Logging Trace Files
*Debug can create log files that give details about an application, such as
* a call stack and start/stop times for any running methods. See Traceview: A Graphical Log Viewer for
* information about reading trace files. To start logging trace files, call one
* of the startMethodTracing() methods. To stop tracing, call
* {@link #stopMethodTracing()}.
*/
public final class Debug
{
private static final String TAG = "Debug";
/**
* Flags for startMethodTracing(). These can be ORed together.
*
* TRACE_COUNT_ALLOCS adds the results from startAllocCounting to the
* trace key file.
*/
public static final int TRACE_COUNT_ALLOCS = VMDebug.TRACE_COUNT_ALLOCS;
/**
* Flags for printLoadedClasses(). Default behavior is to only show
* the class name.
*/
public static final int SHOW_FULL_DETAIL = 1;
public static final int SHOW_CLASSLOADER = (1 << 1);
public static final int SHOW_INITIALIZED = (1 << 2);
// set/cleared by waitForDebugger()
private static volatile boolean mWaiting = false;
private Debug() {}
/*
* How long to wait for the debugger to finish sending requests. I've
* seen this hit 800msec on the device while waiting for a response
* to travel over USB and get processed, so we take that and add
* half a second.
*/
private static final int MIN_DEBUGGER_IDLE = 1300; // msec
/* how long to sleep when polling for activity */
private static final int SPIN_DELAY = 200; // msec
/**
* Default trace file path and file
*/
private static final String DEFAULT_TRACE_PATH_PREFIX =
Environment.getExternalStorageDirectory().getPath() + "/";
private static final String DEFAULT_TRACE_BODY = "dmtrace";
private static final String DEFAULT_TRACE_EXTENSION = ".trace";
private static final String DEFAULT_TRACE_FILE_PATH =
DEFAULT_TRACE_PATH_PREFIX + DEFAULT_TRACE_BODY
+ DEFAULT_TRACE_EXTENSION;
/**
* This class is used to retrieved various statistics about the memory mappings for this
* process. The returns info broken down by dalvik, native, and other. All results are in kB.
*/
public static class MemoryInfo implements Parcelable {
/** The proportional set size for dalvik. */
public int dalvikPss;
/** The private dirty pages used by dalvik. */
public int dalvikPrivateDirty;
/** The shared dirty pages used by dalvik. */
public int dalvikSharedDirty;
/** The proportional set size for the native heap. */
public int nativePss;
/** The private dirty pages used by the native heap. */
public int nativePrivateDirty;
/** The shared dirty pages used by the native heap. */
public int nativeSharedDirty;
/** The proportional set size for everything else. */
public int otherPss;
/** The private dirty pages used by everything else. */
public int otherPrivateDirty;
/** The shared dirty pages used by everything else. */
public int otherSharedDirty;
public MemoryInfo() {
}
/**
* Return total PSS memory usage in kB.
*/
public int getTotalPss() {
return dalvikPss + nativePss + otherPss;
}
/**
* Return total private dirty memory usage in kB.
*/
public int getTotalPrivateDirty() {
return dalvikPrivateDirty + nativePrivateDirty + otherPrivateDirty;
}
/**
* Return total shared dirty memory usage in kB.
*/
public int getTotalSharedDirty() {
return dalvikSharedDirty + nativeSharedDirty + otherSharedDirty;
}
public int describeContents() {
return 0;
}
public void writeToParcel(Parcel dest, int flags) {
dest.writeInt(dalvikPss);
dest.writeInt(dalvikPrivateDirty);
dest.writeInt(dalvikSharedDirty);
dest.writeInt(nativePss);
dest.writeInt(nativePrivateDirty);
dest.writeInt(nativeSharedDirty);
dest.writeInt(otherPss);
dest.writeInt(otherPrivateDirty);
dest.writeInt(otherSharedDirty);
}
public void readFromParcel(Parcel source) {
dalvikPss = source.readInt();
dalvikPrivateDirty = source.readInt();
dalvikSharedDirty = source.readInt();
nativePss = source.readInt();
nativePrivateDirty = source.readInt();
nativeSharedDirty = source.readInt();
otherPss = source.readInt();
otherPrivateDirty = source.readInt();
otherSharedDirty = source.readInt();
}
public static final Creator
* The main differences between this and {@link #startMethodTracing()} are
* that tracing in the qemu emulator traces every cpu instruction of every
* process, including kernel code, so we have more complete information,
* including all context switches. We can also get more detailed information
* such as cache misses. The sequence of calls is determined by
* post-processing the instruction trace. The qemu tracing is also done
* without modifying the application or perturbing the timing of calls
* because no instrumentation is added to the application being traced.
