1 files changed, 258 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/threading/thread_restrictions.cc b/security/sandbox/chromium/base/threading/thread_restrictions.cc
new file mode 100644
index 0000000000..75c37eab4f
--- /dev/null
+++ b/security/sandbox/chromium/base/threading/thread_restrictions.cc
@@ -0,0 +1,258 @@
+// Copyright (c) 2012 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 "base/threading/thread_restrictions.h"
+
+#if DCHECK_IS_ON()
+
+#include "base/debug/stack_trace.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/threading/thread_local.h"
+#include "build/build_config.h"
+
+namespace base {
+
+std::ostream& operator<<(std::ostream&out, const ThreadLocalBoolean& tl) {
+  out << "currently set to " << (tl.Get() ? "true" : "false");
+  return out;
+}
+
+namespace {
+
+#if defined(OS_NACL) || defined(OS_ANDROID)
+// NaCL doesn't support stack sampling and Android is slow at stack
+// sampling and this causes timeouts (crbug.com/959139).
+using ThreadLocalBooleanWithStacks = ThreadLocalBoolean;
+#else
+class ThreadLocalBooleanWithStacks {
+ public:
+  ThreadLocalBooleanWithStacks() = default;
+
+  bool Get() const { return bool_.Get(); }
+
+  void Set(bool val) {
+    stack_.Set(std::make_unique<debug::StackTrace>());
+    bool_.Set(val);
+  }
+
+  friend std::ostream& operator<<(std::ostream& out,
+                                  const ThreadLocalBooleanWithStacks& tl) {
+    out << tl.bool_ << " by ";
+
+    if (!tl.stack_.Get())
+      return out << "default value\n";
+    out << "\n";
+    tl.stack_.Get()->OutputToStream(&out);
+    return out;
+  }
+
+ private:
+  ThreadLocalBoolean bool_;
+  ThreadLocalOwnedPointer<debug::StackTrace> stack_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocalBooleanWithStacks);
+};
+#endif  // defined(OS_NACL)
+
+LazyInstance<ThreadLocalBooleanWithStacks>::Leaky g_blocking_disallowed =
+    LAZY_INSTANCE_INITIALIZER;
+
+LazyInstance<ThreadLocalBooleanWithStacks>::Leaky g_singleton_disallowed =
+    LAZY_INSTANCE_INITIALIZER;
+
+LazyInstance<ThreadLocalBooleanWithStacks>::Leaky
+    g_base_sync_primitives_disallowed = LAZY_INSTANCE_INITIALIZER;
+
+LazyInstance<ThreadLocalBooleanWithStacks>::Leaky
+    g_cpu_intensive_work_disallowed = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+namespace internal {
+
+void AssertBlockingAllowed() {
+  DCHECK(!g_blocking_disallowed.Get().Get())
+      << "Function marked as blocking was called from a scope that disallows "
+         "blocking! If this task is running inside the ThreadPool, it needs "
+         "to have MayBlock() in its TaskTraits. Otherwise, consider making "
+         "this blocking work asynchronous or, as a last resort, you may use "
+         "ScopedAllowBlocking (see its documentation for best practices).\n"
+      << "g_blocking_disallowed " << g_blocking_disallowed.Get();
+}
+
+}  // namespace internal
+
+void DisallowBlocking() {
+  g_blocking_disallowed.Get().Set(true);
+}
+
+ScopedDisallowBlocking::ScopedDisallowBlocking()
+    : was_disallowed_(g_blocking_disallowed.Get().Get()) {
+  g_blocking_disallowed.Get().Set(true);
+}
+
+ScopedDisallowBlocking::~ScopedDisallowBlocking() {
+  DCHECK(g_blocking_disallowed.Get().Get());
+  g_blocking_disallowed.Get().Set(was_disallowed_);
+}
+
+ScopedAllowBlocking::ScopedAllowBlocking()
+    : was_disallowed_(g_blocking_disallowed.Get().Get()) {
+  g_blocking_disallowed.Get().Set(false);
+}
+
+ScopedAllowBlocking::~ScopedAllowBlocking() {
+  DCHECK(!g_blocking_disallowed.Get().Get());
+  g_blocking_disallowed.Get().Set(was_disallowed_);
+}
+
+void DisallowBaseSyncPrimitives() {
+  g_base_sync_primitives_disallowed.Get().Set(true);
+}
+
+ScopedAllowBaseSyncPrimitives::ScopedAllowBaseSyncPrimitives()
+    : was_disallowed_(g_base_sync_primitives_disallowed.Get().Get()) {
+  DCHECK(!g_blocking_disallowed.Get().Get())
+      << "To allow //base sync primitives in a scope where blocking is "
+         "disallowed use ScopedAllowBaseSyncPrimitivesOutsideBlockingScope.\n"
+      << "g_blocking_disallowed " << g_blocking_disallowed.Get();
+  g_base_sync_primitives_disallowed.Get().Set(false);
+}
+
+ScopedAllowBaseSyncPrimitives::~ScopedAllowBaseSyncPrimitives() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get());
+  g_base_sync_primitives_disallowed.Get().Set(was_disallowed_);
+}
+
+ScopedAllowBaseSyncPrimitivesOutsideBlockingScope::
+    ScopedAllowBaseSyncPrimitivesOutsideBlockingScope()
+    : was_disallowed_(g_base_sync_primitives_disallowed.Get().Get()) {
+  g_base_sync_primitives_disallowed.Get().Set(false);
+}
+
+ScopedAllowBaseSyncPrimitivesOutsideBlockingScope::
