--- a/hotspot/agent/src/share/native/jvmdi/sa.cpp Thu Feb 28 10:42:28 2013 -0800
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,601 +0,0 @@
-/*
- * Copyright (c) 2002, 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 <stdio.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <vector>
-#include "sa.hpp"
-#include "jni.h"
-#include "jvmdi.h"
-
-#ifndef WIN32
- #include <inttypes.h>
-#else
- typedef int int32_t;
-#endif
-
-#ifdef WIN32
- #include <windows.h>
- #define YIELD() Sleep(0)
- #define SLEEP() Sleep(10)
- #define vsnprintf _vsnprintf
-#else
- Error: please port YIELD() and SLEEP() macros to your platform
-#endif
-
-using namespace std;
-
-//////////////////////////////////////////////////////////////////////
-// //
-// Exported "interface" for Java language-level interaction between //
-// the SA and the VM. Note that the SA knows about the layout of //
-// certain VM data structures and that knowledge is taken advantage //
-// of in this code, although this interfaces with the VM via JVMDI. //
-// //
-//////////////////////////////////////////////////////////////////////
-
-extern "C" {
- /////////////////////////////////////
- // //
- // Events sent by the VM to the SA //
- // //
- /////////////////////////////////////
-
- // Set by the SA when it attaches. Indicates that events should be
- // posted via these exported variables, and that the VM should wait
- // for those events to be acknowledged by the SA (via its setting
- // saEventPending to 0).
- JNIEXPORT volatile int32_t saAttached = 0;
-
- // Set to nonzero value by the VM when an event has been posted; set
- // back to 0 by the SA when it has processed that event.
- JNIEXPORT volatile int32_t saEventPending = 0;
-
- // Kind of the event (from jvmdi.h)
- JNIEXPORT volatile int32_t saEventKind = 0;
-
- //
- // Exception events
- //
- JNIEXPORT jthread saExceptionThread;
- JNIEXPORT jclass saExceptionClass;
- JNIEXPORT jmethodID saExceptionMethod;
- JNIEXPORT int32_t saExceptionLocation;
- JNIEXPORT jobject saExceptionException;
- JNIEXPORT jclass saExceptionCatchClass;
- JNIEXPORT jmethodID saExceptionCatchMethod;
- JNIEXPORT int32_t saExceptionCatchLocation;
-
- //
- // Breakpoint events
- //
- JNIEXPORT jthread saBreakpointThread;
- JNIEXPORT jclass saBreakpointClass;
- JNIEXPORT jmethodID saBreakpointMethod;
- JNIEXPORT jlocation saBreakpointLocation;
-
- ///////////////////////////////////////
- // //
- // Commands sent by the SA to the VM //
- // //
- ///////////////////////////////////////
-
- extern JNIEXPORT const int32_t SA_CMD_SUSPEND_ALL = 0;
- extern JNIEXPORT const int32_t SA_CMD_RESUME_ALL = 1;
- extern JNIEXPORT const int32_t SA_CMD_TOGGLE_BREAKPOINT = 2;
- extern JNIEXPORT const int32_t SA_CMD_BUF_SIZE = 1024;
-
- // SA sets this to a nonzero value when it is requesting a command
- // to be processed; VM sets it back to 0 when the command has been
- // executed
- JNIEXPORT volatile int32_t saCmdPending = 0;
-
- // SA sets this to one of the manifest constants above to indicate
- // the kind of command to be executed
- JNIEXPORT volatile int32_t saCmdType = 0;
-
- // VM sets this to 0 if the last command succeeded or a nonzero
- // value if it failed
- JNIEXPORT volatile int32_t saCmdResult = 0;
-
- // If last command failed, this buffer will contain a descriptive
- // error message
- JNIEXPORT char saCmdResultErrMsg[SA_CMD_BUF_SIZE];
-
- //
- // Toggling of breakpoint command arguments.
- //
- // Originally there were separate set/clear breakpoint commands
- // taking a class name, method name and signature, and the iteration
- // through the debug information was done in the SA. It turns out
- // that doing this work in the target VM is significantly faster,
- // and since interactivity when setting and clearing breakpoints is
- // important, the solution which resulted in more C/C++ code was used.
