An implementation of the JVMDebugger interface which sits on - top of dbx and relies on the SA's dbx import module for - communication with the debugger.
- -NOTE that since we have the notion of fetching "Java - primitive types" from the remote process (which might have - different sizes than we expect) we have a bootstrapping - problem. We need to know the sizes of these types before we can - fetch them. The current implementation solves this problem by - requiring that it be configured with these type sizes before they - can be fetched. The readJ(Type) routines here will throw a - RuntimeException if they are called before the debugger is - configured with the Java primitive type sizes.
-*/ - -public class DbxDebuggerLocal extends DebuggerBase implements DbxDebugger { - // These may be set by DbxDebuggerRemote - protected boolean unalignedAccessesOkay; - protected DbxThreadFactory threadFactory; - - private String dbxPathName; - private String[] dbxSvcAgentDSOPathNames; - private Process dbxProcess; - private StreamMonitor dbxOutStreamMonitor; - private StreamMonitor dbxErrStreamMonitor; - private PrintWriter dbxOstr; - private PrintWriter out; - private InputLexer in; - private Socket importModuleSocket; - private static final int PORT = 21928; - private static final int LONG_TIMEOUT = 60000; - private static final int DBX_MODULE_NOT_FOUND = 101; - private static final int DBX_MODULE_LOADED = 102; - - //-------------------------------------------------------------------------------- - // Implementation of Debugger interface - // - - /**machDesc may be null if it couldn't be determined yet; i.e., - if we're on SPARC, we need to ask the remote process whether - we're in 32- or 64-bit mode.
- -useCache should be set to true if debugging is being done - locally, and to false if the debugger is being created for the - purpose of supporting remote debugging.
*/ - public DbxDebuggerLocal(MachineDescription machDesc, - String dbxPathName, - String[] dbxSvcAgentDSOPathNames, - boolean useCache) { - this.machDesc = machDesc; - this.dbxPathName = dbxPathName; - this.dbxSvcAgentDSOPathNames = dbxSvcAgentDSOPathNames; - int cacheNumPages; - int cachePageSize; - if (PlatformInfo.getCPU().equals("sparc")) { - cacheNumPages = parseCacheNumPagesProperty(2048); - cachePageSize = 8192; - threadFactory = new DbxSPARCThreadFactory(this); - } else if (PlatformInfo.getCPU().equals("x86")) { - cacheNumPages = 4096; - cachePageSize = 4096; - threadFactory = new DbxX86ThreadFactory(this); - unalignedAccessesOkay = true; - } else { - throw new RuntimeException("Thread access for CPU architecture " + PlatformInfo.getCPU() + " not yet supported"); - } - if (useCache) { - // Cache portion of the remote process's address space. - // Fetching data over the socket connection to dbx is relatively - // slow. For now, this cache works best if it covers the entire - // heap of the remote process. FIXME: at least should make this - // tunable from the outside, i.e., via the UI. This is a 16 MB - // cache divided on SPARC into 2048 8K pages and on x86 into - // 4096 4K pages; the page size must be adjusted to be the OS's - // page size. (FIXME: should pick this up from the debugger.) - initCache(cachePageSize, cacheNumPages); - } - } - - /** Only called by DbxDebuggerRemote */ - protected DbxDebuggerLocal() { - } - - /** FIXME: implement this with a Runtime.exec() of ps followed by - parsing of its output */ - public boolean hasProcessList() throws DebuggerException { - return false; - } - - public List getProcessList() throws DebuggerException { - throw new DebuggerException("Not yet supported"); - } - - /** From the Debugger interface via JVMDebugger */ - public synchronized void attach(int processID) throws DebuggerException { - try { - launchProcess(); - dbxErrStreamMonitor.addTrigger("dbx: no process", 1); - dbxErrStreamMonitor.addTrigger("dbx: Cannot open", 1); - dbxErrStreamMonitor.addTrigger("dbx: Cannot find", DBX_MODULE_NOT_FOUND); - dbxOstr = new