1 files changed, 74 insertions, 0 deletions
diff --git a/toolkit/components/glean/ipc/Support.cpp b/toolkit/components/glean/ipc/Support.cpp
new file mode 100644
index 0000000000..479b9b42b0
--- /dev/null
+++ b/toolkit/components/glean/ipc/Support.cpp
@@ -0,0 +1,74 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* 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/. */
+
+// This file is for support functions for the Rust IPC module.
+// Some information just isn't available to Rust and must be made available over
+// FFI.
+#include "FOGIPC.h"
+#include "mozilla/AppShutdown.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/Unused.h"
+#include "nsThreadUtils.h"
+
+using mozilla::AppShutdown;
+using mozilla::RunOnShutdown;
+using mozilla::ShutdownPhase;
+using mozilla::Unused;
+using mozilla::glean::FlushFOGData;
+using mozilla::glean::SendFOGData;
+using mozilla::ipc::ByteBuf;
+
+extern "C" {
+void FOG_RegisterContentChildShutdown() {
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+    return;
+  }
+
+  // If there is no main thread (too early in startup or too late in shutdown),
+  // there's nothing we can do but log.
+  bool failed =
+      NS_FAILED(NS_DispatchToMainThread(NS_NewRunnableFunction(__func__, [] {
+        // By the time the main thread dispatched this, it may already be too
+        // late.
+        if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+          return;
+        }
+        RunOnShutdown(
+            [] {
+              FlushFOGData(
+                  [](ByteBuf&& aBuf) { SendFOGData(std::move(aBuf)); });
+            },
+            ShutdownPhase::AppShutdownConfirmed);
+      })));
+  if (failed) {
+    NS_WARNING(
+        "Failed to register FOG content child shutdown flush. "
+        "Will lose shutdown data and leak a runnable.");
+    mozilla::glean::fog_ipc::shutdown_registration_failures.Add(1);
+  }
+}
+
+int FOG_GetProcessType() { return XRE_GetProcessType(); }
+
+/**
+ * Called from FOG IPC in Rust when the IPC Payload might be getting full.
+ * We should probably flush before we reach the max IPC message size.
+ */
+void FOG_IPCPayloadFull() {
+  // NS_DispatchToMainThread can leak the runnable (bug 1787589), so let's be
+  // sure not to create it too late in shutdown.
+  // We choose XPCOMShutdown to match gFOG->Shutdown().
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::XPCOMShutdown)) {
+    return;
+  }
+  // FOG IPC must happen on the main thread until bug 1641989.
+  // If there is no main thread (too early in startup or too late in shutdown),
+  // there's nothing we can do but log.
+  Unused << NS_WARN_IF(NS_FAILED(NS_DispatchToMainThread(
+      NS_NewRunnableFunction("FOG IPC Payload getting full", [] {
+        FlushFOGData([](ByteBuf&& aBuf) { SendFOGData(std::move(aBuf)); });
+      }))));
+}
+}