operatively (cancelling is co-operative)
pthread_mutex_lock(&th_lock);
do_exit = th_exit;
pthread_mutex_unlock(&th_lock);
if (do_exit) break;
}
return NULL;
}
//
// END - code running in my custom pthread instance
static void
my_thread_new(void)
{
pthread_attr_t attr;
pthread_mutex_init(&th_lock, NULL);
if (pthread_attr_init(&attr) != 0)
perror("pthread_attr_init");
if (pthread_create(&thread_id, &attr, my_thread_run, NULL) != 0)
perror("pthread_create");
}
static void
my_thread_mainloop_code(void *data)
{
struct info *inf = data;
evas_object_move(rect, inf->x - 50, inf->y - 50);
free(inf);
}
// just test cancelling the thread
static void
down(void *data, Evas *e, Evas_Object *obj, void *event_info)
{
pthread_mutex_lock(&th_lock);
th_exit = 1;
pthread_mutex_unlock(&th_lock);
}
// on window delete - cancel thread then delete window and exit mainloop
static void
del(void *data, Evas_Object *obj, void *event_info)
{
pthread_mutex_lock(&th_lock);
th_exit = 1;
pthread_mutex_unlock(&th_lock);
evas_object_del(obj);
elm_exit();
}
EAPI_MAIN int
elm_main(int argc, char **argv)
{
Evas_Object *o;
elm_policy_set(ELM_POLICY_QUIT, ELM_POLICY_QUIT_LAST_WINDOW_CLOSED);
win = elm_win_util_standard_add("efl-thread-4", "EFL Thread 4");
evas_object_smart_callback_add(win, "delete,request", del, NULL);
o = evas_object_rectangle_add(evas_object_evas_get(win));
evas_object_color_set(o, 50, 80, 180, 255);
evas_object_resize(o, 100, 100);
evas_object_show(o);
// new in the examples - we have a mouse down on the blue box cancel
// the thread
evas_object_event_callback_add(o, EVAS_CALLBACK_MOUSE_DOWN, down, NULL);
rect = o;
// create custom thread to do some "work on the side"
my_thread_new();
evas_object_resize(win, 400, 400);
evas_object_show(win);
elm_run();
pthread_mutex_lock(&th_lock);
th_exit = 1;
pthread_mutex_unlock(&th_lock);
return 0;
}
ELM_MAIN()