// Copyright 2017 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/core/ports/port_locker.h"
#include <algorithm>
#include "mojo/core/ports/port.h"
#ifdef DEBUG
# include
"base/thread_local.h"
#endif
namespace mojo {
namespace core {
namespace ports {
namespace {
#ifdef DEBUG
void UpdateTLS(PortLocker* old_locker, PortLocker* new_locker) {
// Sanity check when DCHECK is on to make sure there is only ever one
// PortLocker extant on the current thread.
static auto* tls =
new base::ThreadLocalPointer<PortLocker>();
DCHECK_EQ(old_locker, tls->Get());
tls->Set(new_locker);
}
#endif
}
// namespace
PortLocker::PortLocker(
const PortRef** port_refs, size_t num_ports)
: port_refs_(port_refs), num_ports_(num_ports) {
#ifdef DEBUG
UpdateTLS(nullptr,
this);
#endif
#ifdef MOZ_USE_SINGLETON_PORT_MUTEX
detail::PortMutex::sSingleton.Lock();
#endif
// Sort the ports by address to lock them in a globally consistent order.
std::sort(
port_refs_, port_refs_ + num_ports_,
[](
const PortRef* a,
const PortRef* b) {
return a->port() < b->port(); });
for (size_t i = 0; i < num_ports_; ++i) {
// TODO(crbug.com/725605): Remove this CHECK.
CHECK(port_refs_[i]->port());
port_refs_[i]->port()->lock_.Lock();
}
}
PortLocker::~PortLocker() {
for (size_t i = 0; i < num_ports_; ++i) {
port_refs_[i]->port()->lock_.Unlock();
}
#ifdef MOZ_USE_SINGLETON_PORT_MUTEX
detail::PortMutex::sSingleton.Unlock();
#endif
#ifdef DEBUG
UpdateTLS(
this, nullptr);
#endif
}
#ifdef DEBUG
// static
void PortLocker::AssertNoPortsLockedOnCurrentThread() {
// Forces a DCHECK if the TLS PortLocker is anything other than null.
UpdateTLS(nullptr, nullptr);
}
#endif
SinglePortLocker::SinglePortLocker(
const PortRef* port_ref)
: port_ref_(port_ref), locker_(&port_ref_, 1) {}
SinglePortLocker::~SinglePortLocker() =
default;
}
// namespace ports
}
// namespace core
}
// namespace mojo
