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* Atomics: implement fetchAndSub on top of fetchAndAddThiago Macieira2014-03-041-6/+2
| | | | | | | | | Instead of looping unnecessarily on top of testAndSet. Task-number: QTBUG-37031 Change-Id: I8120f8405eb76dccc9066749cee0a92b0f2da20e Reviewed-by: Olivier Goffart <ogoffart@woboq.com> Reviewed-by: Sergio Ahumada <sahumada@blackberry.com>
* Add the rest of the non-volatile members of std::atomic to QBasicAtomicThiago Macieira2014-02-161-0/+133
| | | | | | | | | | [ChangeLog][QtCore][Atomic support]Added more operations to the atomic classes, including operator T(), operator=(T), operator++, operator--. For the QAtomicInteger, bit-manipulation operations are also provided, both in operator and in fetchAndXxxYyyyyy modes. Change-Id: I39c07be74e15e0a48f9e931f4342b182004dee1a Reviewed-by: David Faure <david.faure@kdab.com>
* Add a testAndSet overload to the atomics that returns the current valueThiago Macieira2014-02-161-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is extremely useful, since the most common action after a failed compare-and-swap is to loop around, trying again with the current value as found in memory. Code currently written as: do { Type value = atomic.load(); ... } while (!atomic.testAndSetRelaxed(value, desired)); Becomes: Type value = atomic.load(); do { ... } while (!atomic.testAndSetRelaxed(value, desired, value)); In most CPU architectures, the value that was found in memory is known to the compare-and-swap code, so this is more efficient than the previous code. In architectures where the value is not known, the new code is no worse than before. The implementation sometimes modified an existing function, sometimes it added a new one, depending on whether more registers were needed in the assembly (like ARMv6-7), the code became more complex (ARMv5), the optimizer failed (C++11), or it was just plain equivalent (MIPS). Change-Id: I7d6d200ea9746ec8978a0c1e1969dbc3580b9285 Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com> Reviewed-by: Lars Knoll <lars.knoll@digia.com> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
* Replace the type-based QAtomicIntegerTraits with a size-based oneThiago Macieira2014-01-301-14/+2
| | | | | | | | This simplifies the code a lot and avoids silly mistakes where a specific integer type is missing (such as char16_t). Change-Id: Id91dfd1919e783e0a9af7bfa093ca560a01b22d1 Reviewed-by: Lars Knoll <lars.knoll@digia.com>
* Centralize support for QBasicAtomic for ints and longsThiago Macieira2014-01-301-0/+13
| | | | | | | No need to redefine everywhere, since they're required to be supported. Change-Id: I2bdbbd0b0c44871e3bd0edcf0289fc58dd50ff31 Reviewed-by: Lars Knoll <lars.knoll@digia.com>
* Remove use of 'register' from Qt.Stephen Kelly2013-06-171-2/+2
| | | | | | | | | | It is deprecated and clang is starting to warn about it. Patch mostly generated by clang itself, with some careful grep and sed for the platform-specific parts. Change-Id: I8058e6db0f1b41b33a9e8f17a712739159982450 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
* Mark all qtbase headers that aren't cleanThiago Macieira2013-03-031-0/+1
| | | | | | | | | | | | | | | | QtCore has a few headers that, though public, aren't meant to be included directly. Those are the atomic headers, the three _impl.h headers and qt_windows.h. QtGui includes two OpenGL headers that don't compile on their own. Other libraries should not have headers like that (but they do, something we need to fix eventually). Change-Id: I55e4eb057748f47df927ee618f9409acbc189cc1 Reviewed-by: Sean Harmer <sean.harmer@kdab.com> Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
* Remove QT_{BEGIN,END}_HEADER macro usageSergio Ahumada2013-01-291-5/+0
| | | | | | | | | | | The macro was made empty in ba3dc5f3b56d1fab6fe37fe7ae08096d7dc68bcb and is no longer necessary or used. Discussed-on: http://lists.qt-project.org/pipermail/development/2013-January/009284.html Change-Id: Id2bb2e2cabde059305d4af5f12593344ba30f001 Reviewed-by: Laszlo Papp <lpapp@kde.org> Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com> Reviewed-by: hjk <hjk121@nokiamail.com>
* Change copyrights from Nokia to DigiaIikka Eklund2012-09-221-23/+23
| | | | | | | | Change copyrights and license headers from Nokia to Digia Change-Id: If1cc974286d29fd01ec6c19dd4719a67f4c3f00e Reviewed-by: Lars Knoll <lars.knoll@digia.com> Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
* Add Q_DECL_CONSTEXPR to the isXXX functions in the new atomics.Thiago Macieira2012-08-181-8/+8
| | | | | | | | | This allows one to write code that depends on these values at compile-time. Change-Id: I7d78524ed9c70d4141360496d1d764dcbfa92e62 Reviewed-by: Marc Mutz <marc.mutz@kdab.com> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
* Mark all atomic functions as Q_DECL_NOTHROWThiago Macieira2012-08-091-29/+29
| | | | | | | | | | | | | | | | | | | | | | | | | Actually, only the "new" atomics are marked. The old implementation, based on qoldbasicatomic.h is unchanged, but should still work without a problem. The following configurations were tested and do work: - x86 64-bit - x86 32-bit - generic GCC - generic C++11 std::atomic - bootstrap - ARMv6 and 7 - MIPS - MSVC 2010 32-bit - MSVC 2010 64-bit The only two configurations untested are IA-64 and ARMv5. Except for MSVC, all configurations were tested with GCC 4.6 (MIPS and ARM) and 4.7 (x86 and generics). Change-Id: Iecbfeacd9d20b535453e91335165e9a221e0b47e Reviewed-by: Marc Mutz <marc.mutz@kdab.com> Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
