Build 1.0_r1(from source)

android.os
Class Debug

java.lang.Object
  extended by android.os.Debug

public final class Debug
extends Object

Provides various debugging functions for Android applications, including tracing and allocation counts.

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 Running the Traceview Debugging Program for information about reading trace files. To start logging trace files, call one of the startMethodTracing() methods. To stop tracing, call stopMethodTracing().


Nested Class Summary
static class Debug.InstructionCount
          API for gathering and querying instruction counts.
static class Debug.MemoryInfo
          This class is used to retrieved various statistics about the memory mappings for this process.
 
Field Summary
static int SHOW_CLASSLOADER
           
static int SHOW_FULL_DETAIL
          Flags for printLoadedClasses().
static int SHOW_INITIALIZED
           
static int TRACE_COUNT_ALLOCS
          Flags for startMethodTracing().
 
Method Summary
static void changeDebugPort(int port)
          Change the JDWP port -- this is a temporary measure.
static void enableEmulatorTraceOutput()
          Enable "emulator traces", in which information about the current method is made available to the "emulator -trace" feature.
static int getBinderDeathObjectCount()
          Returns the number of death notification links to Binder objects that exist in the current process.
static int getBinderLocalObjectCount()
          Returns the number of active local Binder objects that exist in the current process.
static int getBinderProxyObjectCount()
          Returns the number of references to remote proxy Binder objects that exist in the current process.
static int getBinderReceivedTransactions()
          Returns the number of received transactions from the binder driver.
static int getBinderSentTransactions()
          Returns the number of sent transactions from this process.
static int getGlobalAllocCount()
           
static int getGlobalAllocSize()
           
static int getGlobalExternalAllocCount()
           
static int getGlobalExternalAllocSize()
           
static int getGlobalExternalFreedCount()
           
static int getGlobalExternalFreedSize()
           
static int getGlobalFreedCount()
           
static int getGlobalFreedSize()
           
static int getGlobalGcInvocationCount()
           
static int getLoadedClassCount()
          Get the number of loaded classes.
static void getMemoryInfo(Debug.MemoryInfo memoryInfo)
          Retrieves information about this processes memory usages.
static long getNativeHeapAllocatedSize()
          Returns the amount of allocated memory in the native heap.
static long getNativeHeapFreeSize()
          Returns the amount of free memory in the native heap.
static long getNativeHeapSize()
          Returns the size of the native heap.
static int getThreadAllocCount()
           
static int getThreadAllocSize()
           
static int getThreadExternalAllocCount()
           
static int getThreadExternalAllocSize()
           
static int getThreadGcInvocationCount()
           
static boolean isDebuggerConnected()
          Determine if a debugger is currently attached.
static void printLoadedClasses(int flags)
          Dump a list of all currently loaded class to the log file.
static void resetAllCounts()
           
static void resetGlobalAllocCount()
           
static void resetGlobalAllocSize()
           
static void resetGlobalExternalAllocCount()
           
static void resetGlobalExternalAllocSize()
           
static void resetGlobalExternalFreedCount()
           
static void resetGlobalExternalFreedSize()
           
static void resetGlobalFreedCount()
           
static void resetGlobalFreedSize()
           
static void resetGlobalGcInvocationCount()
           
static void resetThreadAllocCount()
           
static void resetThreadAllocSize()
           
static void resetThreadExternalAllocCount()
           
static void resetThreadExternalAllocSize()
           
static void resetThreadGcInvocationCount()
           
static int setAllocationLimit(int limit)
          Establish an object allocation limit in the current thread.
static int setGlobalAllocationLimit(int limit)
          Establish a global object allocation limit.
static void startAllocCounting()
          Count the number and aggregate size of memory allocations between two points.
static void startMethodTracing()
          Start method tracing with default log name and buffer size.
static void startMethodTracing(String traceName)
          Start method tracing, specifying the trace log file name.
static void startMethodTracing(String traceName, int bufferSize)
          Start method tracing, specifying the trace log file name and the buffer size.
static void startMethodTracing(String traceName, int bufferSize, int flags)
          Start method tracing, specifying the trace log file name and the buffer size.
static void startNativeTracing()
          Enable qemu tracing.
static void stopAllocCounting()
           
static void stopMethodTracing()
          Stop method tracing.
static void stopNativeTracing()
          Stop qemu tracing.
static long threadCpuTimeNanos()
          Get an indication of thread CPU usage.
static void waitForDebugger()
          Wait until a debugger attaches.
static boolean waitingForDebugger()
          Returns "true" if one or more threads is waiting for a debugger to attach.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

TRACE_COUNT_ALLOCS

public static final int TRACE_COUNT_ALLOCS
Flags for startMethodTracing(). These can be ORed together. TRACE_COUNT_ALLOCS adds the results from startAllocCounting to the trace key file.