- //
-
- // Source file name
- JNIEXPORT char saCmdBkptSrcFileName[SA_CMD_BUF_SIZE];
-
- // Package name ('/' as separator instead of '.')
- JNIEXPORT char saCmdBkptPkgName[SA_CMD_BUF_SIZE];
-
- // Line number
- JNIEXPORT int32_t saCmdBkptLineNumber;
-
- // Output back to SA: indicator whether the last failure of a
- // breakpoint toggle command was really an error or just a lack of
- // debug information covering the requested line. 0 if not error.
- // Valid only if saCmdResult != 0.
- JNIEXPORT int32_t saCmdBkptResWasError;
-
- // Output back to SA: resulting line number at which the breakpoint
- // was set or cleared (valid only if saCmdResult == 0)
- JNIEXPORT int32_t saCmdBkptResLineNumber;
-
- // Output back to SA: resulting byte code index at which the
- // breakpoint was set or cleared (valid only if saCmdResult == 0)
- JNIEXPORT int32_t saCmdBkptResBCI;
-
- // Output back to SA: indicator whether the breakpoint operation
- // resulted in a set or cleared breakpoint; nonzero if set, zero if
- // cleared (valid only if saCmdResult == 0)
- JNIEXPORT int32_t saCmdBkptResWasSet;
-
- // Output back to SA: method name the breakpoint was set in (valid
- // only if saCmdResult == 0)
- JNIEXPORT char saCmdBkptResMethodName[SA_CMD_BUF_SIZE];
-
- // Output back to SA: method signature (JNI style) the breakpoint
- // was set in (valid only if saCmdResult == 0)
- JNIEXPORT char saCmdBkptResMethodSig[SA_CMD_BUF_SIZE];
-}
-
-// Internal state
-static JavaVM* jvm = NULL;
-static JVMDI_Interface_1* jvmdi = NULL;
-static jthread debugThreadObj = NULL;
-static bool suspended = false;
-static vector<jthread> suspendedThreads;
-static JVMDI_RawMonitor eventLock = NULL;
-
-class MonitorLocker {
-private:
- JVMDI_RawMonitor lock;
-public:
- MonitorLocker(JVMDI_RawMonitor lock) {
- this->lock = lock;
- if (lock != NULL) {
- jvmdi->RawMonitorEnter(lock);
- }
- }
- ~MonitorLocker() {
- if (lock != NULL) {
- jvmdi->RawMonitorExit(lock);
- }
- }
-};
-
-class JvmdiDeallocator {
-private:
- void* ptr;
-public:
- JvmdiDeallocator(void* ptr) {
- this->ptr = ptr;
- }
- ~JvmdiDeallocator() {
- jvmdi->Deallocate((jbyte*) ptr);
- }
-};
-
-class JvmdiRefListDeallocator {
-private:
- JNIEnv* env;
- jobject* refList;
- jint refCount;
-public:
- JvmdiRefListDeallocator(JNIEnv* env, jobject* refList, jint refCount) {
- this->env = env;
- this->refList = refList;
- this->refCount = refCount;
- }
- ~JvmdiRefListDeallocator() {
- for (int i = 0; i < refCount; i++) {
- env->DeleteGlobalRef(refList[i]);
- }
- jvmdi->Deallocate((jbyte*) refList);
- }
-};
-
-static void
-stop(char* msg) {
- fprintf(stderr, "%s", msg);
- fprintf(stderr, "\n");
- exit(1);
-}
-
-// This fills in the command result error message, sets the command
-// result to -1, and clears the pending command flag
-static void
-reportErrorToSA(const char* str, ...) {
- va_list varargs;
- va_start(varargs, str);
- vsnprintf(saCmdResultErrMsg, sizeof(saCmdResultErrMsg), str, varargs);
- va_end(varargs);
- saCmdResult = -1;
- saCmdPending = 0;
-}
-
-static bool
-packageNameMatches(char* clazzName, char* pkg) {
- int pkgLen = strlen(pkg);
- int clazzNameLen = strlen(clazzName);
-
- if (pkgLen >= clazzNameLen + 1) {
- return false;
- }
-
- if (strncmp(clazzName, pkg, pkgLen)) {
- return false;
- }
-
- // Ensure that '/' is the next character if non-empty package name
- int l = pkgLen;
- if (l > 0) {
- if (clazzName[l] != '/') {
- return false;
- }
- l++;
- }
- // Ensure that there are no more trailing slashes
- while (l < clazzNameLen) {
- if (clazzName[l++] == '/') {
- return false;
- }
- }
- return true;
-}
-
-static void
-executeOneCommand(JNIEnv* env) {
- switch (saCmdType) {
- case SA_CMD_SUSPEND_ALL: {
- if (suspended) {
- reportErrorToSA("Target process already suspended");
- return;
- }
-
- // We implement this by getting all of the threads and calling
- // SuspendThread on each one, except for the thread object
- // corresponding to this thread. Each thread for which the call
- // succeeded (i.e., did not return JVMDI_ERROR_INVALID_THREAD)
- // is added to a list which is remembered for later resumption.
