summaryrefslogtreecommitdiffstats
path: root/src/corelib
diff options
context:
space:
mode:
Diffstat (limited to 'src/corelib')
-rw-r--r--src/corelib/global/qcompilerdetection.h6
-rw-r--r--src/corelib/global/qfloat16.h2
-rw-r--r--src/corelib/global/qrandom.cpp926
-rw-r--r--src/corelib/global/qrandom.h183
-rw-r--r--src/corelib/global/qrandom_p.h18
-rw-r--r--src/corelib/io/qfileselector.cpp6
-rw-r--r--src/corelib/io/qfilesystemwatcher_win.cpp4
-rw-r--r--src/corelib/io/qiodevice.cpp2
-rw-r--r--src/corelib/io/qprocess_win.cpp7
-rw-r--r--src/corelib/io/qstorageinfo_unix.cpp34
-rw-r--r--src/corelib/io/qtemporaryfile.cpp2
-rw-r--r--src/corelib/io/qurl.cpp14
-rw-r--r--src/corelib/kernel/qfunctions_winrt.h1
-rw-r--r--src/corelib/kernel/qwineventnotifier.cpp5
-rw-r--r--src/corelib/statemachine/qstatemachine.cpp2
-rw-r--r--src/corelib/thread/qmutex.h6
-rw-r--r--src/corelib/thread/qsemaphore.h6
-rw-r--r--src/corelib/tools/qdatetimeparser.cpp1
-rw-r--r--src/corelib/tools/qhash.cpp1
-rw-r--r--src/corelib/tools/qversionnumber.cpp4
20 files changed, 856 insertions, 374 deletions
diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index 2c58ff87e9..231ac2c9b0 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -1347,12 +1347,12 @@
} while (false)
#if defined(__cplusplus)
-#if QT_HAS_CPP_ATTRIBUTE(fallthrough)
-# define Q_FALLTHROUGH() [[fallthrough]]
-#elif QT_HAS_CPP_ATTRIBUTE(clang::fallthrough)
+#if QT_HAS_CPP_ATTRIBUTE(clang::fallthrough)
# define Q_FALLTHROUGH() [[clang::fallthrough]]
#elif QT_HAS_CPP_ATTRIBUTE(gnu::fallthrough)
# define Q_FALLTHROUGH() [[gnu::fallthrough]]
+#elif QT_HAS_CPP_ATTRIBUTE(fallthrough)
+# define Q_FALLTHROUGH() [[fallthrough]]
#endif
#endif
#ifndef Q_FALLTHROUGH
diff --git a/src/corelib/global/qfloat16.h b/src/corelib/global/qfloat16.h
index 10598adb1d..a36852fc22 100644
--- a/src/corelib/global/qfloat16.h
+++ b/src/corelib/global/qfloat16.h
@@ -121,7 +121,7 @@ inline qfloat16::qfloat16(float f) Q_DECL_NOTHROW
__m128i packhalf = _mm_cvtps_ph(packsingle, 0);
b16 = _mm_extract_epi16(packhalf, 0);
#elif defined (__ARM_FP16_FORMAT_IEEE)
- __fp16 f16 = f;
+ __fp16 f16 = __fp16(f);
memcpy(&b16, &f16, sizeof(quint16));
#else
quint32 u;
diff --git a/src/corelib/global/qrandom.cpp b/src/corelib/global/qrandom.cpp
index 9abb9ece7f..72ac8d332b 100644
--- a/src/corelib/global/qrandom.cpp
+++ b/src/corelib/global/qrandom.cpp
@@ -43,10 +43,8 @@
#include "qrandom.h"
#include "qrandom_p.h"
#include <qobjectdefs.h>
+#include <qmutex.h>
#include <qthreadstorage.h>
