/*
* Pop one frame pushed on by JNI PushLocalFrame.
*
* If we've gone too far, the previous frame is either a break frame or
* an interpreted frame. Either way, the method pointer won't match.
*/
bool dvmPopLocalFrame(Thread* self)
{
StackSaveArea* saveBlock = SAVEAREA_FROM_FP(self->interpSave.curFrame);
assert(!dvmIsBreakFrame((u4*)self->interpSave.curFrame));
if (saveBlock->method != SAVEAREA_FROM_FP(saveBlock->prevFrame)->method) {
/*
* The previous frame doesn't have the same method pointer -- we've
* been asked to pop too much.
*/
assert(dvmIsBreakFrame((u4*)saveBlock->prevFrame) ||
!dvmIsNativeMethod(
SAVEAREA_FROM_FP(saveBlock->prevFrame)->method));
return false;
}
LOGVV("POP JNI local frame: removing %s, now %s",
saveBlock->method->name,
SAVEAREA_FROM_FP(saveBlock->prevFrame)->method->name);
dvmPopJniLocals(self, saveBlock);
self->interpSave.curFrame = saveBlock->prevFrame;
#ifdef WITH_OFFLOAD
offStackFramePopped(self);
#endif
return true;
}
/*
* Get the calling frame. Pass in the current fp.
*
* Skip "break" frames and reflection invoke frames.
*/
void* dvmGetCallerFP(const void* curFrame)
{
void* caller = SAVEAREA_FROM_FP(curFrame)->prevFrame;
StackSaveArea* saveArea;
retry:
if (dvmIsBreakFrame((u4*)caller)) {
/* pop up one more */
caller = SAVEAREA_FROM_FP(caller)->prevFrame;
if (caller == NULL)
return NULL; /* hit the top */
/*
* If we got here by java.lang.reflect.Method.invoke(), we don't
* want to return Method's class loader. Shift up one and try
* again.
*/
saveArea = SAVEAREA_FROM_FP(caller);
if (dvmIsReflectionMethod(saveArea->method)) {
caller = saveArea->prevFrame;
assert(caller != NULL);
goto retry;
}
}
return caller;
}
/*
* Fill a flat array of methods that comprise the current interpreter
* stack trace. Pass in the current frame ptr. Break frames are
* skipped, but reflection invocations are not.
*
* The current frame will be in element 0.
*/
void dvmFillStackTraceArray(const void* fp, const Method** array, size_t length)
{
assert(fp != NULL);
assert(array != NULL);
size_t i = 0;
while (fp != NULL) {
if (!dvmIsBreakFrame((u4*)fp)) {
assert(i < length);
array[i++] = SAVEAREA_FROM_FP(fp)->method;
}
fp = SAVEAREA_FROM_FP(fp)->prevFrame;
}
}
/*
* Get the caller's caller's class. Pass in the current fp.
*
* This is used by e.g. java.lang.Class, which wants to know about the
* class loader of the method that called it.
*/
ClassObject* dvmGetCaller2Class(const void* curFrame)
{
void* caller = SAVEAREA_FROM_FP(curFrame)->prevFrame;
void* callerCaller;
/* at the top? */
if (dvmIsBreakFrame(caller) && SAVEAREA_FROM_FP(caller)->prevFrame == NULL)
return NULL;
/* go one more */
callerCaller = dvmGetCallerFP(caller);
if (callerCaller == NULL)
return NULL;
return SAVEAREA_FROM_FP(callerCaller)->method->clazz;
}
/*
* Pop a frame we added. There should be one method frame and one break
* frame.
*
* If JNI Push/PopLocalFrame calls were mismatched, we might end up
* popping multiple method frames before we find the break.
*
* Returns "false" if there was no frame to pop.
*/
static bool dvmPopFrame(Thread* self)
{
StackSaveArea* saveBlock;
if (self->interpSave.curFrame == NULL)
return false;
saveBlock = SAVEAREA_FROM_FP(self->interpSave.curFrame);
assert(!dvmIsBreakFrame((u4*)self->interpSave.curFrame));
/*
* Remove everything up to the break frame. If this was a call into
* native code, pop the JNI local references table.
*/
while (saveBlock->prevFrame != NULL && saveBlock->method != NULL) {
/* probably a native->native JNI call */
if (dvmIsNativeMethod(saveBlock->method)) {
LOGVV("Popping JNI stack frame for %s.%s%s",
saveBlock->method->clazz->descriptor,
saveBlock->method->name,
(SAVEAREA_FROM_FP(saveBlock->prevFrame)->method == NULL) ?
"" : " (JNI local)");
dvmPopJniLocals(self, saveBlock);
}
saveBlock = SAVEAREA_FROM_FP(saveBlock->prevFrame);
}
if (saveBlock->method != NULL) {
ALOGE("PopFrame missed the break");
assert(false);
dvmAbort(); // stack trashed -- nowhere to go in this thread
}
LOGVV("POP frame: cur=%p new=%p",
self->interpSave.curFrame, saveBlock->prevFrame);
self->interpSave.curFrame = saveBlock->prevFrame;
#ifdef WITH_OFFLOAD
offStackFramePopped(self);
self->breakFrames--;
CHECK_BREAK_FRAMES();
#endif
return true;
}
/*
* Get the caller's caller's caller's class. Pass in the current fp.
*
* This is used by e.g. java.lang.Class, which wants to know about the
* class loader of the method that called it.
*/
ClassObject* dvmGetCaller3Class(const void* curFrame)
{
void* caller = SAVEAREA_FROM_FP(curFrame)->prevFrame;
int i;
/* at the top? */
if (dvmIsBreakFrame(caller) && SAVEAREA_FROM_FP(caller)->prevFrame == NULL)
return NULL;
/* Walk up two frames if possible. */
for (i = 0; i < 2; i++) {
caller = dvmGetCallerFP(caller);
if (caller == NULL)
return NULL;
}
return SAVEAREA_FROM_FP(caller)->method->clazz;
}
/*
* Pop a frame we added. There should be one method frame and one break
* frame.
*
* If JNI Push/PopLocalFrame calls were mismatched, we might end up
* popping multiple method frames before we find the break.
*
* Returns "false" if there was no frame to pop.
*/
static bool dvmPopFrame(Thread* self)
{
StackSaveArea* saveBlock;
if (self->curFrame == NULL)
return false;
saveBlock = SAVEAREA_FROM_FP(self->curFrame);
assert(!dvmIsBreakFrame(self->curFrame));
/*
* Remove everything up to the break frame. If this was a call into
* native code, pop the JNI local references table.
*/
while (saveBlock->prevFrame != NULL && saveBlock->method != NULL) {
/* probably a native->native JNI call */
if (dvmIsNativeMethod(saveBlock->method)) {
LOGVV("Popping JNI stack frame for %s.%s%s\n",
saveBlock->method->clazz->descriptor,
saveBlock->method->name,
(SAVEAREA_FROM_FP(saveBlock->prevFrame)->method == NULL) ?
