Trace.java revision f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2
1481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown/* 2481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * Copyright (C) 2012 The Android Open Source Project 3481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 4481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * Licensed under the Apache License, Version 2.0 (the "License"); 5481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * you may not use this file except in compliance with the License. 6481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * You may obtain a copy of the License at 7481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 8481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * http://www.apache.org/licenses/LICENSE-2.0 9481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 10481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * Unless required by applicable law or agreed to in writing, software 11481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * distributed under the License is distributed on an "AS IS" BASIS, 12481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * See the License for the specific language governing permissions and 14481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * limitations under the License. 15481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown */ 16481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown 17481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brownpackage android.os; 18481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown 19d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFaddenimport android.util.Log; 20d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden 21481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown/** 22f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * Writes trace events to the system trace buffer. These trace events can be 23f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * collected and visualized using the Systrace tool. 24481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 25481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * This tracing mechanism is independent of the method tracing mechanism 26481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * offered by {@link Debug#startMethodTracing}. In particular, it enables 27f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * tracing of events that occur across multiple processes. 28481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 29481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @hide 30481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown */ 31481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brownpublic final class Trace { 32f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /* 33f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * Writes trace events to the kernel trace buffer. These trace events can be 34f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * collected using the "atrace" program for offline analysis. 35f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis */ 36f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis 37d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden private static final String TAG = "Trace"; 38d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden 398a6787b1c7f5192388436373465c35655cc8ef7cAlex Ray // These tags must be kept in sync with system/core/include/cutils/trace.h. 40f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 41481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static final long TRACE_TAG_NEVER = 0; 42f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 43481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static final long TRACE_TAG_ALWAYS = 1L << 0; 44f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 45481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static final long TRACE_TAG_GRAPHICS = 1L << 1; 46f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 47481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static final long TRACE_TAG_INPUT = 1L << 2; 48f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 49481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static final long TRACE_TAG_VIEW = 1L << 3; 50f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 51192a65e9f6ebdc452520e19f95c68c270b3f96daChris Craik public static final long TRACE_TAG_WEBVIEW = 1L << 4; 52f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 531ded0b1f6af65c2f95f8327f7f3df4cee1bf2346Dianne Hackborn public static final long TRACE_TAG_WINDOW_MANAGER = 1L << 5; 54f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 551ded0b1f6af65c2f95f8327f7f3df4cee1bf2346Dianne Hackborn public static final long TRACE_TAG_ACTIVITY_MANAGER = 1L << 6; 56f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 5709b45a3ad96379b4181d32f8391f63e9c57dc316Andy Stadler public static final long TRACE_TAG_SYNC_MANAGER = 1L << 7; 58f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 59ed853fc4e0ba8ce0692d65064e12cf129b5d1f3eGlenn Kasten public static final long TRACE_TAG_AUDIO = 1L << 8; 60f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 6124dae6c611455ec38675554033e4d18810d77d6cJamie Gennis public static final long TRACE_TAG_VIDEO = 1L << 9; 62f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 639c0d9cf25ffdf4f6545e489b22ba621bf0b7ba29Eino-Ville Talvala public static final long TRACE_TAG_CAMERA = 1L << 10; 64f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 658a6787b1c7f5192388436373465c35655cc8ef7cAlex Ray public static final long TRACE_TAG_HAL = 1L << 11; 66f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** @hide */ 67f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis public static final long TRACE_TAG_APP = 1L << 12; 6883e6eb11d7ec24e7c363beccab0806989ad89ec5Dianne Hackborn 69f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis private static final long TRACE_TAG_NOT_READY = 1L << 63; 70f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis private static final int MAX_SECTION_NAME_LEN = 127; 7183e6eb11d7ec24e7c363beccab0806989ad89ec5Dianne Hackborn 72d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // Must be volatile to avoid word tearing. 73325be8a1ea03308de2ac35d613a2fe751bf16d94Andy McFadden private static volatile long sEnabledTags = TRACE_TAG_NOT_READY; 74481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown 75481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown private static native long nativeGetEnabledTags(); 76481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown private static native void nativeTraceCounter(long tag, String name, int value); 77481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown private static native void nativeTraceBegin(long tag, String name); 78481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown private static native void nativeTraceEnd(long tag); 79f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis private static native void nativeSetAppTracingAllowed(boolean allowed); 80481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown 81a53de0629f3b94472c0f160f5bbe1090b020feabDianne Hackborn static { 82d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // We configure two separate change callbacks, one in Trace.cpp and one here. The 83d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // native callback reads the tags from the system property, and this callback 84d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // reads the value that the native code retrieved. It's essential that the native 85d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // callback executes first. 86d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // 87d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // The system provides ordering through a priority level. Callbacks made through 88d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // SystemProperties.addChangeCallback currently have a negative priority, while 89d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // our native code is using a priority of zero. 90a53de0629f3b94472c0f160f5bbe1090b020feabDianne Hackborn SystemProperties.addChangeCallback(new Runnable() { 91a53de0629f3b94472c0f160f5bbe1090b020feabDianne Hackborn @Override public void run() { 92d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden cacheEnabledTags(); 93a53de0629f3b94472c0f160f5bbe1090b020feabDianne Hackborn } 94a53de0629f3b94472c0f160f5bbe1090b020feabDianne Hackborn }); 95a53de0629f3b94472c0f160f5bbe1090b020feabDianne Hackborn } 96a53de0629f3b94472c0f160f5bbe1090b020feabDianne Hackborn 97481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown private Trace() { 98481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown } 99481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown 100481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown /** 101d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * Caches a copy of the enabled-tag bits. The "master" copy is held by the native code, 102d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * and comes from the PROPERTY_TRACE_TAG_ENABLEFLAGS property. 103d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * <p> 104d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * If the native code hasn't yet read the property, we will cause it to do one-time 105d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * initialization. We don't want to do this during class init, because this class is 106d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * preloaded, so all apps would be stuck with whatever the zygote saw. (The zygote 107d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * doesn't see the system-property update broadcasts.) 108d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * <p> 109d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * We want to defer initialization until the first use by an app, post-zygote. 110d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * <p> 111d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * We're okay if multiple threads call here simultaneously -- the native state is 112d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden * synchronized, and sEnabledTags is volatile (prevents word tearing). 