-#include <private/qsimd_p.h>
-
-#include <random>
#include <errno.h>
@@ -86,6 +84,7 @@ DECLSPEC_IMPORT BOOLEAN WINAPI SystemFunction036(PVOID RandomBuffer, ULONG Rando
#undef Q_ASSERT_X
#undef Q_ASSERT
#define Q_ASSERT(cond) assert(cond)
+#define Q_ASSERT_X(cond, x, msg) assert(cond && msg)
#if defined(QT_NO_DEBUG) && !defined(QT_FORCE_ASSERTS)
# define NDEBUG 1
#endif
@@ -122,14 +121,21 @@ static QT_FUNCTION_TARGET(RDRND) qssize_t qt_random_cpu(void *buffer, qssize_t c
out:
return ptr - reinterpret_cast<unsigned *>(buffer);
}
+#else
+static qssize_t qt_random_cpu(void *, qssize_t)
+{
+ return 0;
+}
#endif
-namespace {
-#if QT_CONFIG(getentropy)
-class SystemRandom
+enum {
+ // may be "overridden" by a member enum
+ FillBufferNoexcept = true
+};
+
+struct QRandomGenerator::SystemGenerator
{
-public:
- enum { EfficientBufferFill = true };
+#if QT_CONFIG(getentropy)
static qssize_t fillBuffer(void *buffer, qssize_t count) Q_DECL_NOTHROW
{
// getentropy can read at most 256 bytes, so break the reading
@@ -147,96 +153,93 @@ public:
Q_UNUSED(ret);
return count;
}
-};
#elif defined(Q_OS_UNIX)
-class SystemRandom
-{
- static QBasicAtomicInt s_fdp1; // "file descriptor plus 1"
- static int openDevice();
-#ifdef Q_CC_GNU
- // If it's not GCC or GCC-like, then we'll leak the file descriptor
- __attribute__((destructor))
-#endif
- static void closeDevice();
- SystemRandom() {}
-public:
- enum { EfficientBufferFill = true };
- static qssize_t fillBuffer(void *buffer, qssize_t count);
-};
-QBasicAtomicInt SystemRandom::s_fdp1 = Q_BASIC_ATOMIC_INITIALIZER(0);
+ enum { FillBufferNoexcept = false };
-void SystemRandom::closeDevice()
-{
- int fd = s_fdp1.loadAcquire() - 1;
- if (fd >= 0)
- qt_safe_close(fd);
-}
+ QBasicAtomicInt fdp1; // "file descriptor plus 1"
+ int openDevice()
+ {
+ int fd = fdp1.loadAcquire() - 1;
+ if (fd != -1)
+ return fd;
+
+ fd = qt_safe_open("/dev/urandom", O_RDONLY);
+ if (fd == -1)
+ fd = qt_safe_open("/dev/random", O_RDONLY | O_NONBLOCK);
+ if (fd == -1) {
+ // failed on both, set to -2 so we won't try again
+ fd = -2;
+ }
-int SystemRandom::openDevice()
-{
- int fd = s_fdp1.loadAcquire() - 1;
- if (fd != -1)
- return fd;
-
- fd = qt_safe_open("/dev/urandom", O_RDONLY);
- if (fd == -1)
- fd = qt_safe_open("/dev/random", O_RDONLY | O_NONBLOCK);
- if (fd == -1) {
- // failed on both, set to -2 so we won't try again
- fd = -2;
+ int opened_fdp1;
+ if (fdp1.testAndSetOrdered(0, fd + 1, opened_fdp1))
+ return fd;
+
