zircon/system/ulib/fs/tracked-remote-dir.cpp

// 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.

#include <fbl/macros.h>
#include <fbl/ref_counted.h>
#include <fbl/string.h>
#include <fs/remote-dir.h>
#include <fs/tracked-remote-dir.h>

namespace fs {

TrackedRemoteDir::TrackedRemoteDir(zx::channel remote)
    : RemoteDir(std::move(remote)), tracker_(this, GetRemote(), ZX_CHANNEL_PEER_CLOSED),
      container_(nullptr) {
    ZX_DEBUG_ASSERT(!IsTracked());
}

zx_status_t TrackedRemoteDir::AddAsTrackedEntry(async_dispatcher_t* dispatcher,
                                                PseudoDir* container, fbl::String name) {
    if (IsTracked()) {
        return ZX_ERR_BAD_STATE;
    }
    ZX_DEBUG_ASSERT(!IsTracked());
    ZX_DEBUG_ASSERT(!tracker_.is_pending());
    ZX_DEBUG_ASSERT(container_ == nullptr);
    ZX_DEBUG_ASSERT(container != nullptr);

    zx_status_t status = container->AddEntry(name, fbl::WrapRefPtr(this));
    if (status != ZX_OK) {
        return status;
    }

    container_ = container;
    name_ = std::move(name);

    // When tracker_ completes, |HandleClose()| is invoked.
    return tracker_.Begin(dispatcher);
}

void TrackedRemoteDir::HandleClose(async_dispatcher_t* dispatcher, async::WaitBase* wait,
                                   zx_status_t status, const zx_packet_signal_t* signal) {
    ZX_DEBUG_ASSERT(IsTracked());
    container_->RemoveEntry(name_, this);
    // After we have removed ourself from the PseudoDirectory, we may have been deleted.
    // Do not deference anything else within |this|.
}

bool TrackedRemoteDir::IsTracked() const {
    return container_ != nullptr;
}

} // namespace fs