*
* One limitation of using this method compared to using
* {@link #startMethodTracing()} on the real device is that the emulator
* does not model all of the real hardware effects such as memory and
* bus contention. The emulator also has a simple cache model and cannot
* capture all the complexities of a real cache.
* Tracing can be started and stopped as many times as desired. When
* the qemu emulator itself is stopped then the buffered trace records
* are flushed and written to the trace file. In fact, it is not necessary
* to call this method at all; simply killing qemu is sufficient. But
* starting and stopping a trace is useful for examining a specific
* region of code.
* When method tracing is enabled, the VM will run more slowly than
* usual, so the timings from the trace files should only be considered
* in relative terms (e.g. was run #1 faster than run #2). The times
* for native methods will not change, so don't try to use this to
* compare the performance of interpreted and native implementations of the
* same method. As an alternative, consider using "native" tracing
* in the emulator via {@link #startNativeTracing()}.
* The {@link #startAllocCounting() start} function resets the counts and enables counting.
* The {@link #stopAllocCounting() stop} function disables the counting so that the analysis
* code doesn't cause additional allocations. The various Counts are kept for the system as a whole and for each thread.
* The per-thread counts for threads other than the current thread
* are not cleared by the "reset" or "start" calls. Pass in the maximum number of allowed allocations. Use -1 to disable
* the limit. Returns the previous limit. The preferred way to use this is:
*
* emulator -trace foo
* will start running the emulator and create a trace file named "foo". This
* method simply enables writing the trace records to the trace file.
*
* get functions return
* the specified value. And the various reset functions reset the specified
* count.
* int prevLimit = -1;
* try {
* prevLimit = Debug.setAllocationLimit(0);
* ... do stuff that's not expected to allocate memory ...
* } finally {
* Debug.setAllocationLimit(prevLimit);
* }
*
* This allows limits to be nested. The try/finally ensures that the
* limit is reset if something fails.
Exceeding the limit causes a dalvik.system.AllocationLimitError to * be thrown from a memory allocation call. The limit is reset to -1 * when this happens.
* *The feature may be disabled in the VM configuration. If so, this * call has no effect, and always returns -1.
*/ public static int setAllocationLimit(int limit) { return VMDebug.setAllocationLimit(limit); } /** * Establish a global object allocation limit. This is similar to * {@link #setAllocationLimit(int)} but applies to all threads in * the VM. It will coexist peacefully with per-thread limits. * * [ The value of "limit" is currently restricted to 0 (no allocations * allowed) or -1 (no global limit). This may be changed in a future * release. ] */ public static int setGlobalAllocationLimit(int limit) { if (limit != 0 && limit != -1) throw new IllegalArgumentException("limit must be 0 or -1"); return VMDebug.setGlobalAllocationLimit(limit); } /** * Dump a list of all currently loaded class to the log file. * * @param flags See constants above. */ public static void printLoadedClasses(int flags) { VMDebug.printLoadedClasses(flags); } /** * Get the number of loaded classes. * @return the number of loaded classes. */ public static int getLoadedClassCount() { return VMDebug.getLoadedClassCount(); } /** * Dump "hprof" data to the specified file. This may cause a GC. * * @param fileName Full pathname of output file (e.g. "/sdcard/dump.hprof"). * @throws UnsupportedOperationException if the VM was built without * HPROF support. * @throws IOException if an error occurs while opening or writing files. */ public static void dumpHprofData(String fileName) throws IOException { VMDebug.dumpHprofData(fileName); } /** * Like dumpHprofData(String), but takes an already-opened * FileDescriptor to which the trace is written. The file name is also * supplied simply for logging. Makes a dup of the file descriptor. * * Primarily for use by the "am" shell command. * * @hide */ public static void dumpHprofData(String fileName, FileDescriptor fd) throws IOException { VMDebug.dumpHprofData(fileName, fd); } /** * Collect "hprof" and send it to DDMS. This may cause a GC. * * @throws UnsupportedOperationException if the VM was built without * HPROF support. * @hide */ public static void dumpHprofDataDdms() { VMDebug.dumpHprofDataDdms(); } /** * Writes native heap data to the specified file descriptor. * * @hide */ public static native void dumpNativeHeap(FileDescriptor fd); /** * Returns a count of the extant instances of a class. * * @hide */ public static long countInstancesOfClass(Class cls) { return VMDebug.countInstancesOfClass(cls, true); } /** * Returns the number of sent transactions from this process. * @return The number of sent transactions or -1 if it could not read t. */ public static native int getBinderSentTransactions(); /** * Returns the number of received transactions from the binder driver. * @return The number of received transactions or -1 if it could not read the stats. */ public static native int getBinderReceivedTransactions(); /** * Returns the number of active local Binder objects that exist in the * current process. */ public static final native int getBinderLocalObjectCount(); /** * Returns the number of references to remote proxy Binder objects that * exist in the current process. */ public static final native int getBinderProxyObjectCount(); /** * Returns the number of death notification links to Binder objects that * exist in the current process. */ public static final native int getBinderDeathObjectCount(); /** * Primes the register map cache. * * Only works for classes in the bootstrap class loader. Does not * cause classes to be loaded if they're not already present. * * The classAndMethodDesc argument is a concatentation of the VM-internal * class descriptor, method name, and method descriptor. Examples: * Landroid/os/Looper;.loop:()V * Landroid/app/ActivityThread;.main:([Ljava/lang/String;)V * * @param classAndMethodDesc the method to prepare * * @hide */ public static final boolean cacheRegisterMap(String classAndMethodDesc) { return VMDebug.cacheRegisterMap(classAndMethodDesc); } /** * Dumps the contents of VM reference tables (e.g. JNI locals and * globals) to the log file. * * @hide */ public static final void dumpReferenceTables() { VMDebug.dumpReferenceTables(); } /** * API for gathering and querying instruction counts. * * Example usage: *
* Debug.InstructionCount icount = new Debug.InstructionCount();
* icount.resetAndStart();
* [... do lots of stuff ...]
