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1 /*
2  * Copyright (C) 2007 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package dalvik.system;
18 
19 import static android.annotation.SystemApi.Client.MODULE_LIBRARIES;
20 
21 import android.annotation.SystemApi;
22 import android.compat.annotation.UnsupportedAppUsage;
23 
24 import java.io.FileDescriptor;
25 import java.io.IOException;
26 import java.util.HashMap;
27 import java.util.Map;
28 
29 import dalvik.annotation.optimization.FastNative;
30 
31 /**
32  * Provides access to some VM-specific debug features. Though this class and
33  * many of its members are public, this class is meant to be wrapped in a more
34  * friendly way for use by application developers. On the Android platform, the
35  * recommended way to access this functionality is through the class
36  * <code>android.os.Debug</code>.
37  *
38  * @hide
39  */
40 @SystemApi(client = MODULE_LIBRARIES)
41 public final class VMDebug {
42     /**
43      * flag for startMethodTracing(), which adds the results from
44      * startAllocCounting to the trace key file.
45      *
46      * @hide
47      */
48     @SystemApi(client = MODULE_LIBRARIES)
49     // Must match android.os.Debug.TRACE_COUNT_ALLOCS.
50     public static final int TRACE_COUNT_ALLOCS = 1;
51 
52     /* constants for getAllocCount */
53     private static final int KIND_ALLOCATED_OBJECTS     = 1<<0;
54     private static final int KIND_ALLOCATED_BYTES       = 1<<1;
55     private static final int KIND_FREED_OBJECTS         = 1<<2;
56     private static final int KIND_FREED_BYTES           = 1<<3;
57     private static final int KIND_GC_INVOCATIONS        = 1<<4;
58     private static final int KIND_CLASS_INIT_COUNT      = 1<<5;
59     private static final int KIND_CLASS_INIT_TIME       = 1<<6;
60     private static final int KIND_EXT_ALLOCATED_OBJECTS = 1<<12;
61     private static final int KIND_EXT_ALLOCATED_BYTES   = 1<<13;
62     private static final int KIND_EXT_FREED_OBJECTS     = 1<<14;
63     private static final int KIND_EXT_FREED_BYTES       = 1<<15;
64 
65     /**
66      * Constant for {@link #getAllocCount(int)}
67      * to get the number of all allocated objects.
68      *
69      * @hide
70      */
71     @SystemApi(client = MODULE_LIBRARIES)
72     public static final int KIND_GLOBAL_ALLOCATED_OBJECTS =
73         KIND_ALLOCATED_OBJECTS;
74 
75     /**
76      * Constant for {@link #getAllocCount(int)}
77      * to get the cumulative size of all objects allocated.
78      *
79      * @hide
80      */
81     @SystemApi(client = MODULE_LIBRARIES)
82     public static final int KIND_GLOBAL_ALLOCATED_BYTES =
83         KIND_ALLOCATED_BYTES;
84 
85     /**
86      * Constant for {@link #getAllocCount(int)}
87      * to get the number of freed objects.
88      *
89      * @hide
90      */
91     @SystemApi(client = MODULE_LIBRARIES)
92     public static final int KIND_GLOBAL_FREED_OBJECTS =
93         KIND_FREED_OBJECTS;
94 
95     /**
96      * Constant for {@link #getAllocCount(int)}
97      * to get the cumulative size of all freed objects.
98      *
99      * @hide
100      */
101     @SystemApi(client = MODULE_LIBRARIES)
102     public static final int KIND_GLOBAL_FREED_BYTES =
103         KIND_FREED_BYTES;
104 
105     /**
106      * Constant for {@link #getAllocCount(int)}
107      * to get the number of times an allocation triggered a blocking GC.
108      *
109      * @hide
110      */
111     @SystemApi(client = MODULE_LIBRARIES)
112     public static final int KIND_GLOBAL_GC_INVOCATIONS =
113         KIND_GC_INVOCATIONS;
114 
115     /**
116      * Constant for {@link #getAllocCount(int)}
117      * to get the number of initialized classes.
118      *
119      * @hide
120      */
121     @SystemApi(client = MODULE_LIBRARIES)
122     public static final int KIND_GLOBAL_CLASS_INIT_COUNT =
123         KIND_CLASS_INIT_COUNT;
124 
125     /**
126      * Constant for {@link #getAllocCount(int)}
127      * to get the cumulative time spent in class initialization.