PrintWriter(dbxProcess.getOutputStream(), true); - dbxOstr.println("debug - " + processID); - dbxOstr.println("kprint -u2 \\(ready\\)"); - boolean seen = dbxErrStreamMonitor.waitFor("(ready)", LONG_TIMEOUT); - if (!seen) { - detach(); - throw new DebuggerException("Timed out while connecting to process " + processID); - } - List retVals = dbxErrStreamMonitor.getTriggersSeen(); - if (retVals.contains(new Integer(1))) { - detach(); - throw new DebuggerException("No such process " + processID); - } - - // Throws DebuggerException upon failure - importDbxModule(); - - dbxOstr.println("svc_agent_run"); - - connectToImportModule(); - - // Set "fail fast" mode on process memory reads - printlnToOutput("peek_fail_fast 1"); - } - catch (IOException e) { - detach(); - throw new DebuggerException("Error while connecting to dbx process", e); - } - } - - /** From the Debugger interface via JVMDebugger */ - public synchronized void attach(String executableName, String coreFileName) throws DebuggerException { - try { - launchProcess(); - // Missing executable - dbxErrStreamMonitor.addTrigger("dbx: Cannot open", 1); - // Missing core file - dbxErrStreamMonitor.addTrigger("dbx: can't read", 2); - // Corrupt executable - dbxErrStreamMonitor.addTrigger("dbx: File", 3); - // Corrupt core file - dbxErrStreamMonitor.addTrigger("dbx: Unable to read", 4); - // Mismatched core and executable - dbxErrStreamMonitor.addTrigger("dbx: core object name", 5); - // Missing loadobject - dbxErrStreamMonitor.addTrigger("dbx: can't stat", 6); - // Successful load of svc module - dbxOstr = new PrintWriter(dbxProcess.getOutputStream(), true); - dbxOstr.println("debug " + executableName + " " + coreFileName); - dbxOstr.println("kprint -u2 \\(ready\\)"); - boolean seen = dbxErrStreamMonitor.waitFor("(ready)", LONG_TIMEOUT); - if (!seen) { - detach(); - throw new DebuggerException("Timed out while attaching to core file"); - } - List retVals = dbxErrStreamMonitor.getTriggersSeen(); - if (retVals.size() > 0) { - detach(); - - if (retVals.contains(new Integer(1))) { - throw new DebuggerException("Can not find executable \"" + executableName + "\""); - } else if (retVals.contains(new Integer(2))) { - throw new DebuggerException("Can not find core file \"" + coreFileName + "\""); - } else if (retVals.contains(new Integer(3))) { - throw new DebuggerException("Corrupt executable \"" + executableName + "\""); - } else if (retVals.contains(new Integer(4))) { - throw new DebuggerException("Corrupt core file \"" + coreFileName + "\""); - } else if (retVals.contains(new Integer(5))) { - throw new DebuggerException("Mismatched core file/executable \"" + coreFileName + "\"/\"" + executableName + "\""); - } else { - throw new DebuggerException("Couldn't find all loaded libraries for executable \"" + executableName + "\""); - } - } - - // Throws DebuggerException upon failure - importDbxModule(); - - dbxOstr.println("svc_agent_run"); - - connectToImportModule(); - - // Set "fail fast" mode on process memory reads - printlnToOutput("peek_fail_fast 1"); - } - catch (IOException e) { - detach(); - throw new DebuggerException("Error while connecting to dbx process", e); - } - } - - /** From the Debugger interface via JVMDebugger */ - public synchronized boolean detach() { - try { - if (dbxProcess == null) { - return false; - } - - if (out != null && dbxOstr != null) { - printlnToOutput("exit"); - dbxOstr.println("exit"); - - // Wait briefly for the process to exit (FIXME: should make this - // nicer) - try { - Thread.sleep(500); - } - catch (InterruptedException e) { - } - } - - shutdown(); - - return true; - } catch (IOException e) { - e.printStackTrace(); - return false; - } - } - - /** From the Debugger interface via JVMDebugger */ - public Address parseAddress(String addressString) throws NumberFormatException { - long addr = utils.scanAddress(addressString); - if (addr == 0) { - return null; - } - return new DbxAddress(this, addr); - } - - /** From the Debugger interface via JVMDebugger */ - public String getOS() { - return