"" : " (JNI local)");
assert(saveBlock->xtra.localRefCookie != 0);
//assert(saveBlock->xtra.localRefCookie >= self->jniLocalRefTable.table &&
// saveBlock->xtra.localRefCookie <=self->jniLocalRefTable.nextEntry);
dvmPopJniLocals(self, saveBlock);
}
saveBlock = SAVEAREA_FROM_FP(saveBlock->prevFrame);
}
if (saveBlock->method != NULL) {
LOGE("PopFrame missed the break\n");
assert(false);
dvmAbort(); // stack trashed -- nowhere to go in this thread
}
LOGVV("POP frame: cur=%p new=%p\n",
self->curFrame, saveBlock->prevFrame);
self->curFrame = saveBlock->prevFrame;
return true;
}
/*
* This is used by the JNI PushLocalFrame call. We push a new frame onto
* the stack that has no ins, outs, or locals, and no break frame above it.
* It's strictly used for tracking JNI local refs, and will be popped off
* by dvmPopFrame if it's not removed explicitly.
*/
bool dvmPushLocalFrame(Thread* self, const Method* method)
{
StackSaveArea* saveBlock;
int stackReq;
u1* stackPtr;
assert(dvmIsNativeMethod(method));
stackReq = sizeof(StackSaveArea); // regular frame
assert(self->curFrame != NULL);
stackPtr = (u1*) SAVEAREA_FROM_FP(self->curFrame);
if (stackPtr - stackReq < self->interpStackEnd) {
/* not enough space; let JNI throw the exception */
LOGW("Stack overflow on PushLocal "
"(req=%d top=%p cur=%p size=%d '%s')\n",
stackReq, self->interpStackStart, self->curFrame,
self->interpStackSize, method->name);
dvmHandleStackOverflow(self, method);
assert(dvmCheckException(self));
return false;
}
/*
* Shift the stack pointer down, leaving space for just the stack save
* area for the break frame, then shift down farther for the full frame.
*/
stackPtr -= sizeof(StackSaveArea);
saveBlock = (StackSaveArea*) stackPtr;
#if !defined(NDEBUG) && !defined(PAD_SAVE_AREA)
/* debug -- memset the new stack */
memset(stackPtr, 0xaf, stackReq);
#endif
#ifdef EASY_GDB
saveBlock->prevSave = FP_FROM_SAVEAREA(self->curFrame);
#endif
saveBlock->prevFrame = self->curFrame;
saveBlock->savedPc = NULL; // not required
#ifdef USE_INDIRECT_REF
saveBlock->xtra.localRefCookie = self->jniLocalRefTable.segmentState.all;
#else
saveBlock->xtra.localRefCookie = self->jniLocalRefTable.nextEntry;
#endif
saveBlock->method = method;
LOGVV("PUSH JNI local frame: old=%p new=%p (size=%d)\n",
self->curFrame, FP_FROM_SAVEAREA(saveBlock),
(u1*)self->curFrame - (u1*)FP_FROM_SAVEAREA(saveBlock));
self->curFrame = FP_FROM_SAVEAREA(saveBlock);
return true;
}
/*
* Main interpreter loop.
*
* This was written with an ARM implementation in mind.
*/
void dvmInterpretPortable(Thread* self)
{
#if defined(EASY_GDB)
StackSaveArea* debugSaveArea = SAVEAREA_FROM_FP(self->interpSave.curFrame);
#endif
DvmDex* methodClassDex; // curMethod->clazz->pDvmDex
JValue retval;
/* core state */
const Method* curMethod; // method we're interpreting
const u2* pc; // program counter
u4* fp; // frame pointer
u2 inst; // current instruction
/* instruction decoding */
u4 ref; // 16 or 32-bit quantity fetched directly
u2 vsrc1, vsrc2, vdst; // usually used for register indexes
/* method call setup */
const Method* methodToCall;
bool methodCallRange;
/* static computed goto table */
DEFINE_GOTO_TABLE(handlerTable);
/* copy state in */
curMethod = self->interpSave.method;
pc = self->interpSave.pc;
fp = self->interpSave.curFrame;
retval = self->interpSave.retval; /* only need for kInterpEntryReturn? */
methodClassDex = curMethod->clazz->pDvmDex;
LOGVV("threadid=%d: %s.%s pc=%#x fp=%p",
self->threadId, curMethod->clazz->descriptor, curMethod->name,
pc - curMethod->insns, fp);
/*
* Handle any ongoing profiling and prep for debugging.
*/
if (self->interpBreak.ctl.subMode != 0) {
TRACE_METHOD_ENTER(self, curMethod);
self->debugIsMethodEntry = true; // Always true on startup
}
/*
* DEBUG: scramble this to ensure we're not relying on it.
*/
methodToCall = (const Method*) -1;
#if 0
if (self->debugIsMethodEntry) {
ILOGD("|-- Now interpreting %s.%s", curMethod->clazz->descriptor,
curMethod->name);
DUMP_REGS(curMethod, self->interpSave.curFrame, false);
}
#endif
FINISH(0); /* fetch and execute first instruction */
/*
* Get the caller's class. Pass in the current fp.
*
* This is used by e.g. java.lang.Class.
*/
ClassObject* dvmGetCallerClass(const void* curFrame)
{
void* caller;
caller = dvmGetCallerFP(curFrame);
if (caller == NULL)
return NULL;
return SAVEAREA_FROM_FP(caller)->method->clazz;
}
/*
* Compute the frame depth.
*
* Excludes "break" frames.
*/
int dvmComputeExactFrameDepth(const void* fp)
{
int count = 0;
for ( ; fp != NULL; fp = SAVEAREA_FROM_FP(fp)->prevFrame) {
if (!dvmIsBreakFrame((u4*)fp))
count++;
}
return count;
}
/*
* Create a flat array of methods that comprise the current interpreter
* stack trace. Pass in the current frame ptr.
*
* Allocates a new array and fills it with method pointers. Break frames
* are skipped, but reflection invocations are not. The caller must free
* "*pArray".
*
* The current frame will be in element 0.
*
* Returns "true" on success, "false" on failure (e.g. malloc failed).
*/
bool dvmCreateStackTraceArray(const void* fp, const Method*** pArray,
int* pLength)
{
const Method** array;
int idx, depth;
depth = dvmComputeExactFrameDepth(fp);
array = (const Method**) malloc(depth * sizeof(Method*));
if (array == NULL)
return false;
for (idx = 0; fp != NULL; fp = SAVEAREA_FROM_FP(fp)->prevFrame) {
if (!dvmIsBreakFrame(fp))
array[idx++] = SAVEAREA_FROM_FP(fp)->method;
}
assert(idx == depth);
*pArray = array;
*pLength = depth;
return true;
}
/*
* Dump the StackSaveArea for the specified frame pointer.
*/
void dvmDumpFp(void* fp, StackSaveArea* otherSaveArea)
{
StackSaveArea* saveArea = SAVEAREA_FROM_FP(fp);
printf("StackSaveArea for fp %p [%p/%p]:\n", fp, saveArea, otherSaveArea);
#ifdef EASY_GDB
printf(" prevSave=%p, prevFrame=%p savedPc=%p meth=%p curPc=%p\n",
saveArea->prevSave, saveArea->prevFrame, saveArea->savedPc,
saveArea->method, saveArea->xtra.currentPc);
#else
printf(" prevFrame=%p savedPc=%p meth=%p curPc=%p fp[0]=0x%08x\n",
saveArea->prevFrame, saveArea->savedPc,
saveArea->method, saveArea->xtra.currentPc,
*(u4*)fp);
#endif
}
static void crawlDalvikStack(Thread *thread, bool print)
{
void *fp = thread->interpSave.curFrame;
StackSaveArea* saveArea = NULL;
int stackLevel = 0;
/* Crawl the Dalvik stack frames to clear the returnAddr field */
while (fp != NULL) {
saveArea = SAVEAREA_FROM_FP(fp);
stackLevel++;
saveArea->returnAddr = NULL;
assert(fp != saveArea->prevFrame);
fp = saveArea->prevFrame;
}
/* Make sure the stack is fully unwound to the bottom */
assert(saveArea == NULL ||
(u1 *) (saveArea+1) == thread->interpStackStart);
}
/*
* Open up the reserved area and throw an exception. The reserved area
* should only be needed to create and initialize the exception itself.
