From 006506278a104bbf8edd1a3eb2c2de75094e6d91 Mon Sep 17 00:00:00 2001
From: Jeff Tinker <jtinker@google.com>
Date: Tue, 9 May 2017 14:31:07 -0700
Subject: [PATCH] Fix widevine drm hal resource leaks

A strong pointer cycle was preventing the drm plugin
from being released.  This change converts the listener
to a weak pointer to break the cycle.

bug:36408047
test: manual testing to verify leaks are fixed
Change-Id: I2e2af392c2b263b7b0943d61dcaee5e94089ce27
---
 .../mediadrm/include_hidl/WVDrmPlugin.h           |  3 ++-
 libwvdrmengine/mediadrm/src_hidl/WVDrmPlugin.cpp  | 15 +++++++++------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/libwvdrmengine/mediadrm/include_hidl/WVDrmPlugin.h b/libwvdrmengine/mediadrm/include_hidl/WVDrmPlugin.h
index 1aa89a46..e14e3588 100644
--- a/libwvdrmengine/mediadrm/include_hidl/WVDrmPlugin.h
+++ b/libwvdrmengine/mediadrm/include_hidl/WVDrmPlugin.h
@@ -38,6 +38,7 @@ using ::android::hardware::hidl_string;
 using ::android::hardware::hidl_vec;
 using ::android::hardware::Return;
 using ::android::sp;
+using ::android::wp;
 
 using android::status_t;
 using std::map;
@@ -350,7 +351,7 @@ struct WVDrmPlugin : public IDrmPlugin, IDrmPluginListener,
   sp<wvcdm::WvContentDecryptionModule> const mCDM;
   WVGenericCryptoInterface* mCrypto;
   map<CdmSessionId, CryptoSession> mCryptoSessions;
-  sp<IDrmPluginListener> mListener;
+  wp<IDrmPluginListener> mListener;
 
   status_t queryProperty(const std::string& property,
                          std::string& stringValue) const;
diff --git a/libwvdrmengine/mediadrm/src_hidl/WVDrmPlugin.cpp b/libwvdrmengine/mediadrm/src_hidl/WVDrmPlugin.cpp
index bcbe9903..1dee072d 100644
--- a/libwvdrmengine/mediadrm/src_hidl/WVDrmPlugin.cpp
+++ b/libwvdrmengine/mediadrm/src_hidl/WVDrmPlugin.cpp
@@ -1122,8 +1122,9 @@ Return<void> WVDrmPlugin::setListener(const sp<IDrmPluginListener>& listener) {
 Return<void> WVDrmPlugin::sendEvent(
     EventType eventType,
     const hidl_vec<uint8_t>& sessionId, const hidl_vec<uint8_t>& data) {
-  if (mListener != NULL) {
-    mListener->sendEvent(eventType, sessionId, data);
+  auto listener = mListener.promote();
+  if (listener != NULL) {
+    listener->sendEvent(eventType, sessionId, data);
   } else {
     ALOGE("Null event listener, event not sent");
   }
@@ -1133,8 +1134,9 @@ Return<void> WVDrmPlugin::sendEvent(
 Return<void> WVDrmPlugin::sendExpirationUpdate(
      const hidl_vec<uint8_t>& sessionId,
      int64_t expiryTimeInMS) {
-  if (mListener != NULL) {
-    mListener->sendExpirationUpdate(sessionId, expiryTimeInMS);
+  auto listener = mListener.promote();
+  if (listener != NULL) {
+    listener->sendExpirationUpdate(sessionId, expiryTimeInMS);
   } else {
     ALOGE("Null event listener, event not sent");
   }
@@ -1144,8 +1146,9 @@ Return<void> WVDrmPlugin::sendExpirationUpdate(
 Return<void> WVDrmPlugin::sendKeysChange(
      const hidl_vec<uint8_t>& sessionId,
      const hidl_vec<KeyStatus>& keyStatusList, bool hasNewUsableKey) {
-  if (mListener != NULL) {
-    mListener->sendKeysChange(sessionId, keyStatusList, hasNewUsableKey);
+  auto listener = mListener.promote();
+  if (listener != NULL) {
+    listener->sendKeysChange(sessionId, keyStatusList, hasNewUsableKey);
   } else {
     ALOGE("Null event listener, event not sent");
   }