PlatformInfo.getOS(); - } - - /** From the Debugger interface via JVMDebugger */ - public String getCPU() { - return PlatformInfo.getCPU(); - } - - public boolean hasConsole() throws DebuggerException { - return true; - } - - public synchronized String consoleExecuteCommand(String cmd) throws DebuggerException { - try { - // A little tricky. We need to cause the dbx import module to - // exit, then print our command on dbx's stdin along with a - // command which will allow our StreamMonitors to - // resynchronize. We need save the output from the StreamMonitors - // along the way. - printlnToOutput("exit"); - importModuleSocket.close(); - importModuleSocket = null; - out = null; - in = null; - dbxOstr.println("kprint \\(ready\\)"); - dbxOstr.flush(); - dbxOutStreamMonitor.waitFor("(ready)", LONG_TIMEOUT); - - dbxOutStreamMonitor.startCapture(); - dbxErrStreamMonitor.startCapture(); - dbxOstr.println(cmd); - dbxOstr.println("kprint \\(ready\\)"); - dbxOutStreamMonitor.waitFor("(ready)", LONG_TIMEOUT); - String result = dbxOutStreamMonitor.stopCapture(); - String result2 = dbxErrStreamMonitor.stopCapture(); - result = result + result2; - // Cut out the "(ready)" string - StringBuffer outBuf = new StringBuffer(result.length()); - BufferedReader reader = new BufferedReader(new StringReader(result)); - // FIXME: bug in BufferedReader? readLine returns null when - // ready() returns true. - String line = null; - do { - line = reader.readLine(); - if ((line != null) && (!line.equals("(ready)"))) { - outBuf.append(line); - outBuf.append("\n"); - } - } while (line != null); - dbxOstr.println("svc_agent_run"); - dbxOstr.flush(); - - connectToImportModule(); - - return outBuf.toString(); - } - catch (IOException e) { - detach(); - throw new DebuggerException("Error while executing command on dbx console", e); - } - } - - public String getConsolePrompt() throws DebuggerException { - return "(dbx) "; - } - - public CDebugger getCDebugger() throws DebuggerException { - return null; - } - - /** From the SymbolLookup interface via Debugger and JVMDebugger */ - public synchronized Address lookup(String objectName, String symbol) { - long addr = lookupInProcess(objectName, symbol); - if (addr == 0) { - return null; - } - return new DbxAddress(this, addr); - } - - /** From the SymbolLookup interface via Debugger and JVMDebugger */ - public synchronized OopHandle lookupOop(String objectName, String symbol) { - long addr = lookupInProcess(objectName, symbol); - if (addr == 0) { - return null; - } - return new DbxOopHandle(this, addr); - } - - /** From the Debugger interface */ - public MachineDescription getMachineDescription() { - return machDesc; - } - - /** Internal routine supporting lazy setting of MachineDescription, - since on SPARC we will need to query the remote process to ask - it what its data model is (32- or 64-bit). NOTE that this is NOT - present in the DbxDebugger interface because it should not be - called across the wire (until we support attaching to multiple - remote processes via RMI -- see the documentation for - DbxDebuggerRemoteIntf.) */ - public void setMachineDescription(MachineDescription machDesc) { - this.machDesc = machDesc; - setBigEndian(machDesc.isBigEndian()); - utils = new DebuggerUtilities(machDesc.getAddressSize(), machDesc.isBigEndian()); - } - - /** Internal routine which queries the remote process about its data - model -- i.e., size of addresses. Returns -1 upon error. - Currently supported return values are 32 and 64. NOTE that this - is NOT present in the DbxDebugger interface because it should - not be called across the wire (until we support attaching to - multiple remote processes via RMI -- see the documentation for - DbxDebuggerRemoteIntf.) */ - public int getRemoteProcessAddressSize() { - if (dbxProcess == null) { - throw new RuntimeException("Not attached to remote process"); - } - - try { - printlnToOutput("address_size"); - int i = in.parseInt(); - return i; - } - catch (IOException e) { - return -1; - } - } - - //-------------------------------------------------------------------------------- - // Implementation of ThreadAccess interface - // - - /** From the ThreadAccess interface via Debugger and JVMDebugger */ - public ThreadProxy getThreadForIdentifierAddress(Address addr) { - return threadFactory.createThreadWrapper(addr); - } - - public ThreadProxy getThreadForThreadId(long id) { - return threadFactory.createThreadWrapper(id); - } - - //---------------------------------------------------------------------- - // Overridden from DebuggerBase because we need to relax alignment - // constraints on x86 - - public long readJLong(long address) - throws UnmappedAddressException, UnalignedAddressException { - checkJavaConfigured(); - // FIXME: allow this to be configurable. Undesirable to add a - // dependency on the runtime package here, though, since this - // package should be strictly underneath it. - if (unalignedAccessesOkay) { - utils.checkAlignment(address, jintSize); - } else { - utils.checkAlignment(address, jlongSize); - } - byte[] data = readBytes(address, jlongSize); - return utils.dataToJLong(data, jlongSize); - } - - //-------------------------------------------------------------------------------- - // Internal routines (for implementation of DbxAddress). - // These must not be called until the MachineDescription has been set up. - // - - /** From the DbxDebugger interface */ - public String addressValueToString(long address) { - return utils.addressValueToString(address); - } - - /** Need to override this to relax alignment checks on Solaris/x86. */ - public long readCInteger(long address, long numBytes, boolean isUnsigned) - throws UnmappedAddressException, UnalignedAddressException { - checkConfigured(); - if (!unalignedAccessesOkay) { - utils.checkAlignment(address, numBytes); - } else { - // Only slightly relaxed semantics -- this is a hack, but is - // necessary on Solaris/x86 where it seems the compiler is - // putting some global 64-bit data on 32-bit boundaries - if (numBytes == 8) { - utils.checkAlignment(address, 4); - } else { - utils.checkAlignment(address, numBytes); - } - } - byte[] data = readBytes(address, numBytes); - return utils.dataToCInteger(data, isUnsigned); - } - - /** From the DbxDebugger interface */ - public DbxAddress readAddress(long address) - throws UnmappedAddressException, UnalignedAddressException { - long value = readAddressValue(address); - return (value == 0 ? null : new DbxAddress(this, value)); - } - - public DbxAddress readCompOopAddress(long address) - throws UnmappedAddressException, UnalignedAddressException { - long value = readCompOopAddressValue(address); - return (value == 0 ? null : new DbxAddress(this, value)); - } - - /** From the DbxDebugger interface */ - public DbxOopHandle readOopHandle(long address) - throws UnmappedAddressException, UnalignedAddressException, NotInHeapException { - long value = readAddressValue(address); - return (value == 0 ? null : new DbxOopHandle(this, value)); - } - public DbxOopHandle readCompOopHandle(long address) - throws UnmappedAddressException, UnalignedAddressException, NotInHeapException { - long value = readCompOopAddressValue(address); - return (value == 0 ? null : new DbxOopHandle(this, value)); - } - - //-------------------------------------------------------------------------------- - // Thread context access. Can not be package private, but should - // only be accessed by the architecture-specific subpackages. - - /** From the DbxDebugger interface. May have to redefine this later. */ - public synchronized long[] getThreadIntegerRegisterSet(int tid) { - try { - printlnToOutput("thr_gregs " + tid); - int num = in.parseInt(); - long[] res = new long[num]; - for (int i = 0; i < num; i++) { - res[i] = in.parseAddress(); - } - return res; - } - catch (Exception e) { - e.printStackTrace(); - return null; - } - } - - //-------------------------------------------------------------------------------- - // Address access. Can not be package private, but should only