* if (icount.collect()) {
* System.out.println("Total instructions executed: "
* + icount.globalTotal());
* System.out.println("Method invocations: "
* + icount.globalMethodInvocations());
* }
*
*/
public static class InstructionCount {
private static final int NUM_INSTR =
OpcodeInfo.MAXIMUM_PACKED_VALUE + 1;
private int[] mCounts;
public InstructionCount() {
mCounts = new int[NUM_INSTR];
}
/**
* Reset counters and ensure counts are running. Counts may
* have already been running.
*
* @return true if counting was started
*/
public boolean resetAndStart() {
try {
VMDebug.startInstructionCounting();
VMDebug.resetInstructionCount();
} catch (UnsupportedOperationException uoe) {
return false;
}
return true;
}
/**
* Collect instruction counts. May or may not stop the
* counting process.
*/
public boolean collect() {
try {
VMDebug.stopInstructionCounting();
VMDebug.getInstructionCount(mCounts);
} catch (UnsupportedOperationException uoe) {
return false;
}
return true;
}
/**
* Return the total number of instructions executed globally (i.e. in
* all threads).
*/
public int globalTotal() {
int count = 0;
for (int i = 0; i < NUM_INSTR; i++) {
count += mCounts[i];
}
return count;
}
/**
* Return the total number of method-invocation instructions
* executed globally.
*/
public int globalMethodInvocations() {
int count = 0;
for (int i = 0; i < NUM_INSTR; i++) {
if (OpcodeInfo.isInvoke(i)) {
count += mCounts[i];
}
}
return count;
}
}
/**
* A Map of typed debug properties.
*/
private static final TypedProperties debugProperties;
/*
* Load the debug properties from the standard files into debugProperties.
*/
static {
if (Config.DEBUG) {
final String TAG = "DebugProperties";
final String[] files = { "/system/debug.prop", "/debug.prop", "/data/debug.prop" };
final TypedProperties tp = new TypedProperties();
// Read the properties from each of the files, if present.
for (String file : files) {
Reader r;
try {
r = new FileReader(file);
} catch (FileNotFoundException ex) {
// It's ok if a file is missing.
continue;
}
try {
tp.load(r);
} catch (Exception ex) {
throw new RuntimeException("Problem loading " + file, ex);
} finally {
try {
r.close();
} catch (IOException ex) {
// Ignore this error.
}
}
}
debugProperties = tp.isEmpty() ? null : tp;
} else {
debugProperties = null;
}
}
/**
* Returns true if the type of the field matches the specified class.
* Handles the case where the class is, e.g., java.lang.Boolean, but
* the field is of the primitive "boolean" type. Also handles all of
* the java.lang.Number subclasses.
*/
private static boolean fieldTypeMatches(Field field, Class cl) {
Class fieldClass = field.getType();
if (fieldClass == cl) {
return true;
}
Field primitiveTypeField;
try {
/* All of the classes we care about (Boolean, Integer, etc.)
* have a Class field called "TYPE" that points to the corresponding
* primitive class.
*/
primitiveTypeField = cl.getField("TYPE");
} catch (NoSuchFieldException ex) {
return false;
}
try {
return fieldClass == (Class) primitiveTypeField.get(null);
} catch (IllegalAccessException ex) {
return false;
}
}
/**
* Looks up the property that corresponds to the field, and sets the field's value
* if the types match.