See Also:
Constant Field Values

SHOW_FULL_DETAIL

public static final int SHOW_FULL_DETAIL
Flags for printLoadedClasses(). Default behavior is to only show the class name.

See Also:
Constant Field Values

SHOW_CLASSLOADER

public static final int SHOW_CLASSLOADER
See Also:
Constant Field Values

SHOW_INITIALIZED

public static final int SHOW_INITIALIZED
See Also:
Constant Field Values
Method Detail

waitForDebugger

public static void waitForDebugger()
Wait until a debugger attaches. As soon as the debugger attaches, this returns, so you will need to place a breakpoint after the waitForDebugger() call if you want to start tracing immediately.


waitingForDebugger

public static boolean waitingForDebugger()
Returns "true" if one or more threads is waiting for a debugger to attach.


isDebuggerConnected

public static boolean isDebuggerConnected()
Determine if a debugger is currently attached.


changeDebugPort

public static void changeDebugPort(int port)
Change the JDWP port -- this is a temporary measure. If a debugger is currently attached the change may not happen until after the debugger disconnects.


startNativeTracing

public static void startNativeTracing()
Enable qemu tracing. For this to work requires running everything inside the qemu emulator; otherwise, this method will have no effect. The trace file is specified on the command line when the emulator is started. For example, the following command line
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.

The main differences between this and 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 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.


stopNativeTracing

public static void stopNativeTracing()
Stop qemu tracing. See startNativeTracing() to start tracing.

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.


enableEmulatorTraceOutput

public static void enableEmulatorTraceOutput()
Enable "emulator traces", in which information about the current method is made available to the "emulator -trace" feature. There is no corresponding "disable" call -- this is intended for use by the framework when tracing should be turned on and left that way, so that traces captured with F9/F10 will include the necessary data. This puts the VM into "profile" mode, which has performance consequences. To temporarily enable tracing, use startNativeTracing().


startMethodTracing

public static void startMethodTracing()
Start method tracing with default log name and buffer size. See Running the Traceview Debugging Program for information about reading these files. Call stopMethodTracing() to stop tracing.


startMethodTracing

public static void startMethodTracing(String traceName)
Start method tracing, specifying the trace log file name. The trace file will be put under "/sdcard" unless an absolute path is given. See Running the Traceview Debugging Program for information about reading trace files.

Parameters:
traceName - Name for the trace log file to create. If no name argument is given, this value defaults to "/sdcard/dmtrace.trace". If the files already exist, they will be truncated. If the trace file given does not end in ".trace", it will be appended for you.

startMethodTracing

public static void startMethodTracing(String traceName,
                                      int bufferSize)
Start method tracing, specifying the trace log file name and the buffer size. The trace files will be put under "/sdcard" unless an absolute path is given. See Running the Traceview Debugging Program for information about reading trace files.

Parameters:
traceName - Name for the trace log file to create. If no name argument is given, this value defaults to "/sdcard/dmtrace.trace". If the files already exist, they will be truncated. If the trace file given does not end in ".trace", it will be appended for you.
bufferSize - The maximum amount of trace data we gather. If not given, it defaults to 8MB.

startMethodTracing

public static void startMethodTracing(String traceName,
                                      int bufferSize,
                                      int flags)
Start method tracing, specifying the trace log file name and the buffer size. The trace files will be put under "/sdcard" unless an absolute path is given. See Running the Traceview Debugging Program for information about reading trace files.

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 startNativeTracing().

Parameters:
traceName - Name for the trace log file to create. If no name argument is given, this value defaults to "/sdcard/dmtrace.trace". If the files already exist, they will be truncated. If the trace file given does not end in ".trace", it will be appended for you.
bufferSize - The maximum amount of trace data we gather. If not given, it defaults to 8MB.

stopMethodTracing

public static void stopMethodTracing()
Stop method tracing.


threadCpuTimeNanos

public static long threadCpuTimeNanos()
Get an indication of thread CPU usage. The value returned indicates the amount of time that the current thread has spent executing code or waiting for certain types of I/O. The time is expressed in nanoseconds, and is only meaningful when compared to the result from an earlier call. Note that nanosecond resolution does not imply nanosecond accuracy. On system which don't support this operation, the call returns -1.


