1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/os/windows/vm/attachListener_windows.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,400 @@
1.4 +/*
1.5 + * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +# include "incls/_precompiled.incl"
1.29 +# include "incls/_attachListener_windows.cpp.incl"
1.30 +
1.31 +#include <windows.h>
1.32 +#include <signal.h> // SIGBREAK
1.33 +
1.34 +// The AttachListener thread services a queue of operations. It blocks in the dequeue
1.35 +// function until an operation is enqueued. A client enqueues an operation by creating
1.36 +// a thread in this process using the Win32 CreateRemoteThread function. That thread
1.37 +// executes a small stub generated by the client. The stub invokes the
1.38 +// JVM_EnqueueOperation function which checks the operation parameters and enqueues
1.39 +// the operation to the queue serviced by the attach listener. The thread created by
1.40 +// the client is a native thread and is restricted to a single page of stack. To keep
1.41 +// it simple operations are pre-allocated at initialization time. An enqueue thus
1.42 +// takes a preallocated operation, populates the operation parameters, adds it to
1.43 +// queue and wakes up the attach listener.
1.44 +//
1.45 +// When an operation has completed the attach listener is required to send the
1.46 +// operation result and any result data to the client. In this implementation the
1.47 +// client is a pipe server. In the enqueue operation it provides the name of pipe
1.48 +// to this process. When the operation is completed this process opens the pipe and
1.49 +// sends the result and output back to the client. Note that writing to the pipe
1.50 +// (and flushing the output) is a blocking operation. This means that a non-responsive
1.51 +// client could potentially hang the attach listener thread indefinitely. In that
1.52 +// case no new operations would be executed but the VM would continue as normal.
1.53 +// As only suitably privileged processes can open this process we concluded that
1.54 +// this wasn't worth worrying about.
1.55 +
1.56 +
1.57 +// forward reference
1.58 +class Win32AttachOperation;
1.59 +
1.60 +
1.61 +class Win32AttachListener: AllStatic {
1.62 + private:
1.63 + enum {
1.64 + preallocate_count = 4 // number of preallocated operations
1.65 + };
1.66 +
1.67 + // protects the preallocated list and the operation list
1.68 + static HANDLE _mutex;
1.69 +
1.70 + // head of preallocated operations list
1.71 + static Win32AttachOperation* _avail;
1.72 +
1.73 + // head and tail of enqueue operations list
1.74 + static Win32AttachOperation* _head;
1.75 + static Win32AttachOperation* _tail;
1.76 +
1.77 +
1.78 + static Win32AttachOperation* head() { return _head; }
1.79 + static void set_head(Win32AttachOperation* head) { _head = head; }
1.80 +
1.81 + static Win32AttachOperation* tail() { return _tail; }
1.82 + static void set_tail(Win32AttachOperation* tail) { _tail = tail; }
1.83 +
1.84 +
1.85 + // used to wakeup the listener
1.86 + static HANDLE _wakeup;
1.87 + static HANDLE wakeup() { return _wakeup; }
1.88 +
1.89 + public:
1.90 + enum {
1.91 + ATTACH_ERROR_DISABLED = 100, // error codes
1.92 + ATTACH_ERROR_RESOURCE = 101,
1.93 + ATTACH_ERROR_ILLEGALARG = 102,
1.94 + ATTACH_ERROR_INTERNAL = 103
1.95 + };
1.96 +
1.97 + static int init();
1.98 + static HANDLE mutex() { return _mutex; }
1.99 +
1.100 + static Win32AttachOperation* available() { return _avail; }
1.101 + static void set_available(Win32AttachOperation* avail) { _avail = avail; }
1.102 +
1.103 + // enqueue an operation to the end of the list
1.104 + static int enqueue(char* cmd, char* arg1, char* arg2, char* arg3, char* pipename);
1.105 +
1.106 + // dequeue an operation from from head of the list
1.107 + static Win32AttachOperation* dequeue();
1.108 +};
1.109 +
1.110 +// statics
1.111 +HANDLE Win32AttachListener::_mutex;
1.112 +HANDLE Win32AttachListener::_wakeup;
1.113 +Win32AttachOperation* Win32AttachListener::_avail;
1.114 +Win32AttachOperation* Win32AttachListener::_head;
1.115 +Win32AttachOperation* Win32AttachListener::_tail;
1.116 +
1.117 +
1.118 +// Win32AttachOperation is an AttachOperation that additionally encapsulates the name
1.119 +// of a pipe which is used to send the operation reply/output to the client.