+    ~ScopedAllowBaseSyncPrimitivesOutsideBlockingScope() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get());
+  g_base_sync_primitives_disallowed.Get().Set(was_disallowed_);
+}
+
+ScopedAllowBaseSyncPrimitivesForTesting::
+    ScopedAllowBaseSyncPrimitivesForTesting()
+    : was_disallowed_(g_base_sync_primitives_disallowed.Get().Get()) {
+  g_base_sync_primitives_disallowed.Get().Set(false);
+}
+
+ScopedAllowBaseSyncPrimitivesForTesting::
+    ~ScopedAllowBaseSyncPrimitivesForTesting() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get());
+  g_base_sync_primitives_disallowed.Get().Set(was_disallowed_);
+}
+
+ScopedAllowUnresponsiveTasksForTesting::ScopedAllowUnresponsiveTasksForTesting()
+    : was_disallowed_base_sync_(g_base_sync_primitives_disallowed.Get().Get()),
+      was_disallowed_blocking_(g_blocking_disallowed.Get().Get()),
+      was_disallowed_cpu_(g_cpu_intensive_work_disallowed.Get().Get()) {
+  g_base_sync_primitives_disallowed.Get().Set(false);
+  g_blocking_disallowed.Get().Set(false);
+  g_cpu_intensive_work_disallowed.Get().Set(false);
+}
+
+ScopedAllowUnresponsiveTasksForTesting::
+    ~ScopedAllowUnresponsiveTasksForTesting() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get());
+  DCHECK(!g_blocking_disallowed.Get().Get());
+  DCHECK(!g_cpu_intensive_work_disallowed.Get().Get());
+  g_base_sync_primitives_disallowed.Get().Set(was_disallowed_base_sync_);
+  g_blocking_disallowed.Get().Set(was_disallowed_blocking_);
+  g_cpu_intensive_work_disallowed.Get().Set(was_disallowed_cpu_);
+}
+
+namespace internal {
+
+void AssertBaseSyncPrimitivesAllowed() {
+  DCHECK(!g_base_sync_primitives_disallowed.Get().Get())
+      << "Waiting on a //base sync primitive is not allowed on this thread to "
+         "prevent jank and deadlock. If waiting on a //base sync primitive is "
+         "unavoidable, do it within the scope of a "
+         "ScopedAllowBaseSyncPrimitives. If in a test, "
+         "use ScopedAllowBaseSyncPrimitivesForTesting.\n"
+      << "g_base_sync_primitives_disallowed "
+      << g_base_sync_primitives_disallowed.Get()
+      << "It can be useful to know that g_blocking_disallowed is "
+      << g_blocking_disallowed.Get();
+}
+
+void ResetThreadRestrictionsForTesting() {
+  g_blocking_disallowed.Get().Set(false);
+  g_singleton_disallowed.Get().Set(false);
+  g_base_sync_primitives_disallowed.Get().Set(false);
+  g_cpu_intensive_work_disallowed.Get().Set(false);
+}
+
+}  // namespace internal
+
+void AssertLongCPUWorkAllowed() {
+  DCHECK(!g_cpu_intensive_work_disallowed.Get().Get())
+      << "Function marked as CPU intensive was called from a scope that "
+         "disallows this kind of work! Consider making this work "
+         "asynchronous.\n"
+      << "g_cpu_intensive_work_disallowed "
+      << g_cpu_intensive_work_disallowed.Get();
+}
+
+void DisallowUnresponsiveTasks() {
+  DisallowBlocking();
+  DisallowBaseSyncPrimitives();
+  g_cpu_intensive_work_disallowed.Get().Set(true);
+}
+
+ThreadRestrictions::ScopedAllowIO::ScopedAllowIO()
+    : was_allowed_(SetIOAllowed(true)) {}
+
+ThreadRestrictions::ScopedAllowIO::~ScopedAllowIO() {
+  SetIOAllowed(was_allowed_);
+}
+
+// static
+bool ThreadRestrictions::SetIOAllowed(bool allowed) {
+  bool previous_disallowed = g_blocking_disallowed.Get().Get();
+  g_blocking_disallowed.Get().Set(!allowed);
+  return !previous_disallowed;
+}
+
+// static
+bool ThreadRestrictions::SetSingletonAllowed(bool allowed) {
+  bool previous_disallowed = g_singleton_disallowed.Get().Get();
+  g_singleton_disallowed.Get().Set(!allowed);
+  return !previous_disallowed;
+}
+
+// static
+void ThreadRestrictions::AssertSingletonAllowed() {
+  DCHECK(!g_singleton_disallowed.Get().Get())
+      << "LazyInstance/Singleton is not allowed to be used on this thread. "
+         "Most likely it's because this thread is not joinable (or the current "
+         "task is running with TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN "
+         "semantics), so AtExitManager may have deleted the object on "
+         "shutdown, leading to a potential shutdown crash. If you need to use "
+         "the object from this context, it'll have to be updated to use Leaky "
+         "traits.\n"
+      << "g_singleton_disallowed " << g_singleton_disallowed.Get();
+}
+
+// static
+void ThreadRestrictions::DisallowWaiting() {
+  DisallowBaseSyncPrimitives();
+}
+
+bool ThreadRestrictions::SetWaitAllowed(bool allowed) {
+  bool previous_disallowed = g_base_sync_primitives_disallowed.Get().Get();
+  g_base_sync_primitives_disallowed.Get().Set(!allowed);
+  return !previous_disallowed;
+}
+
+}  // namespace base
+
+#endif  // DCHECK_IS_ON()