128      *
129      * @hide
130      */
131     @SystemApi(client = MODULE_LIBRARIES)
132     public static final int KIND_GLOBAL_CLASS_INIT_TIME =
133         KIND_CLASS_INIT_TIME;
134 
135     /**
136      * Constant for {@link #getAllocCount(int)}
137      * to get the number of all allocated objects for current thread.
138      *
139      * @hide
140      */
141     @SystemApi(client = MODULE_LIBRARIES)
142     public static final int KIND_THREAD_ALLOCATED_OBJECTS =
143         KIND_ALLOCATED_OBJECTS << 16;
144 
145     /**
146      * Constant for {@link #getAllocCount(int)}
147      * to get the cumulative size of all objects allocated for current thread.
148      *
149      * @hide
150      */
151     @SystemApi(client = MODULE_LIBRARIES)
152     public static final int KIND_THREAD_ALLOCATED_BYTES =
153         KIND_ALLOCATED_BYTES << 16;
154 
155     /**
156      * Constant for {@link #getAllocCount(int)}
157      * to get the number of times an allocation triggered a blocking GC for current thread.
158      *
159      * @hide
160      */
161     @SystemApi(client = MODULE_LIBRARIES)
162     public static final int KIND_THREAD_GC_INVOCATIONS =
163         KIND_GC_INVOCATIONS << 16;
164 
165     /**
166      * Constant for {@link #getAllocCount(int)} to get all possible stats.
167      *
168      * @hide
169      */
170     @SystemApi(client = MODULE_LIBRARIES)
171     public static final int KIND_ALL_COUNTS = 0xffffffff;
172 
173     /* all methods are static */
VMDebug()174     private VMDebug() {}
175 
176     /**
177      * Request JDWP agent to suspend all Java Thread and send VM_START.
178      *
179      * @hide
180      */
181     @SystemApi(client = MODULE_LIBRARIES)
suspendAllAndSendVmStart()182     public static native void suspendAllAndSendVmStart();
183 
184     /**
185      * Returns the time since the last known debugger activity.
186      *
187      * @return the time in milliseconds, or -1 if the debugger is not connected
188      *
189      * @hide
190      */
191     @SystemApi(client = MODULE_LIBRARIES)
192     @FastNative
lastDebuggerActivity()193     public static native long lastDebuggerActivity();
194 
195     /**
196      * Determines if debugging is enabled in this VM.  If debugging is not
197      * enabled, a debugger cannot be attached.
198      *
199      * @return true if debugging is enabled
200      *
201      * @hide
202      */
203     @SystemApi(client = MODULE_LIBRARIES)
204     @FastNative
isDebuggingEnabled()205     public static native boolean isDebuggingEnabled();
206 
207     /**
208      * Determines if a debugger is currently attached.
209      *
210      * @return true if (and only if) a debugger is connected
211      *
212      * @hide
213      */
214     @UnsupportedAppUsage
215     @SystemApi(client = MODULE_LIBRARIES)
216     @FastNative
isDebuggerConnected()217     public static native boolean isDebuggerConnected();
218 
219     /**
220      * Returns an array of strings that identify VM features.  This is
221      * used by DDMS to determine what sorts of operations the VM can
222      * perform.
223      *
224      * @return array of strings identifying VM features
225      *
226      * @hide
227      */
228     @SystemApi(client = MODULE_LIBRARIES)
getVmFeatureList()229     public static native String[] getVmFeatureList();
230 
231     /**
232      * Start method tracing, specifying a file name as well as a default
233      * buffer size. See <a
234      * href="{@docRoot}guide/developing/tools/traceview.html"> Running the
235      * Traceview Debugging Program</a> for information about reading
236      * trace files.
237      *
238      * <p>You can use either a fully qualified path and
239      * name, or just a name. If only a name is specified, the file will
240      * be created under the /sdcard/ directory. If a name is not given,
241      * the default is /sdcard/dmtrace.trace.</p>
242      *
243      * @param traceFileName   name to give the trace file
244      * @param bufferSize      the maximum size of both files combined. If passed
245      *                        as {@code 0}, it defaults to 8MB.
246      * @param flags           flags to control method tracing. The only one that
247      *                        is currently defined is {@link #TRACE_COUNT_ALLOCS}.
248      * @param samplingEnabled if true, sample profiling is enabled. Otherwise,
249      *                        method instrumentation is used.
250      * @param intervalUs      the time between samples in microseconds when
251      *                        sampling is enabled.
