Trace.cpp

Go to the documentation of this file.

//===- Trace.cpp - Implementation of trace backend -----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// DO NOT EDIT!
// This file is distributed as part of an ESI package. The source for this file
// should always be modified within CIRCT (lib/dialect/ESI/runtime/cpp/lib/).
//
//===----------------------------------------------------------------------===//
 
#include "esi/backends/Trace.h"
 
#include "esi/Accelerator.h"
#include "esi/Services.h"
#include "esi/Utils.h"
 
#include <cassert>
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <memory>
#include <new>
#include <sstream>
 
using namespace esi;
using namespace esi::services;
using namespace esi::backends::trace;
 
namespace {
class TraceChannelPort;
class TraceEngine;
} // namespace
 
TraceAccelerator::Impl &TraceAccelerator::getImpl() { return *impl; }
 
struct esi::backends::trace::TraceAccelerator::Impl {
  friend class TraceAccelerator;
  Impl(Mode mode, std::filesystem::path manifestJson,
       std::filesystem::path traceFile)
      : manifestJson(manifestJson), traceFile(traceFile) {
    if (!std::filesystem::exists(manifestJson))
      throw std::runtime_error("manifest file '" + manifestJson.string() +
                               "' does not exist");
 
    if (mode == Write) {
      // Open the trace file for writing.
      traceWrite = new std::ofstream(traceFile);
      if (!traceWrite->is_open())
        throw std::runtime_error("failed to open trace file '" +
                                 traceFile.string() + "'");
    } else if (mode == Discard) {
      traceWrite = nullptr;
    } else {
      assert(false && "not implemented");
    }
  }
 
  ~Impl() {
    if (traceWrite) {
      traceWrite->close();
      delete traceWrite;
    }
  }
 
  Service *createService(TraceAccelerator &conn, Service::Type svcType,
                         AppIDPath idPath, const ServiceImplDetails &details,
                         const HWClientDetails &clients);
 
  void adoptChannelPort(ChannelPort *port) { channels.emplace_back(port); }
 
  void write(const AppIDPath &id, const std::string &portName, const void *data,
             size_t size, const std::string &prefix = "");
  std::ostream &write(std::string service) {
    assert(traceWrite && "traceWrite is null");
    *traceWrite << "[" << service << "] ";
    return *traceWrite;
  }
  bool isWriteable() { return traceWrite; }
 
private:
  std::ofstream *traceWrite;
  std::filesystem::path manifestJson;
  std::filesystem::path traceFile;
  std::vector<std::unique_ptr<ChannelPort>> channels;
};
 
void TraceAccelerator::Impl::write(const AppIDPath &id,
                                   const std::string &portName,
                                   const void *data, size_t size,
                                   const std::string &prefix) {
  if (!isWriteable())
    return;
  std::string b64data;
  utils::encodeBase64(data, size, b64data);
 
  *traceWrite << prefix << (prefix.empty() ? "w" : "W") << "rite " << id << '.'
              << portName << ": " << b64data << std::endl;
}
 
std::unique_ptr<AcceleratorConnection>
TraceAccelerator::connect(Context &ctxt, std::string connectionString) {
  std::string manifestPath;
  std::string traceFile = "trace.log";
 
  // Parse the connection std::string.
  // Format: <mode>SEP<manifest path>[SEP<traceFile>]
  // where SEP is ':' on Unix and ';' on Windows.
  // Using different separators avoids conflicts with Windows drive letters
  // (e.g. "C:/...").
#ifdef _WIN32
  constexpr char SEP = ';';
#else
  constexpr char SEP = ':';
#endif
 
  if (connectionString.size() < 2 || connectionString[1] != SEP)
    throw std::runtime_error(
        std::string("connection string must be of the form ") + "'<mode>" +
        SEP + "<manifest path>[" + SEP + "<traceFile>]'");
 
  char modeChar = connectionString[0];
  std::string rest = connectionString.substr(2);
 
  // Find the optional trace file, separated by the last SEP.
  size_t lastSep = rest.rfind(SEP);
  if (lastSep != std::string::npos) {
    manifestPath = rest.substr(0, lastSep);
    traceFile = rest.substr(lastSep + 1);
 
