vm/Ddm.cpp - platform/dalvik - Gitiles

 /*
  * Copyright (C) 2008 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 /*
  * Handle Dalvik Debug Monitor requests and events.
  *
  * Remember that all DDM traffic is big-endian since it travels over the
  * JDWP connection.
  */
 #include "Dalvik.h"

 #include <fcntl.h>
 #include <errno.h>

 /*
  * "buf" contains a full JDWP packet, possibly with multiple chunks.  We
  * need to process each, accumulate the replies, and ship the whole thing
  * back.
  *
  * Returns "true" if we have a reply.  The reply buffer is newly allocated,
  * and includes the chunk type/length, followed by the data.
  *
  * TODO: we currently assume that the request and reply include a single
  * chunk.  If this becomes inconvenient we will need to adapt.
  */
 bool dvmDdmHandlePacket(const u1* buf, int dataLen, u1** pReplyBuf,
     int* pReplyLen)
 {
     Thread* self = dvmThreadSelf();
     const int kChunkHdrLen = 8;
     ArrayObject* dataArray = NULL;
     Object* chunk = NULL;
     bool result = false;

     assert(dataLen >= 0);

     if (!dvmIsClassInitialized(gDvm.classOrgApacheHarmonyDalvikDdmcChunk)) {
         if (!dvmInitClass(gDvm.classOrgApacheHarmonyDalvikDdmcChunk)) {
             dvmLogExceptionStackTrace();
             dvmClearException(self);
             goto bail;
         }
     }

     /*
      * The chunk handlers are written in the Java programming language, so
      * we need to convert the buffer to a byte array.
      */
     dataArray = dvmAllocPrimitiveArray('B', dataLen, ALLOC_DEFAULT);
     if (dataArray == NULL) {
         ALOGW("array alloc failed (%d)", dataLen);
         dvmClearException(self);
         goto bail;
     }
     memcpy(dataArray->contents, buf, dataLen);

     /*
      * Run through and find all chunks.  [Currently just find the first.]
      */
     unsigned int offset, length, type;
     type = get4BE((u1*)dataArray->contents + 0);
     length = get4BE((u1*)dataArray->contents + 4);
     offset = kChunkHdrLen;
     if (offset+length > (unsigned int) dataLen) {
         ALOGW("WARNING: bad chunk found (len=%u pktLen=%d)", length, dataLen);
         goto bail;
     }

     /*
      * Call the handler.
      */
     JValue callRes;
     dvmCallMethod(self, gDvm.methDalvikDdmcServer_dispatch, NULL, &callRes,
         type, dataArray, offset, length);
     if (dvmCheckException(self)) {
         ALOGI("Exception thrown by dispatcher for 0x%08x", type);
         dvmLogExceptionStackTrace();
         dvmClearException(self);
         goto bail;
     }

     ArrayObject* replyData;
     chunk = (Object*) callRes.l;
     if (chunk == NULL)
         goto bail;

     /* not strictly necessary -- we don't alloc from managed heap here */
     dvmAddTrackedAlloc(chunk, self);

     /*
      * Pull the pieces out of the chunk.  We copy the results into a
      * newly-allocated buffer that the caller can free.  We don't want to
      * continue using the Chunk object because nothing has a reference to it.
      *
      * We could avoid this by returning type/data/offset/length and having
      * the caller be aware of the object lifetime issues, but that
      * integrates the JDWP code more tightly into the VM, and doesn't work
      * if we have responses for multiple chunks.
      *
      * So we're pretty much stuck with copying data around multiple times.
      */
     type = dvmGetFieldInt(chunk, gDvm.offDalvikDdmcChunk_type);
     replyData =
         (ArrayObject*) dvmGetFieldObject(chunk, gDvm.offDalvikDdmcChunk_data);
     offset = dvmGetFieldInt(chunk, gDvm.offDalvikDdmcChunk_offset);
     length = dvmGetFieldInt(chunk, gDvm.offDalvikDdmcChunk_length);

     ALOGV("DDM reply: type=0x%08x data=%p offset=%d length=%d",
         type, replyData, offset, length);

     if (length == 0 || replyData == NULL)
         goto bail;
     if (offset + length > replyData->length) {
         ALOGW("WARNING: chunk off=%d len=%d exceeds reply array len %d",
             offset, length, replyData->length);
         goto bail;
     }

     u1* reply;
     reply = (u1*) malloc(length + kChunkHdrLen);
     if (reply == NULL) {
         ALOGW("malloc %d failed", length+kChunkHdrLen);
         goto bail;
     }
     set4BE(reply + 0, type);
     set4BE(reply + 4, length);
     memcpy(reply+kChunkHdrLen, (const u1*)replyData->contents + offset, length);

     *pReplyBuf = reply;
     *pReplyLen = length + kChunkHdrLen;
     result = true;

     ALOGV("dvmHandleDdm returning type=%.4s buf=%p len=%d",
         (char*) reply, reply, length);

 bail:
     dvmReleaseTrackedAlloc((Object*) dataArray, self);
     dvmReleaseTrackedAlloc(chunk, self);
     return result;
 }

 /* defined in org.apache.harmony.dalvik.ddmc.DdmServer */
 #define CONNECTED       1
 #define DISCONNECTED    2

 /*
  * Broadcast an event to all handlers.
  */
 static void broadcast(int event)
 {
     Thread* self = dvmThreadSelf();

     if (self->status != THREAD_RUNNING) {
         ALOGE("ERROR: DDM broadcast with thread status=%d", self->status);
         /* try anyway? */
     }

     if (!dvmIsClassInitialized(gDvm.classOrgApacheHarmonyDalvikDdmcDdmServer)) {
         if (!dvmInitClass(gDvm.classOrgApacheHarmonyDalvikDdmcDdmServer)) {
             dvmLogExceptionStackTrace();
             dvmClearException(self);
             return;
         }
     }

     JValue unused;
     dvmCallMethod(self, gDvm.methDalvikDdmcServer_broadcast, NULL, &unused,
         event);
     if (dvmCheckException(self)) {
         ALOGI("Exception thrown by broadcast(%d)", event);
         dvmLogExceptionStackTrace();
         dvmClearException(self);
         return;
     }
 }

 /*
  * First DDM packet has arrived over JDWP.  Notify the press.
  *
  * We can do some initialization here too.
  */
 void dvmDdmConnected()
 {
     // TODO: any init

     ALOGV("Broadcasting DDM connect");
     broadcast(CONNECTED);
 }

 /*
  * JDWP connection has dropped.
  *
  * Do some cleanup.
  */
 void dvmDdmDisconnected()
 {
     ALOGV("Broadcasting DDM disconnect");
     broadcast(DISCONNECTED);

     gDvm.ddmThreadNotification = false;
 }


 /*
  * Turn thread notification on or off.
  */
 void dvmDdmSetThreadNotification(bool enable)
 {
     /*
      * We lock the thread list to avoid sending duplicate events or missing
      * a thread change.  We should be okay holding this lock while sending
      * the messages out.  (We have to hold it while accessing a live thread.)
      */
     dvmLockThreadList(NULL);
     gDvm.ddmThreadNotification = enable;

     if (enable) {
         Thread* thread;
         for (thread = gDvm.threadList; thread != NULL; thread = thread->next) {
             //ALOGW("notify %d", thread->threadId);
             dvmDdmSendThreadNotification(thread, true);
         }
     }

     dvmUnlockThreadList();
 }

 /*
  * Send a notification when a thread starts or stops.
  *
  * Because we broadcast the full set of threads when the notifications are
  * first enabled, it's possible for "thread" to be actively executing.
  */
 void dvmDdmSendThreadNotification(Thread* thread, bool started)
 {
     if (!gDvm.ddmThreadNotification) {
         return;
     }

     StringObject* nameObj = NULL;
     Object* threadObj = thread->threadObj;

     if (threadObj != NULL) {
         nameObj = (StringObject*)
             dvmGetFieldObject(threadObj, gDvm.offJavaLangThread_name);
     }

     int type, len;
     u1 buf[256];

     if (started) {
         const u2* chars;
         u2* outChars;
         size_t stringLen;

         type = CHUNK_TYPE("THCR");

         if (nameObj != NULL) {
             stringLen = nameObj->length();
             chars = nameObj->chars();
         } else {
             stringLen = 0;
             chars = NULL;
         }

         /* leave room for the two integer fields */
         if (stringLen > (sizeof(buf) - sizeof(u4)*2) / 2) {
             stringLen = (sizeof(buf) - sizeof(u4)*2) / 2;
         }
         len = stringLen*2 + sizeof(u4)*2;

         set4BE(&buf[0x00], thread->threadId);
         set4BE(&buf[0x04], stringLen);

         /* copy the UTF-16 string, transforming to big-endian */
         outChars = (u2*)(void*)&buf[0x08];
         while (stringLen--) {
             set2BE((u1*) (outChars++), *chars++);
         }
     } else {
         type = CHUNK_TYPE("THDE");

         len = 4;

         set4BE(&buf[0x00], thread->threadId);
     }

     dvmDbgDdmSendChunk(type, len, buf);
 }

 /*
  * Send a notification when a thread's name changes.
  */
 void dvmDdmSendThreadNameChange(int threadId, StringObject* newName)
 {
     if (!gDvm.ddmThreadNotification) {
         return;
     }

     size_t stringLen = newName->length();
     const u2* chars = newName->chars();

     /*
      * Output format:
      *  (4b) thread ID
      *  (4b) stringLen
      *  (xb) string chars
      */
     int bufLen = 4 + 4 + (stringLen * 2);
     u1 buf[bufLen];

     set4BE(&buf[0x00], threadId);
     set4BE(&buf[0x04], stringLen);
     u2* outChars = (u2*)(void*)&buf[0x08];
     while (stringLen--) {
         set2BE((u1*) (outChars++), *chars++);
     }

     dvmDbgDdmSendChunk(CHUNK_TYPE("THNM"), bufLen, buf);
 }

 /*
  * Generate the contents of a THST chunk.  The data encompasses all known
  * threads.
  *
  * Response has:
  *  (1b) header len
  *  (1b) bytes per entry
  *  (2b) thread count
  * Then, for each thread:
  *  (4b) threadId
  *  (1b) thread status
  *  (4b) tid
  *  (4b) utime
  *  (4b) stime
  *  (1b) is daemon?
  *
  * The length fields exist in anticipation of adding additional fields
  * without wanting to break ddms or bump the full protocol version.  I don't
  * think it warrants full versioning.  They might be extraneous and could
  * be removed from a future version.
  *
  * Returns a new byte[] with the data inside, or NULL on failure.  The
  * caller must call dvmReleaseTrackedAlloc() on the array.
  */
 ArrayObject* dvmDdmGenerateThreadStats()
 {
     const int kHeaderLen = 4;
     const int kBytesPerEntry = 18;

     dvmLockThreadList(NULL);

     Thread* thread;
     int threadCount = 0;
     for (thread = gDvm.threadList; thread != NULL; thread = thread->next)
         threadCount++;

     /*
      * Create a temporary buffer.  We can't perform heap allocation with
      * the thread list lock held (could cause a GC).  The output is small
      * enough to sit on the stack.
      */
     int bufLen = kHeaderLen + threadCount * kBytesPerEntry;
     u1 tmpBuf[bufLen];
     u1* buf = tmpBuf;

     set1(buf+0, kHeaderLen);
     set1(buf+1, kBytesPerEntry);
     set2BE(buf+2, (u2) threadCount);
     buf += kHeaderLen;

     for (thread = gDvm.threadList; thread != NULL; thread = thread->next) {
         bool isDaemon = false;

         ProcStatData procStatData;
         if (!dvmGetThreadStats(&procStatData, thread->systemTid)) {
             /* failed; show zero */
             memset(&procStatData, 0, sizeof(procStatData));
         }

         Object* threadObj = thread->threadObj;
         if (threadObj != NULL) {
             isDaemon = dvmGetFieldBoolean(threadObj,
                             gDvm.offJavaLangThread_daemon);
         }

         set4BE(buf+0, thread->threadId);
         set1(buf+4, thread->status);
         set4BE(buf+5, thread->systemTid);
         set4BE(buf+9, procStatData.utime);
         set4BE(buf+13, procStatData.stime);
         set1(buf+17, isDaemon);

         buf += kBytesPerEntry;
     }
     dvmUnlockThreadList();


