From 61c10440898040cbe3eb5eb9d7723f45ab0392a2 Mon Sep 17 00:00:00 2001
From: Ryan Pavlik <ryan.pavlik@collabora.com>
Date: Tue, 6 Apr 2021 17:17:29 -0500
Subject: [PATCH] u/handles: Add graphics sync handle helpers.

---
 src/xrt/auxiliary/util/u_handles.c | 76 +++++++++++++++++++++++++++++-
 src/xrt/auxiliary/util/u_handles.h | 35 ++++++++++++--
 2 files changed, 106 insertions(+), 5 deletions(-)

diff --git a/src/xrt/auxiliary/util/u_handles.c b/src/xrt/auxiliary/util/u_handles.c
index c6ddcce5c..7c9d56e80 100644
--- a/src/xrt/auxiliary/util/u_handles.c
+++ b/src/xrt/auxiliary/util/u_handles.c
@@ -1,4 +1,4 @@
-// Copyright 2020, Collabora, Ltd.
+// Copyright 2020-2021, Collabora, Ltd.
 // SPDX-License-Identifier: BSL-1.0
 /*!
  * @file
@@ -11,6 +11,12 @@
 
 #include "u_handles.h"
 
+/*
+ *
+ * Graphics Buffer Handles
+ *
+ */
+
 #if defined(XRT_GRAPHICS_BUFFER_HANDLE_IS_AHARDWAREBUFFER)
 #include <android/hardware_buffer.h>
 
@@ -89,3 +95,71 @@ u_graphics_buffer_unref(xrt_graphics_buffer_handle_t *handle_ptr)
 	release_graphics_handle(handle);
 	*handle_ptr = XRT_GRAPHICS_BUFFER_HANDLE_INVALID;
 }
+
+/*
+ *
+ * Graphics Sync Handles
+ *
+ */
+
+#if defined(XRT_GRAPHICS_SYNC_HANDLE_IS_FD)
+#include <unistd.h>
+
+static inline void
+release_sync_handle(xrt_graphics_sync_handle_t handle)
+{
+	close(handle);
+}
+
+static inline xrt_graphics_sync_handle_t
+ref_sync_handle(xrt_graphics_sync_handle_t handle)
+{
+	return dup(handle);
+}
+
+#elif defined(XRT_GRAPHICS_SYNC_HANDLE_IS_WIN32_HANDLE)
+
+static inline void
+release_sync_handle(xrt_graphics_sync_handle_t handle)
+{
+	CloseHandle(handle);
+}
+
+static inline xrt_graphics_sync_handle_t
+ref_sync_handle(xrt_graphics_sync_handle_t handle)
+{
+	HANDLE self = GetCurrentProcess();
+	HANDLE result = NULL;
+	if (DuplicateHandle(self, handle, self, &result, 0, FALSE, DUPLICATE_SAME_ACCESS) != 0) {
+		return result;
+	}
+	return NULL;
+}
+
+#else
+#error "need port"
+#endif
+
+xrt_graphics_sync_handle_t
+u_graphics_sync_ref(xrt_graphics_sync_handle_t handle)
+{
+	if (xrt_graphics_sync_handle_is_valid(handle)) {
+		return ref_sync_handle(handle);
+	}
+
+	return XRT_GRAPHICS_SYNC_HANDLE_INVALID;
+}
+
+void
+u_graphics_sync_unref(xrt_graphics_sync_handle_t *handle_ptr)
+{
+	if (handle_ptr == NULL) {
+		return;
+	}
+	xrt_graphics_sync_handle_t handle = *handle_ptr;
+	if (!xrt_graphics_sync_handle_is_valid(handle)) {
+		return;
+	}
+	release_sync_handle(handle);
+	*handle_ptr = XRT_GRAPHICS_SYNC_HANDLE_INVALID;
+}
diff --git a/src/xrt/auxiliary/util/u_handles.h b/src/xrt/auxiliary/util/u_handles.h
index 34e7d9dad..a64d25cbf 100644
--- a/src/xrt/auxiliary/util/u_handles.h
+++ b/src/xrt/auxiliary/util/u_handles.h
@@ -1,4 +1,4 @@
-// Copyright 2020, Collabora, Ltd.
+// Copyright 2020-20211, Collabora, Ltd.
 // SPDX-License-Identifier: BSL-1.0
 /*!
  * @file
@@ -17,13 +17,15 @@
 #ifdef __cplusplus
 extern "C" {
 #endif
+
 /*!
  * Increase the reference count on the buffer handle, returning the new
  * reference.
  *
- * Depending on the underlying type, the value may be the same or different than
- * what was passed in. It should be retained for use at release time,
- * regardless.
+ *
+ * Depending on the underlying type, the value may be the same or different than what was passed in. It should be
+ * retained for use at release time, regardless. (For example, if the underlying native handle does not expose reference
+ * counting, it may be duplicated and the duplicate returned.)
  *
  * @public @memberof xrt_graphics_buffer_handle_t
  */
@@ -42,6 +44,31 @@ u_graphics_buffer_ref(xrt_graphics_buffer_handle_t handle);
 void
 u_graphics_buffer_unref(xrt_graphics_buffer_handle_t *handle);
 
+/*!
+ * Increase the reference count on the sync handle, returning the new
+ * reference.
+ *
+ * Depending on the underlying type, the value may be the same or different than what was passed in. It should be
+ * retained for use at release time, regardless. (For example, if the underlying native handle does not expose reference
+ * counting, it may be duplicated and the duplicate returned.)
+ *
+ * @public @memberof xrt_graphics_sync_handle_t
+ */
+xrt_graphics_sync_handle_t
+u_graphics_sync_ref(xrt_graphics_sync_handle_t handle);
+
+/*!
+ * Decrease the reference count/release the handle reference passed in.
+ *
+ * Be sure to only call this once per handle.
+ *
+ * Performs null-check and clears the value after unreferencing.
+ *
+ * @public @memberof xrt_graphics_sync_handle_t
+ */
+void
+u_graphics_sync_unref(xrt_graphics_sync_handle_t *handle);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif