[theme] callback-style waiting for a theme to load

src/ax.h

@@ -35,6 +35,7 @@ void ax_set_theme_font(
 void ax_set_theme_iconset(
     struct ax_ctxt* ax, const char* iconset_dir);
 
+void ax_theme_wait_until_loaded(struct ax_ctxt* ax, struct ax_theme* thm);
 int ax_select_theme(struct ax_ctxt* ax, struct ax_theme* thm);
 
 #define AX_ERR_THEME_LOADING  1

src/backend/sdl.c

@@ -93,7 +93,6 @@ struct font_list {
     struct font_list* next;
     struct ax_theme* thm;
     size_t cat;
-    struct msgq* cb_mq;
 };
 
 static void load_fonts(
@@ -123,7 +122,6 @@ void ax__backend_step(struct ax_backend* bac)
                l->next = fonts;
                l->thm = m.theme;
                l->cat = m.category;
-               l->cb_mq = m.callback_mq;
                fonts = l;
                break;
            });
@@ -150,6 +148,7 @@ static int load_font(
     struct rgn* rgn, const char* path, size_t size,
     struct ax_font_h** out_fh, const char** out_err)
 {
+    printf("loading `%s' (size %zu)\n", path, size);
     struct ax_font_h* fh = ralloc_typed(rgn, struct ax_font_h, 1);
     if ((fh->font = TTF_OpenFont(path, size)) == NULL) {
         *out_err = TTF_GetError();
@@ -173,13 +172,7 @@ static void load_fonts(struct ax_backend* bac, struct font_list* fl)
                             &fh, &err)) != 0) {
             goto fail;
         }
-        bool is_loaded = ax__theme_set_font_handle(thm, fl->cat, fh);
+        ax__theme_set_font_handle(thm, fl->cat, fh);
-        if (is_loaded) {
-            struct ax_msg_theme_loaded* m =
-                msgq_begin_send_typed(fl->cb_mq, ax_msg_theme_loaded);
-            m->theme = thm;
-            msgq_end_send(fl->cb_mq);
-        }
     }
 
 fail:

src/concurrent/msg.h

@@ -12,7 +12,6 @@ struct ax_msg_shutdown {
 };
 
 struct ax_msg_load_font {
-    struct msgq* callback_mq;
     struct ax_theme* theme;
     int category;
 };

src/concurrent/msgq.h

@@ -13,6 +13,11 @@ struct msgq {
     pthread_cond_t cv;
 };
 
+struct msgq_list {
+    struct msgq* mq;
+    struct msgq_list* next;
+};
+
 struct msgq_msg_list {
     struct msgq_msg_list* next;
     int type;

src/ctxt/ctxt.c

@@ -115,16 +115,11 @@ void ax_end_theme(struct ax_ctxt* ax, struct ax_theme** out_thm)
     ax->thmb = NULL;
     rgn_clear(ax->thmb_rgn);
 
+    ax__theme_load(thm, ax__backend_msgq(ax->bac));
+
     if (out_thm != NULL) {
         *out_thm = thm;
     }
-
-    struct msgq* callback;
-    UNIMPLEMENTED();
-
-    ax__theme_request_load(thm,
-                           ax__backend_msgq(ax->bac),
-                           callback);
 }
 
 void ax_set_theme_color(
@@ -160,6 +155,18 @@ void ax_set_theme_iconset(
     UNIMPLEMENTED();
 }
 
+void ax_theme_wait_until_loaded(struct ax_ctxt* ax, struct ax_theme* thm)
+{
+    struct rgn rgn[1];
+    rgn_init(rgn, SMALL);
+    struct msgq* mq = msgq_new(rgn);
+    ax__theme_on_load(thm, mq);
+    msgq_begin_recv_and_wait(mq);
+    MSGQ_RECV_ALL(mq) {}
+    msgq_end_recv(mq);
+    rgn_cleanup(rgn);
+}
+
 int ax_select_theme(struct ax_ctxt* ax, struct ax_theme* thm)
 {
     ASSERT_NON_NULL(thm, "theme");

src/ctxt/theme.c

@@ -95,7 +95,9 @@ struct ax_theme* ax__theme_builder_finish(
             dflt_font_path :
             rstrdup(dst_rgn, thm->font_path[i]);
     }
-    pthread_mutex_init(&thm->handles_mx, NULL);
+    thm->on_load_rgn = rgn_new(dst_rgn, SMALL);
+    thm->on_load = NULL;
+    pthread_mutex_init(&thm->mx, NULL);
     rgn_pin(dst_rgn, thm, (void*) pthread_mutex_destroy);
     return thm;
 }
@@ -114,50 +116,72 @@ static inline bool is_loaded(struct ax_theme* thm)
     return true;
 }
 
