Mercurial > hg > graal-compiler
view src/os/windows/vm/attachListener_windows.cpp @ 13627:a2aac8373610
more robust handling of errors in Constant.toString()
author | Doug Simon <doug.simon@oracle.com> |
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date | Tue, 14 Jan 2014 11:56:04 +0100 |
parents | 2e8f19c2feef |
children |
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/* * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "runtime/interfaceSupport.hpp" #include "runtime/os.hpp" #include "services/attachListener.hpp" #include "services/dtraceAttacher.hpp" #include <windows.h> #include <signal.h> // SIGBREAK // The AttachListener thread services a queue of operations. It blocks in the dequeue // function until an operation is enqueued. A client enqueues an operation by creating // a thread in this process using the Win32 CreateRemoteThread function. That thread // executes a small stub generated by the client. The stub invokes the // JVM_EnqueueOperation function which checks the operation parameters and enqueues // the operation to the queue serviced by the attach listener. The thread created by // the client is a native thread and is restricted to a single page of stack. To keep // it simple operations are pre-allocated at initialization time. An enqueue thus // takes a preallocated operation, populates the operation parameters, adds it to // queue and wakes up the attach listener. // // When an operation has completed the attach listener is required to send the // operation result and any result data to the client. In this implementation the // client is a pipe server. In the enqueue operation it provides the name of pipe // to this process. When the operation is completed this process opens the pipe and // sends the result and output back to the client. Note that writing to the pipe // (and flushing the output) is a blocking operation. This means that a non-responsive // client could potentially hang the attach listener thread indefinitely. In that // case no new operations would be executed but the VM would continue as normal. // As only suitably privileged processes can open this process we concluded that // this wasn't worth worrying about. // forward reference class Win32AttachOperation; class Win32AttachListener: AllStatic { private: enum { preallocate_count = 4 // number of preallocated operations }; // protects the preallocated list and the operation list static HANDLE _mutex; // head of preallocated operations list static Win32AttachOperation* _avail; // head and tail of enqueue operations list static Win32AttachOperation* _head; static Win32AttachOperation* _tail; static Win32AttachOperation* head() { return _head; } static void set_head(Win32AttachOperation* head) { _head = head; } static Win32AttachOperation* tail() { return _tail; } static void set_tail(Win32AttachOperation* tail) { _tail = tail; } // used to wakeup the listener static HANDLE _wakeup; static HANDLE wakeup() { return _wakeup; } public: enum { ATTACH_ERROR_DISABLED = 100, // error codes ATTACH_ERROR_RESOURCE = 101, ATTACH_ERROR_ILLEGALARG = 102, ATTACH_ERROR_INTERNAL = 103 }; static int init(); static HANDLE mutex() { return _mutex; } static Win32AttachOperation* available() { return _avail; } static void set_available(Win32AttachOperation* avail) { _avail = avail; } // enqueue an operation to the end of the list static int enqueue(char* cmd, char* arg1, char* arg2, char* arg3, char* pipename); // dequeue an operation from from head of the list static Win32AttachOperation* dequeue(); }; // statics HANDLE Win32AttachListener::_mutex; HANDLE Win32AttachListener::_wakeup; Win32AttachOperation* Win32AttachListener::_avail; Win32AttachOperation* Win32AttachListener::_head; Win32AttachOperation* Win32AttachListener::_tail; // Win32AttachOperation is an AttachOperation that additionally encapsulates the name // of a pipe which is used to send the operation reply/output to the client. // Win32AttachOperation can also be linked in a list. class Win32AttachOperation: public AttachOperation { private: friend class Win32AttachListener; enum { pipe_name_max = 256 // maximum pipe name }; char _pipe[pipe_name_max+1]; const char* pipe() const { return _pipe; } void set_pipe(const char* pipe) { assert(strlen(pipe) <= pipe_name_max, "execeds maximum length of pipe name"); strcpy(_pipe, pipe); } HANDLE open_pipe(); static BOOL write_pipe(HANDLE hPipe, char* buf, int len); Win32AttachOperation* _next; Win32AttachOperation* next() const { return _next; } void set_next(Win32AttachOperation* next) { _next = next; } // noarg constructor as operation is preallocated Win32AttachOperation() : AttachOperation("<noname>") { set_pipe("<nopipe>"); set_next(NULL); } public: void Win32AttachOperation::complete(jint result, bufferedStream* result_stream); }; // preallocate the required number of operations int Win32AttachListener::init() { _mutex = (void*)::CreateMutex(NULL, FALSE, NULL); guarantee(_mutex != (HANDLE)NULL, "mutex creation failed"); _wakeup = ::CreateSemaphore(NULL, 0, 1, NULL); guarantee(_wakeup != (HANDLE)NULL, "semaphore creation failed"); set_head(NULL); set_tail(NULL); // preallocate a few operations set_available(NULL); for (int i=0; i<preallocate_count; i++) { Win32AttachOperation* op = new Win32AttachOperation(); op->set_next(available()); set_available(op); } return 0; } // Enqueue an operation. This is called from a native thread that is not attached to VM. // Also we need to be careful not to execute anything that results in more than a 4k stack. // int Win32AttachListener::enqueue(char* cmd, char* arg0, char* arg1, char* arg2, char* pipename) { // listener not running if (!AttachListener::is_initialized()) { return ATTACH_ERROR_DISABLED; } // check that all paramteres to the operation if (strlen(cmd) > AttachOperation::name_length_max) return ATTACH_ERROR_ILLEGALARG; if (strlen(arg0) > AttachOperation::arg_length_max) return ATTACH_ERROR_ILLEGALARG; if (strlen(arg0) > AttachOperation::arg_length_max) return ATTACH_ERROR_ILLEGALARG; if (strlen(pipename) > Win32AttachOperation::pipe_name_max) return ATTACH_ERROR_ILLEGALARG; // check for a well-formed pipename if (strstr(pipename, "\\\\.