startAllocCounting

public static void startAllocCounting()
Count the number and aggregate size of memory allocations between two points. The "start" function resets the counts and enables counting. The "stop" function disables the counting so that the analysis code doesn't cause additional allocations. The "get" function returns the specified value. 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.


stopAllocCounting

public static void stopAllocCounting()

getGlobalAllocCount

public static int getGlobalAllocCount()

getGlobalAllocSize

public static int getGlobalAllocSize()

getGlobalFreedCount

public static int getGlobalFreedCount()

getGlobalFreedSize

public static int getGlobalFreedSize()

getGlobalExternalAllocCount

public static int getGlobalExternalAllocCount()

getGlobalExternalAllocSize

public static int getGlobalExternalAllocSize()

getGlobalExternalFreedCount

public static int getGlobalExternalFreedCount()

getGlobalExternalFreedSize

public static int getGlobalExternalFreedSize()

getGlobalGcInvocationCount

public static int getGlobalGcInvocationCount()

getThreadAllocCount

public static int getThreadAllocCount()

getThreadAllocSize

public static int getThreadAllocSize()

getThreadExternalAllocCount

public static int getThreadExternalAllocCount()

getThreadExternalAllocSize

public static int getThreadExternalAllocSize()

getThreadGcInvocationCount

public static int getThreadGcInvocationCount()

resetGlobalAllocCount

public static void resetGlobalAllocCount()

resetGlobalAllocSize

public static void resetGlobalAllocSize()

resetGlobalFreedCount

public static void resetGlobalFreedCount()

resetGlobalFreedSize

public static void resetGlobalFreedSize()

resetGlobalExternalAllocCount

public static void resetGlobalExternalAllocCount()

resetGlobalExternalAllocSize

public static void resetGlobalExternalAllocSize()

resetGlobalExternalFreedCount

public static void resetGlobalExternalFreedCount()

resetGlobalExternalFreedSize

public static void resetGlobalExternalFreedSize()

resetGlobalGcInvocationCount

public static void resetGlobalGcInvocationCount()

resetThreadAllocCount

public static void resetThreadAllocCount()

resetThreadAllocSize

public static void resetThreadAllocSize()

resetThreadExternalAllocCount

public static void resetThreadExternalAllocCount()

resetThreadExternalAllocSize

public static void resetThreadExternalAllocSize()

resetThreadGcInvocationCount

public static void resetThreadGcInvocationCount()

resetAllCounts

public static void resetAllCounts()

getNativeHeapSize

public static long getNativeHeapSize()
Returns the size of the native heap.

Returns:
The size of the native heap in bytes.

getNativeHeapAllocatedSize

public static long getNativeHeapAllocatedSize()
Returns the amount of allocated memory in the native heap.

Returns:
The allocated size in bytes.

getNativeHeapFreeSize

public static long getNativeHeapFreeSize()
Returns the amount of free memory in the native heap.

Returns:
The freed size in bytes.

getMemoryInfo

public static void getMemoryInfo(Debug.MemoryInfo memoryInfo)
Retrieves information about this processes memory usages. This information is broken down by how much is in use by dalivk, the native heap, and everything else.


setAllocationLimit

public static int setAllocationLimit(int limit)
Establish an object allocation limit in the current thread. Useful for catching regressions in code that is expected to operate without causing any allocations. 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: 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.


setGlobalAllocationLimit

public static int setGlobalAllocationLimit(int limit)
Establish a global object allocation limit. This is similar to 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. ]


printLoadedClasses

public static void printLoadedClasses(int flags)
Dump a list of all currently loaded class to the log file.

Parameters:
flags - See constants above.

getLoadedClassCount

public static int getLoadedClassCount()
Get the number of loaded classes.

Returns:
the number of loaded classes.

getBinderSentTransactions

public static int getBinderSentTransactions()
Returns the number of sent transactions from this process.

Returns:
The number of sent transactions or -1 if it could not read t.

getBinderReceivedTransactions

public static int getBinderReceivedTransactions()
Returns the number of received transactions from the binder driver.

Returns:
The number of received transactions or -1 if it could not read the stats.

getBinderLocalObjectCount

public static final int getBinderLocalObjectCount()
Returns the number of active local Binder objects that exist in the current process.


getBinderProxyObjectCount

public static final int getBinderProxyObjectCount()
Returns the number of references to remote proxy Binder objects that exist in the current process.


getBinderDeathObjectCount

public static final int getBinderDeathObjectCount()
Returns the number of death notification links to Binder objects that exist in the current process.


Build 1.0_r1(from source)

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