*
* If we already opened it and we're continuing to overflow, abort the VM.
*
* We have to leave the "reserved" area open until the "catch" handler has
* finished doing its processing. This is because the catch handler may
* need to resolve classes, which requires calling into the class loader if
* the classes aren't already in the "initiating loader" list.
*/
void dvmHandleStackOverflow(Thread* self, const Method* method)
{
/*
* Can we make the reserved area available?
*/
if (self->stackOverflowed) {
/*
* Already did, nothing to do but bail.
*/
LOGE("DalvikVM: double-overflow of stack in threadid=%d; aborting\n",
self->threadId);
dvmDumpThread(self, false);
dvmAbort();
}
/* open it up to the full range */
LOGI("threadid=%d: stack overflow on call to %s.%s:%s\n",
self->threadId,
method->clazz->descriptor, method->name, method->shorty);
StackSaveArea* saveArea = SAVEAREA_FROM_FP(self->curFrame);
LOGI(" method requires %d+%d+%d=%d bytes, fp is %p (%d left)\n",
method->registersSize * 4, sizeof(StackSaveArea), method->outsSize * 4,
(method->registersSize + method->outsSize) * 4 + sizeof(StackSaveArea),
saveArea, (u1*) saveArea - self->interpStackEnd);
LOGI(" expanding stack end (%p to %p)\n", self->interpStackEnd,
self->interpStackStart - self->interpStackSize);
//dvmDumpThread(self, false);
self->interpStackEnd = self->interpStackStart - self->interpStackSize;
self->stackOverflowed = true;
/*
* If we were trying to throw an exception when the stack overflowed,
* we will blow up when doing the class lookup on StackOverflowError
* because of the pending exception. So, we clear it and make it
* the cause of the SOE.
*/
Object* excep = dvmGetException(self);
if (excep != NULL) {
LOGW("Stack overflow while throwing exception\n");
dvmClearException(self);
}
dvmThrowChainedExceptionByClass(gDvm.classJavaLangStackOverflowError,
NULL, excep);
}
/**
* @brief 遍历dalvik栈
* @param thread 线程结构指针
* @param print 是否打印
*/
static void crawlDalvikStack(Thread *thread, bool print)
{
void *fp = thread->interpSave.curFrame; /* 获取栈指针 */
StackSaveArea* saveArea = NULL;
int stackLevel = 0;
if (print) {
ALOGD("Crawling tid %d (%s / %p %s)", thread->systemTid,
dvmGetThreadStatusStr(thread->status),
thread->inJitCodeCache,
thread->inJitCodeCache ? "jit" : "interp");
}
/* Crawl the Dalvik stack frames to clear the returnAddr field */
/* 遍历清除返回地址字段 */
while (fp != NULL) {
saveArea = SAVEAREA_FROM_FP(fp); /* 取出一个单元 */
if (print) {
if (dvmIsBreakFrame((u4*)fp)) {
ALOGD(" #%d: break frame (%p)",
stackLevel, saveArea->returnAddr);
}
else {
ALOGD(" #%d: %s.%s%s (%p)",
stackLevel,
saveArea->method->clazz->descriptor,
saveArea->method->name,
dvmIsNativeMethod(saveArea->method) ?
" (native)" : "",
saveArea->returnAddr);
}
}
stackLevel++;
saveArea->returnAddr = NULL; /* 设置返回值为NULL */
assert(fp != saveArea->prevFrame);
fp = saveArea->prevFrame;
}
/* Make sure the stack is fully unwound to the bottom */
assert(saveArea == NULL ||
(u1 *) (saveArea+1) == thread->interpStackStart);
}
// work-around to get a reference wrapper to an object so that it can be used
// for certain calls to the JNI environment. almost verbatim copy from Jni.cpp
static jobject dexspyAddLocalReference(::Thread* self, Object* obj) {
if (obj == NULL) {
return NULL;
}
IndirectRefTable* pRefTable = &self->jniLocalRefTable;
void* curFrame = self->interpSave.curFrame;
u4 cookie = SAVEAREA_FROM_FP(curFrame)->xtra.localRefCookie;
jobject jobj = (jobject) pRefTable->add(cookie, obj);
if (UNLIKELY(jobj == NULL)) {
pRefTable->dump("JNI local");
ALOGE("Failed adding to JNI local ref table (has %zd entries)", pRefTable->capacity());
dvmDumpThread(self, false);
dvmAbort(); // spec says call FatalError; this is equivalent
}
if (UNLIKELY(gDvmJni.workAroundAppJniBugs)) {
// Hand out direct pointers to support broken old apps.
return reinterpret_cast<jobject>(obj);
}
return jobj;
}
/*
* Dump stack frames, starting from the specified frame and moving down.
*
* Each frame holds a pointer to the currently executing method, and the
* saved program counter from the caller ("previous" frame). This means
* we don't have the PC for the current method on the stack, which is
* pretty reasonable since it's in the "PC register" for the VM. Because
* exceptions need to show the correct line number we actually *do* have
* an updated version in the fame's "xtra.currentPc", but it's unreliable.
*
* Note "framePtr" could be NULL in rare circumstances.
*/
static void dumpFrames(const DebugOutputTarget* target, void* framePtr,
Thread* thread)
{
const StackSaveArea* saveArea;
const Method* method;
int checkCount = 0;
const u2* currentPc = NULL;
bool first = true;
/*
* The "currentPc" is updated whenever we execute an instruction that
* might throw an exception. Show it here.
*/
if (framePtr != NULL && !dvmIsBreakFrame(framePtr)) {
saveArea = SAVEAREA_FROM_FP(framePtr);
if (saveArea->xtra.currentPc != NULL)
currentPc = saveArea->xtra.currentPc;
}
while (framePtr != NULL) {
saveArea = SAVEAREA_FROM_FP(framePtr);
method = saveArea->method;
if (dvmIsBreakFrame(framePtr)) {
//dvmPrintDebugMessage(target, " (break frame)\n");
} else {
int relPc;
if (currentPc != NULL)
relPc = currentPc - saveArea->method->insns;
else
relPc = -1;
char* className = dvmDescriptorToDot(method->clazz->descriptor);
if (dvmIsNativeMethod(method))
dvmPrintDebugMessage(target,
" at %s.%s(Native Method)\n", className, method->name);
else {
dvmPrintDebugMessage(target,
" at %s.%s(%s:%s%d)\n",
className, method->name, dvmGetMethodSourceFile(method),
(relPc >= 0 && first) ? "~" : "",
relPc < 0 ? -1 : dvmLineNumFromPC(method, relPc));
}
free(className);
if (first) {
/*
* Decorate WAIT and MONITOR threads with some detail on
* the first frame.
