commit e60a4ad3b52096866cece5c17a793269457f8de1
author Tianyu Jiang <tianyuj@google.com> Fri Jan 04 14:37:23 2019 -0800
committer Tianyu Jiang <tianyuj@google.com> Tue Jan 08 01:16:13 2019 +0000
tree b0b78f1d4fc14d028a8e7f862aea627dd83f2eac
parent 30f231caa70687ffda713ea16613a9a3fd0110fc

Post to all existing and non-existing consumers of the buffer

Previously, producer only post to all current clients of the buffer
except for the producer itself. In this change, producer post to all
existing and non-existing clients of the buffer except for the producer
itself.

Fix: 120869419
Test: Vega is able to recover itself during DON after killing vrcore
or compositor process.
Test: on vega_xr and blueline_xr with the following tests
buffer_hub-test buffer_hub_queue-test dvr_buffer_queue-test
dvr_api-test libdvrtracking-test(vega only) buffer_hub_queue_producer-test

Change-Id: I29f24268b7704fbeb06a4302b11dcd89dd13c133

libs/vr/libbufferhub/producer_buffer.cpp

diff --git a/libs/vr/libbufferhub/producer_buffer.cpp b/libs/vr/libbufferhub/producer_buffer.cpp
index 5274bf2..edfdddf 100644
--- a/libs/vr/libbufferhub/producer_buffer.cpp
+++ b/libs/vr/libbufferhub/producer_buffer.cpp
@@ -89,13 +89,10 @@
     return -EBUSY;
   }
 
-  // Set the producer client buffer state to released, other clients' buffer
-  // state to posted.
-  uint32_t current_active_clients_bit_mask =
-      active_clients_bit_mask_->load(std::memory_order_acquire);
-  uint32_t updated_buffer_state = current_active_clients_bit_mask &
-                                  (~client_state_mask()) &
-                                  BufferHubDefs::kHighBitsMask;
+  // Set the producer client buffer state to released, that of all other clients
+  // (both existing and non-existing clients) to posted.
+  uint32_t updated_buffer_state =
+      (~client_state_mask()) & BufferHubDefs::kHighBitsMask;
   while (!buffer_state_->compare_exchange_weak(
       current_buffer_state, updated_buffer_state, std::memory_order_acq_rel,
       std::memory_order_acquire)) {
@@ -176,7 +173,9 @@
   }
   if (BufferHubDefs::AnyClientAcquired(current_buffer_state) ||
       BufferHubDefs::AnyClientGained(current_buffer_state) ||
-      (BufferHubDefs::AnyClientPosted(current_buffer_state) &&
+      (BufferHubDefs::AnyClientPosted(
+           current_buffer_state &
+           active_clients_bit_mask_->load(std::memory_order_acquire)) &&
        !gain_posted_buffer)) {
     ALOGE("%s: not released id=%d state=%" PRIx32 ".", __FUNCTION__, id(),
           current_buffer_state);
@@ -198,7 +197,9 @@
 
     if (BufferHubDefs::AnyClientAcquired(current_buffer_state) ||
         BufferHubDefs::AnyClientGained(current_buffer_state) ||
-        (BufferHubDefs::AnyClientPosted(current_buffer_state) &&
+        (BufferHubDefs::AnyClientPosted(
+             current_buffer_state &
+             active_clients_bit_mask_->load(std::memory_order_acquire)) &&
          !gain_posted_buffer)) {
       ALOGE(
           "%s: Failed to gain the buffer. The buffer is no longer released. "