+static inline void msgq_send_theme_loaded(struct msgq* mq, struct ax_theme* thm)
+{
+    msgq_begin_send_typed(mq, ax_msg_theme_loaded)
+        ->theme = thm;
+    msgq_end_send(mq);
+}
+
 struct ax_font_h* ax__theme_font_handle(
     struct ax_theme* thm,
     enum ax_font_cat i)
 {
-    pthread_mutex_lock(&thm->handles_mx);
+    pthread_mutex_lock(&thm->mx);
     struct ax_font_h* h = thm->font_handle[i];
-    pthread_mutex_unlock(&thm->handles_mx);
+    pthread_mutex_unlock(&thm->mx);
     return h;
 }
 
 bool ax__theme_is_loaded(struct ax_theme* thm)
 {
-    pthread_mutex_lock(&thm->handles_mx);
+    pthread_mutex_lock(&thm->mx);
     bool l = is_loaded(thm);
-    pthread_mutex_unlock(&thm->handles_mx);
+    pthread_mutex_unlock(&thm->mx);
     return l;
 }
 
-bool ax__theme_set_font_handle(
+void ax__theme_set_font_handle(
     struct ax_theme* thm,
     enum ax_font_cat i,
     struct ax_font_h* h)
 {
-    pthread_mutex_lock(&thm->handles_mx);
+    pthread_mutex_lock(&thm->mx);
     thm->font_handle[i] = h;
-    bool l = is_loaded(thm);
+    if (is_loaded(thm)) {
-    pthread_mutex_unlock(&thm->handles_mx);
+        while (thm->on_load != NULL) {
-    return l;
+            msgq_send_theme_loaded(thm->on_load->mq, thm);
+            thm->on_load = thm->on_load->next;
+        }
+    }
+    pthread_mutex_unlock(&thm->mx);
 }
 
-void ax__theme_request_load(
+void ax__theme_load(struct ax_theme* thm, struct msgq* req_mq)
-    struct ax_theme* thm,
-    struct msgq* req_mq,
-    struct msgq* res_mq)
 {
     for (size_t i = 0; i < AX_FONT__COUNT; i++) {
         struct ax_msg_load_font* m = msgq_begin_send_typed(req_mq, ax_msg_load_font);
-        m->callback_mq = res_mq;
         m->theme = thm;
         m->category = i;
         msgq_end_send(req_mq);
     }
 }
 
+void ax__theme_on_load(struct ax_theme* thm, struct msgq* res_mq)
+{
+    pthread_mutex_lock(&thm->mx);
+    if (is_loaded(thm)) {
+        msgq_send_theme_loaded(res_mq, thm);
+    } else {
+        struct msgq_list* l =
+            ralloc_typed(thm->on_load_rgn, struct msgq_list, 1);
+        l->mq = res_mq;
+        l->next = thm->on_load;
+        thm->on_load = l;
+    }
+    pthread_mutex_unlock(&thm->mx);
+}
+
 int ax__string_to_color_cat(const char* str, enum ax_color_cat* out_cat)
 {
     enum ax_color_cat val;

src/ctxt/theme.h

@@ -7,6 +7,7 @@
 
 struct rgn;
 struct msgq;
+struct msgq_list;
 
 #define THEME_BUILDER_DESIRED_REGION_SIZE (16*1024)
 
@@ -43,7 +44,9 @@ struct ax_theme {
     size_t            font_size[AX_FONT__COUNT];
     const char*       font_path[AX_FONT__COUNT];
     struct ax_font_h* font_handle[AX_FONT__COUNT];
-    pthread_mutex_t   handles_mx;
+    struct rgn*       on_load_rgn;
+    struct msgq_list* on_load;
+    pthread_mutex_t   mx;
 };
 
 struct ax_theme_builder {
@@ -99,14 +102,17 @@ struct ax_font_h* ax__theme_font_handle(
 bool ax__theme_is_loaded(
     struct ax_theme* thm);
 
-bool ax__theme_set_font_handle( // returns `true` if the font is now loaded
+void ax__theme_set_font_handle(
     struct ax_theme* thm,
     enum ax_font_cat i,
     struct ax_font_h* h);
 
-void ax__theme_request_load(
+void ax__theme_load(
+    struct ax_theme* thm,
+    struct msgq* req_mq);
+
+void ax__theme_on_load(
     struct ax_theme* thm,
-    struct msgq* req_mq,
     struct msgq* res_mq);
 
 /*

test/main.c

@@ -40,7 +40,9 @@ int main(void)
     ax_set_logger(ax, 0, false);
 
     struct ax_theme* thm = make_example_theme();
-    (void) thm;
+    ax_theme_wait_until_loaded(ax, thm);
+    printf("it loaded!\n");
+    usleep(1000 * 1000 * 2);
 
     /*
     struct ax_evt evt;