     /*
      * Create a byte array to hold the data.
      */
     ArrayObject* arrayObj = dvmAllocPrimitiveArray('B', bufLen, ALLOC_DEFAULT);
     if (arrayObj != NULL)
         memcpy(arrayObj->contents, tmpBuf, bufLen);
     return arrayObj;
 }


 /*
  * Find the specified thread and return its stack trace as an array of
  * StackTraceElement objects.
  */
 ArrayObject* dvmDdmGetStackTraceById(u4 threadId)
 {
     Thread* self = dvmThreadSelf();
     Thread* thread;
     int* traceBuf;

     dvmLockThreadList(self);

     for (thread = gDvm.threadList; thread != NULL; thread = thread->next) {
         if (thread->threadId == threadId)
             break;
     }
     if (thread == NULL) {
         ALOGI("dvmDdmGetStackTraceById: threadid=%d not found", threadId);
         dvmUnlockThreadList();
         return NULL;
     }

     /*
      * Suspend the thread, pull out the stack trace, then resume the thread
      * and release the thread list lock.  If we're being asked to examine
      * our own stack trace, skip the suspend/resume.
      */
     size_t stackDepth;
     if (thread != self)
         dvmSuspendThread(thread);
     traceBuf = dvmFillInStackTraceRaw(thread, &stackDepth);
     if (thread != self)
         dvmResumeThread(thread);
     dvmUnlockThreadList();

     /*
      * Convert the raw buffer into an array of StackTraceElement.
      */
     ArrayObject* trace = dvmGetStackTraceRaw(traceBuf, stackDepth);
     free(traceBuf);
     return trace;
 }

 /*
  * Gather up the allocation data and copy it into a byte[].
  *
  * Returns NULL on failure with an exception raised.
  */
 ArrayObject* dvmDdmGetRecentAllocations()
 {
     u1* data;
     size_t len;

     if (!dvmGenerateTrackedAllocationReport(&data, &len)) {
         /* assume OOM */
         dvmThrowOutOfMemoryError("recent alloc native");
         return NULL;
     }

     ArrayObject* arrayObj = dvmAllocPrimitiveArray('B', len, ALLOC_DEFAULT);
     if (arrayObj != NULL)
         memcpy(arrayObj->contents, data, len);
     return arrayObj;
 }
	/*
	* Copyright (C) 2008 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	/*
	* Handle Dalvik Debug Monitor requests and events.
	*
	* Remember that all DDM traffic is big-endian since it travels over the
	* JDWP connection.
	*/
	#include "Dalvik.h"

	#include <fcntl.h>
	#include <errno.h>

	/*
	* "buf" contains a full JDWP packet, possibly with multiple chunks. We
	* need to process each, accumulate the replies, and ship the whole thing
	* back.
	*
	* Returns "true" if we have a reply. The reply buffer is newly allocated,
	* and includes the chunk type/length, followed by the data.
	*
	* TODO: we currently assume that the request and reply include a single
	* chunk. If this becomes inconvenient we will need to adapt.
	*/
	bool dvmDdmHandlePacket(const u1* buf, int dataLen, u1** pReplyBuf,
	int* pReplyLen)
	{
	Thread* self = dvmThreadSelf();
	const int kChunkHdrLen = 8;
	ArrayObject* dataArray = NULL;
	Object* chunk = NULL;
	bool result = false;

	assert(dataLen >= 0);

	if (!dvmIsClassInitialized(gDvm.classOrgApacheHarmonyDalvikDdmcChunk)) {
	if (!dvmInitClass(gDvm.classOrgApacheHarmonyDalvikDdmcChunk)) {
	dvmLogExceptionStackTrace();
	dvmClearException(self);
	goto bail;
	}
	}

	/*
	* The chunk handlers are written in the Java programming language, so
	* we need to convert the buffer to a byte array.
	*/
	dataArray = dvmAllocPrimitiveArray('B', dataLen, ALLOC_DEFAULT);
	if (dataArray == NULL) {
	ALOGW("array alloc failed (%d)", dataLen);
	dvmClearException(self);
	goto bail;
	}
	memcpy(dataArray->contents, buf, dataLen);