*
* warning: wait status not stable, even in suspend
*/
if (thread->status == THREAD_WAIT ||
thread->status == THREAD_TIMED_WAIT)
{
Monitor* mon = thread->waitMonitor;
Object* obj = dvmGetMonitorObject(mon);
if (obj != NULL) {
className = dvmDescriptorToDot(obj->clazz->descriptor);
dvmPrintDebugMessage(target,
" - waiting on <%p> (a %s)\n", obj, className);
free(className);
}
} else if (thread->status == THREAD_MONITOR) {
Object* obj;
Thread* owner;
if (extractMonitorEnterObject(thread, &obj, &owner)) {
className = dvmDescriptorToDot(obj->clazz->descriptor);
if (owner != NULL) {
char* threadName = dvmGetThreadName(owner);
dvmPrintDebugMessage(target,
" - waiting to lock <%p> (a %s) held by threadid=%d (%s)\n",
obj, className, owner->threadId, threadName);
free(threadName);
} else {
dvmPrintDebugMessage(target,
" - waiting to lock <%p> (a %s) held by ???\n",
obj, className);
}
free(className);
}
}
}
}
/*
* Get saved PC for previous frame. There's no savedPc in a "break"
* frame, because that represents native or interpreted code
* invoked by the VM. The saved PC is sitting in the "PC register",
* a local variable on the native stack.
*/
currentPc = saveArea->savedPc;
first = false;
if (saveArea->prevFrame != NULL && saveArea->prevFrame <= framePtr) {
LOGW("Warning: loop in stack trace at frame %d (%p -> %p)\n",
checkCount, framePtr, saveArea->prevFrame);
break;
}
framePtr = saveArea->prevFrame;
checkCount++;
if (checkCount > 300) {
dvmPrintDebugMessage(target,
" ***** printed %d frames, not showing any more\n",
checkCount);
break;
}
}
dvmPrintDebugMessage(target, "\n");
}
/*
* Lock a monitor.
*/
static void lockMonitor(Thread* self, Monitor* mon)
{
ThreadStatus oldStatus;
u4 waitThreshold, samplePercent;
u8 waitStart, waitEnd, waitMs;
if (mon->owner == self) {
mon->lockCount++;
return;
}
if (dvmTryLockMutex(&mon->lock) != 0) {
oldStatus = dvmChangeStatus(self, THREAD_MONITOR);
waitThreshold = gDvm.lockProfThreshold;
if (waitThreshold) {
waitStart = dvmGetRelativeTimeUsec();
}
const Method* currentOwnerMethod = mon->ownerMethod;
u4 currentOwnerPc = mon->ownerPc;
dvmLockMutex(&mon->lock);
if (waitThreshold) {
waitEnd = dvmGetRelativeTimeUsec();
}
dvmChangeStatus(self, oldStatus);
if (waitThreshold) {
waitMs = (waitEnd - waitStart) / 1000;
if (waitMs >= waitThreshold) {
samplePercent = 100;
} else {
samplePercent = 100 * waitMs / waitThreshold;
}
if (samplePercent != 0 && ((u4)rand() % 100 < samplePercent)) {
const char* currentOwnerFileName = "no_method";
u4 currentOwnerLineNumber = 0;
if (currentOwnerMethod != NULL) {
currentOwnerFileName = dvmGetMethodSourceFile(currentOwnerMethod);
if (currentOwnerFileName == NULL) {
currentOwnerFileName = "no_method_file";
}
currentOwnerLineNumber = dvmLineNumFromPC(currentOwnerMethod, currentOwnerPc);
}
logContentionEvent(self, waitMs, samplePercent,
currentOwnerFileName, currentOwnerLineNumber);
}
}
}
mon->owner = self;
assert(mon->lockCount == 0);
// When debugging, save the current monitor holder for future
// acquisition failures to use in sampled logging.
if (gDvm.lockProfThreshold > 0) {
mon->ownerMethod = NULL;
mon->ownerPc = 0;
if (self->interpSave.curFrame == NULL) {
return;
}
const StackSaveArea* saveArea = SAVEAREA_FROM_FP(self->interpSave.curFrame);
if (saveArea == NULL) {
return;
}
mon->ownerMethod = saveArea->method;
mon->ownerPc = (saveArea->xtra.currentPc - saveArea->method->insns);
}
}
static void logContentionEvent(Thread *self, u4 waitMs, u4 samplePercent,
const char *ownerFileName, u4 ownerLineNumber)
{
const StackSaveArea *saveArea;
const Method *meth;
u4 relativePc;
char eventBuffer[174];
const char *fileName;
char procName[33];
char *cp;
size_t len;
int fd;
/* When a thread is being destroyed it is normal that the frame depth is zero */
if (self->interpSave.curFrame == NULL) {
return;
}
saveArea = SAVEAREA_FROM_FP(self->interpSave.curFrame);
meth = saveArea->method;
cp = eventBuffer;
/* Emit the event list length, 1 byte. */
*cp++ = 9;
/* Emit the process name, <= 37 bytes. */
fd = open("/proc/self/cmdline", O_RDONLY);
memset(procName, 0, sizeof(procName));
read(fd, procName, sizeof(procName) - 1);
close(fd);
len = strlen(procName);
cp = logWriteString(cp, procName, len);
/* Emit the sensitive thread ("main thread") status, 5 bytes. */
bool isSensitive = false;
if (gDvm.isSensitiveThreadHook != NULL) {
isSensitive = gDvm.isSensitiveThreadHook();
}
cp = logWriteInt(cp, isSensitive);
/* Emit self thread name string, <= 37 bytes. */
std::string selfName = dvmGetThreadName(self);
cp = logWriteString(cp, selfName.c_str(), selfName.size());
/* Emit the wait time, 5 bytes. */
cp = logWriteInt(cp, waitMs);
/* Emit the source code file name, <= 37 bytes. */
fileName = dvmGetMethodSourceFile(meth);
if (fileName == NULL) fileName = "";
cp = logWriteString(cp, fileName, strlen(fileName));
/* Emit the source code line number, 5 bytes. */
relativePc = saveArea->xtra.currentPc - saveArea->method->insns;
cp = logWriteInt(cp, dvmLineNumFromPC(meth, relativePc));
/* Emit the lock owner source code file name, <= 37 bytes. */
if (ownerFileName == NULL) {
ownerFileName = "";
} else if (strcmp(fileName, ownerFileName) == 0) {
/* Common case, so save on log space. */
ownerFileName = "-";
}
cp = logWriteString(cp, ownerFileName, strlen(ownerFileName));
/* Emit the source code line number, 5 bytes. */
cp = logWriteInt(cp, ownerLineNumber);
/* Emit the sample percentage, 5 bytes. */
cp = logWriteInt(cp, samplePercent);
assert((size_t)(cp - eventBuffer) <= sizeof(eventBuffer));
android_btWriteLog(EVENT_LOG_TAG_dvm_lock_sample,
EVENT_TYPE_LIST,
eventBuffer,
(size_t)(cp - eventBuffer));
}
/*
* Visits all stack slots except those belonging to native method
* arguments.
*/
static void visitThreadStack(RootVisitor *visitor, Thread *thread, void *arg)
{
assert(visitor != NULL);
assert(thread != NULL);
u4 threadId = thread->threadId;
const StackSaveArea *saveArea;
for (u4 *fp = (u4 *)thread->interpSave.curFrame;
fp != NULL;
fp = (u4 *)saveArea->prevFrame) {
Method *method;
saveArea = SAVEAREA_FROM_FP(fp);
method = (Method *)saveArea->method;
if (method != NULL && !dvmIsNativeMethod(method)) {
#ifdef FASTIVA
// @zee do not call any malloc in gc task.
