Prevent Infinite Recursion in Telecom Sessions (13f23a85) · Commits · e / os / android_frameworks_base

telecomm/java/android/telecom/Logging/Session.java

+51 −19

Original line number	Diff line number	Diff line
		@@ -33,6 +33,8 @@ import java.util.ArrayList;
		*/
		public class Session {

		public static final String LOG_TAG = "Session";

		public static final String START_SESSION = "START_SESSION";
		public static final String START_EXTERNAL_SESSION = "START_EXTERNAL_SESSION";
		public static final String CREATE_SUBSESSION = "CREATE_SUBSESSION";
		@@ -45,6 +47,9 @@ public class Session {
		public static final String EXTERNAL_INDICATOR = "E-";
		public static final String TRUNCATE_STRING = "...";

		// Prevent infinite recursion by setting a reasonable limit.
		private static final int SESSION_RECURSION_LIMIT = 25;

		/**
		* Initial value of mExecutionEndTimeMs and the final value of {@link #getLocalExecutionTime()}
		* if the Session is canceled.
		@@ -226,6 +231,15 @@ public class Session {

		// Builds full session id recursively
		private String getFullSessionId() {
		return getFullSessionId(0);
		}

		// keep track of calls and bail if we hit the recursion limit
		private String getFullSessionId(int parentCount) {
		if (parentCount >= SESSION_RECURSION_LIMIT) {
		Log.w(LOG_TAG, "getFullSessionId: Hit recursion limit!");
		return TRUNCATE_STRING + mSessionId;
		}
		// Cache mParentSession locally to prevent a concurrency problem where
		// Log.endParentSessions() is called while a logging statement is running (Log.i, for
		// example) and setting mParentSession to null in a different thread after the null check
		@@ -235,42 +249,57 @@ public class Session {
		return mSessionId;
		} else {
		if (Log.VERBOSE) {
		return parentSession.getFullSessionId() +
		return parentSession.getFullSessionId(parentCount + 1)
		// Append "_X" to subsession to show subsession designation.
		SESSION_SEPARATION_CHAR_CHILD + mSessionId;
		+ SESSION_SEPARATION_CHAR_CHILD + mSessionId;
		} else {
		// Only worry about the base ID at the top of the tree.
		return parentSession.getFullSessionId();
		return parentSession.getFullSessionId(parentCount + 1);
		}

		}
		}

		// Print out the full Session tree from any subsession node
		public String printFullSessionTree() {
		// Get to the top of the tree
		private Session getRootSession(String callingMethod) {
		int currParentCount = 0;
		Session topNode = this;
		while (topNode.getParentSession() != null) {
		if (currParentCount >= SESSION_RECURSION_LIMIT) {
		Log.w(LOG_TAG, "getRootSession: Hit recursion limit from " + callingMethod);
		break;
		}
		topNode = topNode.getParentSession();
		currParentCount++;
		}
		return topNode.printSessionTree();
		return topNode;
		}

		// Print out the full Session tree from any subsession node
		public String printFullSessionTree() {
		return getRootSession("printFullSessionTree").printSessionTree();
		}

		// Recursively move down session tree using DFS, but print out each node when it is reached.
		public String printSessionTree() {
		private String printSessionTree() {
		StringBuilder sb = new StringBuilder();
		printSessionTree(0, sb);
		printSessionTree(0, sb, 0);
		return sb.toString();
		}

		private void printSessionTree(int tabI, StringBuilder sb) {
		private void printSessionTree(int tabI, StringBuilder sb, int currChildCount) {
		// Prevent infinite recursion.
		if (currChildCount >= SESSION_RECURSION_LIMIT) {
		Log.w(LOG_TAG, "printSessionTree: Hit recursion limit!");
		sb.append(TRUNCATE_STRING);
		return;
		}
		sb.append(toString());
		for (Session child : mChildSessions) {
		sb.append("\n");
		for (int i = 0; i <= tabI; i++) {
		sb.append("\t");
		}
		child.printSessionTree(tabI + 1, sb);
		child.printSessionTree(tabI + 1, sb, currChildCount + 1);
		}
		}

		@@ -279,11 +308,17 @@ public class Session {
		// recent) will be truncated to "..."
		public String getFullMethodPath(boolean truncatePath) {
		StringBuilder sb = new StringBuilder();
		getFullMethodPath(sb, truncatePath);
		getFullMethodPath(sb, truncatePath, 0);
		return sb.toString();
		}

		private synchronized void getFullMethodPath(StringBuilder sb, boolean truncatePath) {
		private synchronized void getFullMethodPath(StringBuilder sb, boolean truncatePath,
		int parentCount) {
		if (parentCount >= SESSION_RECURSION_LIMIT) {
		Log.w(LOG_TAG, "getFullMethodPath: Hit recursion limit!");
		sb.append(TRUNCATE_STRING);
		return;
		}
		// Return cached value for method path. When returning the truncated path, recalculate the
		// full path without using the cached value.
		if (!TextUtils.isEmpty(mFullMethodPathCache) && !truncatePath) {
		@@ -296,7 +331,7 @@ public class Session {
		// Check to see if the session has been renamed yet. If it has not, then the session
		// has not been continued.
		isSessionStarted = !mShortMethodName.equals(parentSession.mShortMethodName);
		parentSession.getFullMethodPath(sb, truncatePath);
		parentSession.getFullMethodPath(sb, truncatePath, parentCount + 1);
		sb.append(SUBSESSION_SEPARATION_CHAR);
		}
		// Encapsulate the external session's method name so it is obvious what part of the session
		@@ -319,13 +354,10 @@ public class Session {
		mFullMethodPathCache = sb.toString();
		}
		}

		// Recursively move to the top of the tree to see if the parent session is external.
		private boolean isSessionExternal() {
		if (getParentSession() == null) {
		return isExternal();
		} else {
		return getParentSession().isSessionExternal();
		}
		return getRootSession("isSessionExternal").isExternal();
		}

		@Override