Fix: agent: read: end of loop condition should exclude 0

[lttng-ust.git] / liblttng-ust-java-agent / java / lttng-ust-agent-common / org / lttng / ust / agent / client / LttngTcpSessiondClient.java

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
index a0adceae6d32b0e9c1f9031b20dc422b07953678..c63850050444ad42a47a8dccce94b3b30f2b638e 100644 (file)
--- a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
@@ -133,11 +133,31 @@ public class LttngTcpSessiondClient implements Runnable {
                                handleSessiondCmd();
                        } catch (UnknownHostException uhe) {
                                uhe.printStackTrace();
+                               /*
+                                * Terminate agent thread.
+                                */
+                               close();
                        } catch (IOException ioe) {
+                               /*
+                                * I/O exception may have been triggered by a session daemon
+                                * closing the socket. Close our own socket and
+                                * retry connecting after a delay.
+                                */
                                try {
+                                       if (this.sessiondSock != null) {
+                                               this.sessiondSock.close();
+                                       }
                                        Thread.sleep(3000);
                                } catch (InterruptedException e) {
-                                       e.printStackTrace();
+                                       /*
+                                        * Retry immediately if sleep is interrupted.
+                                        */
+                               } catch (IOException closeioe) {
+                                       closeioe.printStackTrace();
+                                       /*
+                                        * Terminate agent thread.
+                                        */
+                                       close();
                                }
                        }
                }
@@ -254,7 +274,7 @@ public class LttngTcpSessiondClient implements Runnable {
                /* Data read from the socket */
                byte inputData[] = null;
                /* Reply data written to the socket, sent to the sessiond */
-               byte responseData[] = null;
+               LttngAgentResponse response;
 
                while (true) {
                        /* Get header from session daemon. */
@@ -282,8 +302,7 @@ public class LttngTcpSessiondClient implements Runnable {
                        case CMD_LIST:
                        {
                                SessiondCommand listLoggerCmd = new SessiondListLoggersCommand();
-                               LttngAgentResponse response = listLoggerCmd.execute(logAgent);
-                               responseData = response.getBytes();
+                               response = listLoggerCmd.execute(logAgent);
                                log("Received list loggers command");
                                break;
                        }
@@ -291,38 +310,35 @@ public class LttngTcpSessiondClient implements Runnable {
                        {
                                if (inputData == null) {
                                        /* Invalid command */
-                                       responseData = LttngAgentResponse.FAILURE_RESPONSE.getBytes();
+                                       response = LttngAgentResponse.FAILURE_RESPONSE;
                                        break;
                                }
                                SessiondCommand enableEventCmd = new SessiondEnableEventCommand(inputData);
-                               LttngAgentResponse response = enableEventCmd.execute(logAgent);
-                               responseData = response.getBytes();
-                               log("Received enable event command");
+                               response = enableEventCmd.execute(logAgent);
+                               log("Received enable event command: " + enableEventCmd.toString());
                                break;
                        }
                        case CMD_EVENT_DISABLE:
                        {
                                if (inputData == null) {
                                        /* Invalid command */
-                                       responseData = LttngAgentResponse.FAILURE_RESPONSE.getBytes();
+                                       response = LttngAgentResponse.FAILURE_RESPONSE;
                                        break;
                                }
                                SessiondCommand disableEventCmd = new SessiondDisableEventCommand(inputData);
-                               LttngAgentResponse response = disableEventCmd.execute(logAgent);
-                               responseData = response.getBytes();
-                               log("Received disable event command");
+                               response = disableEventCmd.execute(logAgent);
+                               log("Received disable event command: " + disableEventCmd.toString());
                                break;
                        }
                        case CMD_APP_CTX_ENABLE:
                        {
                                if (inputData == null) {
                                        /* This commands expects a payload, invalid command */
-                                       responseData = LttngAgentResponse.FAILURE_RESPONSE.getBytes();
+                                       response = LttngAgentResponse.FAILURE_RESPONSE;
                                        break;
                                }
                                SessiondCommand enableAppCtxCmd = new SessiondEnableAppContextCommand(inputData);
-                               LttngAgentResponse response = enableAppCtxCmd.execute(logAgent);
-                               responseData = response.getBytes();
+                               response = enableAppCtxCmd.execute(logAgent);
                                log("Received enable app-context command");
                                break;
                        }
@@ -330,28 +346,33 @@ public class LttngTcpSessiondClient implements Runnable {
                        {
                                if (inputData == null) {
                                        /* This commands expects a payload, invalid command */
-                                       responseData = LttngAgentResponse.FAILURE_RESPONSE.getBytes();
+                                       response = LttngAgentResponse.FAILURE_RESPONSE;
                                        break;
                                }
                                SessiondCommand disableAppCtxCmd = new SessiondDisableAppContextCommand(inputData);
-                               LttngAgentResponse response = disableAppCtxCmd.execute(logAgent);
-                               responseData = response.getBytes();
+                               response = disableAppCtxCmd.execute(logAgent);
                                log("Received disable app-context command");
                                break;
                        }
                        default:
                        {
                                /* Unknown command, send empty reply */
-                               responseData = new byte[4];
-                               ByteBuffer buf = ByteBuffer.wrap(responseData);
-                               buf.order(ByteOrder.BIG_ENDIAN);
+                               response = null;
                                log("Received unknown command, ignoring");
                                break;
                        }
                        }
 