// cf) dvmGetExpandedRegisterMap()
const RegisterMap* pMap = NULL;
#else
const RegisterMap* pMap = dvmGetExpandedRegisterMap(method);
#endif
const u1* regVector = NULL;
#ifndef FASTIVA
if (pMap != NULL) {
/* found map, get registers for this address */
int addr = saveArea->xtra.currentPc - method->insns;
regVector = dvmRegisterMapGetLine(pMap, addr);
}
#endif
if (regVector == NULL) {
/*
* Either there was no register map or there is no
* info for the current PC. Perform a conservative
* scan.
*/
for (size_t i = 0; i < method->registersSize; ++i) {
if (dvmIsValidObject((Object *)fp[i])) {
(*visitor)(&fp[i], threadId, ROOT_JAVA_FRAME, arg);
}
}
} else {
/*
* Precise scan. v0 is at the lowest address on the
* interpreted stack, and is the first bit in the
* register vector, so we can walk through the
* register map and memory in the same direction.
*
* A '1' bit indicates a live reference.
*/
u2 bits = 1 << 1;
for (size_t i = 0; i < method->registersSize; ++i) {
bits >>= 1;
if (bits == 1) {
/* set bit 9 so we can tell when we're empty */
bits = *regVector++ | 0x0100;
}
if ((bits & 0x1) != 0) {
/*
* Register is marked as live, it's a valid root.
*/
#if WITH_EXTRA_GC_CHECKS
if (fp[i] != 0 && !dvmIsValidObject((Object *)fp[i])) {
/* this is very bad */
ALOGE("PGC: invalid ref in reg %d: %#x",
method->registersSize - 1 - i, fp[i]);
ALOGE("PGC: %s.%s addr %#x",
method->clazz->descriptor, method->name,
saveArea->xtra.currentPc - method->insns);
continue;
}
#endif
(*visitor)(&fp[i], threadId, ROOT_JAVA_FRAME, arg);
}
}
dvmReleaseRegisterMapLine(pMap, regVector);
}
}
/*
* Don't fall into an infinite loop if things get corrupted.
*/
assert((uintptr_t)saveArea->prevFrame > (uintptr_t)fp ||
saveArea->prevFrame == NULL);
}
#ifdef FASTIVA
int* stack_bottom = (int*)thread->m_pNativeStackBottom;
int* stack_top = (int*)thread->m_pNativeStackPointer;
const bool DUMP_STACK = 0;
if (DUMP_STACK) {
ALOGE("##### scan_stack %i %p~%p", thread->systemTid, stack_top, stack_bottom);
}
assert(thread->status != THREAD_RUNNING || thread == dvmThreadSelf());
while (stack_top < stack_bottom) {
if (dvmIsValidObject((Object*)stack_top[0])) {
(*visitor)(stack_top, threadId, ROOT_JAVA_FRAME, arg);
}
stack_top ++;
}
#endif
}
/*
* We're calling an interpreted method from an internal VM function or
* via reflection.
*
* Push a frame for an interpreted method onto the stack. This is only
* used when calling into interpreted code from native code. (The
* interpreter does its own stack frame manipulation for interp-->interp
* calls.)
*
* The size we need to reserve is the sum of parameters, local variables,
* saved goodies, and outbound parameters.
*
* We start by inserting a "break" frame, which ensures that the interpreter
* hands control back to us after the function we call returns or an
* uncaught exception is thrown.
*/
static bool dvmPushInterpFrame(Thread* self, const Method* method)
{
StackSaveArea* saveBlock;
StackSaveArea* breakSaveBlock;
int stackReq;
u1* stackPtr;
assert(!dvmIsNativeMethod(method));
assert(!dvmIsAbstractMethod(method));
stackReq = method->registersSize * 4 // params + locals
+ sizeof(StackSaveArea) * 2 // break frame + regular frame
+ method->outsSize * 4; // args to other methods
if (self->interpSave.curFrame != NULL)
stackPtr = (u1*) SAVEAREA_FROM_FP(self->interpSave.curFrame);
else
stackPtr = self->interpStackStart;
if (stackPtr - stackReq < self->interpStackEnd) {
/* not enough space */
ALOGW("Stack overflow on call to interp "
"(req=%d top=%p cur=%p size=%d %s.%s)",
stackReq, self->interpStackStart, self->interpSave.curFrame,
self->interpStackSize, method->clazz->descriptor, method->name);
dvmHandleStackOverflow(self, method);
assert(dvmCheckException(self));
return false;
}
/*
* Shift the stack pointer down, leaving space for the function's
* args/registers and save area.
*/
stackPtr -= sizeof(StackSaveArea);
breakSaveBlock = (StackSaveArea*)stackPtr;
stackPtr -= method->registersSize * 4 + sizeof(StackSaveArea);
saveBlock = (StackSaveArea*) stackPtr;
#if !defined(NDEBUG) && !defined(PAD_SAVE_AREA)
/* debug -- memset the new stack, unless we want valgrind's help */
memset(stackPtr - (method->outsSize*4), 0xaf, stackReq);
#endif
#ifdef EASY_GDB
breakSaveBlock->prevSave =
(StackSaveArea*)FP_FROM_SAVEAREA(self->interpSave.curFrame);
saveBlock->prevSave = breakSaveBlock;
#endif
breakSaveBlock->prevFrame = self->interpSave.curFrame;
breakSaveBlock->savedPc = NULL; // not required
breakSaveBlock->xtra.localRefCookie = 0; // not required
breakSaveBlock->method = NULL;
saveBlock->prevFrame = FP_FROM_SAVEAREA(breakSaveBlock);
saveBlock->savedPc = NULL; // not required
saveBlock->xtra.currentPc = NULL; // not required?
saveBlock->method = method;
LOGVV("PUSH frame: old=%p new=%p (size=%d)",
self->interpSave.curFrame, FP_FROM_SAVEAREA(saveBlock),
(u1*)self->interpSave.curFrame - (u1*)FP_FROM_SAVEAREA(saveBlock));
self->interpSave.curFrame = FP_FROM_SAVEAREA(saveBlock);
return true;
}
/*
* Visits all stack slots. TODO: visit native methods.
*/
static void visitThreadStack(Visitor *visitor, Thread *thread, void *arg)
{
const StackSaveArea *saveArea;
u4 *framePtr;
assert(visitor != NULL);
assert(thread != NULL);
framePtr = (u4 *)thread->curFrame;
for (; framePtr != NULL; framePtr = saveArea->prevFrame) {
Method *method;
saveArea = SAVEAREA_FROM_FP(framePtr);
method = (Method *)saveArea->method;
if (method != NULL && !dvmIsNativeMethod(method)) {
const RegisterMap* pMap = dvmGetExpandedRegisterMap(method);
const u1* regVector = NULL;
size_t i;
if (pMap != NULL) {
/* found map, get registers for this address */
int addr = saveArea->xtra.currentPc - method->insns;
regVector = dvmRegisterMapGetLine(pMap, addr);
}
if (regVector == NULL) {
/*
* Either there was no register map or there is no
* info for the current PC. Perform a conservative
* scan.
