/** Execute the given command in the target VM. */
InputStream execute(String cmd, Object... args) throws AgentLoadException, IOException {
assert args.length <= 3; // includes null
// did we detach?
String p;
synchronized (this) {
if (this.path == null) {
throw new IOException("Detached from target VM");
}
p = this.path;
}
// create UNIX socket
int s = socket();
// connect to target VM
try {
connect(s, p);
} catch (IOException x) {
close(s);
throw x;
}
IOException ioe = null;
// connected - write request
// <ver> <cmd> <args...>
try {
writeString(s, PROTOCOL_VERSION);
writeString(s, cmd);
for (int i = 0; i < 3; i++) {
if (i < args.length && args[i] != null) {
writeString(s, (String) args[i]);
} else {
writeString(s, "");
}
}
} catch (IOException x) {
ioe = x;
}
// Create an input stream to read reply
SocketInputStream sis = new SocketInputStream(s);
// Read the command completion status
int completionStatus;
try {
completionStatus = readInt(sis);
} catch (IOException x) {
sis.close();
if (ioe != null) {
throw ioe;
} else {
throw x;
}
}
if (completionStatus != 0) {
sis.close();
// In the event of a protocol mismatch then the target VM
// returns a known error so that we can throw a reasonable
// error.
if (completionStatus == ATTACH_ERROR_BADVERSION) {
throw new IOException("Protocol mismatch with target VM");
}
// Special-case the "load" command so that the right exception is
// thrown.
if (cmd.equals("load")) {
throw new AgentLoadException("Failed to load agent library");
} else {
throw new IOException("Command failed in target VM");
}
}
// Return the input stream so that the command output can be read
return sis;
}
