simpleperf/record.h

/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed 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 SIMPLE_PERF_RECORD_H_
#define SIMPLE_PERF_RECORD_H_

#include <stdio.h>
#include <sys/types.h>

#include <memory>
#include <queue>
#include <string>
#include <vector>

#include <android-base/logging.h>

#include "build_id.h"
#include "perf_event.h"

struct KernelMmap;
struct ModuleMmap;
struct ThreadComm;
struct ThreadMmap;

enum user_record_type {
  PERF_RECORD_USER_DEFINED_TYPE_START = 64,
  PERF_RECORD_ATTR = 64,
  PERF_RECORD_EVENT_TYPE,
  PERF_RECORD_TRACING_DATA,
  PERF_RECORD_BUILD_ID,
  PERF_RECORD_FINISHED_ROUND,

  SIMPLE_PERF_RECORD_TYPE_START = 32768,
  SIMPLE_PERF_RECORD_KERNEL_SYMBOL,
  SIMPLE_PERF_RECORD_DSO,
  SIMPLE_PERF_RECORD_SYMBOL,
  SIMPLE_PERF_RECORD_SPLIT,
  SIMPLE_PERF_RECORD_SPLIT_END,
};

// perf_event_header uses u16 to store record size. However, that is not
// enough for storing records like KERNEL_SYMBOL or TRACING_DATA. So define
// a simpleperf_record_header struct to store record header for simpleperf
// defined records (type > SIMPLE_PERF_RECORD_TYPE_START).
struct simpleperf_record_header {
  uint32_t type;
  uint16_t size1;
  uint16_t size0;
};

static_assert(
    sizeof(simpleperf_record_header) == sizeof(perf_event_header),
    "simpleperf_record_header should have the same size as perf_event_header");

struct PerfSampleIpType {
  uint64_t ip;
};

struct PerfSampleTidType {
  uint32_t pid, tid;
};

struct PerfSampleTimeType {
  uint64_t time;
};

struct PerfSampleAddrType {
  uint64_t addr;
};

struct PerfSampleIdType {
  uint64_t id;
};

struct PerfSampleStreamIdType {
  uint64_t stream_id;
};

struct PerfSampleCpuType {
  uint32_t cpu, res;
};

struct PerfSamplePeriodType {
  uint64_t period;
};

struct PerfSampleCallChainType {
  uint64_t ip_nr;
  const uint64_t* ips;
};

struct PerfSampleRawType {
  uint32_t size;
  const char* data;
};

struct BranchStackItemType {
  uint64_t from;
  uint64_t to;
  uint64_t flags;
};

struct PerfSampleBranchStackType {
  uint64_t stack_nr;
  const BranchStackItemType* stack;
};

struct PerfSampleRegsUserType {
  uint64_t abi;
  uint64_t reg_mask;
  uint64_t reg_nr;
  const uint64_t* regs;
};

struct PerfSampleStackUserType {
  uint64_t size;
  const char* data;
  uint64_t dyn_size;
};

struct RecordHeader {
 public:
  uint32_t type;
  uint16_t misc;
  uint32_t size;

  RecordHeader() : type(0), misc(0), size(0) {}

  explicit RecordHeader(const char* p) {
    auto pheader = reinterpret_cast<const perf_event_header*>(p);
    if (pheader->type < SIMPLE_PERF_RECORD_TYPE_START) {
      type = pheader->type;
      misc = pheader->misc;
      size = pheader->size;
    } else {
      auto sheader = reinterpret_cast<const simpleperf_record_header*>(p);
      type = sheader->type;
      misc = 0;
      size = (sheader->size1 << 16) | sheader->size0;
    }
  }

  void MoveToBinaryFormat(char*& p) const {
    if (type < SIMPLE_PERF_RECORD_TYPE_START) {
      auto pheader = reinterpret_cast<perf_event_header*>(p);
      pheader->type = type;
      pheader->misc = misc;
      CHECK_LT(size, 1u << 16);
      pheader->size = static_cast<uint16_t>(size);
    } else {
      auto sheader = reinterpret_cast<simpleperf_record_header*>(p);
      sheader->type = type;
      CHECK_EQ(misc, 0u);
      sheader->size1 = size >> 16;
      sheader->size0 = size & 0xffff;
    }
    p += sizeof(perf_event_header);
  }
};