+ // failed, another thread has opened the file descriptor
+ if (fd >= 0)
+ qt_safe_close(fd);
+ return opened_fdp1 - 1;
}
- int opened_fdp1;
- if (s_fdp1.testAndSetOrdered(0, fd + 1, opened_fdp1)) {
- if (fd >= 0) {
- static const SystemRandom closer;
- Q_UNUSED(closer);
- }
- return fd;
+#ifdef Q_CC_GNU
+ // If it's not GCC or GCC-like, then we'll leak the file descriptor
+ __attribute__((destructor))
+#endif
+ static void closeDevice()
+ {
+ int fd = self().fdp1.load() - 1;
+ if (fd >= 0)
+ qt_safe_close(fd);
}
- // failed, another thread has opened the file descriptor
- if (fd >= 0)
- qt_safe_close(fd);
- return opened_fdp1 - 1;
-}
+ Q_DECL_CONSTEXPR SystemGenerator() : fdp1 Q_BASIC_ATOMIC_INITIALIZER(0) {}
-qssize_t SystemRandom::fillBuffer(void *buffer, qssize_t count)
-{
- int fd = openDevice();
- if (Q_UNLIKELY(fd < 0))
- return 0;
+ qssize_t fillBuffer(void *buffer, qssize_t count)
+ {
+ int fd = openDevice();
+ if (Q_UNLIKELY(fd < 0))
+ return 0;
- qint64 n = qt_safe_read(fd, buffer, count);
- return qMax<qssize_t>(n, 0); // ignore any errors
-}
-#endif // Q_OS_UNIX
+ qint64 n = qt_safe_read(fd, buffer, count);
+ return qMax<qssize_t>(n, 0); // ignore any errors
+ }
-#if defined(Q_OS_WIN) && !defined(Q_OS_WINRT)
-class SystemRandom
-{
-public:
- enum { EfficientBufferFill = true };
- static qssize_t fillBuffer(void *buffer, qssize_t count) Q_DECL_NOTHROW
+#elif defined(Q_OS_WIN) && !defined(Q_OS_WINRT)
+ qssize_t fillBuffer(void *buffer, qssize_t count) Q_DECL_NOTHROW
{
auto RtlGenRandom = SystemFunction036;
return RtlGenRandom(buffer, ULONG(count)) ? count: 0;
}
-};
#elif defined(Q_OS_WINRT)
-class SystemRandom
-{
-public:
- enum { EfficientBufferFill = false };
- static qssize_t fillBuffer(void *, qssize_t) Q_DECL_NOTHROW
+ qssize_t fillBuffer(void *, qssize_t) Q_DECL_NOTHROW
{
// always use the fallback
return 0;
}
-};
#endif // Q_OS_WINRT
-} // unnamed namespace
+
+ static SystemGenerator &self();
+ void generate(quint32 *begin, quint32 *end) Q_DECL_NOEXCEPT_EXPR(FillBufferNoexcept);
+
+ // For std::mersenne_twister_engine implementations that use something
+ // other than quint32 (unsigned int) to fill their buffers.
+ template <typename T> void generate(T *begin, T *end)
+ {
+ Q_STATIC_ASSERT(sizeof(T) >= sizeof(quint32));
+ if (sizeof(T) == sizeof(quint32)) {
+ // Microsoft Visual Studio uses unsigned long, but that's still 32-bit
+ generate(reinterpret_cast<quint32 *>(begin), reinterpret_cast<quint32 *>(end));
+ } else {
+ // Slow path. Fix your C++ library.
