SF: Remove obsolete HWComposer members

Remove mExternalHwcDisplayId, an obsolete special case for legacy multi-
display mode. Assert primary display existence instead of propagating to
callers, which is closer to how headless mode would work, i.e. injecting
a placeholder primary display. Remove isVirtual checks now that they are
enforced at compile time. Prevent primary display disconnection for now.

Bug: 182939859
Test: libsurfaceflinger_unittest
Change-Id: I507db6a3ac0bda93005a86b38cca6ebbcd5c0155
diff --git a/services/surfaceflinger/tests/unittests/SurfaceFlinger_HandleTransactionLockedTest.cpp b/services/surfaceflinger/tests/unittests/SurfaceFlinger_HandleTransactionLockedTest.cpp
index b713334..313ab03 100644
--- a/services/surfaceflinger/tests/unittests/SurfaceFlinger_HandleTransactionLockedTest.cpp
+++ b/services/surfaceflinger/tests/unittests/SurfaceFlinger_HandleTransactionLockedTest.cpp
@@ -282,7 +282,8 @@
 }
 
 TEST_F(HandleTransactionLockedTest, processesHotplugDisconnectPrimaryDisplay) {
-    processesHotplugDisconnectCommon<SimplePrimaryDisplayCase>();
+    EXPECT_EXIT(processesHotplugDisconnectCommon<SimplePrimaryDisplayCase>(),
+                testing::KilledBySignal(SIGABRT), "Primary display cannot be disconnected.");
 }
 
 TEST_F(HandleTransactionLockedTest, processesHotplugDisconnectExternalDisplay) {
@@ -290,96 +291,106 @@
 }
 
 TEST_F(HandleTransactionLockedTest, processesHotplugConnectThenDisconnectPrimary) {
-    using Case = SimplePrimaryDisplayCase;
+    EXPECT_EXIT(
+            [this] {
+                using Case = SimplePrimaryDisplayCase;
 
-    // --------------------------------------------------------------------
-    // Preconditions
+                // --------------------------------------------------------------------
+                // Preconditions
 
-    setupCommonPreconditions<Case>();
+                setupCommonPreconditions<Case>();
 
-    // A hotplug connect event is enqueued for a display
-    Case::Display::injectPendingHotplugEvent(this, Connection::CONNECTED);
-    // A hotplug disconnect event is also enqueued for the same display
-    Case::Display::injectPendingHotplugEvent(this, Connection::DISCONNECTED);
+                // A hotplug connect event is enqueued for a display
+                Case::Display::injectPendingHotplugEvent(this, Connection::CONNECTED);
+                // A hotplug disconnect event is also enqueued for the same display
+                Case::Display::injectPendingHotplugEvent(this, Connection::DISCONNECTED);
 
-    // --------------------------------------------------------------------
-    // Call Expectations
+                // --------------------------------------------------------------------
+                // Call Expectations
 
-    setupCommonCallExpectationsForConnectProcessing<Case>();
-    setupCommonCallExpectationsForDisconnectProcessing<Case>();
+                setupCommonCallExpectationsForConnectProcessing<Case>();
+                setupCommonCallExpectationsForDisconnectProcessing<Case>();
 
-    EXPECT_CALL(*mComposer,
-                setVsyncEnabled(Case::Display::HWC_DISPLAY_ID, IComposerClient::Vsync::DISABLE))
-            .WillOnce(Return(Error::NONE));
-    EXPECT_CALL(*mConsumer, consumerDisconnect()).WillOnce(Return(NO_ERROR));
+                EXPECT_CALL(*mComposer,
+                            setVsyncEnabled(Case::Display::HWC_DISPLAY_ID,
+                                            IComposerClient::Vsync::DISABLE))
+                        .WillOnce(Return(Error::NONE));
+                EXPECT_CALL(*mConsumer, consumerDisconnect()).WillOnce(Return(NO_ERROR));
 
-    // --------------------------------------------------------------------
-    // Invocation
+                // --------------------------------------------------------------------
+                // Invocation
 
-    mFlinger.handleTransactionLocked(eDisplayTransactionNeeded);
+                mFlinger.handleTransactionLocked(eDisplayTransactionNeeded);
 
-    // --------------------------------------------------------------------
-    // Postconditions
+                // --------------------------------------------------------------------
+                // Postconditions
 