// SampleId is optional at the end of a record in binary format. Its content is
// determined by sample_id_all and sample_type in perf_event_attr. To avoid the
// complexity of referring to perf_event_attr each time, we copy sample_id_all
// and sample_type inside the SampleId structure.
struct SampleId {
  bool sample_id_all;
  uint64_t sample_type;

  PerfSampleTidType tid_data;    // Valid if sample_id_all && PERF_SAMPLE_TID.
  PerfSampleTimeType time_data;  // Valid if sample_id_all && PERF_SAMPLE_TIME.
  PerfSampleIdType id_data;      // Valid if sample_id_all && PERF_SAMPLE_ID.
  PerfSampleStreamIdType
      stream_id_data;  // Valid if sample_id_all && PERF_SAMPLE_STREAM_ID.
  PerfSampleCpuType cpu_data;  // Valid if sample_id_all && PERF_SAMPLE_CPU.

  SampleId();

  // Create the content of sample_id. It depends on the attr we use.
  size_t CreateContent(const perf_event_attr& attr, uint64_t event_id);

  // Parse sample_id from binary format in the buffer pointed by p.
  void ReadFromBinaryFormat(const perf_event_attr& attr, const char* p,
                            const char* end);

  // Write the binary format of sample_id to the buffer pointed by p.
  void WriteToBinaryFormat(char*& p) const;
  void Dump(size_t indent) const;
  size_t Size() const;
};

// Usually one record contains the following three parts in order in binary
// format:
//   RecordHeader (at the head of a record, containing type and size info)
//   data depends on the record type
//   SampleId (optional part at the end of a record)
// We hold the common parts (RecordHeader and SampleId) in the base class
// Record, and hold the type specific data part in classes derived from Record.
struct Record {
  RecordHeader header;
  SampleId sample_id;

  Record() : binary_(nullptr), own_binary_(false) {}
  explicit Record(const char* p) : header(p), binary_(p), own_binary_(false) {}
  Record(Record&& other);

  virtual ~Record() {
    if (own_binary_) {
      delete[] binary_;
    }
  }

  void OwnBinary() { own_binary_ = true; }

  uint32_t type() const { return header.type; }

  uint16_t misc() const { return header.misc; }

  uint32_t size() const { return header.size; }

  static uint32_t header_size() { return sizeof(perf_event_header); }

  bool InKernel() const {
    return (header.misc & PERF_RECORD_MISC_CPUMODE_MASK) ==
           PERF_RECORD_MISC_KERNEL;
  }

  void SetTypeAndMisc(uint32_t type, uint16_t misc) {
    header.type = type;
    header.misc = misc;
  }

  void SetSize(uint32_t size) { header.size = size; }

  void Dump(size_t indent = 0) const;

  const char* Binary() const { return binary_; }

  virtual uint64_t Timestamp() const;
  virtual uint32_t Cpu() const;

 protected:
  void UpdateBinary(const char* new_binary);
  virtual void DumpData(size_t) const = 0;

  const char* binary_;
  bool own_binary_;

  DISALLOW_COPY_AND_ASSIGN(Record);
};

struct MmapRecord : public Record {
  struct MmapRecordDataType {
    uint32_t pid, tid;
    uint64_t addr;
    uint64_t len;
    uint64_t pgoff;
  };
  const MmapRecordDataType* data;
  const char* filename;

  MmapRecord(const perf_event_attr& attr, const char* p);

  MmapRecord(const perf_event_attr& attr, bool in_kernel, uint32_t pid,
             uint32_t tid, uint64_t addr, uint64_t len, uint64_t pgoff,
             const std::string& filename, uint64_t event_id, uint64_t time = 0);

  void SetDataAndFilename(const MmapRecordDataType& data,
                          const std::string& filename);

 protected:
  void DumpData(size_t indent) const override;
};

struct Mmap2Record : public Record {
  struct Mmap2RecordDataType {
    uint32_t pid, tid;
    uint64_t addr;
    uint64_t len;
    uint64_t pgoff;
    uint32_t maj;
    uint32_t min;
    uint64_t ino;
    uint64_t ino_generation;
    uint32_t prot, flags;
  };
  const Mmap2RecordDataType* data;
  const char* filename;