113d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden */ 114d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden private static long cacheEnabledTags() { 115d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden long tags = nativeGetEnabledTags(); 116325be8a1ea03308de2ac35d613a2fe751bf16d94Andy McFadden if (tags == TRACE_TAG_NOT_READY) { 117d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden Log.w(TAG, "Unexpected value from nativeGetEnabledTags: " + tags); 118d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden // keep going 119d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden } 120d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden sEnabledTags = tags; 121d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden return tags; 122d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden } 123d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden 124d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden /** 125481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * Returns true if a trace tag is enabled. 126481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 127481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @param traceTag The trace tag to check. 128481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @return True if the trace tag is valid. 129f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 130f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * @hide 131481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown */ 132481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static boolean isTagEnabled(long traceTag) { 133d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden long tags = sEnabledTags; 134325be8a1ea03308de2ac35d613a2fe751bf16d94Andy McFadden if (tags == TRACE_TAG_NOT_READY) { 135d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden tags = cacheEnabledTags(); 136d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden } 137d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden return (tags & traceTag) != 0; 138481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown } 139481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown 140481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown /** 141481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * Writes trace message to indicate the value of a given counter. 142481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 143481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @param traceTag The trace tag. 144481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @param counterName The counter name to appear in the trace. 145481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @param counterValue The counter value. 146f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 147f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * @hide 148481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown */ 149481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static void traceCounter(long traceTag, String counterName, int counterValue) { 150d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden if (isTagEnabled(traceTag)) { 151481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown nativeTraceCounter(traceTag, counterName, counterValue); 152481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown } 153481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown } 154481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown 155481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown /** 156f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * Set whether application tracing is allowed for this process. This is intended to be set 157f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * once at application start-up time based on whether the application is debuggable. 158f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 159f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * @hide 160f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis */ 161f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis public static void setAppTracingAllowed(boolean allowed) { 162f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis nativeSetAppTracingAllowed(allowed); 163f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis 164f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis // Setting whether app tracing is allowed may change the tags, so we update the cached 165f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis // tags here. 166f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis cacheEnabledTags(); 167f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis } 168f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis 169f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** 170f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * Writes a trace message to indicate that a given section of code has 171f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * begun. Must be followed by a call to {@link #traceEnd} using the same 172f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * tag. 173481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 174481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @param traceTag The trace tag. 175481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @param methodName The method name to appear in the trace. 176f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 177f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * @hide 178481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown */ 179481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static void traceBegin(long traceTag, String methodName) { 180d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden if (isTagEnabled(traceTag)) { 181481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown nativeTraceBegin(traceTag, methodName); 182481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown } 183481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown } 184481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown 185481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown /** 186481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * Writes a trace message to indicate that the current method has ended. 187481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * Must be called exactly once for each call to {@link #traceBegin} using the same tag. 188481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * 189481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown * @param traceTag The trace tag. 190f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 191f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * @hide 192481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown */ 193481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown public static void traceEnd(long traceTag) { 194d11ca4dd2ca90e1412b24f4526a56f7b963054a8Andy McFadden if (isTagEnabled(traceTag)) { 195481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown nativeTraceEnd(traceTag); 196481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown } 197481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown } 198f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis 199f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** 200f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * Writes a trace message to indicate that a given section of code has begun. This call must 201f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * be followed by a corresponding call to {@link #traceEnd()} on the same thread. 202f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 203f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * <p class="note"> At this time the vertical bar character '|', newline character '\n', and 204f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * null character '\0' are used internally by the tracing mechanism. If sectionName contains 205f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * these characters they will be replaced with a space character in the trace. 206f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 207f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * @param sectionName The name of the code section to appear in the trace. This may be at 208f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * most 127 Unicode code units long. 209f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 210f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * @hide 211f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis */ 212f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis public static void traceBegin(String sectionName) { 213f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis if (isTagEnabled(TRACE_TAG_APP)) { 214f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis if (sectionName.length() > MAX_SECTION_NAME_LEN) { 215f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis throw new IllegalArgumentException("sectionName is too long"); 216f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis } 217f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis nativeTraceBegin(TRACE_TAG_APP, sectionName); 218f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis } 219f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis } 220f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis 221f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis /** 222f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * Writes a trace message to indicate that a given section of code has ended. This call must 223f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * be preceeded by a corresponding call to {@link #traceBegin(String)}. Calling this method 224f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * will mark the end of the most recently begun section of code, so care must be taken to 225f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * ensure that traceBegin / traceEnd pairs are properly nested and called from the same thread. 226f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * 227f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis * @hide 228f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis */ 229f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis public static void traceEnd() { 230f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis if (isTagEnabled(TRACE_TAG_APP)) { 231f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis nativeTraceEnd(TRACE_TAG_APP); 232f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis } 233f9c7d6bc15b68393c1f0aa85c3c023c31244c3f2Jamie Gennis } 234481c1570dc5cdf58265b53f657801709dd05d1dfJeff Brown} 235