- // Note that this currently has race conditions since a thread
- // might be started after we call GetAllThreads and since a
- // thread for which we got an error earlier might be resumed by
- // the VM while we are busy suspending other threads. We could
- // solve this by looping until there are no more threads we can
- // suspend, but a more robust and scalable solution is to add
- // this functionality to the JVMDI interface (i.e.,
- // "suspendAll"). Probably need to provide an exclude list for
- // such a routine.
- jint threadCount;
- jthread* threads;
- if (jvmdi->GetAllThreads(&threadCount, &threads) != JVMDI_ERROR_NONE) {
- reportErrorToSA("Error while getting thread list");
- return;
- }
-
-
- for (int i = 0; i < threadCount; i++) {
- jthread thr = threads[i];
- if (!env->IsSameObject(thr, debugThreadObj)) {
- jvmdiError err = jvmdi->SuspendThread(thr);
- if (err == JVMDI_ERROR_NONE) {
- // Remember this thread and do not free it
- suspendedThreads.push_back(thr);
- continue;
- } else {
- fprintf(stderr, " SA: Error %d while suspending thread\n", err);
- // FIXME: stop, resume all threads, report error
- }
- }
- env->DeleteGlobalRef(thr);
- }
-
- // Free up threads
- jvmdi->Deallocate((jbyte*) threads);
-
- // Suspension is complete
- suspended = true;
- break;
- }
-
- case SA_CMD_RESUME_ALL: {
- if (!suspended) {
- reportErrorToSA("Target process already suspended");
- return;
- }
-
- saCmdResult = 0;
- bool errorOccurred = false;
- jvmdiError firstError;
- for (int i = 0; i < suspendedThreads.size(); i++) {
- jthread thr = suspendedThreads[i];
- jvmdiError err = jvmdi->ResumeThread(thr);
- env->DeleteGlobalRef(thr);
- if (err != JVMDI_ERROR_NONE) {
- if (!errorOccurred) {
- errorOccurred = true;
- firstError = err;
- }
- }
- }
- suspendedThreads.clear();
- suspended = false;
- if (errorOccurred) {
- reportErrorToSA("Error %d while resuming threads", firstError);
- return;
- }
- break;
- }
-
- case SA_CMD_TOGGLE_BREAKPOINT: {
- saCmdBkptResWasError = 1;
-
- // Search line number info for all loaded classes
- jint classCount;
- jclass* classes;
-
- jvmdiError glcRes = jvmdi->GetLoadedClasses(&classCount, &classes);
- if (glcRes != JVMDI_ERROR_NONE) {
- reportErrorToSA("Error %d while getting loaded classes", glcRes);
- return;
- }
- JvmdiRefListDeallocator rld(env, (jobject*) classes, classCount);
-
- bool done = false;
- bool gotOne = false;
- jclass targetClass;
- jmethodID targetMethod;
- jlocation targetLocation;
- jint targetLineNumber;
-
- for (int i = 0; i < classCount && !done; i++) {
- fflush(stderr);
- jclass clazz = classes[i];
- char* srcName;
- jvmdiError sfnRes = jvmdi->GetSourceFileName(clazz, &srcName);
- if (sfnRes == JVMDI_ERROR_NONE) {
- JvmdiDeallocator de1(srcName);
- if (!strcmp(srcName, saCmdBkptSrcFileName)) {
- // Got a match. Now see whether the package name of the class also matches
- char* clazzName;
- jvmdiError sigRes = jvmdi->GetClassSignature(clazz, &clazzName);
- if (sigRes != JVMDI_ERROR_NONE) {
- reportErrorToSA("Error %d while getting a class's signature", sigRes);
- return;
- }
- JvmdiDeallocator de2(clazzName);
- if (packageNameMatches(clazzName + 1, saCmdBkptPkgName)) {
- // Iterate through all methods
- jint methodCount;
- jmethodID* methods;
- if (jvmdi->GetClassMethods(clazz, &methodCount, &methods) != JVMDI_ERROR_NONE) {
