From e8ac4e6a3414a40f47685ab128993b70413eb190 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Wed, 17 Apr 2024 16:05:18 +0200
Subject: [PATCH] spa: add SPA_IO_AsyncBuffers

This structure has 2 io_buffers. Readers and writers operate on different
io_buffers to implement an asynchronous transfer.
---
 spa/include/spa/node/io.h        | 7 +++++++
 spa/include/spa/node/type-info.h | 1 +
 test/test-spa-node.c             | 1 +
 3 files changed, 9 insertions(+)

diff --git a/spa/include/spa/node/io.h b/spa/include/spa/node/io.h
index 35661e0b7..a0a2c90f7 100644
--- a/spa/include/spa/node/io.h
+++ b/spa/include/spa/node/io.h
@@ -40,6 +40,7 @@ enum spa_io_type {
 	SPA_IO_Position,	/**< position information in the graph, struct spa_io_position */
 	SPA_IO_RateMatch,	/**< rate matching between nodes, struct spa_io_rate_match */
 	SPA_IO_Memory,		/**< memory pointer, struct spa_io_memory (currently not used in PipeWire) */
+	SPA_IO_AsyncBuffers,	/**< async area to exchange buffers, struct spa_io_async_buffers */
 };
 
 /**
@@ -307,6 +308,12 @@ struct spa_io_rate_match {
 	uint32_t padding[7];
 };
 
+/** async buffers */
+struct spa_io_async_buffers {
+	struct spa_io_buffers buffers[2];	/**< async buffers, writers write to current (cycle+1)&1,
+						  *  readers read from (cycle)&1 */
+};
+
 /**
  * \}
  */
diff --git a/spa/include/spa/node/type-info.h b/spa/include/spa/node/type-info.h
index 1f3ce8d0d..5b956348b 100644
--- a/spa/include/spa/node/type-info.h
+++ b/spa/include/spa/node/type-info.h
@@ -34,6 +34,7 @@ static const struct spa_type_info spa_type_io[] = {
 	{ SPA_IO_Position, SPA_TYPE_Int, SPA_TYPE_INFO_IO_BASE "Position", NULL },
 	{ SPA_IO_RateMatch, SPA_TYPE_Int, SPA_TYPE_INFO_IO_BASE "RateMatch", NULL },
 	{ SPA_IO_Memory, SPA_TYPE_Int, SPA_TYPE_INFO_IO_BASE "Memory", NULL },
+	{ SPA_IO_AsyncBuffers, SPA_TYPE_Int, SPA_TYPE_INFO_IO_BASE "AsyncBuffers", NULL },
 	{ 0, 0, NULL, NULL },
 };
 
diff --git a/test/test-spa-node.c b/test/test-spa-node.c
index 72ffe64da..4b91d3c76 100644
--- a/test/test-spa-node.c
+++ b/test/test-spa-node.c
@@ -71,6 +71,7 @@ PWTEST(node_io_abi)
 	pwtest_int_eq(SPA_IO_Position, 7);
 	pwtest_int_eq(SPA_IO_RateMatch, 8);
 	pwtest_int_eq(SPA_IO_Memory, 9);
+	pwtest_int_eq(SPA_IO_AsyncBuffers, 10);
 
 	/* position state */
 	pwtest_int_eq(SPA_IO_POSITION_STATE_STOPPED, 0);