1 files changed, 225 insertions, 0 deletions
diff --git a/netwerk/ipc/ProxyAutoConfigChild.cpp b/netwerk/ipc/ProxyAutoConfigChild.cpp
new file mode 100644
index 0000000000..1ab78c65e3
--- /dev/null
+++ b/netwerk/ipc/ProxyAutoConfigChild.cpp
@@ -0,0 +1,225 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ProxyAutoConfigChild.h"
+
+#include "mozilla/ipc/Endpoint.h"
+#include "mozilla/net/SocketProcessChild.h"
+#include "mozilla/SpinEventLoopUntil.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "nsThreadUtils.h"
+#include "ProxyAutoConfig.h"
+
+namespace mozilla::net {
+
+static bool sThreadLocalSetup = false;
+static uint32_t sThreadLocalIndex = 0xdeadbeef;
+StaticRefPtr<nsIThread> ProxyAutoConfigChild::sPACThread;
+bool ProxyAutoConfigChild::sShutdownObserverRegistered = false;
+static StaticRefPtr<ProxyAutoConfigChild> sActor;
+
+namespace {
+
+class ShutdownObserver final : public nsIObserver {
+ public:
+  ShutdownObserver() = default;
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+ private:
+  ~ShutdownObserver() = default;
+};
+
+NS_IMPL_ISUPPORTS(ShutdownObserver, nsIObserver)
+
+NS_IMETHODIMP
+ShutdownObserver::Observe(nsISupports* aSubject, const char* aTopic,
+                          const char16_t* aData) {
+  ProxyAutoConfigChild::ShutdownPACThread();
+  return NS_OK;
+}
+
+}  // namespace
+
+// static
+void ProxyAutoConfigChild::BindProxyAutoConfigChild(
+    RefPtr<ProxyAutoConfigChild>&& aActor,
+    Endpoint<PProxyAutoConfigChild>&& aEndpoint) {
+  // We only allow one ProxyAutoConfigChild at a time, so we need to
+  // wait until the old one to be destroyed.
+  if (sActor) {
+    NS_DispatchToCurrentThread(NS_NewRunnableFunction(
+        "BindProxyAutoConfigChild",
+        [actor = std::move(aActor), endpoint = std::move(aEndpoint)]() mutable {
+          ProxyAutoConfigChild::BindProxyAutoConfigChild(std::move(actor),
+                                                         std::move(endpoint));
+        }));
+    return;
+  }
+
+  if (aEndpoint.Bind(aActor)) {
+    sActor = aActor;
+  }
+}
+
+// static
+bool ProxyAutoConfigChild::Create(Endpoint<PProxyAutoConfigChild>&& aEndpoint) {
+  if (!sPACThread && !CreatePACThread()) {
+    NS_WARNING("Failed to create pac thread!");
+    return false;
+  }
+
+  if (!sShutdownObserverRegistered) {
+    nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+    if (NS_WARN_IF(!obs)) {
+      return false;
+    }
+    nsCOMPtr<nsIObserver> observer = new ShutdownObserver();
+    nsresult rv = obs->AddObserver(observer, "xpcom-shutdown-threads", false);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return false;
+    }
+    sShutdownObserverRegistered = true;
+  }
+
+  RefPtr<ProxyAutoConfigChild> actor = new ProxyAutoConfigChild();
+  if (NS_FAILED(sPACThread->Dispatch(NS_NewRunnableFunction(
+          "ProxyAutoConfigChild::ProxyAutoConfigChild",
+          [actor = std::move(actor),
+           endpoint = std::move(aEndpoint)]() mutable {
+            MOZ_ASSERT(endpoint.IsValid());
+            ProxyAutoConfigChild::BindProxyAutoConfigChild(std::move(actor),
+                                                           std::move(endpoint));
+          })))) {
+    NS_WARNING("Failed to dispatch runnable!");
+    return false;
+  }
+
+  return true;
+}
+
+// static
+bool ProxyAutoConfigChild::CreatePACThread() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (SocketProcessChild::GetSingleton()->IsShuttingDown()) {
+    NS_WARNING("Trying to create pac thread after shutdown has already begun!");
+    return false;
+  }
+
+  nsCOMPtr<nsIThread> thread;
+  if (NS_FAILED(NS_NewNamedThread("ProxyResolution", getter_AddRefs(thread)))) {
+    NS_WARNING("NS_NewNamedThread failed!");
+    return false;
+  }
+
+  sPACThread = thread.forget();
+  return true;
+}
+
+// static
+void ProxyAutoConfigChild::ShutdownPACThread() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (sPACThread) {
+    // Wait until all actos are released.