	/*
	* Run through and find all chunks. [Currently just find the first.]
	*/
	unsigned int offset, length, type;
	type = get4BE((u1*)dataArray->contents + 0);
	length = get4BE((u1*)dataArray->contents + 4);
	offset = kChunkHdrLen;
	if (offset+length > (unsigned int) dataLen) {
	ALOGW("WARNING: bad chunk found (len=%u pktLen=%d)", length, dataLen);
	goto bail;
	}

	/*
	* Call the handler.
	*/
	JValue callRes;
	dvmCallMethod(self, gDvm.methDalvikDdmcServer_dispatch, NULL, &callRes,
	type, dataArray, offset, length);
	if (dvmCheckException(self)) {
	ALOGI("Exception thrown by dispatcher for 0x%08x", type);
	dvmLogExceptionStackTrace();
	dvmClearException(self);
	goto bail;
	}

	ArrayObject* replyData;
	chunk = (Object*) callRes.l;
	if (chunk == NULL)
	goto bail;

	/* not strictly necessary -- we don't alloc from managed heap here */
	dvmAddTrackedAlloc(chunk, self);

	/*
	* Pull the pieces out of the chunk. We copy the results into a
	* newly-allocated buffer that the caller can free. We don't want to
	* continue using the Chunk object because nothing has a reference to it.
	*
	* We could avoid this by returning type/data/offset/length and having
	* the caller be aware of the object lifetime issues, but that
	* integrates the JDWP code more tightly into the VM, and doesn't work
	* if we have responses for multiple chunks.
	*
	* So we're pretty much stuck with copying data around multiple times.
	*/
	type = dvmGetFieldInt(chunk, gDvm.offDalvikDdmcChunk_type);
	replyData =
	(ArrayObject*) dvmGetFieldObject(chunk, gDvm.offDalvikDdmcChunk_data);
	offset = dvmGetFieldInt(chunk, gDvm.offDalvikDdmcChunk_offset);
	length = dvmGetFieldInt(chunk, gDvm.offDalvikDdmcChunk_length);

	ALOGV("DDM reply: type=0x%08x data=%p offset=%d length=%d",
	type, replyData, offset, length);

	if (length == 0 \|\| replyData == NULL)
	goto bail;
	if (offset + length > replyData->length) {
	ALOGW("WARNING: chunk off=%d len=%d exceeds reply array len %d",
	offset, length, replyData->length);
	goto bail;
	}

	u1* reply;
	reply = (u1*) malloc(length + kChunkHdrLen);
	if (reply == NULL) {
	ALOGW("malloc %d failed", length+kChunkHdrLen);
	goto bail;
	}
	set4BE(reply + 0, type);
	set4BE(reply + 4, length);
	memcpy(reply+kChunkHdrLen, (const u1*)replyData->contents + offset, length);

	*pReplyBuf = reply;
	*pReplyLen = length + kChunkHdrLen;
	result = true;

	ALOGV("dvmHandleDdm returning type=%.4s buf=%p len=%d",
	(char*) reply, reply, length);

	bail:
	dvmReleaseTrackedAlloc((Object*) dataArray, self);
	dvmReleaseTrackedAlloc(chunk, self);
	return result;
	}

	/* defined in org.apache.harmony.dalvik.ddmc.DdmServer */
	#define CONNECTED 1
	#define DISCONNECTED 2

	/*
	* Broadcast an event to all handlers.
	*/
	static void broadcast(int event)
	{
	Thread* self = dvmThreadSelf();

	if (self->status != THREAD_RUNNING) {
	ALOGE("ERROR: DDM broadcast with thread status=%d", self->status);
	/* try anyway? */
	}

	if (!dvmIsClassInitialized(gDvm.classOrgApacheHarmonyDalvikDdmcDdmServer)) {
	if (!dvmInitClass(gDvm.classOrgApacheHarmonyDalvikDdmcDdmServer)) {
	dvmLogExceptionStackTrace();
	dvmClearException(self);
	return;
	}
	}

	JValue unused;
	dvmCallMethod(self, gDvm.methDalvikDdmcServer_broadcast, NULL, &unused,
	event);
	if (dvmCheckException(self)) {
	ALOGI("Exception thrown by broadcast(%d)", event);
	dvmLogExceptionStackTrace();
	dvmClearException(self);
	return;
	}
	}

	/*
	* First DDM packet has arrived over JDWP. Notify the press.
	*
	* We can do some initialization here too.
	*/
	void dvmDdmConnected()
	{
	// TODO: any init