- reportErrorToSA("Error while getting methods of class %s", clazzName);
- return;
- }
- JvmdiDeallocator de3(methods);
- for (int j = 0; j < methodCount && !done; j++) {
- jmethodID m = methods[j];
- jint entryCount;
- JVMDI_line_number_entry* table;
- jvmdiError lnRes = jvmdi->GetLineNumberTable(clazz, m, &entryCount, &table);
- if (lnRes == JVMDI_ERROR_NONE) {
- JvmdiDeallocator de4(table);
- // Look for line number greater than or equal to requested line
- for (int k = 0; k < entryCount && !done; k++) {
- JVMDI_line_number_entry& entry = table[k];
- if (entry.line_number >= saCmdBkptLineNumber &&
- (!gotOne || entry.line_number < targetLineNumber)) {
- gotOne = true;
- targetClass = clazz;
- targetMethod = m;
- targetLocation = entry.start_location;
- targetLineNumber = entry.line_number;
- done = (targetLineNumber == saCmdBkptLineNumber);
- }
- }
- } else if (lnRes != JVMDI_ERROR_ABSENT_INFORMATION) {
- reportErrorToSA("Unexpected error %d while fetching line number table", lnRes);
- return;
- }
- }
- }
- }
- } else if (sfnRes != JVMDI_ERROR_ABSENT_INFORMATION) {
- reportErrorToSA("Unexpected error %d while fetching source file name", sfnRes);
- return;
- }
- }
-
- bool wasSet = true;
- if (gotOne) {
- // Really toggle this breakpoint
- jvmdiError bpRes;
- bpRes = jvmdi->SetBreakpoint(targetClass, targetMethod, targetLocation);
- if (bpRes == JVMDI_ERROR_DUPLICATE) {
- bpRes = jvmdi->ClearBreakpoint(targetClass, targetMethod, targetLocation);
- wasSet = false;
- }
- if (bpRes != JVMDI_ERROR_NONE) {
- reportErrorToSA("Unexpected error %d while setting or clearing breakpoint at bci %d, line %d",
- bpRes, targetLocation, targetLineNumber);
- return;
- }
- } else {
- saCmdBkptResWasError = 0;
- reportErrorToSA("No debug information found covering this line");
- return;
- }
-
- // Provide result
- saCmdBkptResLineNumber = targetLineNumber;
- saCmdBkptResBCI = targetLocation;
- saCmdBkptResWasSet = (wasSet ? 1 : 0);
- {
- char* methodName;
- char* methodSig;
- if (jvmdi->GetMethodName(targetClass, targetMethod, &methodName, &methodSig)
- == JVMDI_ERROR_NONE) {
- JvmdiDeallocator mnd(methodName);
- JvmdiDeallocator msd(methodSig);
- strncpy(saCmdBkptResMethodName, methodName, SA_CMD_BUF_SIZE);
- strncpy(saCmdBkptResMethodSig, methodSig, SA_CMD_BUF_SIZE);
- } else {
- strncpy(saCmdBkptResMethodName, "<error>", SA_CMD_BUF_SIZE);
- strncpy(saCmdBkptResMethodSig, "<error>", SA_CMD_BUF_SIZE);
- }
- }
- break;
- }
-
- default:
- reportErrorToSA("Command %d not yet supported", saCmdType);
- return;
- }
-
- // Successful command execution
- saCmdResult = 0;
- saCmdPending = 0;
-}
-
-static void
-saCommandThread(void *arg) {
- JNIEnv* env = NULL;
- if (jvm->GetEnv((void **) &env, JNI_VERSION_1_2) != JNI_OK) {
- stop("Error while starting Serviceability Agent "
- "command thread: could not get JNI environment");
- }
-
- while (1) {
- // Wait for command
- while (!saCmdPending) {
- SLEEP();
- }
-
- executeOneCommand(env);
- }
-}
-
-static void
-saEventHook(JNIEnv *env, JVMDI_Event *event)
-{
- MonitorLocker ml(eventLock);
-
- saEventKind = event->kind;
-
- if (event->kind == JVMDI_EVENT_VM_INIT) {
- // Create event lock
- if (jvmdi->CreateRawMonitor("Serviceability Agent Event Lock", &eventLock)
- != JVMDI_ERROR_NONE) {
- stop("Unable to create Serviceability Agent's event lock");
- }
- // Start thread which receives commands from the SA.