252      *
253      * @hide
254      */
255     @SystemApi(client = MODULE_LIBRARIES)
startMethodTracing(String traceFileName, int bufferSize, int flags, boolean samplingEnabled, int intervalUs)256     public static void startMethodTracing(String traceFileName, int bufferSize, int flags, boolean samplingEnabled, int intervalUs) {
257         startMethodTracingFilename(traceFileName, checkBufferSize(bufferSize), flags, samplingEnabled, intervalUs);
258     }
259 
260     /**
261      * Like {@link #startMethodTracing(String, int, int)}, but taking an already-opened
262      * {@code FileDescriptor} in which the trace is written.  The file name is also
263      * supplied simply for logging.  Makes a dup of the file descriptor.
264      * Streams tracing data to the file if streamingOutput is true.
265      *
266      * @param traceFileName   name to give the trace file
267      * @param fd              already opened {@code FileDescriptor} in which trace is written
268      * @param bufferSize      the maximum size of both files combined. If passed
269      *                        as {@code 0}, it defaults to 8MB.
270      * @param flags           flags to control method tracing. The only one that
271      *                        is currently defined is {@link #TRACE_COUNT_ALLOCS}.
272      * @param samplingEnabled if true, sample profiling is enabled. Otherwise,
273      *                        method instrumentation is used.
274      * @param intervalUs      the time between samples in microseconds when
275      *                        sampling is enabled.
276      * @param streamingOutput streams tracing data to the duped {@code fd} file descriptor
277      *                        if {@code streamingOutput} is {@code true}.
278      *
279      * @hide
280      */
281     @SystemApi(client = MODULE_LIBRARIES)
startMethodTracing(String traceFileName, FileDescriptor fd, int bufferSize, int flags, boolean samplingEnabled, int intervalUs, boolean streamingOutput)282     public static void startMethodTracing(String traceFileName, FileDescriptor fd, int bufferSize,
283                                           int flags, boolean samplingEnabled, int intervalUs,
284                                           boolean streamingOutput) {
285         if (fd == null) {
286             throw new NullPointerException("fd == null");
287         }
288         startMethodTracingFd(traceFileName, fd.getInt$(), checkBufferSize(bufferSize), flags,
289                              samplingEnabled, intervalUs, streamingOutput);
290     }
291 
292     /**
293      * Starts method tracing without a backing file.  When {@link #stopMethodTracing()}
294      * is called, the result is sent directly to DDMS.  (If DDMS is not
295      * attached when tracing ends, the profiling data will be discarded.)
296      *
297      * @param bufferSize      the maximum size of both files combined. If passed
298      *                        as {@code 0}, it defaults to 8MB.
299      * @param flags           flags to control method tracing. The only one that
300      *                        is currently defined is {@link #TRACE_COUNT_ALLOCS}.
301      * @param samplingEnabled if true, sample profiling is enabled. Otherwise,
302      *                        method instrumentation is used.
303      * @param intervalUs      the time between samples in microseconds when
304      *                        sampling is enabled.
305      *
306      * @hide
307      */
308     @SystemApi(client = MODULE_LIBRARIES)
startMethodTracingDdms(int bufferSize, int flags, boolean samplingEnabled, int intervalUs)309     public static void startMethodTracingDdms(int bufferSize, int flags, boolean samplingEnabled, int intervalUs) {
310         startMethodTracingDdmsImpl(checkBufferSize(bufferSize), flags, samplingEnabled, intervalUs);
311     }
312 
checkBufferSize(int bufferSize)313     private static int checkBufferSize(int bufferSize) {
314         if (bufferSize == 0) {
315             // Default to 8MB per the documentation.
316             bufferSize = 8 * 1024 * 1024;
317         }
318         if (bufferSize < 1024) {
319             throw new IllegalArgumentException("buffer size < 1024: " + bufferSize);
320         }
321         return bufferSize;
322     }
323 
startMethodTracingDdmsImpl(int bufferSize, int flags, boolean samplingEnabled, int intervalUs)324     private static native void startMethodTracingDdmsImpl(int bufferSize, int flags, boolean samplingEnabled, int intervalUs);
startMethodTracingFd(String traceFileName, int fd, int bufferSize, int flags, boolean samplingEnabled, int intervalUs, boolean streamingOutput)325     private static native void startMethodTracingFd(String traceFileName, int fd, int bufferSize,
326             int flags, boolean samplingEnabled, int intervalUs, boolean streamingOutput);
startMethodTracingFilename(String traceFileName, int bufferSize, int flags, boolean samplingEnabled, int intervalUs)327     private static native void startMethodTracingFilename(String traceFileName, int bufferSize, int flags, boolean samplingEnabled, int intervalUs);
328 
329     /**
330      * Determine whether method tracing is currently active and what type is
331      * active.
