From b8a959b00fe57fc431034f9bea3c7b3380d4b6a5 Mon Sep 17 00:00:00 2001
From: Tianjie Xu <xunchang@google.com>
Date: Fri, 14 Jun 2019 15:35:31 -0700
Subject: Add a new key_pressed_mutex

The following variables in recovery ui were protected by
key_queue_mutex. But the purpose of key_queue_mutex is to protect the
key_queue, which will be changed after we already have a key code. So
getting the key pressed should be orthogonal to the key queue. And
adding a mutex will help to avoid deadlocks in b/135078366.

Variables include:
  char key_pressed[KEY_MAX + 1];
  int key_last_down;
  bool key_long_press;
  int key_down_count;
  bool enable_reboot;

Bug: 135078366
Test: boot into recovery and press keys
Change-Id: Ie2cfcf1f2fec49b53f8fac97aa9a2c60f15b84f9
---
 recovery_ui/include/recovery_ui/ui.h | 16 ++++++++++------
 recovery_ui/ui.cpp                   | 12 ++++++------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/recovery_ui/include/recovery_ui/ui.h b/recovery_ui/include/recovery_ui/ui.h
index 797e2f0d5..0b29c29f1 100644
--- a/recovery_ui/include/recovery_ui/ui.h
+++ b/recovery_ui/include/recovery_ui/ui.h
@@ -230,18 +230,22 @@ class RecoveryUI {
 
   bool InitScreensaver();
   void SetScreensaverState(ScreensaverState state);
+
   // Key event input queue
   std::mutex key_queue_mutex;
   std::condition_variable key_queue_cond;
   bool key_interrupted_;
   int key_queue[256], key_queue_len;
-  char key_pressed[KEY_MAX + 1];  // under key_queue_mutex
-  int key_last_down;              // under key_queue_mutex
-  bool key_long_press;            // under key_queue_mutex
-  int key_down_count;             // under key_queue_mutex
-  bool enable_reboot;             // under key_queue_mutex
-  int rel_sum;
 
+  // key press events
+  std::mutex key_press_mutex;
+  char key_pressed[KEY_MAX + 1];
+  int key_last_down;
+  bool key_long_press;
+  int key_down_count;
+  bool enable_reboot;
+
+  int rel_sum;
   int consecutive_power_keys;
   int last_key;
 
diff --git a/recovery_ui/ui.cpp b/recovery_ui/ui.cpp
index cf0d3b563..51ad169c5 100644
--- a/recovery_ui/ui.cpp
+++ b/recovery_ui/ui.cpp
@@ -346,7 +346,7 @@ void RecoveryUI::ProcessKey(int key_code, int updown) {
   bool long_press = false;
 
   {
-    std::lock_guard<std::mutex> lg(key_queue_mutex);
+    std::lock_guard<std::mutex> lg(key_press_mutex);
     key_pressed[key_code] = updown;
     if (updown) {
       ++key_down_count;
@@ -393,7 +393,7 @@ void RecoveryUI::TimeKey(int key_code, int count) {
   std::this_thread::sleep_for(750ms);  // 750 ms == "long"
   bool long_press = false;
   {
-    std::lock_guard<std::mutex> lg(key_queue_mutex);
+    std::lock_guard<std::mutex> lg(key_press_mutex);
     if (key_last_down == key_code && key_down_count == count) {
       long_press = key_long_press = true;
     }
@@ -518,13 +518,13 @@ bool RecoveryUI::IsUsbConnected() {
 }
 
 bool RecoveryUI::IsKeyPressed(int key) {
-  std::lock_guard<std::mutex> lg(key_queue_mutex);
+  std::lock_guard<std::mutex> lg(key_press_mutex);
   int pressed = key_pressed[key];
   return pressed;
 }
 
 bool RecoveryUI::IsLongPress() {
-  std::lock_guard<std::mutex> lg(key_queue_mutex);
+  std::lock_guard<std::mutex> lg(key_press_mutex);
   bool result = key_long_press;
   return result;
 }
@@ -548,7 +548,7 @@ void RecoveryUI::FlushKeys() {
 
 RecoveryUI::KeyAction RecoveryUI::CheckKey(int key, bool is_long_press) {
   {
-    std::lock_guard<std::mutex> lg(key_queue_mutex);
+    std::lock_guard<std::mutex> lg(key_press_mutex);
     key_long_press = false;
   }
 
@@ -592,6 +592,6 @@ RecoveryUI::KeyAction RecoveryUI::CheckKey(int key, bool is_long_press) {
 void RecoveryUI::KeyLongPress(int) {}
 
 void RecoveryUI::SetEnableReboot(bool enabled) {
-  std::lock_guard<std::mutex> lg(key_queue_mutex);
+  std::lock_guard<std::mutex> lg(key_press_mutex);
   enable_reboot = enabled;
 }
-- 
cgit v1.2.3