1.120 +// Win32AttachOperation can also be linked in a list.
1.121 +
1.122 +class Win32AttachOperation: public AttachOperation {
1.123 + private:
1.124 + friend class Win32AttachListener;
1.125 +
1.126 + enum {
1.127 + pipe_name_max = 256 // maximum pipe name
1.128 + };
1.129 +
1.130 + char _pipe[pipe_name_max+1];
1.131 +
1.132 + const char* pipe() const { return _pipe; }
1.133 + void set_pipe(const char* pipe) {
1.134 + assert(strlen(pipe) <= pipe_name_max, "execeds maximum length of pipe name");
1.135 + strcpy(_pipe, pipe);
1.136 + }
1.137 +
1.138 + HANDLE open_pipe();
1.139 + static BOOL write_pipe(HANDLE hPipe, char* buf, int len);
1.140 +
1.141 + Win32AttachOperation* _next;
1.142 +
1.143 + Win32AttachOperation* next() const { return _next; }
1.144 + void set_next(Win32AttachOperation* next) { _next = next; }
1.145 +
1.146 + // noarg constructor as operation is preallocated
1.147 + Win32AttachOperation() : AttachOperation("<noname>") {
1.148 + set_pipe("<nopipe>");
1.149 + set_next(NULL);
1.150 + }
1.151 +
1.152 + public:
1.153 + void Win32AttachOperation::complete(jint result, bufferedStream* result_stream);
1.154 +};
1.155 +
1.156 +
1.157 +// preallocate the required number of operations
1.158 +int Win32AttachListener::init() {
1.159 + _mutex = (void*)::CreateMutex(NULL, FALSE, NULL);
1.160 + guarantee(_mutex != (HANDLE)NULL, "mutex creation failed");
1.161 +
1.162 + _wakeup = ::CreateSemaphore(NULL, 0, 1, NULL);
1.163 + guarantee(_wakeup != (HANDLE)NULL, "semaphore creation failed");
1.164 +
1.165 + set_head(NULL);
1.166 + set_tail(NULL);
1.167 +
1.168 + // preallocate a few operations
1.169 + set_available(NULL);
1.170 + for (int i=0; i<preallocate_count; i++) {
1.171 + Win32AttachOperation* op = new Win32AttachOperation();
1.172 + op->set_next(available());
1.173 + set_available(op);
1.174 + }
1.175 +
1.176 + return 0;
1.177 +}
1.178 +
1.179 +// Enqueue an operation. This is called from a native thread that is not attached to VM.
1.180 +// Also we need to be careful not to execute anything that results in more than a 4k stack.