  Mmap2Record(const perf_event_attr& attr, const char* p);

  void SetDataAndFilename(const Mmap2RecordDataType& data,
                          const std::string& filename);

 protected:
  void DumpData(size_t indent) const override;
};

struct CommRecord : public Record {
  struct CommRecordDataType {
    uint32_t pid, tid;
  };
  const CommRecordDataType* data;
  const char* comm;

  CommRecord(const perf_event_attr& attr, const char* p);

  CommRecord(const perf_event_attr& attr, uint32_t pid, uint32_t tid,
             const std::string& comm, uint64_t event_id);

 protected:
  void DumpData(size_t indent) const override;
};

struct ExitOrForkRecord : public Record {
  struct ExitOrForkRecordDataType {
    uint32_t pid, ppid;
    uint32_t tid, ptid;
    uint64_t time;
  };
  const ExitOrForkRecordDataType* data;

  ExitOrForkRecord(const perf_event_attr& attr, const char* p);

  ExitOrForkRecord() : data(nullptr) {}

 protected:
  void DumpData(size_t indent) const override;
};

struct ExitRecord : public ExitOrForkRecord {
  ExitRecord(const perf_event_attr& attr, const char* p)
      : ExitOrForkRecord(attr, p) {}
};

struct ForkRecord : public ExitOrForkRecord {
  ForkRecord(const perf_event_attr& attr, const char* p)
      : ExitOrForkRecord(attr, p) {}

  ForkRecord(const perf_event_attr& attr, uint32_t pid, uint32_t tid,
             uint32_t ppid, uint32_t ptid, uint64_t event_id);
};

struct LostRecord : public Record {
  uint64_t id;
  uint64_t lost;

  LostRecord(const perf_event_attr& attr, const char* p);

 protected:
  void DumpData(size_t indent) const override;
};

struct SampleRecord : public Record {
  uint64_t sample_type;  // sample_type is a bit mask determining which fields
                         // below are valid.

  PerfSampleIpType ip_data;               // Valid if PERF_SAMPLE_IP.
  PerfSampleTidType tid_data;             // Valid if PERF_SAMPLE_TID.
  PerfSampleTimeType time_data;           // Valid if PERF_SAMPLE_TIME.
  PerfSampleAddrType addr_data;           // Valid if PERF_SAMPLE_ADDR.
  PerfSampleIdType id_data;               // Valid if PERF_SAMPLE_ID.
  PerfSampleStreamIdType stream_id_data;  // Valid if PERF_SAMPLE_STREAM_ID.
  PerfSampleCpuType cpu_data;             // Valid if PERF_SAMPLE_CPU.
  PerfSamplePeriodType period_data;       // Valid if PERF_SAMPLE_PERIOD.

  PerfSampleCallChainType callchain_data;  // Valid if PERF_SAMPLE_CALLCHAIN.
  PerfSampleRawType raw_data;              // Valid if PERF_SAMPLE_RAW.
  PerfSampleBranchStackType
      branch_stack_data;                  // Valid if PERF_SAMPLE_BRANCH_STACK.
  PerfSampleRegsUserType regs_user_data;  // Valid if PERF_SAMPLE_REGS_USER.
  PerfSampleStackUserType stack_user_data;  // Valid if PERF_SAMPLE_STACK_USER.

  SampleRecord(const perf_event_attr& attr, const char* p);
  void ReplaceRegAndStackWithCallChain(const std::vector<uint64_t>& ips);
  uint64_t Timestamp() const override;
  uint32_t Cpu() const override;

  uint64_t GetValidStackSize() const {
    // If stack_user_data.dyn_size == 0, it may be because the kernel misses
    // the patch to update dyn_size, like in N9 (See b/22612370). So assume
    // all stack data is valid if dyn_size == 0.
    if (stack_user_data.dyn_size == 0) {
      return stack_user_data.size;
    }
    return stack_user_data.dyn_size;
  }

 protected:
  void DumpData(size_t indent) const override;
};

// BuildIdRecord is defined in user-space, stored in BuildId feature section in
// record file.
struct BuildIdRecord : public Record {
  uint32_t pid;
  BuildId build_id;
  const char* filename;

  explicit BuildIdRecord(const char* p);

  BuildIdRecord(bool in_kernel, pid_t pid, const BuildId& build_id,
                const std::string& filename);

 protected:
  void DumpData(size_t indent) const override;
};

struct KernelSymbolRecord : public Record {
  uint32_t kallsyms_size;
  const char* kallsyms;

  explicit KernelSymbolRecord(const char* p);