-    // HWComposer should not have an entry for the display
-    EXPECT_FALSE(hasPhysicalHwcDisplay(Case::Display::HWC_DISPLAY_ID));
+                // HWComposer should not have an entry for the display
+                EXPECT_FALSE(hasPhysicalHwcDisplay(Case::Display::HWC_DISPLAY_ID));
 
-    // SF should not have a display token.
-    const auto displayId = Case::Display::DISPLAY_ID::get();
-    ASSERT_TRUE(PhysicalDisplayId::tryCast(displayId));
-    ASSERT_TRUE(mFlinger.mutablePhysicalDisplayTokens().count(displayId) == 0);
+                // SF should not have a display token.
+                const auto displayId = Case::Display::DISPLAY_ID::get();
+                ASSERT_TRUE(PhysicalDisplayId::tryCast(displayId));
+                ASSERT_TRUE(mFlinger.mutablePhysicalDisplayTokens().count(displayId) == 0);
+            }(),
+            testing::KilledBySignal(SIGABRT), "Primary display cannot be disconnected.");
 }
 
 TEST_F(HandleTransactionLockedTest, processesHotplugDisconnectThenConnectPrimary) {
-    using Case = SimplePrimaryDisplayCase;
+    EXPECT_EXIT(
+            [this] {
+                using Case = SimplePrimaryDisplayCase;
 
-    // --------------------------------------------------------------------
-    // Preconditions
+                // --------------------------------------------------------------------
+                // Preconditions
 
-    setupCommonPreconditions<Case>();
+                setupCommonPreconditions<Case>();
 
-    // The display is already completely set up.
-    Case::Display::injectHwcDisplay(this);
-    auto existing = Case::Display::makeFakeExistingDisplayInjector(this);
-    existing.inject();
+                // The display is already completely set up.
+                Case::Display::injectHwcDisplay(this);
+                auto existing = Case::Display::makeFakeExistingDisplayInjector(this);
+                existing.inject();
 
-    // A hotplug disconnect event is enqueued for a display
-    Case::Display::injectPendingHotplugEvent(this, Connection::DISCONNECTED);
-    // A hotplug connect event is also enqueued for the same display
-    Case::Display::injectPendingHotplugEvent(this, Connection::CONNECTED);
+                // A hotplug disconnect event is enqueued for a display
+                Case::Display::injectPendingHotplugEvent(this, Connection::DISCONNECTED);
+                // A hotplug connect event is also enqueued for the same display
+                Case::Display::injectPendingHotplugEvent(this, Connection::CONNECTED);
 
-    // --------------------------------------------------------------------
-    // Call Expectations
+                // --------------------------------------------------------------------
+                // Call Expectations
 
-    setupCommonCallExpectationsForConnectProcessing<Case>();
-    setupCommonCallExpectationsForDisconnectProcessing<Case>();
+                setupCommonCallExpectationsForConnectProcessing<Case>();
+                setupCommonCallExpectationsForDisconnectProcessing<Case>();
 
-    // --------------------------------------------------------------------
-    // Invocation
+                // --------------------------------------------------------------------
+                // Invocation
 
-    mFlinger.handleTransactionLocked(eDisplayTransactionNeeded);
+                mFlinger.handleTransactionLocked(eDisplayTransactionNeeded);
 
-    // --------------------------------------------------------------------
-    // Postconditions
+                // --------------------------------------------------------------------
+                // Postconditions
 
-    // The existing token should have been removed
-    verifyDisplayIsNotConnected(existing.token());
-    const auto displayId = Case::Display::DISPLAY_ID::get();
-    ASSERT_TRUE(PhysicalDisplayId::tryCast(displayId));
-    ASSERT_TRUE(mFlinger.mutablePhysicalDisplayTokens().count(displayId) == 1);
-    EXPECT_NE(existing.token(), mFlinger.mutablePhysicalDisplayTokens()[displayId]);
+                // The existing token should have been removed
+                verifyDisplayIsNotConnected(existing.token());
+                const auto displayId = Case::Display::DISPLAY_ID::get();
+                ASSERT_TRUE(PhysicalDisplayId::tryCast(displayId));
+                ASSERT_TRUE(mFlinger.mutablePhysicalDisplayTokens().count(displayId) == 1);
+                EXPECT_NE(existing.token(), mFlinger.mutablePhysicalDisplayTokens()[displayId]);
 