332      *
333      * @hide
334      */
335     @SystemApi(client = MODULE_LIBRARIES)
getMethodTracingMode()336     public static native int getMethodTracingMode();
337 
338     /**
339      * Stops method tracing.
340      *
341      * @hide
342      */
343     @SystemApi(client = MODULE_LIBRARIES)
stopMethodTracing()344     public static native void stopMethodTracing();
345 
346     /**
347      * Get an indication of thread CPU usage. The value returned indicates the
348      * amount of time that the current thread has spent executing code or
349      * waiting for certain types of I/O.
350      * <p>
351      * The time is expressed in nanoseconds, and is only meaningful when
352      * compared to the result from an earlier call. Note that nanosecond
353      * resolution does not imply nanosecond accuracy.
354      *
355      * @return the CPU usage. A value of -1 means the system does not support
356      *         this feature.
357      *
358      * @hide
359      */
360     @SystemApi(client = MODULE_LIBRARIES)
361     @FastNative
threadCpuTimeNanos()362     public static native long threadCpuTimeNanos();
363 
364     /**
365      * Starts counting the number and aggregate size of memory allocations.
366      *
367      * @hide
368      */
369     @SystemApi(client = MODULE_LIBRARIES)
startAllocCounting()370     public static native void startAllocCounting();
371 
372     /**
373      * Stops counting the number and aggregate size of memory allocations.
374      *
375      * @hide
376      */
377     @SystemApi(client = MODULE_LIBRARIES)
stopAllocCounting()378     public static native void stopAllocCounting();
379 
380     /**
381      * Returns information on the number of objects allocated by the runtime between a
382      * {@link #startAllocCounting() start} and {@link #stopAllocCounting() stop}.
383      *
384      * @param kind either {@code KIND_GLOBAL_*} or {@code KIND_THREAD_*}.
385      *
386      * @hide
387      */
388     @SystemApi(client = MODULE_LIBRARIES)
getAllocCount(int kind)389     public static native int getAllocCount(int kind);
390 
391     /**
392      * Resets counting the number and aggregate size of memory allocations for the given kinds.
393      *
394      * @param kinds a union of {@code KIND_GLOBAL_*} and {@code KIND_THREAD_*}.
395      *
396      * @hide
397      */
398     @SystemApi(client = MODULE_LIBRARIES)
resetAllocCount(int kinds)399     public static native void resetAllocCount(int kinds);
400 
401     /**
402      * This method exists for binary compatibility.  It was part of
403      * the allocation limits API which was removed in Android 3.0 (Honeycomb).
404      *
405      * @hide
406      */
407     @Deprecated
setAllocationLimit(int limit)408     public static int setAllocationLimit(int limit) {
409         return -1;
410     }
411 
412     /**
413      * This method exists for binary compatibility.  It was part of
414      * the allocation limits API which was removed in Android 3.0 (Honeycomb).
415      *
416      * @hide
417      */
418     @Deprecated
setGlobalAllocationLimit(int limit)419     public static int setGlobalAllocationLimit(int limit) {
420         return -1;
421     }
422 
423     /**
424      * Count the number of instructions executed between two points.
425      *
426      * @hide
427      */
428     @Deprecated
startInstructionCounting()429     public static void startInstructionCounting() {}
430 
431     /**
432      *
433      * @hide
434      */
435     @Deprecated
stopInstructionCounting()436     public static void stopInstructionCounting() {}
437 
438     /**
439      *
440      * @hide
441      */
442     @Deprecated
getInstructionCount(int[] counts)443     public static void getInstructionCount(int[] counts) {}
444 
445     /**
446      *
447      * @hide
448      */
449     @Deprecated
resetInstructionCount()450     public static void resetInstructionCount() {}
451 
452     /**
453      * Dumps a list of loaded class to the log file.
454      *
455      * @param flags a union of {@link android.os.Debug.SHOW_FULL_DETAIL},
456      *    {@link android.os.Debug.SHOW_CLASSLOADER}, and {@link android.os.Debug.SHOW_INITIALIZED}.