    // Validate that the trace file name is non-empty when present.
    if (traceFile.empty())
      throw std::runtime_error(
          std::string("connection string must be of the form ") + "'<mode>" +
          SEP + "<manifest path>[" + SEP +
          "<traceFile>]': "
          "trace file name cannot be empty");
  } else {
    manifestPath = rest;
  }
 
  // Validate that manifest path is non-empty.
  if (manifestPath.empty())
    throw std::runtime_error(
        std::string("connection string must be of the form ") + "'<mode>" +
        SEP + "<manifest path>[" + SEP +
        "<traceFile>]': "
        "manifest path cannot be empty");
 
  // Parse the mode.
  Mode mode;
  if (modeChar == 'w')
    mode = Write;
  else if (modeChar == '-')
    mode = Discard;
  else
    throw std::runtime_error("unknown mode '" + std::string(1, modeChar) + "'");
 
  return std::make_unique<TraceAccelerator>(ctxt, mode,
                                            std::filesystem::path(manifestPath),
                                            std::filesystem::path(traceFile));
}
 
TraceAccelerator::TraceAccelerator(Context &ctxt, Mode mode,
                                   std::filesystem::path manifestJson,
                                   std::filesystem::path traceFile)
    : AcceleratorConnection(ctxt) {
  impl = std::make_unique<Impl>(mode, manifestJson, traceFile);
}
TraceAccelerator::~TraceAccelerator() { disconnect(); }
 
namespace {
class TraceSysInfo : public SysInfo {
public:
  TraceSysInfo(AcceleratorConnection &conn, std::filesystem::path manifestJson)
      : SysInfo(conn), manifestJson(manifestJson) {}
 
  uint32_t getEsiVersion() const override {
    return Manifest(conn.getCtxt(), getJsonManifest()).getApiVersion();
  }
 
  std::string getJsonManifest() const override {
    // Read in the whole json file and return it.
    std::ifstream manifest(manifestJson);
    if (!manifest.is_open())
      throw std::runtime_error("failed to open manifest file '" +
                               manifestJson.string() + "'");
    std::stringstream buffer;
    buffer << manifest.rdbuf();
    manifest.close();
    return buffer.str();
  }
 
  std::vector<uint8_t> getCompressedManifest() const override {
    throw std::runtime_error(
        "compressed manifest not supported by trace backend");
  }
 
private:
  std::filesystem::path manifestJson;
};
} // namespace
 
namespace {
class WriteTraceChannelPort : public WriteChannelPort {
public:
  WriteTraceChannelPort(TraceAccelerator::Impl &impl, const Type *type,
                        const AppIDPath &id, const std::string &portName)
      : WriteChannelPort(type), impl(impl), id(id), portName(portName) {}
 
protected:
  void writeImpl(const MessageData &data) override {
    impl.write(id, portName, data.getBytes(), data.getSize());
  }
 
  bool tryWriteImpl(const MessageData &data) override {
    impl.write(id, portName, data.getBytes(), data.getSize(), "try");
    return true;
  }
 
  TraceAccelerator::Impl &impl;
  AppIDPath id;
  std::string portName;
};
} // namespace
 
namespace {
class ReadTraceChannelPort : public ReadChannelPort {
public:
  ReadTraceChannelPort(TraceAccelerator::Impl &impl, const Type *type)
      : ReadChannelPort(type) {}
  ~ReadTraceChannelPort() { disconnect(); }
 
private:
  MessageData genMessage() {
    std::ptrdiff_t numBits = getType()->getBitWidth();
    if (numBits < 0)
      // TODO: support other types.
      throw std::runtime_error("unsupported type for read: " +
                               getType()->getID());
 
    std::ptrdiff_t size = (numBits + 7) / 8;
    // Zero-width types need a 1-byte placeholder.
    if (size == 0)
      return MessageData({0});
    std::vector<uint8_t> bytes(size);
    for (std::ptrdiff_t i = 0; i < size; ++i)
      bytes[i] = rand() % 256;
    return MessageData(bytes);
  }
 
  bool pollImpl() override {
    if (!pendingMessage)
      pendingMessage = std::make_unique<MessageData>(genMessage());
    if (!invokeCallback(pendingMessage))
      return false;
    pendingMessage.reset();
    return true;
  }
 
  std::unique_ptr<SegmentedMessageData> pendingMessage;
};
} // namespace
 
namespace {
class TraceEngine : public Engine {
public:
  TraceEngine(AcceleratorConnection &conn, TraceAccelerator::Impl &impl)
      : Engine(conn), impl(impl) {}
 