*/
private static void modifyFieldIfSet(final Field field, final TypedProperties properties,
final String propertyName) {
if (field.getType() == java.lang.String.class) {
int stringInfo = properties.getStringInfo(propertyName);
switch (stringInfo) {
case TypedProperties.STRING_SET:
// Handle as usual below.
break;
case TypedProperties.STRING_NULL:
try {
field.set(null, null); // null object for static fields; null string
} catch (IllegalAccessException ex) {
throw new IllegalArgumentException(
"Cannot set field for " + propertyName, ex);
}
return;
case TypedProperties.STRING_NOT_SET:
return;
case TypedProperties.STRING_TYPE_MISMATCH:
throw new IllegalArgumentException(
"Type of " + propertyName + " " +
" does not match field type (" + field.getType() + ")");
default:
throw new IllegalStateException(
"Unexpected getStringInfo(" + propertyName + ") return value " +
stringInfo);
}
}
Object value = properties.get(propertyName);
if (value != null) {
if (!fieldTypeMatches(field, value.getClass())) {
throw new IllegalArgumentException(
"Type of " + propertyName + " (" + value.getClass() + ") " +
" does not match field type (" + field.getType() + ")");
}
try {
field.set(null, value); // null object for static fields
} catch (IllegalAccessException ex) {
throw new IllegalArgumentException(
"Cannot set field for " + propertyName, ex);
}
}
}
/**
* Equivalent to setFieldsOn(cl, false).
*
* @see #setFieldsOn(Class, boolean)
*
* @hide
*/
public static void setFieldsOn(Class cl) {
setFieldsOn(cl, false);
}
/**
* Reflectively sets static fields of a class based on internal debugging
* properties. This method is a no-op if android.util.Config.DEBUG is
* false.
* * NOTE TO APPLICATION DEVELOPERS: Config.DEBUG will * always be false in release builds. This API is typically only useful * for platform developers. *
* Class setup: define a class whose only fields are non-final, static * primitive types (except for "char") or Strings. In a static block * after the field definitions/initializations, pass the class to * this method, Debug.setFieldsOn(). Example: *
* package com.example;
*
* import android.os.Debug;
*
* public class MyDebugVars {
* public static String s = "a string";
* public static String s2 = "second string";
* public static String ns = null;
* public static boolean b = false;
* public static int i = 5;
* @Debug.DebugProperty
* public static float f = 0.1f;
* @@Debug.DebugProperty
* public static double d = 0.5d;
*
* // This MUST appear AFTER all fields are defined and initialized!
* static {
* // Sets all the fields
* Debug.setFieldsOn(MyDebugVars.class);
*
* // Sets only the fields annotated with @Debug.DebugProperty
* // Debug.setFieldsOn(MyDebugVars.class, true);
* }
* }
*
* setFieldsOn() may override the value of any field in the class based
* on internal properties that are fixed at boot time.
* * These properties are only set during platform debugging, and are not * meant to be used as a general-purpose properties store. * * {@hide} * * @param cl The class to (possibly) modify * @param partial If false, sets all static fields, otherwise, only set * fields with the {@link android.os.Debug.DebugProperty} * annotation * @throws IllegalArgumentException if any fields are final or non-static, * or if the type of the field does not match the type of * the internal debugging property value. */ public static void setFieldsOn(Class cl, boolean partial) { if (Config.DEBUG) { if (debugProperties != null) { /* Only look for fields declared directly by the class, * so we don't mysteriously change static fields in superclasses. */ for (Field field : cl.getDeclaredFields()) { if (!partial || field.getAnnotation(DebugProperty.class) != null) { final String propertyName = cl.getName() + "." + field.getName(); boolean isStatic = Modifier.isStatic(field.getModifiers()); boolean isFinal = Modifier.isFinal(field.getModifiers()); if (!isStatic || isFinal) { throw new IllegalArgumentException(propertyName + " must be static and non-final"); } modifyFieldIfSet(field, debugProperties, propertyName); } } } } else { Log.wtf(TAG, "setFieldsOn(" + (cl == null ? "null" : cl.getName()) + ") called in non-DEBUG build"); } } /** * Annotation to put on fields you want to set with * {@link Debug#setFieldsOn(Class, boolean)}. * * @hide */ @Target({ ElementType.FIELD }) @Retention(RetentionPolicy.RUNTIME) public @interface DebugProperty { } /** * Get a debugging dump of a system service by name. * *
Most services require the caller to hold android.permission.DUMP. * * @param name of the service to dump * @param fd to write dump output to (usually an output log file) * @param args to pass to the service's dump method, may be null * @return true if the service was dumped successfully, false if * the service could not be found or had an error while dumping */ public static boolean dumpService(String name, FileDescriptor fd, String[] args) { IBinder service = ServiceManager.getService(name); if (service == null) { Log.e(TAG, "Can't find service to dump: " + name); return false; } try { service.dump(fd, args); return true; } catch (RemoteException e) { Log.e(TAG, "Can't dump service: " + name, e); return false; } } }