1.181 +//
1.182 +int Win32AttachListener::enqueue(char* cmd, char* arg0, char* arg1, char* arg2, char* pipename) {
1.183 + // listener not running
1.184 + if (!AttachListener::is_initialized()) {
1.185 + return ATTACH_ERROR_DISABLED;
1.186 + }
1.187 +
1.188 + // check that all paramteres to the operation
1.189 + if (strlen(cmd) > AttachOperation::name_length_max) return ATTACH_ERROR_ILLEGALARG;
1.190 + if (strlen(arg0) > AttachOperation::arg_length_max) return ATTACH_ERROR_ILLEGALARG;
1.191 + if (strlen(arg0) > AttachOperation::arg_length_max) return ATTACH_ERROR_ILLEGALARG;
1.192 + if (strlen(pipename) > Win32AttachOperation::pipe_name_max) return ATTACH_ERROR_ILLEGALARG;
1.193 +
1.194 + // check for a well-formed pipename
1.195 + if (strstr(pipename, "\\\\.\\pipe\\") != pipename) return ATTACH_ERROR_ILLEGALARG;
1.196 +
1.197 + // grab the lock for the list
1.198 + DWORD res = ::WaitForSingleObject(mutex(), INFINITE);
1.199 + if (res != WAIT_OBJECT_0) {
1.200 + return ATTACH_ERROR_INTERNAL;
1.201 + }
1.202 +
1.203 + // try to get an operation from the available list
1.204 + Win32AttachOperation* op = available();
1.205 + if (op != NULL) {
1.206 + set_available(op->next());
1.207 +
1.208 + // add to end (tail) of list
1.209 + op->set_next(NULL);
1.210 + if (tail() == NULL) {
1.211 + set_head(op);
1.212 + } else {
1.213 + tail()->set_next(op);
1.214 + }
1.215 + set_tail(op);
1.216 +
1.217 + op->set_name(cmd);
1.218 + op->set_arg(0, arg0);
1.219 + op->set_arg(1, arg1);
1.220 + op->set_arg(2, arg2);
1.221 + op->set_pipe(pipename);
1.222 +
1.223 + // wakeup the thread waiting for operations
1.224 + ::ReleaseSemaphore(wakeup(), 1, NULL);
1.225 + }
1.226 + ::ReleaseMutex(mutex());
1.227 +
1.228 + return (op != NULL) ? 0 : ATTACH_ERROR_RESOURCE;
1.229 +}
1.230 +
1.231 +
1.232 +// dequeue the operation from the head of the operation list. If
1.233 +Win32AttachOperation* Win32AttachListener::dequeue() {
1.234 + for (;;) {
1.235 + DWORD res = ::WaitForSingleObject(wakeup(), INFINITE);
1.236 + guarantee(res == WAIT_OBJECT_0, "wait failed");
1.237 +
1.238 + res = ::WaitForSingleObject(mutex(), INFINITE);
1.239 + guarantee(res == WAIT_OBJECT_0, "wait failed");
1.240 +
1.241 + Win32AttachOperation* op = head();
1.242 + if (op != NULL) {
1.243 + set_head(op->next());
1.244 + if (head() == NULL) { // list is empty
1.245 + set_tail(NULL);
1.246 + }
1.247 + }
1.248 + ::ReleaseMutex(mutex());
1.249 +
1.250 + if (op != NULL) {
1.251 + return op;
1.252 + }
1.253 + }
1.254 +}
1.255 +
1.256 +
1.257 +// open the pipe to the client
1.258 +HANDLE Win32AttachOperation::open_pipe() {
1.259 + HANDLE hPipe;
1.260 +
1.261 + hPipe = ::CreateFile( pipe(), // pipe name
1.262 + GENERIC_WRITE, // write only
1.263 + 0, // no sharing
1.264 + NULL, // default security attributes
1.265 + OPEN_EXISTING, // opens existing pipe
1.266 + 0, // default attributes
1.267 + NULL); // no template file
1.268 +
1.269 + if (hPipe != INVALID_HANDLE_VALUE) {
1.270 + // shouldn't happen as there is a pipe created per operation
1.271 + if (::GetLastError() == ERROR_PIPE_BUSY) {
1.272 + return INVALID_HANDLE_VALUE;
1.273 + }
1.274 + }
1.275 + return hPipe;
1.276 +}
1.277 +
1.278 +// write to the pipe
1.279 +BOOL Win32AttachOperation::write_pipe(HANDLE hPipe, char* buf, int len) {
1.280 + do {
1.281 + DWORD nwrote;
1.282 +
1.283 + BOOL fSuccess = WriteFile( hPipe, // pipe handle
1.284 + (LPCVOID)buf, // message
1.285 + (DWORD)len, // message length
1.286 + &nwrote, // bytes written
1.287 + NULL); // not overlapped
1.288 + if (!fSuccess) {
1.289 + return fSuccess;
1.290 + }
1.291 + buf += nwrote;
