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Fix deadlock when pending key release sessions are deallocated

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[ Merge from http://go/wvgerrit/27261/ ]

Sessions created to release keys are periodically cleaned up if the
key release operation does not complete within a specific
amount of time. If other sessions are open, they will be released
through the timer thread. This would result in deadlock as a mutex
was taken twice.

Test: Verified by cdm_extended_duration_test
(AutomatedOfflineSessionReleaseOnOpenSession and
AutomatedOfflineSessionReleaseOnTimerEvent tests)

b/37546078

Change-Id: I7d45f939bdce77e5db461a401364da4f42c1c034
This commit is contained in:
Rahul Frias
2017-05-11 20:12:33 -07:00
parent ee283ec61c
commit 02fe2ef693
2 changed files with 164 additions and 26 deletions
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2
libwvdrmengine/cdm/core/src/cdm_engine.cpp
View File

@@ -1443,6 +1443,7 @@ void CdmEngine::OnTimerEvent() {
bool is_initial_usage_update = false;
bool is_usage_update_needed = false;
{
AutoLock lock(session_list_lock_);
for (CdmSessionMap::iterator iter = sessions_.begin();
iter != sessions_.end(); ++iter) {
@@ -1477,6 +1478,7 @@ void CdmEngine::OnTimerEvent() {
}
}
}
}
CloseExpiredReleaseSessions();
}

136
libwvdrmengine/cdm/test/cdm_extended_duration_test.cpp
View File

@@ -988,6 +988,142 @@ TEST_F(WvCdmExtendedDurationTest, UsageOverflowTest) {
}
}
// This test verifies that sessions allocated internally during key release
// message generation are deallocated after their time to live period expires
// by timer events (if other sessions are open).
TEST_F(WvCdmExtendedDurationTest, AutomatedOfflineSessionReleaseOnTimerEvent) {
Unprovision();
Provision();
// Leave session open to run the CDM timer
CdmSessionId streaming_session_id;
decryptor_.OpenSession(g_key_system, NULL, kDefaultCdmIdentifier, NULL,
&streaming_session_id);
// override default settings unless configured through the command line
std::string key_id;
std::string client_auth;
GetOfflineConfiguration(&key_id, &client_auth);
uint32_t initial_open_sessions =
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS);
uint32_t max_sessions =
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_MAX_NUMBER_OF_SESSIONS);
decryptor_.OpenSession(g_key_system, NULL, kDefaultCdmIdentifier, NULL,
&session_id_);
GenerateKeyRequest(kOfflineClip4, kLicenseTypeOffline);
VerifyKeyRequestResponse(kUatLicenseServer, client_auth, false);
EXPECT_FALSE(key_set_id_.empty());
decryptor_.CloseSession(session_id_);
CdmKeySetId key_set_id = key_set_id_;
session_id_.clear();
key_set_id_.clear();
decryptor_.OpenSession(g_key_system, NULL, kDefaultCdmIdentifier, NULL,
&session_id_);
EXPECT_EQ(wvcdm::KEY_ADDED, decryptor_.RestoreKey(session_id_, key_set_id));
decryptor_.CloseSession(session_id_);
session_id_.clear();
GenerateKeyRelease(key_set_id);
uint32_t open_sessions =
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS);
EXPECT_GT(open_sessions, initial_open_sessions);
sleep(kMinute + kClockTolerance);
open_sessions =
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS);
EXPECT_EQ(open_sessions, initial_open_sessions);
session_id_.clear();
GenerateKeyRelease(key_set_id);
key_set_id_ = key_set_id;
VerifyKeyRequestResponse(kUatLicenseServer, client_auth, false);
decryptor_.CloseSession(streaming_session_id);
}
// This test verifies that sessions allocated internally during key release
// message generation are deallocated after their time to live period expires
// when a new session is opened.
TEST_F(WvCdmExtendedDurationTest, AutomatedOfflineSessionReleaseOnOpenSession) {
Unprovision();
Provision();
// override default settings unless configured through the command line
std::string key_id;
std::string client_auth;
GetOfflineConfiguration(&key_id, &client_auth);
uint32_t initial_open_sessions =
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS);
uint32_t max_sessions =
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_MAX_NUMBER_OF_SESSIONS);
decryptor_.OpenSession(g_key_system, NULL, kDefaultCdmIdentifier, NULL,
&session_id_);
GenerateKeyRequest(kOfflineClip4, kLicenseTypeOffline);
VerifyKeyRequestResponse(kUatLicenseServer, client_auth, false);
EXPECT_FALSE(key_set_id_.empty());
decryptor_.CloseSession(session_id_);
CdmKeySetId key_set_id = key_set_id_;
session_id_.clear();
key_set_id_.clear();
decryptor_.OpenSession(g_key_system, NULL, kDefaultCdmIdentifier, NULL,
&session_id_);
EXPECT_EQ(wvcdm::KEY_ADDED, decryptor_.RestoreKey(session_id_, key_set_id));
decryptor_.CloseSession(session_id_);
session_id_.clear();
GenerateKeyRelease(key_set_id);
decryptor_.OpenSession(g_key_system, NULL, kDefaultCdmIdentifier, NULL,
&session_id_);
EXPECT_GT(
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS),
initial_open_sessions);
decryptor_.CloseSession(session_id_);
EXPECT_GT(
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS),
initial_open_sessions);
sleep(kMinute + kClockTolerance);
EXPECT_GT(
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS),
initial_open_sessions);
decryptor_.OpenSession(g_key_system, NULL, kDefaultCdmIdentifier, NULL,
&session_id_);
EXPECT_GT(
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS),
initial_open_sessions);
decryptor_.CloseSession(session_id_);
EXPECT_EQ(
QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_NUMBER_OF_OPEN_SESSIONS),
initial_open_sessions);
session_id_.clear();
GenerateKeyRelease(key_set_id);
key_set_id_ = key_set_id;
VerifyKeyRequestResponse(kUatLicenseServer, client_auth, false);
}
// This test verifies that sessions allocated internally during
// key release message generation are deallocated after their
// time to live period expires.