*/
for (i = 0; i < method->registersSize; ++i) {
if (dvmIsValidObject((Object *)framePtr[i])) {
(*visitor)(&framePtr[i], arg);
}
}
} else {
/*
* Precise scan. v0 is at the lowest address on the
* interpreted stack, and is the first bit in the
* register vector, so we can walk through the
* register map and memory in the same direction.
*
* A '1' bit indicates a live reference.
*/
u2 bits = 1 << 1;
for (i = 0; i < method->registersSize; ++i) {
bits >>= 1;
if (bits == 1) {
/* set bit 9 so we can tell when we're empty */
bits = *regVector++ | 0x0100;
}
if ((bits & 0x1) != 0) {
/*
* Register is marked as live, it's a valid root.
*/
(*visitor)(&framePtr[i], arg);
}
}
dvmReleaseRegisterMapLine(pMap, regVector);
}
}
/*
* Don't fall into an infinite loop if things get corrupted.
*/
assert((uintptr_t)saveArea->prevFrame > (uintptr_t)framePtr ||
saveArea->prevFrame == NULL);
}
}
/*
* Dump the stack for the specified thread, which is still running.
*
* This is very dangerous, because stack frames are being pushed on and
* popped off, and if the thread exits we'll be looking at freed memory.
* The plan here is to take a snapshot of the stack and then dump that
* to try to minimize the chances of catching it mid-update. This should
* work reasonably well on a single-CPU system.
*
* There is a small chance that calling here will crash the VM.
*/
void dvmDumpRunningThreadStack(const DebugOutputTarget* target, Thread* thread)
{
StackSaveArea* saveArea;
const u1* origStack;
u1* stackCopy = NULL;
int origSize, fpOffset;
void* fp;
int depthLimit = 200;
if (thread == NULL || thread->interpSave.curFrame == NULL) {
dvmPrintDebugMessage(target,
"DumpRunning: Thread at %p has no curFrame (threadid=%d)\n",
thread, (thread != NULL) ? thread->threadId : 0);
return;
}
/* wait for a full quantum */
sched_yield();
/* copy the info we need, then the stack itself */
origSize = thread->interpStackSize;
origStack = (const u1*) thread->interpStackStart - origSize;
stackCopy = (u1*) malloc(origSize);
fpOffset = (u1*) thread->interpSave.curFrame - origStack;
memcpy(stackCopy, origStack, origSize);
/*
* Run through the stack and rewrite the "prev" pointers.
*/
//ALOGI("DR: fpOff=%d (from %p %p)",fpOffset, origStack,
// thread->interpSave.curFrame);
fp = stackCopy + fpOffset;
while (true) {
int prevOffset;
if (depthLimit-- < 0) {
/* we're probably screwed */
dvmPrintDebugMessage(target, "DumpRunning: depth limit hit\n");
dvmAbort();
}
saveArea = SAVEAREA_FROM_FP(fp);
if (saveArea->prevFrame == NULL)
break;
prevOffset = (u1*) saveArea->prevFrame - origStack;
if (prevOffset < 0 || prevOffset > origSize) {
dvmPrintDebugMessage(target,
"DumpRunning: bad offset found: %d (from %p %p)\n",
prevOffset, origStack, saveArea->prevFrame);
saveArea->prevFrame = NULL;
break;
}
saveArea->prevFrame = (u4*)(stackCopy + prevOffset);
fp = saveArea->prevFrame;
}
/*
* We still need to pass the Thread for some monitor wait stuff.
*/
dumpFrames(target, stackCopy + fpOffset, thread);
free(stackCopy);
}
/*
* We're calling a JNI native method from an internal VM fuction or
* via reflection. This is also used to create the "fake" native-method
* frames at the top of the interpreted stack.
*
* This actually pushes two frames; the first is a "break" frame.
*
* The top frame has additional space for JNI local reference tracking.
*/
bool dvmPushJNIFrame(Thread* self, const Method* method)
{
StackSaveArea* saveBlock;
StackSaveArea* breakSaveBlock;
int stackReq;
u1* stackPtr;
assert(dvmIsNativeMethod(method));
stackReq = method->registersSize * 4 // params only
+ sizeof(StackSaveArea) * 2; // break frame + regular frame
if (self->interpSave.curFrame != NULL)
stackPtr = (u1*) SAVEAREA_FROM_FP(self->interpSave.curFrame);
else
stackPtr = self->interpStackStart;
if (stackPtr - stackReq < self->interpStackEnd) {
/* not enough space */
ALOGW("Stack overflow on call to native "
"(req=%d top=%p cur=%p size=%d '%s')",
stackReq, self->interpStackStart, self->interpSave.curFrame,
self->interpStackSize, method->name);
dvmHandleStackOverflow(self, method);
assert(dvmCheckException(self));
return false;
}
/*
* Shift the stack pointer down, leaving space for just the stack save
* area for the break frame, then shift down farther for the full frame.
* We leave space for the method args, which are copied in later.
*/
stackPtr -= sizeof(StackSaveArea);
breakSaveBlock = (StackSaveArea*)stackPtr;
stackPtr -= method->registersSize * 4 + sizeof(StackSaveArea);
saveBlock = (StackSaveArea*) stackPtr;
#if !defined(NDEBUG) && !defined(PAD_SAVE_AREA)
/* debug -- memset the new stack */
memset(stackPtr, 0xaf, stackReq);
#endif
#ifdef EASY_GDB
if (self->interpSave.curFrame == NULL)
breakSaveBlock->prevSave = NULL;
else {
void* fp = FP_FROM_SAVEAREA(self->interpSave.curFrame);
breakSaveBlock->prevSave = (StackSaveArea*)fp;
}
saveBlock->prevSave = breakSaveBlock;
#endif
breakSaveBlock->prevFrame = self->interpSave.curFrame;
breakSaveBlock->savedPc = NULL; // not required
breakSaveBlock->xtra.localRefCookie = 0; // not required
breakSaveBlock->method = NULL;
saveBlock->prevFrame = FP_FROM_SAVEAREA(breakSaveBlock);
saveBlock->savedPc = NULL; // not required
saveBlock->xtra.localRefCookie = self->jniLocalRefTable.segmentState.all;
saveBlock->method = method;
LOGVV("PUSH JNI frame: old=%p new=%p (size=%d)",
self->interpSave.curFrame, FP_FROM_SAVEAREA(saveBlock),
(u1*)self->interpSave.curFrame - (u1*)FP_FROM_SAVEAREA(saveBlock));
self->interpSave.curFrame = FP_FROM_SAVEAREA(saveBlock);
return true;
}
/*
* Dump stack frames, starting from the specified frame and moving down.
*
* Each frame holds a pointer to the currently executing method, and the
* saved program counter from the caller ("previous" frame). This means
* we don't have the PC for the current method on the stack, which is
* pretty reasonable since it's in the "PC register" for the VM. Because
* exceptions need to show the correct line number we actually *do* have
* an updated version in the fame's "xtra.currentPc", but it's unreliable.
*
* Note "framePtr" could be NULL in rare circumstances.
*/
static void dumpFrames(const DebugOutputTarget* target, void* framePtr,
Thread* thread)
{
const StackSaveArea* saveArea;
const Method* method;
int checkCount = 0;
const u2* currentPc = NULL;
bool first = true;
/*
* We call functions that require us to be holding the thread list lock.