\\pipe\\") != pipename) return ATTACH_ERROR_ILLEGALARG; // grab the lock for the list DWORD res = ::WaitForSingleObject(mutex(), INFINITE); if (res != WAIT_OBJECT_0) { return ATTACH_ERROR_INTERNAL; } // try to get an operation from the available list Win32AttachOperation* op = available(); if (op != NULL) { set_available(op->next()); // add to end (tail) of list op->set_next(NULL); if (tail() == NULL) { set_head(op); } else { tail()->set_next(op); } set_tail(op); op->set_name(cmd); op->set_arg(0, arg0); op->set_arg(1, arg1); op->set_arg(2, arg2); op->set_pipe(pipename); // wakeup the thread waiting for operations ::ReleaseSemaphore(wakeup(), 1, NULL); } ::ReleaseMutex(mutex()); return (op != NULL) ? 0 : ATTACH_ERROR_RESOURCE; } // dequeue the operation from the head of the operation list. If Win32AttachOperation* Win32AttachListener::dequeue() { for (;;) { DWORD res = ::WaitForSingleObject(wakeup(), INFINITE); guarantee(res == WAIT_OBJECT_0, "wait failed"); res = ::WaitForSingleObject(mutex(), INFINITE); guarantee(res == WAIT_OBJECT_0, "wait failed"); Win32AttachOperation* op = head(); if (op != NULL) { set_head(op->next()); if (head() == NULL) { // list is empty set_tail(NULL); } } ::ReleaseMutex(mutex()); if (op != NULL) { return op; } } } // open the pipe to the client HANDLE Win32AttachOperation::open_pipe() { HANDLE hPipe; hPipe = ::CreateFile( pipe(), // pipe name GENERIC_WRITE, // write only 0, // no sharing NULL, // default security attributes OPEN_EXISTING, // opens existing pipe 0, // default attributes NULL); // no template file if (hPipe != INVALID_HANDLE_VALUE) { // shouldn't happen as there is a pipe created per operation if (::GetLastError() == ERROR_PIPE_BUSY) { return INVALID_HANDLE_VALUE; } } return hPipe; } // write to the pipe BOOL Win32AttachOperation::write_pipe(HANDLE hPipe, char* buf, int len) { do { DWORD nwrote; BOOL fSuccess = WriteFile( hPipe, // pipe handle (LPCVOID)buf, // message (DWORD)len, // message length &nwrote, // bytes written NULL); // not overlapped if (!fSuccess) { return fSuccess; } buf += nwrote; len -= nwrote; } while (len > 0); return TRUE; } // Complete the operation: // - open the pipe to the client // - write the operation result (a jint) // - write the operation output (the result stream) // void Win32AttachOperation::complete(jint result, bufferedStream* result_stream) { JavaThread* thread = JavaThread::current(); ThreadBlockInVM tbivm(thread); thread->set_suspend_equivalent(); // cleared by handle_special_suspend_equivalent_condition() or // java_suspend_self() via check_and_wait_while_suspended() HANDLE hPipe = open_pipe(); if (hPipe != INVALID_HANDLE_VALUE) { BOOL fSuccess; char msg[32]; sprintf(msg, "%d\n", result); fSuccess = write_pipe(hPipe, msg, (int)strlen(msg)); if (fSuccess) { write_pipe(hPipe, (char*) result_stream->base(), (int)(result_stream->size())); } // Need to flush buffers FlushFileBuffers(hPipe); CloseHandle(hPipe); } DWORD res = ::WaitForSingleObject(Win32AttachListener::mutex(), INFINITE); if (res == WAIT_OBJECT_0) { // put the operation back on the available list set_next(Win32AttachListener::available()); Win32AttachListener::set_available(this); ::ReleaseMutex(Win32AttachListener::mutex()); } // were we externally suspended while we were waiting? thread->check_and_wait_while_suspended(); } // AttachOperation functions AttachOperation* AttachListener::dequeue() { JavaThread* thread = JavaThread::current(); ThreadBlockInVM tbivm(thread); thread->set_suspend_equivalent(); // cleared by handle_special_suspend_equivalent_condition() or // java_suspend_self() via check_and_wait_while_suspended() AttachOperation* op = Win32AttachListener::dequeue(); // were we externally suspended while we were waiting? thread->check_and_wait_while_suspended(); return op; } void AttachListener::vm_start() { // nothing to do } int AttachListener::pd_init() { return Win32AttachListener::init(); } // always startup on Windows NT/2000/XP bool AttachListener::init_at_startup() { return os::win32::is_nt(); } // no trigger mechanism on Windows to start Attach Listener lazily bool AttachListener::is_init_trigger() { return false; } void AttachListener::abort() { // nothing to do } void AttachListener::pd_data_dump() { os::signal_notify(SIGBREAK); } AttachOperationFunctionInfo* AttachListener::pd_find_operation(const char* n) { return NULL; } jint AttachListener::pd_set_flag(AttachOperation* op, outputStream* out) { out->print_cr("flag '%s' cannot be changed", op->arg(0)); return JNI_ERR; } void AttachListener::pd_detachall() { // do nothing for now } // Native thread started by remote client executes this. extern "C" { JNIEXPORT jint JNICALL JVM_EnqueueOperation(char* cmd, char* arg0, char* arg1, char* arg2, char* pipename) { return (jint)Win32AttachListener::enqueue(cmd, arg0, arg1, arg2, pipename); } } // extern