Merge "Add synchronization to PIC shared memory" into main (912193ba) · Commits · e / os / android_frameworks_base

core/java/android/app/PropertyInvalidatedCache.java

+45 −32

Original line number	Diff line number	Diff line
		@@ -717,12 +717,10 @@ public class PropertyInvalidatedCache<Query, Result> {
		// The shared memory.
		private volatile NonceStore mStore;

		// The index of the nonce in shared memory.
		// The index of the nonce in shared memory. This changes from INVALID only when the local
		// object is completely initialized.
		private volatile int mHandle = NonceStore.INVALID_NONCE_INDEX;

		// True if the string has been stored, ever.
		private volatile boolean mRecorded = false;

		// A short name that is saved in shared memory. This is the portion of the property name
		// that follows the prefix.
		private final String mShortName;
		@@ -736,48 +734,63 @@ public class PropertyInvalidatedCache<Query, Result> {
		}
		}

		// Fetch the nonce from shared memory. If the shared memory is not available, return
		// UNSET. If the shared memory is available but the nonce name is not known (it may not
		// have been invalidated by the server yet), return UNSET.
		@Override
		long getNonceInternal() {
		if (mHandle == NonceStore.INVALID_NONCE_INDEX) {
		// Initialize the mStore and mHandle variables. This function does nothing if the
		// variables are already initialized. Synchronization ensures that initialization happens
		// no more than once. The function returns the new value of mHandle.
		//
		// If the "update" boolean is true, then the property is registered with the nonce store
		// before the associated handle is fetched.
		private int initialize(boolean update) {
		synchronized (mLock) {
		int handle = mHandle;
		if (handle == NonceStore.INVALID_NONCE_INDEX) {
		if (mStore == null) {
		mStore = NonceStore.getInstance();
		if (mStore == null) {
		return NONCE_UNSET;
		return NonceStore.INVALID_NONCE_INDEX;
		}
		}
		mHandle = mStore.getHandleForName(mShortName);
		if (mHandle == NonceStore.INVALID_NONCE_INDEX) {
		return NONCE_UNSET;
		if (update) {
		mStore.storeName(mShortName);
		}
		handle = mStore.getHandleForName(mShortName);
		if (handle == NonceStore.INVALID_NONCE_INDEX) {
		return NonceStore.INVALID_NONCE_INDEX;
		}
		// The handle must be valid.
		mHandle = handle;
		}
		return handle;
		}
		return mStore.getNonce(mHandle);
		}

		// Set the nonce in shared mmory. If the shared memory is not available, throw an
		// exception. Otherwise, if the nonce name has never been recorded, record it now and
		// fetch the handle for the name. If the handle cannot be created, throw an exception.
		// Fetch the nonce from shared memory. If the shared memory is not available, return
		// UNSET. If the shared memory is available but the nonce name is not known (it may not
		// have been invalidated by the server yet), return UNSET.
		@Override
		void setNonceInternal(long value) {
		if (mHandle == NonceStore.INVALID_NONCE_INDEX \|\| !mRecorded) {
		if (mStore == null) {
		mStore = NonceStore.getInstance();
		if (mStore == null) {
		throw new IllegalStateException("setNonce: shared memory not ready");
		long getNonceInternal() {
		int handle = mHandle;
		if (handle == NonceStore.INVALID_NONCE_INDEX) {
		handle = initialize(false);
		if (handle == NonceStore.INVALID_NONCE_INDEX) {
		return NONCE_UNSET;
		}
		}
		// Always store the name before fetching the handle. storeName() is idempotent
		// but does take a little time, so this code calls it just once.
		mStore.storeName(mShortName);
		mRecorded = true;
		mHandle = mStore.getHandleForName(mShortName);
		if (mHandle == NonceStore.INVALID_NONCE_INDEX) {
		throw new IllegalStateException("setNonce: shared memory store failed");
		return mStore.getNonce(handle);
		}

		// Set the nonce in shared memory. If the shared memory is not available or if the nonce
		// cannot be registered in shared memory, throw an exception.
		@Override
		void setNonceInternal(long value) {
		int handle = mHandle;
		if (handle == NonceStore.INVALID_NONCE_INDEX) {
		handle = initialize(true);
		if (handle == NonceStore.INVALID_NONCE_INDEX) {
		throw new IllegalStateException("unable to assign nonce handle: " + mName);
		}
		}
		mStore.setNonce(mHandle, value);
		mStore.setNonce(handle, value);
		}
		}