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Diffstat (limited to 'include/comphelper/crashzone.hxx')
-rw-r--r-- | include/comphelper/crashzone.hxx | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/include/comphelper/crashzone.hxx b/include/comphelper/crashzone.hxx new file mode 100644 index 0000000000..c4e87e6b79 --- /dev/null +++ b/include/comphelper/crashzone.hxx @@ -0,0 +1,77 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * 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/. + */ + +#ifndef INCLUDED_COMPHELPER_CRASHZONE_H +#define INCLUDED_COMPHELPER_CRASHZONE_H + +#include <sal/config.h> + +#include <atomic> +#include <csignal> +#include <type_traits> + +struct CrashWatchdogTimingsValues +{ + /// delays to take various actions in 1/4 of a second increments. + int mnDisableEntries; + int const mnAbortAfter; +}; + +/** + * A generic class for detecting if a given crash or a lock-up came from a specific + * area of code (such as OpenGL). + * Use this helper to track that. + * The class is a template so that there can be multiple instances of static variables. + */ +template <typename Dummy> class CrashZone +{ +// gnEnterCount and gnLeaveCount are accessed both from multiple threads (cf. +// WatchdogThread::execute; so need to be of atomic type) and from signal handlers (cf. +// VCLExceptionSignal_impl; so need to be of lock-free atomic type). sig_atomic_t is chosen as +// the underlying type under the assumption that it is most likely to lead to an atomic type +// that is actually lock-free. However, gnEnterCount and gnLeaveCount are both monotonically +// increasing, so will eventually overflow, so the underlying type better be unsigned, which +// sig_atomic_t is not guaranteed to be: +#if !defined ARM32 || (defined ARM32 && defined __ARM_PCS_VFP) + using AtomicCounter = std::atomic<std::make_unsigned_t<std::sig_atomic_t>>; + static_assert(AtomicCounter::is_always_lock_free); +#else + using AtomicCounter = volatile std::make_unsigned_t<std::sig_atomic_t>; +#endif + + /// how many times have we entered a zone + static inline AtomicCounter gnEnterCount = 0; + /// how many times have we left a new zone + static inline AtomicCounter gnLeaveCount = 0; + +public: + CrashZone() { enter(); } + ~CrashZone() { leave(); } + static bool isInZone() { return gnEnterCount != gnLeaveCount; } + static const AtomicCounter& enterCount() { return gnEnterCount; } +#if defined ARM32 && !defined __ARM_PCS_VFP && defined __clang__ +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Wdeprecated-volatile" +#endif + // prefer creating instances to manually calling enter()/leave() + static void enter() { gnEnterCount++; } + static void leave() { gnLeaveCount++; } +#if defined ARM32 && !defined __ARM_PCS_VFP && defined __clang__ +#pragma clang diagnostic pop +#endif + // these should be implemented for each specific zone if needed + // static void hardDisable(); + // static const CrashWatchdogTimingsValues& getCrashWatchdogTimingsValues(); + // static void checkDebug(int nUnchanged, const CrashWatchdogTimingsValues& aTimingValues); + // static const char* name(); +}; + +#endif // INCLUDED_COMPHELPER_CRASHZONE_H + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |