#include "stdafx.h"

#include "Emu/IdManager.h"

#include "Emu/Cell/ErrorCodes.h"
#include "Emu/Cell/PPUThread.h"

#include "util/asm.hpp"

#include "sys_mutex.h"

LOG_CHANNEL(sys_mutex);

lv2_mutex::lv2_mutex(utils::serial &ar)
    : protocol(ar), recursive(ar), adaptive(ar), key(ar), name(ar) {
  ar(lock_count, control.raw().owner);

  // For backwards compatibility
  control.raw().owner >>= 1;
}

std::function<void(void *)> lv2_mutex::load(utils::serial &ar) {
  return load_func(make_shared<lv2_mutex>(exact_t<utils::serial &>(ar)));
}

void lv2_mutex::save(utils::serial &ar) {
  ar(protocol, recursive, adaptive, key, name, lock_count,
     control.raw().owner << 1);
}

error_code sys_mutex_create(ppu_thread &ppu, vm::ptr<u32> mutex_id,
                            vm::ptr<sys_mutex_attribute_t> attr) {
  ppu.state += cpu_flag::wait;

  sys_mutex.trace("sys_mutex_create(mutex_id=*0x%x, attr=*0x%x)", mutex_id,
                  attr);

  if (!mutex_id || !attr) {
    return CELL_EFAULT;
  }

  const auto _attr = *attr;

  const u64 ipc_key = lv2_obj::get_key(_attr);

  if (ipc_key) {
    sys_mutex.warning(
        "sys_mutex_create(mutex_id=*0x%x, attr=*0x%x): IPC=0x%016x", mutex_id,
        attr, ipc_key);
  }

  switch (_attr.protocol) {
  case SYS_SYNC_FIFO:
    break;
  case SYS_SYNC_PRIORITY:
    break;
  case SYS_SYNC_PRIORITY_INHERIT:
    sys_mutex.warning("sys_mutex_create(): SYS_SYNC_PRIORITY_INHERIT");
    break;
  default: {
    sys_mutex.error("sys_mutex_create(): unknown protocol (0x%x)",
                    _attr.protocol);
    return CELL_EINVAL;
  }
  }

  switch (_attr.recursive) {
  case SYS_SYNC_RECURSIVE:
    break;
  case SYS_SYNC_NOT_RECURSIVE:
    break;
  default: {
    sys_mutex.error("sys_mutex_create(): unknown recursive (0x%x)",
                    _attr.recursive);
    return CELL_EINVAL;
  }
  }

  if (_attr.adaptive != SYS_SYNC_NOT_ADAPTIVE) {
    sys_mutex.todo("sys_mutex_create(): unexpected adaptive (0x%x)",
                   _attr.adaptive);
  }

  if (auto error = lv2_obj::create<lv2_mutex>(
          _attr.pshared, _attr.ipc_key, _attr.flags, [&]() {
            return make_shared<lv2_mutex>(_attr.protocol, _attr.recursive,
                                          _attr.adaptive, ipc_key,
                                          _attr.name_u64);
          })) {
    return error;
  }

  ppu.check_state();
  *mutex_id = idm::last_id();
  return CELL_OK;
}

error_code sys_mutex_destroy(ppu_thread &ppu, u32 mutex_id) {
  ppu.state += cpu_flag::wait;

  sys_mutex.trace("sys_mutex_destroy(mutex_id=0x%x)", mutex_id);

  const auto mutex = idm::withdraw<lv2_obj, lv2_mutex>(
      mutex_id, [](lv2_mutex &mutex) -> CellError {
        std::lock_guard lock(mutex.mutex);

        if (atomic_storage<u32>::load(mutex.control.raw().owner)) {
          return CELL_EBUSY;
        }

        if (mutex.cond_count) {
          return CELL_EPERM;
        }

        lv2_obj::on_id_destroy(mutex, mutex.key);
        return {};
      });

  if (!mutex) {
    return CELL_ESRCH;
  }

  if (mutex->key) {
    sys_mutex.warning("sys_mutex_destroy(mutex_id=0x%x): IPC=0x%016x", mutex_id,
                      mutex->key);
  }

  if (mutex.ret) {
    return mutex.ret;
  }

  return CELL_OK;
}

error_code sys_mutex_lock(ppu_thread &ppu, u32 mutex_id, u64 timeout) {
  ppu.state += cpu_flag::wait;

  sys_mutex.trace("sys_mutex_lock(mutex_id=0x%x, timeout=0x%llx)", mutex_id,
                  timeout);

  const auto mutex = idm::get<lv2_obj, lv2_mutex>(
      mutex_id, [&, notify = lv2_obj::notify_all_t()](lv2_mutex &mutex) {
        CellError result = mutex.try_lock(ppu);

        if (result == CELL_EBUSY &&
            !atomic_storage<ppu_thread *>::load(mutex.control.raw().sq)) {
          // Try busy waiting a bit if advantageous
          for (u32 i = 0, end = lv2_obj::has_ppus_in_running_state() ? 3 : 10;
               id_manager::g_mutex.is_lockable() && i < end; i++) {
            busy_wait(300);
            result = mutex.try_lock(ppu);

            if (!result ||
                atomic_storage<ppu_thread *>::load(mutex.control.raw().sq)) {
              break;
            }
          }
        }

        if (result == CELL_EBUSY) {
          lv2_obj::prepare_for_sleep(ppu);

          ppu.cancel_sleep = 1;

          if (mutex.try_own(ppu) || !mutex.sleep(ppu, timeout)) {
            result = {};
          }

          if (ppu.cancel_sleep != 1) {
            notify.cleanup();
          }

          ppu.cancel_sleep = 0;
        }

        return result;
      });

  if (!mutex) {
    return CELL_ESRCH;
  }

  if (mutex.ret) {
    if (mutex.ret != CELL_EBUSY) {
      return mutex.ret;
    }
  } else {
    return CELL_OK;
  }

  ppu.gpr[3] = CELL_OK;

  while (auto state = +ppu.state) {
    if (state & cpu_flag::signal &&
        ppu.state.test_and_reset(cpu_flag::signal)) {
      break;
    }

    if (is_stopped(state)) {
      std::lock_guard lock(mutex->mutex);

      for (auto cpu =
               atomic_storage<ppu_thread *>::load(mutex->control.raw().sq);
           cpu; cpu = cpu->next_cpu) {
        if (cpu == &ppu) {
          ppu.state += cpu_flag::again;
          return {};
        }
      }

      break;
    }

    for (usz i = 0; cpu_flag::signal - ppu.state && i < 40; i++) {
      busy_wait(500);
    }

    if (ppu.state & cpu_flag::signal) {
      continue;
    }

    if (timeout) {
      if (lv2_obj::wait_timeout(timeout, &ppu)) {
        // Wait for rescheduling
        if (ppu.check_state()) {
          continue;
        }

        ppu.state += cpu_flag::wait;

        if (!atomic_storage<ppu_thread *>::load(mutex->control.raw().sq)) {
          // Waiters queue is empty, so the thread must have been signaled
          mutex->mutex.lock_unlock();
          break;
        }

        std::lock_guard lock(mutex->mutex);

        bool success = false;

        mutex->control.fetch_op([&](lv2_mutex::control_data_t &data) {
          success = false;

          ppu_thread *sq = static_cast<ppu_thread *>(data.sq);

          const bool retval = &ppu == sq;

          if (!mutex->unqueue<false>(sq, &ppu)) {
            return false;
          }

          success = true;

          if (!retval) {
            return false;
          }

          data.sq = sq;
          return true;
        });

        if (success) {
          ppu.next_cpu = nullptr;
          ppu.gpr[3] = CELL_ETIMEDOUT;
        }

        break;
      }
    } else {
      ppu.state.wait(state);
    }
  }

  return not_an_error(ppu.gpr[3]);
}

error_code sys_mutex_trylock(ppu_thread &ppu, u32 mutex_id) {
  ppu.state += cpu_flag::wait;

  sys_mutex.trace("sys_mutex_trylock(mutex_id=0x%x)", mutex_id);

  const auto mutex = idm::check<lv2_obj, lv2_mutex>(
      mutex_id, [&](lv2_mutex &mutex) { return mutex.try_lock(ppu); });

  if (!mutex) {
    return CELL_ESRCH;
  }

  if (mutex.ret) {
    if (mutex.ret == CELL_EBUSY) {
      return not_an_error(CELL_EBUSY);
    }

    return mutex.ret;
  }

  return CELL_OK;
}

error_code sys_mutex_unlock(ppu_thread &ppu, u32 mutex_id) {
  ppu.state += cpu_flag::wait;

  sys_mutex.trace("sys_mutex_unlock(mutex_id=0x%x)", mutex_id);

  const auto mutex = idm::check<lv2_obj, lv2_mutex>(
      mutex_id,
      [&, notify = lv2_obj::notify_all_t()](lv2_mutex &mutex) -> CellError {
        auto result = mutex.try_unlock(ppu);

        if (result == CELL_EBUSY) {
          std::lock_guard lock(mutex.mutex);

          if (auto cpu = mutex.reown<ppu_thread>()) {
            if (cpu->state & cpu_flag::again) {
              ppu.state += cpu_flag::again;
              return {};
            }

            mutex.awake(cpu);
          }

          result = {};
        }

        notify.cleanup();
        return result;
      });

  if (!mutex) {
    return CELL_ESRCH;
  }

  if (mutex.ret) {
    return mutex.ret;
  }

  return CELL_OK;
}