tools/fidlcat/lib/exception_decoder.h

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef TOOLS_FIDLCAT_LIB_EXCEPTION_DECODER_H_
#define TOOLS_FIDLCAT_LIB_EXCEPTION_DECODER_H_

#include "src/developer/debug/zxdb/client/process.h"
#include "src/developer/debug/zxdb/client/session.h"
#include "src/developer/debug/zxdb/client/thread.h"
#include "src/developer/debug/zxdb/client/thread_observer.h"
#include "tools/fidlcat/lib/decoder.h"

namespace fidlcat {

class InterceptionWorkflow;
class SyscallDecoderDispatcher;

// Handles the decoding of an exception.
// The decoding starts when ExceptionDecoder::Decode is called. Then all the decoding steps are
// executed one after the other (see the comments for Decode and the following methods).
class ExceptionDecoder {
 public:
  ExceptionDecoder(InterceptionWorkflow* workflow, SyscallDecoderDispatcher* dispatcher,
                   zxdb::Thread* thread, int64_t timestamp)
      : workflow_(workflow),
        dispatcher_(dispatcher),
        weak_thread_(thread->GetWeakPtr()),
        process_name_(thread->GetProcess()->GetName()),
        process_id_(thread->GetProcess()->GetKoid()),
        thread_id_(thread->GetKoid()),
        timestamp_(timestamp) {}

  SyscallDecoderDispatcher* dispatcher() const { return dispatcher_; }
  zxdb::Thread* get_thread() const { return weak_thread_.get(); }
  const std::string& process_name() const { return process_name_; }
  uint64_t process_id() const { return process_id_; }
  uint64_t thread_id() const { return thread_id_; }
  int64_t timestamp() const { return timestamp_; }

  std::stringstream& Error(DecoderError::Type type) { return error_.Set(type); }

  // Asks for the full statck then display the exception.
  void Decode();

  // Creates an event, uses it and then destroys the decoder..
  void Decoded();

  // Destroys this object and remove it from the |syscall_decoders_| list in the
  // SyscallDecoderDispatcher. This function is called when the event has been created or if we had
  // an error and no request is pending (|has_error_| is true and |pending_request_count_| is zero).
  void Destroy();

 private:
  InterceptionWorkflow* const workflow_;
  SyscallDecoderDispatcher* const dispatcher_;
  const fxl::WeakPtr<zxdb::Thread> weak_thread_;
  const std::string process_name_;
  const uint64_t process_id_;
  const uint64_t thread_id_;
  const int64_t timestamp_;
  DecoderError error_;
};

}  // namespace fidlcat

#endif  // TOOLS_FIDLCAT_LIB_EXCEPTION_DECODER_H_