// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "mojo/edk/system/waiter_list.h"

#include "base/logging.h"
#include "mojo/edk/system/handle_signals_state.h"
#include "mojo/edk/system/waiter.h"

namespace mojo {
namespace system {

WaiterList::WaiterList() {
}

WaiterList::~WaiterList() {
  DCHECK(waiters_.empty());
}

void WaiterList::AwakeWaitersForStateChange(const HandleSignalsState& state) {
  for (WaiterInfoList::iterator it = waiters_.begin(); it != waiters_.end();
       ++it) {
    if (state.satisfies(it->signals))
      it->waiter->Awake(MOJO_RESULT_OK, it->context);
    else if (!state.can_satisfy(it->signals))
      it->waiter->Awake(MOJO_RESULT_FAILED_PRECONDITION, it->context);
  }
}

void WaiterList::CancelAllWaiters() {
  for (WaiterInfoList::iterator it = waiters_.begin(); it != waiters_.end();
       ++it) {
    it->waiter->Awake(MOJO_RESULT_CANCELLED, it->context);
  }
  waiters_.clear();
}

void WaiterList::AddWaiter(Waiter* waiter,
                           MojoHandleSignals signals,
                           uint32_t context) {
  waiters_.push_back(WaiterInfo(waiter, signals, context));
}

void WaiterList::RemoveWaiter(Waiter* waiter) {
  // We allow a thread to wait on the same handle multiple times simultaneously,
  // so we need to scan the entire list and remove all occurrences of |waiter|.
  for (WaiterInfoList::iterator it = waiters_.begin(); it != waiters_.end();) {
    WaiterInfoList::iterator maybe_delete = it;
    ++it;
    if (maybe_delete->waiter == waiter)
      waiters_.erase(maybe_delete);
  }
}

}  // namespace system
}  // namespace mojo