* It's probable that the caller has already done so, but it's not
* guaranteed. If it's not locked, lock it now.
*/
bool needThreadUnlock = dvmTryLockThreadList();
/*
* The "currentPc" is updated whenever we execute an instruction that
* might throw an exception. Show it here.
*/
if (framePtr != NULL && !dvmIsBreakFrame((u4*)framePtr)) {
saveArea = SAVEAREA_FROM_FP(framePtr);
if (saveArea->xtra.currentPc != NULL)
currentPc = saveArea->xtra.currentPc;
}
while (framePtr != NULL) {
saveArea = SAVEAREA_FROM_FP(framePtr);
method = saveArea->method;
if (dvmIsBreakFrame((u4*)framePtr)) {
//dvmPrintDebugMessage(target, " (break frame)\n");
} else {
int relPc;
if (currentPc != NULL)
relPc = currentPc - saveArea->method->insns;
else
relPc = -1;
std::string methodName(dvmHumanReadableMethod(method, false));
if (dvmIsNativeMethod(method)) {
dvmPrintDebugMessage(target, " at %s(Native Method)\n",
methodName.c_str());
} else {
dvmPrintDebugMessage(target, " at %s(%s:%s%d)\n",
methodName.c_str(), dvmGetMethodSourceFile(method),
(relPc >= 0 && first) ? "~" : "",
relPc < 0 ? -1 : dvmLineNumFromPC(method, relPc));
}
if (first) {
/*
* Decorate WAIT and MONITOR threads with some detail on
* the first frame.
*
* warning: wait status not stable, even in suspend
*/
if (thread->status == THREAD_WAIT ||
thread->status == THREAD_TIMED_WAIT)
{
Monitor* mon = thread->waitMonitor;
Object* obj = dvmGetMonitorObject(mon);
if (obj != NULL) {
Thread* joinThread = NULL;
if (obj->clazz == gDvm.classJavaLangVMThread) {
joinThread = dvmGetThreadFromThreadObject(obj);
}
if (joinThread == NULL) {
joinThread = dvmGetObjectLockHolder(obj);
}
printWaitMessage(target, "on", obj, joinThread);
}
} else if (thread->status == THREAD_MONITOR) {
Object* obj;
Thread* owner;
if (extractMonitorEnterObject(thread, &obj, &owner)) {
printWaitMessage(target, "to lock", obj, owner);
}
}
}
}
/*
* Get saved PC for previous frame. There's no savedPc in a "break"
* frame, because that represents native or interpreted code
* invoked by the VM. The saved PC is sitting in the "PC register",
* a local variable on the native stack.
*/
currentPc = saveArea->savedPc;
first = false;
if (saveArea->prevFrame != NULL && saveArea->prevFrame <= framePtr) {
ALOGW("Warning: loop in stack trace at frame %d (%p -> %p)",
checkCount, framePtr, saveArea->prevFrame);
break;
}
framePtr = saveArea->prevFrame;
checkCount++;
if (checkCount > 300) {
dvmPrintDebugMessage(target,
" ***** printed %d frames, not showing any more\n",
checkCount);
break;
}
}
if (needThreadUnlock) {
dvmUnlockThreadList();
}
}
/*
* Extract the object that is the target of a monitor-enter instruction
* in the top stack frame of "thread".
*
* The other thread might be alive, so this has to work carefully.
*
* The thread list lock must be held.
*
* Returns "true" if we successfully recover the object. "*pOwner" will
* be NULL if we can't determine the owner for some reason (e.g. race
* condition on ownership transfer).
*/
static bool extractMonitorEnterObject(Thread* thread, Object** pLockObj,
Thread** pOwner)
{
void* framePtr = thread->interpSave.curFrame;
if (framePtr == NULL || dvmIsBreakFrame((u4*)framePtr))
return false;
const StackSaveArea* saveArea = SAVEAREA_FROM_FP(framePtr);
const Method* method = saveArea->method;
const u2* currentPc = saveArea->xtra.currentPc;
/* check Method* */
if (!dvmLinearAllocContains(method, sizeof(Method))) {
ALOGD("ExtrMon: method %p not valid", method);
return false;
}
/* check currentPc */
u4 insnsSize = dvmGetMethodInsnsSize(method);
if (currentPc < method->insns ||
currentPc >= method->insns + insnsSize)
{
ALOGD("ExtrMon: insns %p not valid (%p - %p)",
currentPc, method->insns, method->insns + insnsSize);
return false;
}
/* check the instruction */
if ((*currentPc & 0xff) != OP_MONITOR_ENTER) {
ALOGD("ExtrMon: insn at %p is not monitor-enter (0x%02x)",
currentPc, *currentPc & 0xff);
return false;
}
/* get and check the register index */
unsigned int reg = *currentPc >> 8;
if (reg >= method->registersSize) {
ALOGD("ExtrMon: invalid register %d (max %d)",
reg, method->registersSize);
return false;
}
/* get and check the object in that register */
u4* fp = (u4*) framePtr;
Object* obj = (Object*) fp[reg];
if (obj != NULL && !dvmIsHeapAddress(obj)) {
ALOGD("ExtrMon: invalid object %p at %p[%d]", obj, fp, reg);
return false;
}
*pLockObj = obj;
/*
* Try to determine the object's lock holder; it's okay if this fails.
*
* We're assuming the thread list lock is already held by this thread.
* If it's not, we may be living dangerously if we have to scan through
* the thread list to find a match. (The VM will generally be in a
* suspended state when executing here, so this is a minor concern
* unless we're dumping while threads are running, in which case there's
* a good chance of stuff blowing up anyway.)
*/
*pOwner = dvmGetObjectLockHolder(obj);
return true;
}
void
hprofFillInStackTrace(void *objectPtr)
{
DvmHeapChunk *chunk;
StackTraceEntry stackTraceEntry;
Thread* self;
void* fp;
int i;
if (objectPtr == NULL) {
return;
}
self = dvmThreadSelf();
if (self == NULL) {
return;
}
fp = self->curFrame;
/* Serial number to be filled in later. */
stackTraceEntry.trace.serialNumber = -1;
/*
* TODO - The HAT tool doesn't care about thread data, so we can defer
* actually emitting thread records and assigning thread serial numbers.
*/
stackTraceEntry.trace.threadSerialNumber = (int) self;
memset(&stackTraceEntry.trace.frameIds, 0,
sizeof(stackTraceEntry.trace.frameIds));
i = 0;
while ((fp != NULL) && (i < STACK_DEPTH)) {
const StackSaveArea* saveArea = SAVEAREA_FROM_FP(fp);
const Method* method = saveArea->method;
StackFrameEntry frame;
if (!dvmIsBreakFrame(fp)) {
frame.frame.method = method;
if (dvmIsNativeMethod(method)) {
frame.frame.pc = 0; /* no saved PC for native methods */
} else {
assert(saveArea->xtra.currentPc >= method->insns &&
saveArea->xtra.currentPc <
method->insns + dvmGetMethodInsnsSize(method));
frame.frame.pc = (int) (saveArea->xtra.currentPc -
method->insns);
}
// Canonicalize the frame and cache it in the hprof context
stackTraceEntry.trace.frameIds[i++] =
hprofLookupStackFrameId(&frame);
}
assert(fp != saveArea->prevFrame);
fp = saveArea->prevFrame;
}
/* Store the stack trace serial number in the object header */
chunk = ptr2chunk(objectPtr);
chunk->stackTraceSerialNumber =
hprofLookupStackSerialNumber(&stackTraceEntry);
}
/*
* Main interpreter loop.
