| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| #ifndef IMPALA_COMMON_THREAD_DEBUG_INFO_H |
| #define IMPALA_COMMON_THREAD_DEBUG_INFO_H |
| |
| #include <string> |
| #include <sys/syscall.h> |
| #include <unistd.h> |
| |
| #include "glog/logging.h" |
| #include "gutil/macros.h" |
| #include "gutil/strings/util.h" |
| #include "util/debug-util.h" |
| |
| namespace impala { |
| |
| class ScopedThreadContext; |
| |
| /// Stores information about the current thread that can be useful in a debug session. |
| /// An object of this class needs to be allocated on the stack in order to include |
| /// it in minidumps. While this object is alive, it is available through the global |
| /// function 'GetThreadDebugInfo()'. |
| /// During a debug session, locate this object in the core file or in the minidump, |
| /// then inspect its members. |
| class ThreadDebugInfo { |
| public: |
| /// Only one ThreadDebugInfo object can be alive per thread at a time. |
| /// This object is not copyable, nor movable |
| ThreadDebugInfo() { |
| system_thread_id_ = syscall(SYS_gettid); |
| |
| // This call makes the global (thread local) pointer point to this object. |
| InitializeThreadDebugInfo(this); |
| } |
| |
| ~ThreadDebugInfo() { |
| // Resets the global (thread local) pointer to null. |
| CloseThreadDebugInfo(); |
| } |
| |
| const TUniqueId& GetQueryId() const { return query_id_; } |
| const TUniqueId& GetInstanceId() const { return instance_id_; } |
| const char* GetThreadName() const { return thread_name_; } |
| int64_t GetSystemThreadId() const { return system_thread_id_; } |
| int64_t GetParentSystemThreadId() const { return parent_.system_thread_id_; } |
| const char* GetParentThreadName() const { return parent_.thread_name_; } |
| |
| /// Saves 'query_id' to member 'query_id_' |
| void SetQueryId(const TUniqueId& query_id) { |
| query_id_ = query_id; |
| } |
| /// Saves 'instance_id' to member 'instance_id_' |
| void SetInstanceId(const TUniqueId& instance_id) { |
| instance_id_ = instance_id; |
| } |
| |
| /// Saves param 'thread_name' to member 'thread_name_'. |
| /// If the length of param 'thread_name' is larger than THREAD_NAME_SIZE, |
| /// we store the front of 'thread_name' + '...' + the last few bytes |
| /// of thread name, e.g.: "Long Threadname with more te...001afec4)" |
| void SetThreadName(const std::string& thread_name) { |
| const int64_t length = thread_name.length(); |
| |
| if (length < THREAD_NAME_SIZE) { |
| thread_name.copy(thread_name_, length); |
| } else { |
| const int64_t tail_length = THREAD_NAME_TAIL_LENGTH; |
| // 4 is the length of "..." and '\0' |
| const int64_t front_length = THREAD_NAME_SIZE - tail_length - 4; |
| // copy 'front_length' sized front of 'thread_name' to 'thread_name_' |
| thread_name.copy(thread_name_, front_length); |
| // append "..." |
| for (int i = 0; i < 3; ++i) thread_name_[front_length + i] = '.'; |
| // append 'tail_length' sized tail of 'thread_name' to 'thread_name_' |
| thread_name.copy(thread_name_ + front_length + 3, tail_length, |
| length - tail_length); |
| } |
| } |
| |
| void SetParentInfo(const ThreadDebugInfo* parent) { |
| if (parent == nullptr) return; |
| parent_.system_thread_id_ = parent->system_thread_id_; |
| strings::strlcpy(parent_.thread_name_, parent->thread_name_, THREAD_NAME_SIZE); |
| query_id_ = parent->query_id_; |
| instance_id_ = parent->instance_id_; |
| } |
| |
| private: |
| /// Initializes a thread local pointer with thread_debug_info. |
| static void InitializeThreadDebugInfo(ThreadDebugInfo* thread_debug_info); |
| /// Resets the thread local pointer to nullptr. |
| static void CloseThreadDebugInfo(); |
| |
| static constexpr int64_t THREAD_NAME_SIZE = 256; |
| static constexpr int64_t THREAD_NAME_TAIL_LENGTH = 8; |
| static const TUniqueId ZERO_THREAD_ID; |
| |
| /// This struct contains information we want to store about the parent. |
| struct ParentInfo { |
| int64_t system_thread_id_ = 0; |
| char thread_name_[THREAD_NAME_SIZE] = {}; |
| }; |
| |
| ParentInfo parent_; |
| int64_t system_thread_id_ = 0; |
| char thread_name_[THREAD_NAME_SIZE] = {}; |
| // Will be "0" (the default TUniqueId with hi=lo=0) when thread isn't |
| // part of query or instance execution. |
| TUniqueId query_id_; |
| TUniqueId instance_id_; |
| |
| friend class ScopedThreadContext; |
| friend class ThreadDebugInfo_Scoping_Test; |
| |
| DISALLOW_COPY_AND_ASSIGN(ThreadDebugInfo); |
| }; |
| |
| /// An RAII-style wrapper to clear thread debug info query and instance |
| /// context at destruction. |
| class ScopedThreadContext { |
| public: |
| ~ScopedThreadContext() { |
| thread_debug_info_->SetQueryId(ThreadDebugInfo::ZERO_THREAD_ID); |
| thread_debug_info_->SetInstanceId(ThreadDebugInfo::ZERO_THREAD_ID); |
| } |
| ScopedThreadContext(ThreadDebugInfo* thread_debug_info, const TUniqueId& query_id, |
| const TUniqueId& instance_id = ThreadDebugInfo::ZERO_THREAD_ID) { |
| thread_debug_info_ = thread_debug_info; |
| thread_debug_info->SetQueryId(query_id); |
| thread_debug_info->SetInstanceId(instance_id); |
| } |
| private: |
| ThreadDebugInfo* thread_debug_info_; |
| DISALLOW_COPY_AND_ASSIGN(ScopedThreadContext); |
| }; |
| |
| /// Returns a pointer to the ThreadDebugInfo object for this thread. |
| /// Returns nullptr if there is no ThreadDebugInfo object for the current thread. |
| ThreadDebugInfo* GetThreadDebugInfo(); |
| |
| } |
| |
| #endif |
| |