The refused instruction is dropped and the stack advances, as it would + * on an ACK, so one refused command no longer stalls everything queued + * behind it. It is dropped only when it is still queued - a GET's + * instruction is already gone by the time its response is awaited. The + * connection is left up: a refusal means the device declined this command, + * not that the link is gone. + */ + private void processNackFromCommand() { + stopTimerCheckForAckOrResp(); //cancel the ack timer + printLogDataForDebugging("NACK Received for Command: \t\t" + btCommandToString(mCurrentCommand)); + + byte refusedCommand = mCurrentCommand; + + /* Only the ACK-wait state still has the refused instruction queued: a + * GET's instruction is removed as soon as its ACK arrives, so removing + * one here as well would drop whatever was queued behind it and silently + * skip that command. */ + boolean instructionStillQueued = mWaitForAck; + + mWaitForAck=false; + mWaitForResponse=false; + + //Drop the refused instruction, as the ACK path does for its own command + if(instructionStillQueued && getListofInstructions().size()>0){ + removeInstruction(0); + } + removeAllNulls(); + + mTransactionCompleted=true; + setInstructionStackLock(false); + + eventCommandRefused(refusedCommand); + } + + /** + * Called when the Shimmer refused a command with a NACK. The transaction has + * already been unwound and the connection is still up. + * + *
Deliberately concrete rather than abstract so that existing subclasses + * keep compiling; override to surface the refusal to the application. A + * refusal is expected in normal use - most SET commands are rejected while + * the device is sensing, and some GETs are rejected for hardware that does + * not have the feature. + * + * @param command the command byte that was refused + */ + protected void eventCommandRefused(byte command) { + //Default: no application-level notification, the log line above stands + } + // TODO: Consider removing this, replace by SET then GET and let the // RESPONSE update the variables in ShimmerObject - removes duplication of // code and ensure ShimmerObject it up-to-date with exactly what is on diff --git a/ShimmerDriver/src/main/java/com/shimmerresearch/comms/radioProtocol/LiteProtocol.java b/ShimmerDriver/src/main/java/com/shimmerresearch/comms/radioProtocol/LiteProtocol.java index dc1634651..56dddebf3 100644 --- a/ShimmerDriver/src/main/java/com/shimmerresearch/comms/radioProtocol/LiteProtocol.java +++ b/ShimmerDriver/src/main/java/com/shimmerresearch/comms/radioProtocol/LiteProtocol.java @@ -126,6 +126,12 @@ public class InstructionsGet{ protected String mDirectoryName; protected int numBytesToReadFromExpBoard=0; private static final int MAX_CALIB_DUMP_MAX = 4096; + /* The generated LiteProtocolInstructionSet has no NACK entry, so the value + * is declared here rather than read from InstructionsSet. Adding it to + * grpcprotosrc/src/LiteProtocolInstructionSet.proto and regenerating would + * be tidier, but that rewrites a large generated file committed in two + * places for the sake of one constant. */ + private static final int NACK_COMMAND_PROCESSED_VALUE = 0xFE; /** @@ -606,6 +612,12 @@ else if(isKnownGetCommand(mCurrentCommand)){ } } + /* The Shimmer refused the command. Without this branch the NACK + * was discarded and the transaction stalled until the ACK timer + * expired, which is treated as a lost connection. */ + else if((((int)byteBuffer[0])&0xFF)==NACK_COMMAND_PROCESSED_VALUE) { + processNackFromCommand(); + } } } } @@ -640,8 +652,16 @@ else if(bytesAvailableToBeRead()){ byteBuffer=readBytes(1); mIamAlive = true; + /* As in the ACK-wait path above, and matching ShimmerBluetooth: a + * NACK can land here instead if the firmware only discovers it + * cannot serve a GET while building the response. Checked before + * isKnownResponseByte() so it is handled as a refusal rather than + * falling through to the ACK/response timeout. */ + if((((int)byteBuffer[0])&0xFF)==NACK_COMMAND_PROCESSED_VALUE){ + processNackFromCommand(); + } //Check to see whether it is a response byte - if(isKnownResponseByte(byteBuffer[0])){ + else if(isKnownResponseByte(byteBuffer[0])){ byte responseCommand = byteBuffer[0]; if(mUseShimmerBluetoothApproach){ @@ -1295,6 +1315,49 @@ private int availableBytes() throws ShimmerException { public void eventLogAndStreamStatusChanged(int currentCommand){ mProtocolListener.eventLogAndStreamStatusChangedCallback(currentCommand); } + + /** + * Unwinds the in-flight transaction after the Shimmer answered a command + * with NACK (0xFE) instead of ACK. The refused instruction is dropped so the + * stack advances, and the connection is left up - a refusal means the device + * declined this command, not that the link is gone. + */ + private void processNackFromCommand() { + stopTimerCheckForAckOrResp(); //cancel the ack timer + printLogDataForDebugging("NACK Received for Command: \t\t" + btCommandToString(mCurrentCommand)); + + int refusedCommand = ((int)mCurrentCommand)&0xFF; + + /* Only the ACK-wait state still has the refused instruction queued: a + * GET's instruction is removed as soon as its ACK arrives, so removing + * one here as well would drop whatever was queued behind it. */ + boolean instructionStillQueued = mWaitForAck; + + mWaitForAck=false; + mWaitForResponse=false; + + if(instructionStillQueued && getListofInstructions().size()>0){ + getListofInstructions().remove(0); + } + getListofInstructions().removeAll(Collections.singleton(null)); + + mTransactionCompleted=true; + setInstructionStackLock(false); + + eventCommandRefused(refusedCommand); + } + + /** + * Called when the Shimmer refused a command with a NACK. The transaction has + * already been unwound and the connection is still up. Concrete rather than + * a new ProtocolListener callback so that existing implementers keep + * compiling; override to surface the refusal to the application. + * + * @param command the command value that was refused + */ + protected void eventCommandRefused(int command) { + //Default: no application-level notification, the log line above stands + } private void isNowStreaming() { mProtocolListener.isNowStreaming(); diff --git a/ShimmerDriver/src/main/java/com/shimmerresearch/driver/ShimmerObject.java b/ShimmerDriver/src/main/java/com/shimmerresearch/driver/ShimmerObject.java index 4a6808c69..b2a435524 100644 --- a/ShimmerDriver/src/main/java/com/shimmerresearch/driver/ShimmerObject.java +++ b/ShimmerDriver/src/main/java/com/shimmerresearch/driver/ShimmerObject.java @@ -457,6 +457,7 @@ public class BTStream { public static final byte GET_RWC_COMMAND = (byte) 0x91; public static final byte ROUTINE_COMMUNICATION = (byte) 0xE0; + public static final byte NACK_COMMAND_PROCESSED = (byte) 0xFE; public static final byte ACK_COMMAND_PROCESSED = (byte) 0xFF; public static final byte START_LOGGING_ONLY_COMMAND = (byte) 0x92;