  KernelSymbolRecord(const std::string& kallsyms);

 protected:
  void DumpData(size_t indent) const override;
};

struct DsoRecord : public Record {
  uint64_t dso_type;
  uint64_t dso_id;
  uint64_t min_vaddr;
  const char* dso_name;

  explicit DsoRecord(const char* p);

  DsoRecord(uint64_t dso_type, uint64_t dso_id, const std::string& dso_name,
            uint64_t min_vaddr);

 protected:
  void DumpData(size_t indent) const override;
};

struct SymbolRecord : public Record {
  uint64_t addr;
  uint64_t len;
  uint64_t dso_id;
  const char* name;

  explicit SymbolRecord(const char* p);

  SymbolRecord(uint64_t addr, uint64_t len, const std::string& name,
               uint64_t dso_id);

 protected:
  void DumpData(size_t indent) const override;
};

struct TracingDataRecord : public Record {
  uint32_t data_size;
  const char* data;

  explicit TracingDataRecord(const char* p);

  TracingDataRecord(const std::vector<char>& tracing_data);

 protected:
  void DumpData(size_t indent) const override;
};

// UnknownRecord is used for unknown record types, it makes sure all unknown
// records are not changed when modifying perf.data.
struct UnknownRecord : public Record {
  const char* data;

  explicit UnknownRecord(const char* p);

 protected:
  void DumpData(size_t indent) const override;
};

// Read record from the buffer pointed by [p]. But the record doesn't own
// the buffer.
std::unique_ptr<Record> ReadRecordFromBuffer(const perf_event_attr& attr,
                                             uint32_t type, const char* p);

// Read record from the buffer pointed by [p]. And the record owns the buffer.
std::unique_ptr<Record> ReadRecordFromOwnedBuffer(const perf_event_attr& attr,
                                                  uint32_t type, const char* p);

// Read records from the buffer pointed by [buf]. None of the records own
// the buffer.
std::vector<std::unique_ptr<Record>> ReadRecordsFromBuffer(
    const perf_event_attr& attr, const char* buf, size_t buf_size);

// RecordCache is a cache used when receiving records from the kernel.
// It sorts received records based on type and timestamp, and pops records
// in sorted order. Records from the kernel need to be sorted because
// records may come from different cpus at the same time, and it is affected
// by the order in which we collect records from different cpus.
// RecordCache pushes records and pops sorted record online. It uses two checks
// to help ensure that records are popped in order. Each time we pop a record A,
// it is the earliest record among all records in the cache. In addition, we
// have checks for min_cache_size and min_time_diff. For min_cache_size check,
// we check if the cache size >= min_cache_size, which is based on the
// assumption that if we have received (min_cache_size - 1) records after
// record A, we are not likely to receive a record earlier than A. For
// min_time_diff check, we check if record A is generated min_time_diff ns
// earlier than the latest record, which is based on the assumption that if we
// have received a record for time t, we are not likely to receive a record for
// time (t - min_time_diff) or earlier.
class RecordCache {
 public:
  explicit RecordCache(bool has_timestamp, size_t min_cache_size = 1000u,
                       uint64_t min_time_diff_in_ns = 1000000u);
  ~RecordCache();
  void Push(std::unique_ptr<Record> record);
  void Push(std::vector<std::unique_ptr<Record>> records);
  std::unique_ptr<Record> Pop();
  std::vector<std::unique_ptr<Record>> PopAll();
  std::unique_ptr<Record> ForcedPop();

 private:
  struct RecordWithSeq {
    uint32_t seq;
    Record* record;

    RecordWithSeq(uint32_t seq, Record* record) : seq(seq), record(record) {}
    bool IsHappensBefore(const RecordWithSeq& other) const;
  };

  struct RecordComparator {
    bool operator()(const RecordWithSeq& r1, const RecordWithSeq& r2);
  };

  bool has_timestamp_;
  size_t min_cache_size_;
  uint64_t min_time_diff_in_ns_;
  uint64_t last_time_;
  uint32_t cur_seq_;
  std::priority_queue<RecordWithSeq, std::vector<RecordWithSeq>,
                      RecordComparator> queue_;
};

#endif  // SIMPLE_PERF_RECORD_H_