gralloc: Add foreign buffer usage flag
Adds GRALLOC_USAGE_FOREIGN_BUFFERS, which a consumer may set as a usage
flag if it intends to attach buffers that it has not detached from the
BufferQueue. It provides a hint to the producer (who may query the
consumer usage bits) that it may receive a buffer from another
BufferQueue, so that it can exit during initialization, hopefully with a
meaningful error message, if such buffers are not supported.
Also adds GRALLOC_USAGE_ALLOC_MASK, which is applied to usage bits
before calling alloc on the gralloc module, and prevents the module from
seeing GRALLOC_USAGE_FOREIGN_BUFFERS, since that usage flag is of no use
while allocating buffers.
Bug: 19801661
Change-Id: I17b927de94245f4df7cfd3f4483b544da3e9cd35
diff --git a/include/hardware/gralloc.h b/include/hardware/gralloc.h
index 7d00114..7aeb84e 100644
--- a/include/hardware/gralloc.h
+++ b/include/hardware/gralloc.h
@@ -127,6 +127,17 @@
/* buffer may be used as a cursor */
GRALLOC_USAGE_CURSOR = 0x00008000,
+ /* Set by the consumer to indicate to the producer that they may attach a
+ * buffer that they did not detach from the BufferQueue. Will be filtered
+ * out by GRALLOC_USAGE_ALLOC_MASK, so gralloc modules will not need to
+ * handle this flag. */
+ GRALLOC_USAGE_FOREIGN_BUFFERS = 0x00010000,
+
+ /* Mask of all flags which could be passed to a gralloc module for buffer
+ * allocation. Any flags not in this mask do not need to be handled by
+ * gralloc modules. */
+ GRALLOC_USAGE_ALLOC_MASK = ~(GRALLOC_USAGE_FOREIGN_BUFFERS),
+
/* implementation-specific private usage flags */
GRALLOC_USAGE_PRIVATE_0 = 0x10000000,
GRALLOC_USAGE_PRIVATE_1 = 0x20000000,