be - // accessed by the architecture-specific subpackages. - - /** From the Debugger interface */ - public long getAddressValue(Address addr) { - if (addr == null) return 0; - return ((DbxAddress) addr).getValue(); - } - - /** From the DbxDebugger interface */ - public Address newAddress(long value) { - if (value == 0) return null; - return new DbxAddress(this, value); - } - - //-------------------------------------------------------------------------------- - // Internals only below this point - // - - private void launchProcess() throws IOException { - dbxProcess = Runtime.getRuntime().exec(dbxPathName); - // dbxOutStreamMonitor = new StreamMonitor(dbxProcess.getInputStream()); - // dbxErrStreamMonitor = new StreamMonitor(dbxProcess.getErrorStream()); - dbxOutStreamMonitor = new StreamMonitor(dbxProcess.getInputStream(), "dbx stdout", true); - dbxErrStreamMonitor = new StreamMonitor(dbxProcess.getErrorStream(), "dbx stderr", true); - } - - /** Requires that dbxErrStreamMonitor has a trigger on "dbx: Cannot - find" with number DBX_MODULE_NOT_FOUND as well as one on "dbx: - warning:" (plus the serviceability agent's dbx module path name, - to avoid conflation with inability to load individual object - files) with number DBX_MODULE_FAILED_TO_LOAD. The former - indicates an absence of libsvc_agent_dbx.so, while the latter - indicates that the module failed to load, specifically because - the architecture was mismatched. (I don't see a way to detect - from the dbx command prompt whether it's running the v8 or v9 - executbale, so we try to import both flavors of the import - module; the "v8" file name convention doesn't actually include - the v8 prefix, so this code should work for Intel as well.) */ - private void importDbxModule() throws DebuggerException { - // Trigger for a successful load - dbxOutStreamMonitor.addTrigger("Defining svc_agent_run", DBX_MODULE_LOADED); - for (int i = 0; i < dbxSvcAgentDSOPathNames.length; i++) { - dbxOstr.println("import " + dbxSvcAgentDSOPathNames[i]); - dbxOstr.println("kprint -u2 \\(Ready\\)"); - boolean seen = dbxErrStreamMonitor.waitFor("(Ready)", LONG_TIMEOUT); - if (!seen) { - detach(); - throw new DebuggerException("Timed out while importing dbx module from file\n" + dbxSvcAgentDSOPathNames[i]); - } - List retVals = dbxErrStreamMonitor.getTriggersSeen(); - if (retVals.contains(new Integer(DBX_MODULE_NOT_FOUND))) { - detach(); - throw new DebuggerException("Unable to find the Serviceability Agent's dbx import module at pathname \"" + - dbxSvcAgentDSOPathNames[i] + "\""); - } else { - retVals = dbxOutStreamMonitor.getTriggersSeen(); - if (retVals.contains(new Integer(DBX_MODULE_LOADED))) { - System.out.println("importDbxModule: imported " + dbxSvcAgentDSOPathNames[i]); - return; - } - } - } - - // Failed to load all flavors - detach(); - String errMsg = ("Unable to find a version of the Serviceability Agent's dbx import module\n" + - "matching the architecture of dbx at any of the following locations:"); - for (int i = 0; i < dbxSvcAgentDSOPathNames.length; i++) { - errMsg = errMsg + "\n" + dbxSvcAgentDSOPathNames[i]; - } - throw new DebuggerException(errMsg); - } - - /** Terminate the debugger forcibly */ - private void shutdown() { - - if (dbxProcess != null) { - // See whether the process has exited and, if not, terminate it - // forcibly - try { - dbxProcess.exitValue(); - } - catch (IllegalThreadStateException e) { - dbxProcess.destroy(); - } - } - - try { - if (importModuleSocket != null) { - importModuleSocket.close(); - } - } - catch (IOException e) { - } - - // Release references to all objects - clear(); - clearCache(); - } - - /** Looks up an address in the remote process's address space. - Returns 0 if symbol not found or upon error. Package private to - allow DbxDebuggerRemoteIntfImpl access. */ - synchronized long lookupInProcess(String objectName, String symbol) { - try { - printlnToOutput("lookup " + objectName + " " + symbol); - return in.parseAddress(); - } - catch (Exception e) { - return 