From 031555c85d8513a293bf4f329f1a87b576024b1f Mon Sep 17 00:00:00 2001
From: Andri Yngvason <andri@yngvason.is>
Date: Sun, 29 Aug 2021 14:26:12 +0000
Subject: [PATCH] fb: Add hold/release logic

---
 include/fb.h      |  6 ++++++
 include/neatvnc.h |  3 +++
 src/fb.c          | 18 ++++++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/include/fb.h b/include/fb.h
index 4c56886..ddde05f 100644
--- a/include/fb.h
+++ b/include/fb.h
@@ -24,6 +24,9 @@
 
 struct nvnc_fb {
 	int ref;
+	int hold_count;
+	nvnc_fb_release_fn on_release;
+	void* userdata;
 	void* addr;
 	enum nvnc_fb_flags flags;
 	size_t size;
@@ -32,3 +35,6 @@ struct nvnc_fb {
 	uint32_t fourcc_format;
 	uint64_t fourcc_modifier;
 };
+
+void nvnc_fb_hold(struct nvnc_fb* fb);
+void nvnc_fb_release(struct nvnc_fb* fb);
diff --git a/include/neatvnc.h b/include/neatvnc.h
index 7a15233..92e2d79 100644
--- a/include/neatvnc.h
+++ b/include/neatvnc.h
@@ -50,6 +50,7 @@ typedef bool (*nvnc_auth_fn)(const char* username, const char* password,
                              void* userdata);
 typedef void (*nvnc_render_fn)(struct nvnc_display*, struct nvnc_fb*);
 typedef void (*nvnc_cut_text_fn)(struct nvnc*, const char* text, uint32_t len);
+typedef void (*nvnc_fb_release_fn)(struct nvnc_fb*, void* userdata);
 
 extern const char nvnc_version[];
 
@@ -87,6 +88,8 @@ void nvnc_fb_unref(struct nvnc_fb* fb);
 
 enum nvnc_fb_flags nvnc_fb_get_flags(const struct nvnc_fb*);
 void nvnc_fb_set_flags(struct nvnc_fb*, enum nvnc_fb_flags);
+void nvnc_fb_set_release_fn(struct nvnc_fb* fb, nvnc_fb_release_fn fn,
+			    void* userdata);
 
 void* nvnc_fb_get_addr(const struct nvnc_fb* fb);
 uint16_t nvnc_fb_get_width(const struct nvnc_fb* fb);
diff --git a/src/fb.c b/src/fb.c
index 9685ba0..c935a59 100644
--- a/src/fb.c
+++ b/src/fb.c
@@ -110,3 +110,21 @@ void nvnc_fb_unref(struct nvnc_fb* fb)
 	if (--fb->ref == 0)
 		nvnc__fb_free(fb);
 }
+
+EXPORT
+void nvnc_fb_set_release_fn(struct nvnc_fb* fb, nvnc_fb_release_fn fn, void* userdata)
+{
+	fb->on_release = fn;
+	fb->userdata = userdata;
+}
+
+void nvnc_fb_hold(struct nvnc_fb* fb)
+{
+	fb->hold_count++;
+}
+
+void nvnc_fb_release(struct nvnc_fb* fb)
+{
+	if (--fb->hold_count == 0 && fb->on_release)
+		fb->on_release(fb, fb->userdata);
+}