+ std::generate(begin, end, [this]() {
+ quint32 datum;
+ generate(&datum, &datum + 1);
+ return datum;
+ });
+ }
+ }
+};
#if defined(Q_OS_WIN)
static void fallback_update_seed(unsigned) {}
@@ -255,6 +258,7 @@ static void fallback_update_seed(unsigned) {}
static void fallback_fill(quint32 *, qssize_t) Q_DECL_NOTHROW
{
// no fallback necessary, getentropy cannot fail under normal circumstances
+ Q_UNREACHABLE();
}
#elif defined(Q_OS_BSD4)
static void fallback_update_seed(unsigned) {}
@@ -350,31 +354,25 @@ static void fallback_fill(quint32 *ptr, qssize_t left) Q_DECL_NOTHROW
}
#endif
-static qssize_t fill_cpu(quint32 *buffer, qssize_t count) Q_DECL_NOTHROW
+Q_NEVER_INLINE void QRandomGenerator::SystemGenerator::generate(quint32 *begin, quint32 *end)
+ Q_DECL_NOEXCEPT_EXPR(FillBufferNoexcept)
{
-#if defined(Q_PROCESSOR_X86) && QT_COMPILER_SUPPORTS_HERE(RDRND)
- if (qCpuHasFeature(RDRND) && (uint(qt_randomdevice_control) & SkipHWRNG) == 0)
- return qt_random_cpu(buffer, count);
-#else
- Q_UNUSED(buffer);
- Q_UNUSED(count);
-#endif
- return 0;
-}
+ quint32 *buffer = begin;
+ qssize_t count = end - begin;
-static void fill_internal(quint32 *buffer, qssize_t count)
- Q_DECL_NOEXCEPT_EXPR(noexcept(SystemRandom::fillBuffer(buffer, count)))
-{
if (Q_UNLIKELY(uint(qt_randomdevice_control) & SetRandomData)) {
uint value = uint(qt_randomdevice_control) & RandomDataMask;
std::fill_n(buffer, count, value);
return;
}
- qssize_t filled = fill_cpu(buffer, count);
+ qssize_t filled = 0;
+ if (qt_has_hwrng() && (uint(qt_randomdevice_control) & SkipHWRNG) == 0)
+ filled += qt_random_cpu(buffer, count);
+
if (filled != count && (uint(qt_randomdevice_control) & SkipSystemRNG) == 0) {
qssize_t bytesFilled =
- SystemRandom::fillBuffer(buffer + filled, (count - filled) * qssize_t(sizeof(*buffer)));
+ fillBuffer(buffer + filled, (count - filled) * qssize_t(sizeof(*buffer)));
filled += bytesFilled / qssize_t(sizeof(*buffer));
}
if (filled)
@@ -386,147 +384,262 @@ static void fill_internal(quint32 *buffer, qssize_t count)
}
}
-static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
- Q_DECL_NOEXCEPT_EXPR(noexcept(fill_internal(static_cast<quint32 *>(buffer), 1)))
+struct QRandomGenerator::SystemAndGlobalGenerators
{
- struct ThreadState {
- enum {
- DesiredBufferByteSize = 32,
- BufferCount = DesiredBufferByteSize / sizeof(quint32)
- };
- quint32 buffer[BufferCount];
- int idx = BufferCount;
- };
-
- // Verify that the pointers are properly aligned for 32-bit
- Q_ASSERT(quintptr(buffer) % sizeof(quint32) == 0);
- Q_ASSERT(quintptr(bufferEnd) % sizeof(quint32) == 0);
+ // Construction notes:
+ // 1) The global PRNG state is in a different cacheline compared to the
+ // mutex that protects it. This avoids any false cacheline sharing of
+ // the state in case another thread tries to lock the mutex. It's not
+ // a common scenario, but since sizeof(QRandomGenerator) >= 2560, the
+ // overhead is actually acceptable.
+ // 2) We use both Q_DECL_ALIGN and std::aligned_storage<..., 64> because
+ // some implementations of std::aligned_storage can't align to more
+ // than a primitive type's alignment.
+ // 3) We don't store the entire system QRandomGenerator, only the space
+ // used by the QRandomGenerator::type member. This is fine because we
+ // (ab)use the common initial sequence exclusion to aliasing rules.
+ QBasicMutex globalPRNGMutex;
+ struct ShortenedSystem { uint type; } system_;
+ SystemGenerator sys;
+ Q_DECL_ALIGN(64) std::aligned_storage<sizeof(QRandomGenerator64), 64>::type global_;
+
+#ifdef Q_COMPILER_CONSTEXPR
+ constexpr SystemAndGlobalGenerators()
+ : globalPRNGMutex{}, system_{0}, sys{}, global_{}
+ {}
+#endif
- quint32 *ptr = reinterpret_cast<quint32 *>(buffer);
- quint32 * const end = reinterpret_cast<quint32 *>(bufferEnd);
+ void confirmLiteral()
+ {
+#if defined(Q_COMPILER_CONSTEXPR) && !defined(Q_CC_MSVC) && !defined(Q_OS_INTEGRITY)
+ // Currently fails to compile with MSVC 2017, saying QBasicMutex is not
+ // a literal type. Disassembly with MSVC 2013 and 2015 shows it is
+ // actually a literal; MSVC 2017 has a bug relating to this, so we're
+ // withhold judgement for now. Integrity's compiler is unable to
+ // guarantee g's alignment for some reason.