	ALOGV("Broadcasting DDM connect");
	broadcast(CONNECTED);
	}

	/*
	* JDWP connection has dropped.
	*
	* Do some cleanup.
	*/
	void dvmDdmDisconnected()
	{
	ALOGV("Broadcasting DDM disconnect");
	broadcast(DISCONNECTED);

	gDvm.ddmThreadNotification = false;
	}


	/*
	* Turn thread notification on or off.
	*/
	void dvmDdmSetThreadNotification(bool enable)
	{
	/*
	* We lock the thread list to avoid sending duplicate events or missing
	* a thread change. We should be okay holding this lock while sending
	* the messages out. (We have to hold it while accessing a live thread.)
	*/
	dvmLockThreadList(NULL);
	gDvm.ddmThreadNotification = enable;

	if (enable) {
	Thread* thread;
	for (thread = gDvm.threadList; thread != NULL; thread = thread->next) {
	//ALOGW("notify %d", thread->threadId);
	dvmDdmSendThreadNotification(thread, true);
	}
	}

	dvmUnlockThreadList();
	}

	/*
	* Send a notification when a thread starts or stops.
	*
	* Because we broadcast the full set of threads when the notifications are
	* first enabled, it's possible for "thread" to be actively executing.
	*/
	void dvmDdmSendThreadNotification(Thread* thread, bool started)
	{
	if (!gDvm.ddmThreadNotification) {
	return;
	}

	StringObject* nameObj = NULL;
	Object* threadObj = thread->threadObj;

	if (threadObj != NULL) {
	nameObj = (StringObject*)
	dvmGetFieldObject(threadObj, gDvm.offJavaLangThread_name);
	}

	int type, len;
	u1 buf[256];

	if (started) {
	const u2* chars;
	u2* outChars;
	size_t stringLen;

	type = CHUNK_TYPE("THCR");

	if (nameObj != NULL) {
	stringLen = nameObj->length();
	chars = nameObj->chars();
	} else {
	stringLen = 0;
	chars = NULL;
	}

	/* leave room for the two integer fields */
	if (stringLen > (sizeof(buf) - sizeof(u4)*2) / 2) {
	stringLen = (sizeof(buf) - sizeof(u4)*2) / 2;
	}
	len = stringLen2 + sizeof(u4)2;

	set4BE(&buf[0x00], thread->threadId);
	set4BE(&buf[0x04], stringLen);

	/* copy the UTF-16 string, transforming to big-endian */
	outChars = (u2)(void)&buf[0x08];
	while (stringLen--) {
	set2BE((u1) (outChars++), chars++);
	}
	} else {
	type = CHUNK_TYPE("THDE");

	len = 4;

	set4BE(&buf[0x00], thread->threadId);
	}

	dvmDbgDdmSendChunk(type, len, buf);
	}

	/*
	* Send a notification when a thread's name changes.
	*/
	void dvmDdmSendThreadNameChange(int threadId, StringObject* newName)
	{
	if (!gDvm.ddmThreadNotification) {
	return;
	}

	size_t stringLen = newName->length();
	const u2* chars = newName->chars();

	/*
	* Output format:
	* (4b) thread ID
	* (4b) stringLen
	* (xb) string chars
	*/
	int bufLen = 4 + 4 + (stringLen * 2);
	u1 buf[bufLen];

	set4BE(&buf[0x00], threadId);
	set4BE(&buf[0x04], stringLen);
	u2* outChars = (u2)(void)&buf[0x08];
	while (stringLen--) {
	set2BE((u1) (outChars++), chars++);
	}

	dvmDbgDdmSendChunk(CHUNK_TYPE("THNM"), bufLen, buf);
	}

	/*
	* Generate the contents of a THST chunk. The data encompasses all known
	* threads.
	*
	* Response has:
	* (1b) header len
	* (1b) bytes per entry
	* (2b) thread count
	* Then, for each thread:
	* (4b) threadId
	* (1b) thread status
	* (4b) tid
	* (4b) utime
	* (4b) stime
	* (1b) is daemon?
	*
	* The length fields exist in anticipation of adding additional fields
	* without wanting to break ddms or bump the full protocol version. I don't
	* think it warrants full versioning. They might be extraneous and could
	* be removed from a future version.
	*
	* Returns a new byte[] with the data inside, or NULL on failure. The
	* caller must call dvmReleaseTrackedAlloc() on the array.
	*/
	ArrayObject* dvmDdmGenerateThreadStats()
	{
	const int kHeaderLen = 4;
	const int kBytesPerEntry = 18;

	dvmLockThreadList(NULL);

