// Copyright 2019 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "base/debug/task_trace.h" #include "base/ranges/algorithm.h" #include "build/build_config.h" #if BUILDFLAG(IS_ANDROID) #include #endif // BUILDFLAG(IS_ANDROID) #include #include #if BUILDFLAG(IS_ANDROID) #include "base/no_destructor.h" #endif #include "base/pending_task.h" #include "base/task/common/task_annotator.h" namespace base { namespace debug { namespace { #if BUILDFLAG(IS_ANDROID) // Android sends stdout and stderr to /dev/null; logging should be done through // the __android_log_write() function. Here we create an override of // std::stringbuf that writes to the Android log. class AndroidErrBuffer : public std::stringbuf { protected: int sync() override { __android_log_write(ANDROID_LOG_ERROR, "chromium", str().c_str()); return 0; } }; std::ostream& DefaultOutputStream() { static NoDestructor buf; static NoDestructor out(buf.get()); return *out; } #else // Use stderr by default. std::ostream& DefaultOutputStream() { return std::cerr; } #endif // BUILDFLAG(IS_ANDROID) } // namespace TaskTrace::TaskTrace() { const PendingTask* current_task = TaskAnnotator::CurrentTaskForThread(); if (!current_task) return; std::array task_trace; task_trace[0] = current_task->posted_from.program_counter(); ranges::copy(current_task->task_backtrace, task_trace.begin() + 1); size_t length = 0; while (length < task_trace.size() && task_trace[length]) ++length; if (length == 0) return; stack_trace_.emplace(task_trace.data(), length); trace_overflow_ = current_task->task_backtrace_overflow; } bool TaskTrace::empty() const { return !stack_trace_.has_value(); } void TaskTrace::Print() const { OutputToStream(&DefaultOutputStream()); } void TaskTrace::OutputToStream(std::ostream* os) const { *os << "Task trace:" << std::endl; if (!stack_trace_) { *os << "No active task."; return; } *os << *stack_trace_; if (trace_overflow_) { *os << "Task trace buffer limit hit, update " "PendingTask::kTaskBacktraceLength to increase." << std::endl; } } std::string TaskTrace::ToString() const { std::stringstream stream; OutputToStream(&stream); return stream.str(); } base::span TaskTrace::AddressesForTesting() const { if (empty()) return {}; size_t count = 0; const void* const* addresses = stack_trace_->Addresses(&count); return {addresses, count}; } std::ostream& operator<<(std::ostream& os, const TaskTrace& task_trace) { task_trace.OutputToStream(&os); return os; } } // namespace debug } // namespace base