                        /* Send response to the session daemon. */
-                       log("Sending response");
+                       byte[] responseData;
+                       if (response == null) {
+                               responseData = new byte[4];
+                               ByteBuffer buf = ByteBuffer.wrap(responseData);
+                               buf.order(ByteOrder.BIG_ENDIAN);
+                       } else {
+                               log("Sending response: " + response.toString());
+                               responseData = response.getBytes();
+                       }
                        this.outToSessiond.write(responseData, 0, responseData.length);
                        this.outToSessiond.flush();
                }
@@ -363,10 +384,17 @@ public class LttngTcpSessiondClient implements Runnable {
         */
        private SessiondCommandHeader recvHeader() throws IOException {
                byte data[] = new byte[SessiondCommandHeader.HEADER_SIZE];
+               int bytesLeft = data.length;
+               int bytesOffset = 0;
 
-               int readLen = this.inFromSessiond.read(data, 0, data.length);
-               if (readLen != data.length) {
-                       throw new IOException();
+               while (bytesLeft > 0) {
+                       int bytesRead = this.inFromSessiond.read(data, bytesOffset, bytesLeft);
+
+                       if (bytesRead < 0) {
+                               throw new IOException();
+                       }
+                       bytesLeft -= bytesRead;
+                       bytesOffset += bytesRead;
                }
                return new SessiondCommandHeader(data);
        }
@@ -380,15 +408,22 @@ public class LttngTcpSessiondClient implements Runnable {
         */
        private byte[] recvPayload(SessiondCommandHeader headerCmd) throws IOException {
                byte payload[] = new byte[(int) headerCmd.getDataSize()];
+               int bytesLeft = payload.length;
+               int bytesOffset = 0;
 
                /* Failsafe check so we don't waste our time reading 0 bytes. */
-               if (payload.length == 0) {
+               if (bytesLeft == 0) {
                        return null;
                }
 
-               int read = inFromSessiond.read(payload, 0, payload.length);
-               if (read != payload.length) {
-                       throw new IOException("Unexpected number of bytes read in sessiond command payload");
+               while (bytesLeft > 0) {
+                       int bytesRead = inFromSessiond.read(payload, bytesOffset, bytesLeft);
+
+                       if (bytesRead < 0) {
+                               throw new IOException();
+                       }
+                       bytesLeft -= bytesRead;
+                       bytesOffset += bytesRead;
                }
                return payload;
        }