	Thread* thread;
	int threadCount = 0;
	for (thread = gDvm.threadList; thread != NULL; thread = thread->next)
	threadCount++;

	/*
	* Create a temporary buffer. We can't perform heap allocation with
	* the thread list lock held (could cause a GC). The output is small
	* enough to sit on the stack.
	*/
	int bufLen = kHeaderLen + threadCount * kBytesPerEntry;
	u1 tmpBuf[bufLen];
	u1* buf = tmpBuf;

	set1(buf+0, kHeaderLen);
	set1(buf+1, kBytesPerEntry);
	set2BE(buf+2, (u2) threadCount);
	buf += kHeaderLen;

	for (thread = gDvm.threadList; thread != NULL; thread = thread->next) {
	bool isDaemon = false;

	ProcStatData procStatData;
	if (!dvmGetThreadStats(&procStatData, thread->systemTid)) {
	/* failed; show zero */
	memset(&procStatData, 0, sizeof(procStatData));
	}

	Object* threadObj = thread->threadObj;
	if (threadObj != NULL) {
	isDaemon = dvmGetFieldBoolean(threadObj,
	gDvm.offJavaLangThread_daemon);
	}

	set4BE(buf+0, thread->threadId);
	set1(buf+4, thread->status);
	set4BE(buf+5, thread->systemTid);
	set4BE(buf+9, procStatData.utime);
	set4BE(buf+13, procStatData.stime);
	set1(buf+17, isDaemon);

	buf += kBytesPerEntry;
	}
	dvmUnlockThreadList();


	/*
	* Create a byte array to hold the data.
	*/
	ArrayObject* arrayObj = dvmAllocPrimitiveArray('B', bufLen, ALLOC_DEFAULT);
	if (arrayObj != NULL)
	memcpy(arrayObj->contents, tmpBuf, bufLen);
	return arrayObj;
	}


	/*
	* Find the specified thread and return its stack trace as an array of
	* StackTraceElement objects.
	*/
	ArrayObject* dvmDdmGetStackTraceById(u4 threadId)
	{
	Thread* self = dvmThreadSelf();
	Thread* thread;
	int* traceBuf;

	dvmLockThreadList(self);

	for (thread = gDvm.threadList; thread != NULL; thread = thread->next) {
	if (thread->threadId == threadId)
	break;
	}
	if (thread == NULL) {
	ALOGI("dvmDdmGetStackTraceById: threadid=%d not found", threadId);
	dvmUnlockThreadList();
	return NULL;
	}

	/*
	* Suspend the thread, pull out the stack trace, then resume the thread
	* and release the thread list lock. If we're being asked to examine
	* our own stack trace, skip the suspend/resume.
	*/
	size_t stackDepth;
	if (thread != self)
	dvmSuspendThread(thread);
	traceBuf = dvmFillInStackTraceRaw(thread, &stackDepth);
	if (thread != self)
	dvmResumeThread(thread);
	dvmUnlockThreadList();

	/*
	* Convert the raw buffer into an array of StackTraceElement.
	*/
	ArrayObject* trace = dvmGetStackTraceRaw(traceBuf, stackDepth);
	free(traceBuf);
	return trace;
	}

	/*
	* Gather up the allocation data and copy it into a byte[].
	*
	* Returns NULL on failure with an exception raised.
	*/
	ArrayObject* dvmDdmGetRecentAllocations()
	{
	u1* data;
	size_t len;

	if (!dvmGenerateTrackedAllocationReport(&data, &len)) {
	/* assume OOM */
	dvmThrowOutOfMemoryError("recent alloc native");
	return NULL;
	}

	ArrayObject* arrayObj = dvmAllocPrimitiveArray('B', len, ALLOC_DEFAULT);
	if (arrayObj != NULL)
	memcpy(arrayObj->contents, data, len);
	return arrayObj;
	}