- jclass threadClass = env->FindClass("java/lang/Thread");
- if (threadClass == NULL) stop("Unable to find class java/lang/Thread");
- jstring threadName = env->NewStringUTF("Serviceability Agent Command Thread");
- if (threadName == NULL) stop("Unable to allocate debug thread name");
- jmethodID ctor = env->GetMethodID(threadClass, "<init>", "(Ljava/lang/String;)V");
- if (ctor == NULL) stop("Unable to find appropriate constructor for java/lang/Thread");
- // Allocate thread object
- jthread thr = (jthread) env->NewObject(threadClass, ctor, threadName);
- if (thr == NULL) stop("Unable to allocate debug thread's java/lang/Thread instance");
- // Remember which thread this is
- debugThreadObj = env->NewGlobalRef(thr);
- if (debugThreadObj == NULL) stop("Unable to allocate global ref for debug thread object");
- // Start thread
- jvmdiError err;
- if ((err = jvmdi->RunDebugThread(thr, &saCommandThread, NULL, JVMDI_THREAD_NORM_PRIORITY))
- != JVMDI_ERROR_NONE) {
- char buf[256];
- sprintf(buf, "Error %d while starting debug thread", err);
- stop(buf);
- }
- // OK, initialization is done
- return;
- }
-
- if (!saAttached) {
- return;
- }
-
- switch (event->kind) {
- case JVMDI_EVENT_EXCEPTION: {
- fprintf(stderr, "SA: Exception thrown -- ignoring\n");
- saExceptionThread = event->u.exception.thread;
- saExceptionClass = event->u.exception.clazz;
- saExceptionMethod = event->u.exception.method;
- saExceptionLocation = event->u.exception.location;
- saExceptionException = event->u.exception.exception;
- saExceptionCatchClass = event->u.exception.catch_clazz;
- saExceptionCatchClass = event->u.exception.catch_clazz;
- saExceptionCatchMethod = event->u.exception.catch_method;
- saExceptionCatchLocation = event->u.exception.catch_location;
- // saEventPending = 1;
- break;
- }
-
- case JVMDI_EVENT_BREAKPOINT: {
- saBreakpointThread = event->u.breakpoint.thread;
- saBreakpointClass = event->u.breakpoint.clazz;
- saBreakpointMethod = event->u.breakpoint.method;
- saBreakpointLocation = event->u.breakpoint.location;
- saEventPending = 1;
- break;
- }
-
- default:
- break;
- }
-
- while (saAttached && saEventPending) {
- SLEEP();
- }
-}
-
-extern "C" {
-JNIEXPORT jint JNICALL
-JVM_OnLoad(JavaVM *vm, char *options, void *reserved)
-{
- jvm = vm;
- if (jvm->GetEnv((void**) &jvmdi, JVMDI_VERSION_1) != JNI_OK) {
- return -1;
- }
- if (jvmdi->SetEventHook(&saEventHook) != JVMDI_ERROR_NONE) {
- return -1;
- }
- return 0;
-}
-};