+    SpinEventLoopUntil("ProxyAutoConfigChild::ShutdownPACThread"_ns,
+                       [&]() { return !sActor; });
+
+    nsCOMPtr<nsIThread> thread = sPACThread.get();
+    sPACThread = nullptr;
+    MOZ_ALWAYS_SUCCEEDS(thread->Shutdown());
+  }
+}
+
+ProxyAutoConfigChild::ProxyAutoConfigChild()
+    : mPAC(MakeUnique<ProxyAutoConfig>()) {
+  if (!sThreadLocalSetup) {
+    sThreadLocalSetup = true;
+    PR_NewThreadPrivateIndex(&sThreadLocalIndex, nullptr);
+  }
+
+  mPAC->SetThreadLocalIndex(sThreadLocalIndex);
+}
+
+ProxyAutoConfigChild::~ProxyAutoConfigChild() = default;
+
+mozilla::ipc::IPCResult ProxyAutoConfigChild::RecvConfigurePAC(
+    const nsACString& aPACURI, const nsACString& aPACScriptData,
+    const bool& aIncludePath, const uint32_t& aExtraHeapSize) {
+  mPAC->ConfigurePAC(aPACURI, aPACScriptData, aIncludePath, aExtraHeapSize,
+                     GetMainThreadSerialEventTarget());
+  mPACLoaded = true;
+  NS_DispatchToCurrentThread(
+      NewRunnableMethod("ProxyAutoConfigChild::ProcessPendingQ", this,
+                        &ProxyAutoConfigChild::ProcessPendingQ));
+  return IPC_OK();
+}
+
+void ProxyAutoConfigChild::PendingQuery::Resolve(nsresult aStatus,
+                                                 const nsACString& aResult) {
+  mResolver(std::tuple<const nsresult&, const nsACString&>(aStatus, aResult));
+}
+
+mozilla::ipc::IPCResult ProxyAutoConfigChild::RecvGetProxyForURI(
+    const nsACString& aTestURI, const nsACString& aTestHost,
+    GetProxyForURIResolver&& aResolver) {
+  mPendingQ.insertBack(
+      new PendingQuery(aTestURI, aTestHost, std::move(aResolver)));
+  ProcessPendingQ();
+  return IPC_OK();
+}
+
+void ProxyAutoConfigChild::ProcessPendingQ() {
+  while (ProcessPending()) {
+    ;
+  }
+
+  if (mShutdown) {
+    mPAC->Shutdown();
+  } else {
+    // do GC while the thread has nothing pending
+    mPAC->GC();
+  }
+}
+
+bool ProxyAutoConfigChild::ProcessPending() {
+  if (mPendingQ.isEmpty()) {
+    return false;
+  }
+
+  if (mInProgress || !mPACLoaded) {
+    return false;
+  }
+
+  if (mShutdown) {
+    return true;
+  }
+
+  mInProgress = true;
+  RefPtr<PendingQuery> query = mPendingQ.popFirst();
+  nsCString result;
+  nsresult rv = mPAC->GetProxyForURI(query->URI(), query->Host(), result);
+  query->Resolve(rv, result);
+  mInProgress = false;
+  return true;
+}
+
+void ProxyAutoConfigChild::ActorDestroy(ActorDestroyReason aWhy) {
+  mPendingQ.clear();
+  mShutdown = true;
+  mPAC->Shutdown();
+
+  // To avoid racing with the main thread, we need to dispatch
+  // ProxyAutoConfigChild::Destroy again.
+  MOZ_ALWAYS_SUCCEEDS(NS_DispatchToCurrentThread(NewNonOwningRunnableMethod(
+      "ProxyAutoConfigChild::Destroy", this, &ProxyAutoConfigChild::Destroy)));
+}
+
+void ProxyAutoConfigChild::Destroy() { sActor = nullptr; }
+
+}  // namespace mozilla::net