Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "nsThreadUtils.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/RLBoxSandboxPool.h"
#ifdef MOZ_USING_WASM_SANDBOXING
# include "wasm2c_rt_mem.h"
#endif
using namespace mozilla;
NS_IMPL_ISUPPORTS(RLBoxSandboxPool, nsITimerCallback, nsINamed)
void RLBoxSandboxPool::StartTimer() {
mMutex.AssertCurrentThreadOwns();
MOZ_ASSERT(!mTimer, "timer already initialized");
if (NS_IsMainThread() &&
PastShutdownPhase(ShutdownPhase::AppShutdownConfirmed)) {
// If we're shutting down, setting the time might fail, and we don't need it
// (since all the memory will be cleaned up soon anyway). Note that
// PastShutdownPhase() can only be called on the main thread, but that's
// fine, because other threads will have joined already by the point timers
// start failing to register.
mPool.Clear();
return;
}
DebugOnly<nsresult> rv = NS_NewTimerWithCallback(
getter_AddRefs(mTimer), this, mDelaySeconds * 1000,
nsITimer::TYPE_ONE_SHOT, GetMainThreadSerialEventTarget());
MOZ_ASSERT(NS_SUCCEEDED(rv), "failed to create timer");
}
void RLBoxSandboxPool::CancelTimer() {
mMutex.AssertCurrentThreadOwns();
if (mTimer) {
mTimer->Cancel();
mTimer = nullptr;
}
}
NS_IMETHODIMP RLBoxSandboxPool::Notify(nsITimer* aTimer) {
MutexAutoLock lock(mMutex);
mPool.Clear();
mTimer = nullptr;
return NS_OK;
}
NS_IMETHODIMP RLBoxSandboxPool::GetName(nsACString& aName) {
aName.AssignLiteral("RLBoxSandboxPool");
return NS_OK;
}
void RLBoxSandboxPool::Push(UniquePtr<RLBoxSandboxDataBase> sbxData) {
MutexAutoLock lock(mMutex);
mPool.AppendElement(std::move(sbxData));
if (!mTimer) {
StartTimer();
}
}
UniquePtr<RLBoxSandboxPoolData> RLBoxSandboxPool::PopOrCreate(
uint64_t aMinSize) {
MutexAutoLock lock(mMutex);
UniquePtr<RLBoxSandboxDataBase> sbxData;
if (!mPool.IsEmpty()) {
const int64_t lastIndex = ReleaseAssertedCast<int64_t>(mPool.Length()) - 1;
for (int64_t i = lastIndex; i >= 0; i--) {
if (mPool[i]->mSize >= aMinSize) {
sbxData = std::move(mPool[i]);
mPool.RemoveElementAt(i);
// If we reuse a sandbox from the pool, reset the timer to clear the
// pool
CancelTimer();
if (!mPool.IsEmpty()) {
StartTimer();
}
break;
}
}
}
if (!sbxData) {
#ifdef MOZ_USING_WASM_SANDBOXING
// RLBox's wasm sandboxes have a limited platform dependent capacity. We
// track this capacity in this pool.
const w2c_mem_capacity w2c_capacity = get_valid_wasm2c_memory_capacity(
aMinSize, true /* 32-bit wasm memory*/);
const uint64_t chosenCapacity = w2c_capacity.max_size;
#else
// Note the noop sandboxes have no capacity limit. In this case we simply
// specify a value of 4gb. This is not actually enforced by the noop
// sandbox.
const uint64_t chosenCapacity = static_cast<uint64_t>(1) << 32;
#endif
sbxData = CreateSandboxData(chosenCapacity);
NS_ENSURE_TRUE(sbxData, nullptr);
}
return MakeUnique<RLBoxSandboxPoolData>(std::move(sbxData), this);
}