457      *
458      * @hide
459      */
460     @SystemApi(client = MODULE_LIBRARIES)
461     @FastNative
printLoadedClasses(int flags)462     public static native void printLoadedClasses(int flags);
463 
464     /**
465      * Gets the number of loaded classes.
466      *
467      * @return the number of loaded classes
468      *
469      * @hide
470      */
471     @SystemApi(client = MODULE_LIBRARIES)
472     @FastNative
getLoadedClassCount()473     public static native int getLoadedClassCount();
474 
475     /**
476      * Dumps "hprof" data to the specified file.  This may cause a GC.
477      *
478      * The VM may create a temporary file in the same directory.
479      *
480      * @param filename Full pathname of output file (e.g. "/sdcard/dump.hprof").
481      * @throws UnsupportedOperationException if the VM was built without
482      *         HPROF support.
483      * @throws IOException if an error occurs while opening or writing files.
484      *
485      * @hide
486      */
487     @SystemApi(client = MODULE_LIBRARIES)
dumpHprofData(String filename)488     public static void dumpHprofData(String filename) throws IOException {
489         if (filename == null) {
490             throw new NullPointerException("filename == null");
491         }
492         dumpHprofData(filename, null);
493     }
494 
495     /**
496      * Collects "hprof" heap data and sends it to DDMS.  This may cause a GC.
497      *
498      * @throws UnsupportedOperationException if the VM was built without
499      *         HPROF support.
500      *
501      * @hide
502      */
503     @SystemApi(client = MODULE_LIBRARIES)
dumpHprofDataDdms()504     public static native void dumpHprofDataDdms();
505 
506     /**
507      * Dumps "hprof" heap data to a file, by name or descriptor.
508      *
509      * @param fileName Name of output file.  If fd is non-null, the
510      *        file name is only used in log messages (and may be null).
511      * @param fd Descriptor of open file that will receive the output.
512      *        If this is null, the fileName is used instead.
513      * @throws {@link IOException} if an error occurs while opening or writing files.
514      *
515      * @hide
516      */
517     @SystemApi(client = MODULE_LIBRARIES)
dumpHprofData(String fileName, FileDescriptor fd)518     public static void dumpHprofData(String fileName, FileDescriptor fd)
519             throws IOException {
520        dumpHprofData(fileName, fd != null ? fd.getInt$() : -1);
521     }
522 
dumpHprofData(String fileName, int fd)523     private static native void dumpHprofData(String fileName, int fd)
524             throws IOException;
525 
526     /**
527      * Dumps the contents of the VM reference tables (e.g. JNI locals and
528      * globals) to the log file.
529      *
530      * @hide
531      */
532     @UnsupportedAppUsage
533     @SystemApi(client = MODULE_LIBRARIES)
dumpReferenceTables()534     public static native void dumpReferenceTables();
535 
536     /**
537      * Counts the instances of a class.
538      * It is the caller's responsibility to do GC if they don't want unreachable
539      * objects to get counted.
540      *
541      * @param klass the class to be counted.
542      * @param assignable if true, any instance whose class is assignable to
543      *                   {@code klass}, as defined by {@link Class#isAssignableFrom},
544      *                   is counted. If false, only instances whose class is
545      *                   equal to {@code klass} are counted.
546      * @return the number of matching instances.
547      *
548      * @hide
549      */
550     @SystemApi(client = MODULE_LIBRARIES)
countInstancesOfClass(Class klass, boolean assignable)551     public static native long countInstancesOfClass(Class klass, boolean assignable);
552 
553     /**
554      * Counts the instances of classes.
555      * It is the caller's responsibility to do GC if they don't want unreachable
556      * objects to get counted.
557      *
558      * @param classes the classes to be counted.
559      * @param assignable if true, any instance whose class is assignable to
560      *                   {@code classes[i]}, as defined by {@link Class#isAssignableFrom},
561      *                   is counted. If false, only instances whose class is
562      *                   equal to {@code classes[i]} are counted.
