From c191c9a4669b64f36c36e956fc1249a422f2629c Mon Sep 17 00:00:00 2001
From: Jakob Bornecrantz <jakob@collabora.com>
Date: Fri, 18 Dec 2020 15:04:00 +0000
Subject: [PATCH] ipc: Support sending sync handles on layer_commit

---
 src/xrt/ipc/client/ipc_client_compositor.c | 25 +++++++++++++++++++---
 src/xrt/ipc/server/ipc_server_handler.c    | 19 +++++++++++++++-
 src/xrt/ipc/shared/proto.json              |  1 +
 3 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/src/xrt/ipc/client/ipc_client_compositor.c b/src/xrt/ipc/client/ipc_client_compositor.c
index 01abb3ec1..bc6c4086a 100644
--- a/src/xrt/ipc/client/ipc_client_compositor.c
+++ b/src/xrt/ipc/client/ipc_client_compositor.c
@@ -28,6 +28,10 @@
 #include <errno.h>
 #include <assert.h>
 
+#ifdef XRT_GRAPHICS_SYNC_HANDLE_IS_FD
+#include <unistd.h>
+#endif
+
 
 /*
  *
@@ -616,7 +620,7 @@ ipc_compositor_layer_commit(struct xrt_compositor *xc,
 {
 	struct ipc_client_compositor *icc = ipc_client_compositor(xc);
 
-	assert(!xrt_graphics_sync_handle_is_valid(sync_handle));
+	bool valid_sync = xrt_graphics_sync_handle_is_valid(sync_handle);
 
 	struct ipc_shared_memory *ism = icc->ipc_c->ism;
 	struct ipc_layer_slot *slot = &ism->slots[icc->layers.slot_id];
@@ -624,12 +628,27 @@ ipc_compositor_layer_commit(struct xrt_compositor *xc,
 	// Last bit of data to put in the shared memory area.
 	slot->num_layers = icc->layers.num_layers;
 
-	IPC_CALL_CHK(ipc_call_compositor_layer_sync(
-	    icc->ipc_c, frame_id, icc->layers.slot_id, &icc->layers.slot_id));
+	IPC_CALL_CHK(ipc_call_compositor_layer_sync( //
+	    icc->ipc_c,                              //
+	    frame_id,                                //
+	    icc->layers.slot_id,                     //
+	    &sync_handle,                            //
+	    valid_sync ? 1 : 0,                      //
+	    &icc->layers.slot_id));                  //
 
 	// Reset.
 	icc->layers.num_layers = 0;
 
+#ifdef XRT_GRAPHICS_SYNC_HANDLE_IS_FD
+	// Need to consume this handle.
+	if (valid_sync) {
+		close(sync_handle);
+		sync_handle = XRT_GRAPHICS_SYNC_HANDLE_INVALID;
+	}
+#else
+#error "Not yet implemented for this platform"
+#endif
+
 	return res;
 }
 
diff --git a/src/xrt/ipc/server/ipc_server_handler.c b/src/xrt/ipc/server/ipc_server_handler.c
index 222204922..f377efc72 100644
--- a/src/xrt/ipc/server/ipc_server_handler.c
+++ b/src/xrt/ipc/server/ipc_server_handler.c
@@ -14,6 +14,10 @@
 #include "server/ipc_server.h"
 #include "ipc_server_generated.h"
 
+#ifdef XRT_GRAPHICS_SYNC_HANDLE_IS_FD
+#include <unistd.h>
+#endif
+
 
 /*
  *
@@ -183,11 +187,24 @@ xrt_result_t
 ipc_handle_compositor_layer_sync(volatile struct ipc_client_state *ics,
                                  int64_t frame_id,
                                  uint32_t slot_id,
-                                 uint32_t *out_free_slot_id)
+                                 uint32_t *out_free_slot_id,
+                                 const xrt_graphics_sync_handle_t *handles,
+                                 const uint32_t num_handles)
 {
 	struct ipc_shared_memory *ism = ics->server->ism;
 	struct ipc_layer_slot *slot = &ism->slots[slot_id];
 
+	for (uint32_t i = 0; i < num_handles; i++) {
+		if (!xrt_graphics_sync_handle_is_valid(handles[i])) {
+			continue;
+		}
+#ifdef XRT_GRAPHICS_SYNC_HANDLE_IS_FD
+		close(handles[i]);
+#else
+#error "Need port to transport these graphics buffers"
+#endif
+	}
+
 	// Copy current slot data to our state.
 	ics->render_state = *slot;
 	ics->rendering_state = true;
diff --git a/src/xrt/ipc/shared/proto.json b/src/xrt/ipc/shared/proto.json
index dbbcdcc95..a9e5f38c4 100644
--- a/src/xrt/ipc/shared/proto.json
+++ b/src/xrt/ipc/shared/proto.json
@@ -99,6 +99,7 @@
 			{"name": "frame_id", "type": "int64_t"},
 			{"name": "slot_id", "type": "uint32_t"}
 		],
+		"in_handles": {"type": "xrt_graphics_sync_handle_t"},
 		"out": [
 			{"name": "free_slot_id", "type": "uint32_t"}
 		]