  std::unique_ptr<ChannelPort> createPort(AppIDPath idPath,
                                          const std::string &channelName,
                                          BundleType::Direction dir,
                                          const Type *type) override {
    std::unique_ptr<ChannelPort> port;
    if (BundlePort::isWrite(dir))
      port = std::make_unique<WriteTraceChannelPort>(impl, type, idPath,
                                                     channelName);
    else
      port = std::make_unique<ReadTraceChannelPort>(impl, type);
    return port;
  }
 
private:
  TraceAccelerator::Impl &impl;
};
} // namespace
 
void TraceAccelerator::createEngine(const std::string &dmaEngineName,
                                    AppIDPath idPath,
                                    const ServiceImplDetails &details,
                                    const HWClientDetails &clients) {
  registerEngine(idPath, std::make_unique<TraceEngine>(*this, getImpl()),
                 clients);
}
 
class TraceMMIO : public MMIO {
public:
  TraceMMIO(TraceAccelerator &conn, const AppIDPath &idPath,
            const HWClientDetails &clients)
      : MMIO(conn, idPath, clients), impl(conn.getImpl()) {}
 
  virtual uint64_t read(uint32_t addr) const override {
    uint64_t data = rand();
    if (impl.isWriteable())
      impl.write("MMIO") << "[" << std::hex << addr << "] -> " << data
                         << std::endl;
    return data;
  }
  virtual void write(uint32_t addr, uint64_t data) override {
    if (!impl.isWriteable())
      return;
    impl.write("MMIO") << "[" << std::hex << addr << "] <- " << data
                       << std::endl;
  }
 
private:
  TraceAccelerator::Impl &impl;
};
 
class TraceHostMem : public HostMem {
public:
  TraceHostMem(TraceAccelerator &conn) : HostMem(conn), impl(conn.getImpl()) {}
 
  struct TraceHostMemRegion : public HostMemRegion {
    TraceHostMemRegion(std::size_t size, TraceAccelerator::Impl &impl)
        : ptr(malloc(size)), size(size), impl(impl) {}
    virtual ~TraceHostMemRegion() {
      if (ptr && impl.isWriteable())
        impl.write("HostMem") << "free " << ptr << std::endl;
      free(ptr);
    }
    virtual void *getPtr() const override { return ptr; }
    virtual std::size_t getSize() const override { return size; }
 
  private:
    void *ptr;
    std::size_t size;
    TraceAccelerator::Impl &impl;
  };
 
  virtual std::unique_ptr<HostMemRegion>
  allocate(std::size_t size, HostMem::Options opts) const override {
    if (size == 0)
      return nullptr;
    std::unique_ptr<HostMemRegion> ret(new (std::nothrow)
                                           TraceHostMemRegion(size, impl));
    if (!ret || !ret->getPtr())
      return nullptr;
    if (impl.isWriteable())
      impl.write("HostMem 0x")
          << ret->getPtr() << " allocate " << size
          << " bytes. Writeable: " << opts.writeable
          << ", useLargePages: " << opts.useLargePages << std::endl;
    return ret;
  }
  virtual bool mapMemory(void *ptr, std::size_t size,
                         HostMem::Options opts) const override {
 
    if (impl.isWriteable())
      impl.write("HostMem")
          << "map 0x" << ptr << " size " << size
          << " bytes. Writeable: " << opts.writeable
          << ", useLargePages: " << opts.useLargePages << std::endl;
    return true;
  }
  virtual void unmapMemory(void *ptr) const override {
    if (impl.isWriteable())
      impl.write("HostMem") << "unmap 0x" << ptr << std::endl;
  }
 
private:
  TraceAccelerator::Impl &impl;
};
 
Service *TraceAccelerator::createService(Service::Type svcType,
                                         AppIDPath idPath, std::string implName,
                                         const ServiceImplDetails &details,
                                         const HWClientDetails &clients) {
  if (svcType == typeid(SysInfo))
    return new TraceSysInfo(*this, getImpl().manifestJson);
  if (svcType == typeid(MMIO))
    return new TraceMMIO(*this, idPath, clients);
  if (svcType == typeid(HostMem))
    return new TraceHostMem(*this);
  return nullptr;
}
 
REGISTER_ACCELERATOR("trace", TraceAccelerator);