+
+ constexpr SystemAndGlobalGenerators g = {};
+ Q_UNUSED(g);
+ Q_STATIC_ASSERT(std::is_literal_type<SystemAndGlobalGenerators>::value);
+#endif
+ }
-#if defined(Q_COMPILER_THREAD_LOCAL) && !defined(QT_BOOTSTRAPPED)
- if (SystemRandom::EfficientBufferFill && (end - ptr) < ThreadState::BufferCount
- && uint(qt_randomdevice_control) == 0) {
- thread_local ThreadState state;
- qssize_t itemsAvailable = ThreadState::BufferCount - state.idx;
+ static SystemAndGlobalGenerators *self()
+ {
+ static SystemAndGlobalGenerators g;
+ Q_STATIC_ASSERT(sizeof(g) > sizeof(QRandomGenerator64));
+ return &g;
+ }
- // copy as much as we already have
- qssize_t itemsToCopy = qMin(qssize_t(end - ptr), itemsAvailable);
- memcpy(ptr, state.buffer + state.idx, size_t(itemsToCopy) * sizeof(*ptr));
- ptr += itemsToCopy;
+ static QRandomGenerator64 *system()
+ {
+ // Though we never call the constructor, the system QRandomGenerator is
+ // properly initialized by the zero initialization performed in self().
+ // Though QRandomGenerator is has non-vacuous initialization, we
+ // consider it initialized because of the common initial sequence.
+ return reinterpret_cast<QRandomGenerator64 *>(&self()->system_);
+ }
- if (ptr != end) {
- // refill the buffer and try again
- fill_internal(state.buffer, ThreadState::BufferCount);
- state.idx = 0;
+ static QRandomGenerator64 *globalNoInit()
+ {
+ // This function returns the pointer to the global QRandomGenerator,
+ // but does not initialize it. Only call it directly if you meant to do
+ // a pointer comparison.
+ return reinterpret_cast<QRandomGenerator64 *>(&self()->global_);
+ }
- itemsToCopy = end - ptr;
- memcpy(ptr, state.buffer + state.idx, size_t(itemsToCopy) * sizeof(*ptr));
- ptr = end;
- }
+ static void securelySeed(QRandomGenerator *rng)
+ {
+ // force reconstruction, just to be pedantic
+ new (rng) QRandomGenerator{System{}};
- // erase what we copied and advance
-# ifdef Q_OS_WIN
- // Microsoft recommends this
- SecureZeroMemory(state.buffer + state.idx, size_t(itemsToCopy) * sizeof(*ptr));
-# else
- // We're quite confident the compiler will not optimize this out because
- // we're writing to a thread-local buffer
- memset(state.buffer + state.idx, 0, size_t(itemsToCopy) * sizeof(*ptr));
-# endif
- state.idx += itemsToCopy;
+ rng->type = MersenneTwister;
+ new (&rng->storage.engine()) RandomEngine(self()->sys);
}
-#endif // Q_COMPILER_THREAD_LOCAL && !QT_BOOTSTRAPPED
- if (ptr != end) {
- // fill directly in the user buffer
- fill_internal(ptr, end - ptr);
- }
+ struct PRNGLocker {
+ const bool locked;
+ PRNGLocker(const QRandomGenerator *that)
+ : locked(that == globalNoInit())
+ {
+ if (locked)
+ self()->globalPRNGMutex.lock();
+ }
+ ~PRNGLocker()
+ {
+ if (locked)
+ self()->globalPRNGMutex.unlock();
+ }
+ };
+};
+
+inline QRandomGenerator::SystemGenerator &QRandomGenerator::SystemGenerator::self()
+{
+ return SystemAndGlobalGenerators::self()->sys;
}
/*!