* Add a T parameter to the memory barrier functions in atomics.Thiago Macieira2012-08-071-14/+22
| | | | | | | | This is so we can insert valgrind (helgrind) annotation macros. They require the actual address of the variable to work. Change-Id: I988f6a46385ad58143c53ad34b6cf0f58be2cdb8 Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
* Make loadAcquire const.Stephen Kelly2012-02-291-3/+3
| | | | | Change-Id: Iad2d60d1abe363a3b85eaf152861d0979a997d81 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
* Silence syncqt warnings for atomic implementation headersBradley T. Hughes2012-02-061-0/+4
| | | | | | | | | | Most of these headers are either forwarding headers, or we explicitly stop syncqt so that it doesn't generate class includes for the atomic implementation. Either way, syncqt doesn't see the QT_END_* (and sometimes not QT_BEGIN_*), which this commit fixes. Change-Id: Icc8da6f384f38b1ff4eb265c731ce2f2ed92a1a3 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
* Port the Windows atomic implementation to use QGenericAtomicOpsBradley T. Hughes2012-02-021-20/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | First, we do not need to have the QT_INTERLOCKED_REMOVE_VOLATILE(a) macro anymore either, since the value stored in QBasicAtomicInteger is not volatile. Windows provides Interlocked*Pointer() functions in some configurations, so we provide a partial specialization of QAtomicOps for pointer types. For integer types, QAtomicOps selects an implementation based on the size of the type. At the moment, we only support 32-bit types, but it will be possible to add 64-bit later. Note that the 32-bit specialization of QAtomicOpsBySize declares the Type typedef as long, not int, since the Windows Interlocked*() API takes parameters as longs and long pointers. Since this typedef differs from the type given to QBasicAtomicInteger<T> by the QBasicAtomicInt typedef, we need to templatise the _q_value parameter separately from the other arguments in QGenericAtomicOps. This templatisation would be necessary to port other architectures, such as PA_RISC, where we need to have an int[4] array in the atomic type while the arguments do not need this array. Change-Id: Id71fa1ae334da2023553cb402b45e6c285f1d344 Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com> Reviewed-by: João Abecasis <joao.abecasis@nokia.com> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
* Remove "All rights reserved" line from license headers.Jason McDonald2012-01-301-0/+1
| | | | | | | | | | As in the past, to avoid rewriting various autotests that contain line-number information, an extra blank line has been inserted at the end of the license text to ensure that this commit does not change the total number of lines in the license header. Change-Id: I311e001373776812699d6efc045b5f742890c689 Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>
* Add Contact: information in the license headerBradley T. Hughes2012-01-201-0/+1
| | | | | | | | Contact point is the Qt Project, and needs to be included for all new files added to the repository. Change-Id: Id0e7219e1d11a169f1a91439728cbda55ab29eeb Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
* Use Q_FOREVER instead of foreverBradley T. Hughes2012-01-201-2/+2
| | | | | | | | | | Public headers should compile with QT_NO_KEYWORDS defined. Change-Id: I5620b4b2600f5e39bb402b97d14fdb257dfe9942 Reviewed-by: Robin Burchell <robin+qt@viroteck.net> Reviewed-by: Jonas Gastal <jgastal@profusion.mobi> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
* Add the new QBasicAtomicXXX implementation - no backends yetThiago Macieira2012-01-201-0/+232
The new implementation is API- and ABI-compatible with the old implementation, provided that QBasicAtomicInt isn't used as an argument in a function call or the return value: now, QBasicAtomicInt is a typedef to QBasicAtomicInteger<int>. The new design is based on CRTP: the QGenericAtomicOps template class takes as a template parameter the derived class itself. This way, we implement a "poor man's virtual" without a virtual table and everything is inline. QGenericAtomicOps implements most of the atomics code that is repeated in many classes all over: * Acquire semantics are obtained by placing an acquire barrier after the Relaxed operation * Release semantics are obtained by placing a release barrier before the Relaxed operation * Ordered semantics are obtained by placing an ordered barrier before the Relaxed operation (either way would be fine) * fetchAndStoreRelaxed and fetchAndAddRelaxed are implemented on top of testAndSetRelaxed * ref and deref are implemented on top of fetchAndAddRelaxed It also adds load, loadAcquire, store and storeRelease: the default implementations of loadAcquire and storeRelease operate on a volatile variable and add barriers. There are no direct operators for accessing the value. Each architecture-specific implementation can override any of the functions or the memory barrier functions. It must implement at least the testAndSetRelaxed function. In addition, by specialising one template class, the implementations can allow QBasicAtomicInteger for additional types (of different sizes). At the very least, int, unsigned and pointers must be supported. Change-Id: I6da647e225bb330d3cfc16f84d0e7849dff85ec7 Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>
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