Home | History | Annotate | Download | only in trace_processor 
      1 /*
      2  * Copyright (C) 2019 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 #ifndef SRC_TRACE_PROCESSOR_FTRACE_UTILS_H_
     18 #define SRC_TRACE_PROCESSOR_FTRACE_UTILS_H_
     19 
     20 #include <stddef.h>
     21 #include <array>
     22 
     23 #include "perfetto/base/logging.h"
     24 #include "perfetto/base/string_view.h"
     25 #include "perfetto/base/string_writer.h"
     26 
     27 namespace perfetto {
     28 namespace trace_processor {
     29 namespace ftrace_utils {
     30 
     31 // A strongly typed representation of the TaskState enum given in sched_switch
     32 // events.
     33 class TaskState {
     34  public:
     35   using TaskStateStr = std::array<char, 4>;
     36 
     37   // The ordering and values of these fields comes from the kernel in the file
     38   // https://android.googlesource.com/kernel/msm.git/+/android-msm-wahoo-4.4-pie-qpr1/include/linux/sched.h#212
     39   enum Atom : uint16_t {
     40     kRunnable = 0,
     41     kInterruptibleSleep = 1,
     42     kUninterruptibleSleep = 2,
     43     kStopped = 4,
     44     kTraced = 8,
     45     kExitDead = 16,
     46     kExitZombie = 32,
     47     kTaskDead = 64,
     48     kWakeKill = 128,
     49     kWaking = 256,
     50     kParked = 512,
     51     kNoLoad = 1024,
     52 
     53     // kMaxState is used by sched switch to show a task was kernel preempted.
     54     // The difficult thing is that in newer kernels a task_new state is added
     55     // and kMaxState increases to 4096. Without the kernel version and the
     56     // mapping of this to the correct version of this enum we cannot be
     57     // accurate. Since task_new is rare we ignore it for now.
     58     kTaskNewOrMaxState = 2048,
     59     kMaxState = 4096,
     60     kValid = 0x8000,
     61   };
     62 
     63   TaskState() = default;
     64   explicit TaskState(uint16_t raw_state) : state_(raw_state | kValid) {}
     65   explicit TaskState(const char* state_str);
     66 
     67   // Returns if this TaskState has a valid representation.
     68   bool is_valid() const { return state_ & kValid; }
     69 
     70   // Returns the string representation of this (valid) TaskState. This array
     71   // is null terminated.
     72   // Note: This function CHECKs that |is_valid()| is true.
     73   TaskStateStr ToString() const;
     74 
     75   // Returns the raw state this class was created from.
     76   uint16_t raw_state() const {
     77     PERFETTO_DCHECK(is_valid());
     78     return state_ & ~kValid;
     79   }
     80 
     81   // Returns if this TaskState is runnable.
     82   bool is_runnable() const {
     83     return ((state_ & (kMaxState - 1)) == 0) ||
     84            ((state_ & (kTaskNewOrMaxState - 1)) == 0);
     85   }
     86 
     87   // Returns whether kernel preemption caused the exit state.
     88   bool is_kernel_preempt() const {
     89     return state_ & kTaskNewOrMaxState || state_ & kMaxState;
     90   }
     91 
     92  private:
     93   uint16_t state_ = 0;
     94 };
     95 
     96 void FormatSystracePrefix(int64_t timestamp,
     97                           uint32_t cpu,
     98                           uint32_t pid,
     99                           uint32_t tgid,
    100                           base::StringView name,
    101                           base::StringWriter* writer);
    102 
    103 }  // namespace ftrace_utils
    104 }  // namespace trace_processor
    105 }  // namespace perfetto
    106 
    107 #endif  // SRC_TRACE_PROCESSOR_FTRACE_UTILS_H_
    108