From fa785531f7510e3dee799dd4b37279e1e04f4a81 Mon Sep 17 00:00:00 2001 From: Jeff Brown Date: Tue, 24 May 2011 11:23:27 -0700 Subject: [PATCH] Coalesce input events that arrive faster than 333Hz. (DO NOT MERGE) Some drivers report individual finger updates one at a time instead of all at once. When 10 fingers are down, this can cause the framework to have to handle 10 times as many events each with 10 times as much data. Applications like PointerLocation would get significantly bogged down by all of the redundant samples. This change coalesces samples that are closely spaced in time, before they are dispatched, as part of the motion event batching protocol. Increased the size of the InputChannel shared memory buffer so that applications can catch up faster if they accumulate a backlog of samples. Change-Id: Ibc6abf8af027d9003011ac75caa12941080caba3 --- libs/ui/InputTransport.cpp | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/libs/ui/InputTransport.cpp b/libs/ui/InputTransport.cpp index 9d1b8b94e..93d0d1f8a 100644 --- a/libs/ui/InputTransport.cpp +++ b/libs/ui/InputTransport.cpp @@ -27,8 +27,14 @@ namespace android { +#define ROUND_UP(value, boundary) (((value) + (boundary) - 1) & ~((boundary) - 1)) +#define MIN_HISTORY_DEPTH 20 + // Must be at least sizeof(InputMessage) + sufficient space for pointer data -static const int DEFAULT_MESSAGE_BUFFER_SIZE = 16384; +static const int DEFAULT_MESSAGE_BUFFER_SIZE = ROUND_UP( + sizeof(InputMessage) + MIN_HISTORY_DEPTH + * (sizeof(InputMessage::SampleData) + MAX_POINTERS * sizeof(PointerCoords)), + 4096); // Signal sent by the producer to the consumer to inform it that a new message is // available to be consumed in the shared memory buffer.