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author | Luis Hector Chavez <lhchavez@google.com> | 2016-12-28 10:56:26 -0800 |
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committer | Luis Hector Chavez <lhchavez@google.com> | 2016-12-28 10:56:26 -0800 |
commit | 645501c2ab19a559ce82a1d5a29ced159a4c30fb (patch) | |
tree | b3d9637e908d074f905d3dacbeb1db8361fafb8a /mojo/public/cpp/bindings/lib/sync_call_restrictions.cc | |
parent | 3d72bec9be57b7d199d2cbd7139308bb3c3c34bb (diff) | |
download | libmojo-645501c2ab19a559ce82a1d5a29ced159a4c30fb.tar.gz |
Initial import of libmojo r405848
This brings libmojo in sync with libchrome.
Bug: 27569341
Test: mma -j32 libmojo
Change-Id: Ia7cb877e46dd3f86f18888b5d8d80bef5468b266
Diffstat (limited to 'mojo/public/cpp/bindings/lib/sync_call_restrictions.cc')
-rw-r--r-- | mojo/public/cpp/bindings/lib/sync_call_restrictions.cc | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/mojo/public/cpp/bindings/lib/sync_call_restrictions.cc b/mojo/public/cpp/bindings/lib/sync_call_restrictions.cc new file mode 100644 index 0000000..3d864af --- /dev/null +++ b/mojo/public/cpp/bindings/lib/sync_call_restrictions.cc @@ -0,0 +1,91 @@ +// Copyright 2016 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/public/cpp/bindings/sync_call_restrictions.h" + +#if ENABLE_SYNC_CALL_RESTRICTIONS + +#include "base/lazy_instance.h" +#include "base/logging.h" +#include "base/threading/thread_local.h" +#include "mojo/public/c/system/core.h" + +namespace mojo { + +namespace { + +class SyncCallSettings { + public: + static SyncCallSettings* current(); + + bool allowed() const { + return scoped_allow_count_ > 0 || system_defined_value_; + } + + void IncreaseScopedAllowCount() { scoped_allow_count_++; } + void DecreaseScopedAllowCount() { + DCHECK_LT(0u, scoped_allow_count_); + scoped_allow_count_--; + } + + private: + SyncCallSettings(); + ~SyncCallSettings(); + + bool system_defined_value_ = true; + size_t scoped_allow_count_ = 0; +}; + +base::LazyInstance<base::ThreadLocalPointer<SyncCallSettings>> + g_sync_call_settings = LAZY_INSTANCE_INITIALIZER; + +// static +SyncCallSettings* SyncCallSettings::current() { + SyncCallSettings* result = g_sync_call_settings.Pointer()->Get(); + if (!result) { + result = new SyncCallSettings(); + DCHECK_EQ(result, g_sync_call_settings.Pointer()->Get()); + } + return result; +} + +SyncCallSettings::SyncCallSettings() { + MojoResult result = MojoGetProperty(MOJO_PROPERTY_TYPE_SYNC_CALL_ALLOWED, + &system_defined_value_); + DCHECK_EQ(MOJO_RESULT_OK, result); + + DCHECK(!g_sync_call_settings.Pointer()->Get()); + g_sync_call_settings.Pointer()->Set(this); +} + +SyncCallSettings::~SyncCallSettings() { + g_sync_call_settings.Pointer()->Set(nullptr); +} + +} // namespace + +// static +void SyncCallRestrictions::AssertSyncCallAllowed() { + if (!SyncCallSettings::current()->allowed()) { + LOG(FATAL) << "Mojo sync calls are not allowed in this process because " + << "they can lead to jank and deadlock. If you must make an " + << "exception, please see " + << "SyncCallRestrictions::ScopedAllowSyncCall and consult " + << "mojo/OWNERS."; + } +} + +// static +void SyncCallRestrictions::IncreaseScopedAllowCount() { + SyncCallSettings::current()->IncreaseScopedAllowCount(); +} + +// static +void SyncCallRestrictions::DecreaseScopedAllowCount() { + SyncCallSettings::current()->DecreaseScopedAllowCount(); +} + +} // namespace mojo + +#endif // ENABLE_SYNC_CALL_RESTRICTIONS |