563      * @return an array containing the number of matching instances. The value
564      *         for index {@code i} is the number of instances of
565      *         the class {@code classes[i]}
566      *
567      * @hide
568      */
569     @SystemApi(client = MODULE_LIBRARIES)
countInstancesOfClasses(Class[] classes, boolean assignable)570     public static native long[] countInstancesOfClasses(Class[] classes, boolean assignable);
571 
572     /* Map from the names of the runtime stats supported by getRuntimeStat() to their IDs */
573     private static final HashMap<String, Integer> runtimeStatsMap = new HashMap<>();
574 
575     static {
576         runtimeStatsMap.put("art.gc.gc-count", 0);
577         runtimeStatsMap.put("art.gc.gc-time", 1);
578         runtimeStatsMap.put("art.gc.bytes-allocated", 2);
579         runtimeStatsMap.put("art.gc.bytes-freed", 3);
580         runtimeStatsMap.put("art.gc.blocking-gc-count", 4);
581         runtimeStatsMap.put("art.gc.blocking-gc-time", 5);
582         runtimeStatsMap.put("art.gc.gc-count-rate-histogram", 6);
583         runtimeStatsMap.put("art.gc.blocking-gc-count-rate-histogram", 7);
584         runtimeStatsMap.put("art.gc.objects-allocated", 8);
585         runtimeStatsMap.put("art.gc.total-time-waiting-for-gc", 9);
586         runtimeStatsMap.put("art.gc.pre-oome-gc-count", 10);
587     }
588 
589     /**
590      * Returns the value of a particular runtime statistic or {@code null} if no
591      * such runtime statistic exists.
592      *
593      * @param statName the name of the runtime statistic to look up.
594      *
595      * @return the value of the runtime statistic.
596      *
597      * @hide
598      */
599     @SystemApi(client = MODULE_LIBRARIES)
getRuntimeStat(String statName)600     public static String getRuntimeStat(String statName) {
601         if (statName == null) {
602             throw new NullPointerException("statName == null");
603         }
604         Integer statId = runtimeStatsMap.get(statName);
605         if (statId != null) {
606             return getRuntimeStatInternal(statId);
607         }
608         return null;
609     }
610 
611     /**
612      * Returns a map of the names/values of the runtime statistics
613      * that {@link #getRuntimeStat()} supports.
614      *
615      * @return a map of the names/values of the supported runtime statistics.
616      *
617      * @hide
618      */
619     @SystemApi(client = MODULE_LIBRARIES)
getRuntimeStats()620     public static Map<String, String> getRuntimeStats() {
621         HashMap<String, String> map = new HashMap<>();
622         String[] values = getRuntimeStatsInternal();
623         for (String name : runtimeStatsMap.keySet()) {
624             int id = runtimeStatsMap.get(name);
625             String value = values[id];
626             map.put(name, value);
627         }
628         return map;
629     }
630 
getRuntimeStatInternal(int statId)631     private static native String getRuntimeStatInternal(int statId);
getRuntimeStatsInternal()632     private static native String[] getRuntimeStatsInternal();
633 
634     /**
635      * Attaches an agent to the VM.
636      *
637      * @param agent       The path to the agent .so file plus optional agent arguments.
638      * @param classLoader The classloader to use as a loading context.
639      *
640      * @throws IOException if an error occurs while opening {@code agent} file.
641      *
642      * @hide
643      */
644     @SystemApi(client = MODULE_LIBRARIES)
attachAgent(String agent, ClassLoader classLoader)645     public static void attachAgent(String agent, ClassLoader classLoader) throws IOException {
646         nativeAttachAgent(agent, classLoader);
647     }
648 
nativeAttachAgent(String agent, ClassLoader classLoader)649     private static native void nativeAttachAgent(String agent, ClassLoader classLoader)
650             throws IOException;
651 
652     /**
653      * Exempts a class from any future non-SDK API access checks.
654      * Methods declared in the class will be allowed to perform
655      * reflection/JNI against the framework completely unrestricted.
656      * Note that this does not affect uses of non-SDK APIs that the class links against.
657      * Note that this does not affect methods declared outside this class, e.g.
658      * inherited from a superclass or an implemented interface.
659      *
660      * @param klass The class whose methods should be exempted.
661      *
662      * @hide
663      */
664     @UnsupportedAppUsage
allowHiddenApiReflectionFrom(Class<?> klass)665     public static native void allowHiddenApiReflectionFrom(Class<?> klass);
666 
667     /**
668      * Sets the number of frames recorded for allocation tracking.
669      *
670      * @param stackDepth The number of frames captured for each stack trace.
671      *
672      * @hide
673      */
674     @SystemApi(client = MODULE_LIBRARIES)
setAllocTrackerStackDepth(int stackDepth)675     public static native void setAllocTrackerStackDepth(int stackDepth);
676 }
677