f64b1ca000
This change adds some utility functionality for doing userland tracing into the kernel trace log. Change-Id: Id0a8cee9ea515b1d8765afd1cecf472a88b4b9e8
48 lines
1.4 KiB
C++
48 lines
1.4 KiB
C++
/*
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* Copyright (C) 2012 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <cutils/properties.h>
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#include <utils/Log.h>
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#include <utils/Trace.h>
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namespace android {
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volatile int32_t Tracer::sIsReady = 0;
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int Tracer::sTraceFD = -1;
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uint64_t Tracer::sEnabledTags = 0;
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Mutex Tracer::sMutex;
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void Tracer::init() {
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Mutex::Autolock lock(sMutex);
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if (!sIsReady) {
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const char* const traceFileName =
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"/sys/kernel/debug/tracing/trace_marker";
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sTraceFD = open(traceFileName, O_WRONLY);
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if (sTraceFD == -1) {
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ALOGE("error opening trace file: %s (%d)", strerror(errno), errno);
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} else {
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char value[PROPERTY_VALUE_MAX];
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property_get("atrace.tags.enableflags", value, "0");
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sEnabledTags = strtoll(value, NULL, 0) | ATRACE_TAG_ALWAYS;
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}
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android_atomic_release_store(1, &sIsReady);
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}
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}
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} // namespace andoid
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