1.292 + len -= nwrote;
1.293 + }
1.294 + while (len > 0);
1.295 + return TRUE;
1.296 +}
1.297 +
1.298 +// Complete the operation:
1.299 +// - open the pipe to the client
1.300 +// - write the operation result (a jint)
1.301 +// - write the operation output (the result stream)
1.302 +//
1.303 +void Win32AttachOperation::complete(jint result, bufferedStream* result_stream) {
1.304 + JavaThread* thread = JavaThread::current();
1.305 + ThreadBlockInVM tbivm(thread);
1.306 +
1.307 + thread->set_suspend_equivalent();
1.308 + // cleared by handle_special_suspend_equivalent_condition() or
1.309 + // java_suspend_self() via check_and_wait_while_suspended()
1.310 +
1.311 + HANDLE hPipe = open_pipe();
1.312 + if (hPipe != INVALID_HANDLE_VALUE) {
1.313 + BOOL fSuccess;
1.314 +
1.315 + char msg[32];
1.316 + sprintf(msg, "%d\n", result);
1.317 +
1.318 + fSuccess = write_pipe(hPipe, msg, (int)strlen(msg));
1.319 + if (fSuccess) {
1.320 + write_pipe(hPipe, (char*) result_stream->base(), (int)(result_stream->size()));
1.321 + }
1.322 +
1.323 + // Need to flush buffers
1.324 + FlushFileBuffers(hPipe);
1.325 + CloseHandle(hPipe);
1.326 + }
1.327 +
1.328 + DWORD res = ::WaitForSingleObject(Win32AttachListener::mutex(), INFINITE);
1.329 + if (res == WAIT_OBJECT_0) {
1.330 +
1.331 + // put the operation back on the available list
1.332 + set_next(Win32AttachListener::available());
1.333 + Win32AttachListener::set_available(this);
1.334 +
1.335 + ::ReleaseMutex(Win32AttachListener::mutex());
1.336 + }
1.337 +
1.338 + // were we externally suspended while we were waiting?
1.339 + thread->check_and_wait_while_suspended();
1.340 +}
1.341 +
1.342 +
1.343 +// AttachOperation functions
1.344 +
1.345 +AttachOperation* AttachListener::dequeue() {
1.346 + JavaThread* thread = JavaThread::current();
1.347 + ThreadBlockInVM tbivm(thread);
1.348 +
1.349 + thread->set_suspend_equivalent();
1.350 + // cleared by handle_special_suspend_equivalent_condition() or
1.351 + // java_suspend_self() via check_and_wait_while_suspended()
1.352 +
1.353 + AttachOperation* op = Win32AttachListener::dequeue();
1.354 +
1.355 + // were we externally suspended while we were waiting?
1.356 + thread->check_and_wait_while_suspended();
1.357 +
1.358 + return op;
1.359 +}
1.360 +
1.361 +int AttachListener::pd_init() {
1.362 + return Win32AttachListener::init();
1.363 +}
1.364 +
1.365 +// always startup on Windows NT/2000/XP
1.366 +bool AttachListener::init_at_startup() {
1.367 + return os::win32::is_nt();
1.368 +}
1.369 +
1.370 +// no trigger mechanism on Windows to start Attach Listener lazily
1.371 +bool AttachListener::is_init_trigger() {
1.372 + return false;
1.373 +}
1.374 +
1.375 +void AttachListener::abort() {
1.376 + // nothing to do
1.377 +}
1.378 +
1.379 +void AttachListener::pd_data_dump() {
1.380 + os::signal_notify(SIGBREAK);
1.381 +}
1.382 +
1.383 +AttachOperationFunctionInfo* AttachListener::pd_find_operation(const char* n) {
1.384 + return NULL;
1.385 +}
1.386 +
1.387 +jint AttachListener::pd_set_flag(AttachOperation* op, outputStream* out) {
1.388 + out->print_cr("flag '%s' cannot be changed", op->arg(0));
1.389 + return JNI_ERR;
1.390 +}
1.391 +
1.392 +void AttachListener::pd_detachall() {
1.393 + // do nothing for now
1.394 +}
1.395 +
1.396 +// Native thread started by remote client executes this.
1.397 +extern "C" {
1.398 + JNIEXPORT jint JNICALL
1.399 + JVM_EnqueueOperation(char* cmd, char* arg0, char* arg1, char* arg2, char* pipename) {
1.400 + return (jint)Win32AttachListener::enqueue(cmd, arg0, arg1, arg2, pipename);
1.401 + }
1.402 +
1.403 +} // extern