0; - } - } - - /** This reads bytes from the remote process. */ - public synchronized ReadResult readBytesFromProcess(long address, long numBytes) - throws DebuggerException { - if (numBytes < 0) { - throw new DebuggerException("Can not read negative number (" + numBytes + ") of bytes from process"); - } - try { - String cmd = "peek " + utils.addressValueToString(address) + " " + numBytes; - printlnToOutput(cmd); - while (in.readByte() != 'B') { - } - byte res = in.readByte(); - if (res == 0) { - System.err.println("Failing command: " + cmd); - throw new DebuggerException("Read of remote process address space failed"); - } - // NOTE: must read ALL of the data regardless of whether we need - // to throw an UnmappedAddressException. Otherwise will corrupt - // the input stream each time we have a failure. Not good. Do - // not want to risk "flushing" the input stream in case a huge - // read has a hangup in the middle and we leave data on the - // stream. - byte[] buf = new byte[(int) numBytes]; - boolean bailOut = false; - long failureAddress = 0; - int numReads = 0; - while (numBytes > 0) { - long len = in.readUnsignedInt(); - boolean isMapped = ((in.readByte() == 0) ? false : true); - if (!isMapped) { - if (!bailOut) { - bailOut = true; - failureAddress = address; - } - } else { - // This won't work if we have unmapped regions, but if we do - // then we're going to throw an exception anyway - - // NOTE: there is a factor of 20 speed difference between - // these two ways of doing this read. - in.readBytes(buf, 0, (int) len); - } - - // Do NOT do this: - // for (int i = 0; i < (int) len; i++) { - // buf[i] = in.readByte(); - // } - - numBytes -= len; - address += len; - ++numReads; - } - if (Assert.ASSERTS_ENABLED) { - Assert.that(numBytes == 0, "Bug in debug server's implementation of peek: numBytesLeft == " + - numBytes + ", should be 0 (did " + numReads + " reads)"); - } - if (bailOut) { - return new ReadResult(failureAddress); - } - return new ReadResult(buf); - } - catch (IOException e) { - throw new DebuggerException(e); - } - } - - public void writeBytesToProcess(long address, long numBytes, byte[] data) - throws UnmappedAddressException, DebuggerException { - // FIXME - throw new DebuggerException("Unimplemented"); - } - - /** This provides DbxDebuggerRemoteIntfImpl access to readBytesFromProcess */ - ReadResult readBytesFromProcessInternal(long address, long numBytes) - throws DebuggerException { - return readBytesFromProcess(address, numBytes); - } - - /** Convenience routine */ - private void printlnToOutput(String s) throws IOException { - out.println(s); - if (out.checkError()) { - throw new IOException("Error occurred while writing to debug server"); - } - } - - private void clear() { - dbxProcess = null; - dbxOstr = null; - out = null; - in = null; - importModuleSocket = null; - } - - /** Connects to the dbx import module, setting up out and in - streams. Factored out to allow access to the dbx console. */ - private void connectToImportModule() throws IOException { - // Try for 20 seconds to connect to dbx import module; time out - // with failure if didn't succeed - importModuleSocket = null; - long endTime = System.currentTimeMillis() + LONG_TIMEOUT; - - while ((importModuleSocket == null) && (System.currentTimeMillis() < endTime)) { - try { - importModuleSocket = new Socket(InetAddress.getLocalHost(), PORT); - importModuleSocket.setTcpNoDelay(true); - } - catch (IOException e) { - // Swallow IO exceptions while attempting connection - try { - // Don't swamp the CPU - Thread.sleep(1000); - } - catch (InterruptedException ex) { - } - } - } - - if (importModuleSocket == null) { - // Failed to connect because of timeout - detach(); - throw new DebuggerException("Timed out while attempting to connect to remote dbx process"); - } - - out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(importModuleSocket.getOutputStream(), "US-ASCII")), true); - in = new InputLexer(new BufferedInputStream(importModuleSocket.getInputStream())); - } -}