-    // A new display should be connected in its place
+                // A new display should be connected in its place
 
-    verifyPhysicalDisplayIsConnected<Case>();
+                verifyPhysicalDisplayIsConnected<Case>();
 
-    // --------------------------------------------------------------------
-    // Cleanup conditions
+                // --------------------------------------------------------------------
+                // Cleanup conditions
 
-    EXPECT_CALL(*mComposer,
-                setVsyncEnabled(Case::Display::HWC_DISPLAY_ID, IComposerClient::Vsync::DISABLE))
-            .WillOnce(Return(Error::NONE));
-    EXPECT_CALL(*mConsumer, consumerDisconnect()).WillOnce(Return(NO_ERROR));
+                EXPECT_CALL(*mComposer,
+                            setVsyncEnabled(Case::Display::HWC_DISPLAY_ID,
+                                            IComposerClient::Vsync::DISABLE))
+                        .WillOnce(Return(Error::NONE));
+                EXPECT_CALL(*mConsumer, consumerDisconnect()).WillOnce(Return(NO_ERROR));
+            }(),
+            testing::KilledBySignal(SIGABRT), "Primary display cannot be disconnected.");
 }
 
 TEST_F(HandleTransactionLockedTest, processesVirtualDisplayAdded) {
diff --git a/services/surfaceflinger/tests/unittests/SurfaceFlinger_SetupNewDisplayDeviceInternalTest.cpp b/services/surfaceflinger/tests/unittests/SurfaceFlinger_SetupNewDisplayDeviceInternalTest.cpp
index e32c4bf..7ead0af 100644
--- a/services/surfaceflinger/tests/unittests/SurfaceFlinger_SetupNewDisplayDeviceInternalTest.cpp
+++ b/services/surfaceflinger/tests/unittests/SurfaceFlinger_SetupNewDisplayDeviceInternalTest.cpp
@@ -292,7 +292,9 @@
 }
 
 TEST_F(SetupNewDisplayDeviceInternalTest, createSimpleExternalDisplay) {
-    setupNewDisplayDeviceInternalTest<SimpleExternalDisplayCase>();
+    // External displays must be secondary, as the primary display cannot be disconnected.
+    EXPECT_EXIT(setupNewDisplayDeviceInternalTest<SimpleExternalDisplayCase>(),
+                testing::KilledBySignal(SIGABRT), "Missing primary display");
 }
 
 TEST_F(SetupNewDisplayDeviceInternalTest, createNonHwcVirtualDisplay) {
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index 56ae414..e036f4d 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -439,8 +439,7 @@
 
     auto& mutableHwcDisplayData() { return getHwComposer().mDisplayData; }
     auto& mutableHwcPhysicalDisplayIdMap() { return getHwComposer().mPhysicalDisplayIdMap; }
-    auto& mutableInternalHwcDisplayId() { return getHwComposer().mInternalHwcDisplayId; }
-    auto& mutableExternalHwcDisplayId() { return getHwComposer().mExternalHwcDisplayId; }
+    auto& mutablePrimaryHwcDisplayId() { return getHwComposer().mPrimaryHwcDisplayId; }
     auto& mutableUseFrameRateApi() { return mFlinger->useFrameRateApi; }
 
     auto fromHandle(const sp<IBinder>& handle) {
@@ -600,13 +599,12 @@
                 LOG_ALWAYS_FATAL_IF(!physicalId);
                 flinger->mutableHwcPhysicalDisplayIdMap().emplace(mHwcDisplayId, *physicalId);
                 if (mIsPrimary) {
-                    flinger->mutableInternalHwcDisplayId() = mHwcDisplayId;
+                    flinger->mutablePrimaryHwcDisplayId() = mHwcDisplayId;
                 } else {
-                    // If there is an external HWC display there should always be an internal ID
+                    // If there is an external HWC display, there should always be a primary ID
                     // as well. Set it to some arbitrary value.
-                    auto& internalId = flinger->mutableInternalHwcDisplayId();
-                    if (!internalId) internalId = mHwcDisplayId - 1;
-                    flinger->mutableExternalHwcDisplayId() = mHwcDisplayId;
+                    auto& primaryId = flinger->mutablePrimaryHwcDisplayId();
+                    if (!primaryId) primaryId = mHwcDisplayId - 1;
                 }
             }
         }