*
* This was written with an ARM implementation in mind.
*/
bool INTERP_FUNC_NAME(Thread* self, InterpState* interpState)
{
#if defined(EASY_GDB)
StackSaveArea* debugSaveArea = SAVEAREA_FROM_FP(self->curFrame);
#endif
#if INTERP_TYPE == INTERP_DBG
bool debugIsMethodEntry = interpState->debugIsMethodEntry;
#endif
#if defined(WITH_TRACKREF_CHECKS)
int debugTrackedRefStart = interpState->debugTrackedRefStart;
#endif
DvmDex* methodClassDex; // curMethod->clazz->pDvmDex
JValue retval;
/* core state */
const Method* curMethod; // method we're interpreting
const u2* pc; // program counter
u4* fp; // frame pointer
u2 inst; // current instruction
/* instruction decoding */
u2 ref; // 16-bit quantity fetched directly
u2 vsrc1, vsrc2, vdst; // usually used for register indexes
/* method call setup */
const Method* methodToCall;
bool methodCallRange;
#if defined(THREADED_INTERP)
/* static computed goto table */
DEFINE_GOTO_TABLE(handlerTable);
#endif
#if defined(WITH_JIT)
#if 0
LOGD("*DebugInterp - entrypoint is %d, tgt is 0x%x, %s\n",
interpState->entryPoint,
interpState->pc,
interpState->method->name);
#endif
#if INTERP_TYPE == INTERP_DBG
/* Check to see if we've got a trace selection request. */
if (
/*
* Only perform dvmJitCheckTraceRequest if the entry point is
* EntryInstr and the jit state is either kJitTSelectRequest or
* kJitTSelectRequestHot. If debugger/profiler happens to be attached,
* dvmJitCheckTraceRequest will change the jitState to kJitDone but
* but stay in the dbg interpreter.
*/
(interpState->entryPoint == kInterpEntryInstr) &&
(interpState->jitState == kJitTSelectRequest ||
interpState->jitState == kJitTSelectRequestHot) &&
dvmJitCheckTraceRequest(self, interpState)) {
interpState->nextMode = INTERP_STD;
//LOGD("Invalid trace request, exiting\n");
return true;
}
#endif /* INTERP_TYPE == INTERP_DBG */
#endif /* WITH_JIT */
/* copy state in */
curMethod = interpState->method;
pc = interpState->pc;
fp = interpState->fp;
retval = interpState->retval; /* only need for kInterpEntryReturn? */
methodClassDex = curMethod->clazz->pDvmDex;
LOGVV("threadid=%d: entry(%s) %s.%s pc=0x%x fp=%p ep=%d\n",
self->threadId, (interpState->nextMode == INTERP_STD) ? "STD" : "DBG",
curMethod->clazz->descriptor, curMethod->name, pc - curMethod->insns,
fp, interpState->entryPoint);
/*
* DEBUG: scramble this to ensure we're not relying on it.
*/
methodToCall = (const Method*) -1;
#if INTERP_TYPE == INTERP_DBG
if (debugIsMethodEntry) {
ILOGD("|-- Now interpreting %s.%s", curMethod->clazz->descriptor,
curMethod->name);
DUMP_REGS(curMethod, interpState->fp, false);
}
#endif
switch (interpState->entryPoint) {
case kInterpEntryInstr:
/* just fall through to instruction loop or threaded kickstart */
break;
case kInterpEntryReturn:
CHECK_JIT();
goto returnFromMethod;
case kInterpEntryThrow:
goto exceptionThrown;
default:
dvmAbort();
}
#ifdef THREADED_INTERP
FINISH(0); /* fetch and execute first instruction */
#else
while (1) {
CHECK_DEBUG_AND_PROF(); /* service debugger and profiling */
CHECK_TRACKED_REFS(); /* check local reference tracking */
/* fetch the next 16 bits from the instruction stream */
inst = FETCH(0);
switch (INST_INST(inst)) {
/*
* Main interpreter loop.
*
* This was written with an ARM implementation in mind.
* portable���͵Ľ������Ľ���ѭ�����
*/
void dvmInterpretPortable(Thread* self)
{
#if defined(EASY_GDB)
// ��������Ƿ�����ԣ�������ջ֡�ĵ�ַ
StackSaveArea* debugSaveArea = SAVEAREA_FROM_FP(self->interpSave.curFrame);
#endif
DvmDex* methodClassDex; // curMethod->clazz->pDvmDex
JValue retval;
/* core state */
const Method* curMethod; // method we're interpreting ��ǰ����Ҫ���͵ķ���
const u2* pc; // program counter ���������
u4* fp; // frame pointer ָ֡��
u2 inst; // current instruction ��ǰָ��
/* instruction decoding */
u4 ref; // 16 or 32-bit quantity fetched directly
u2 vsrc1, vsrc2, vdst; // usually used for register indexes
/* method call setup */
const Method* methodToCall;
bool methodCallRange;
/*
* static computed goto table
* ��̬����õ���ת��
* ʵ���Ͼ��Ƕ���õ�һ�����
* �þ�̬��ת����libdex��dexopcode.h�ж���
* [��Ҫע����壺�ñ�ֻ�ṩ����cʵ�ֵĽ�������ʹ��]
* ������������
* static const void* handlerTable[0x100] = { \
* H(OP_NOP), \
* H(OP_MOVE), \
* ....
* }
* ���������opcode-gen������߶�̬���ɵģ�����˵�����������ʲô�����ɵģ���Ҫ�ο��ù��ߵ�ʵ��
*
* # define H(_op) &&op_##_op
* ʵ�����������������&&op_OP_NOP �����ĵ�ַ
*/
DEFINE_GOTO_TABLE(handlerTable);
/* copy state in
* ��ʼ��һЩ״ֵ̬
*/
curMethod = self->interpSave.method;
pc = self->interpSave.pc;
fp = self->interpSave.curFrame;
retval = self->interpSave.retval; /* only need for kInterpEntryReturn? */
methodClassDex = curMethod->clazz->pDvmDex; //��ȡdex��ص�����(������Ҫ�ο�vm\DvmDex.cpp��������ʵ��)
LOGVV("threadid=%d: %s.%s pc=%#x fp=%p",
self->threadId, curMethod->clazz->descriptor, curMethod->name,
pc - curMethod->insns, fp);
/*
* Handle any ongoing profiling and prep for debugging.
* ������Ҫ�Ƿ�����ԣ�����������һ�����巽���Ľ���
*/
if (self->interpBreak.ctl.subMode != 0) {
TRACE_METHOD_ENTER(self, curMethod);
self->debugIsMethodEntry = true; // Always true on startup
}
/*
* DEBUG: scramble this to ensure we're not relying on it.
*/
methodToCall = (const Method*) -1;
#if 0
if (self->debugIsMethodEntry) {
ILOGD("|-- Now interpreting %s.%s", curMethod->clazz->descriptor,
curMethod->name);
DUMP_REGS(curMethod, self->interpSave.curFrame, false);
}
#endif
//�����￪ʼ����ȡָ�ִ�У����صĽ�
// ������ʵ���Ͻ�����һ��do - while��ѭ����ֱ��ִ����Ϸ���
FINISH(0); /* fetch and execute first instruction */