\class QRandomGenerator
\inmodule QtCore
+ \reentrant
\since 5.10
\brief The QRandomGenerator class allows one to obtain random values from a
- high-quality, seed-less Random Number Generator.
+ high-quality Random Number Generator.
QRandomGenerator may be used to generate random values from a high-quality
- random number generator. Unlike qrand(), QRandomGenerator does not need to be
- seeded. That also means it is not possible to force it to produce a
- reliable sequence, which may be needed for debugging.
+ random number generator. Like the C++ random engines, QRandomGenerator can
+ be seeded with user-provided values through the constructor.
+ When seeded, the sequence of numbers generated by this
+ class is deterministic. That is to say, given the same seed data,
+ QRandomGenerator will generate the same sequence of numbers. But given
+ different seeds, the results should be considerably different.
+
+ QRandomGenerator::securelySeeded() can be used to create a QRandomGenerator
+ that is securely seeded with QRandomGenerator::system(), meaning that the
+ sequence of numbers it generates cannot be easily predicted. Additionally,
+ QRandomGenerator::global() returns a global instance of QRandomGenerator
+ that Qt will ensure to be securely seeded. This object is thread-safe, may
+ be shared for most uses, and is always seeded from
+ QRandomGenerator::system()
+
+ QRandomGenerator::system() may be used to access the system's
+ cryptographically-safe random generator. On Unix systems, it's equivalent
+ to reading from \c {/dev/urandom} or the \c {getrandom()} or \c
+ {getentropy()} system calls.
The class can generate 32-bit or 64-bit quantities, or fill an array of
those. The most common way of generating new values is to call the generate(),
generate64() or fillRange() functions. One would use it as:
\code
- quint32 value = QRandomGenerator::generate();
+ quint32 value = QRandomGenerator::global()->generate();
\endcode
- Additionally, it provides a floating-point function generateDouble() that returns
- a number in the range [0, 1) (that is, inclusive of zero and exclusive of
- 1). There's also a set of convenience functions that facilitate obtaining a
- random number in a bounded, integral range.
+ Additionally, it provides a floating-point function generateDouble() that
+ returns a number in the range [0, 1) (that is, inclusive of zero and
+ exclusive of 1). There's also a set of convenience functions that
+ facilitate obtaining a random number in a bounded, integral range.
- \warning This class is not suitable for bulk data creation. See below for the
- technical reasons.
+ \section1 Seeding and determinism
+
+ QRandomGenerator may be seeded with specific seed data. When that is done,
+ the numbers generated by the object will always be the same, as in the
+ following example:
+
+ \code
+ QRandomGenerator prng1(1234), prng2(1234);
+ Q_ASSERT(prng1.generate32() == prng2.generate32());
+ Q_ASSERT(prng1.generate64() == prng2.generate64());
+ \endcode
- \section1 Frequency and entropy exhaustion
+ The seed data takes the form of one or more 32-bit words. The ideal seed
+ size is approximately equal to the size of the QRandomGenerator class
+ itself. Due to mixing of the seed data, QRandomGenerator cannot guarantee
+ that distinct seeds will produce different sequences.
+
+ QRandomGenerator::global(), like all generators created by
+ QRandomGenerator::securelySeeded(), is always seeded from
+ QRandomGenerator::system(), so it's not possible to make it produce
+ identical sequences.
+
+ \section1 Bulk data
+
+ When operating in deterministic mode, QRandomGenerator may be used for bulk
+ data generation. In fact, applications that do not need
+ cryptographically-secure or true random data are advised to use a regular
+ QRandomGenerator instead of QRandomGenerator::system() for their random
+ data needs.
+
+ For ease of use, QRandomGenerator provides a global object that can
+ be easily used, as in the following example:
+
+ \code
+ int x = QRandomGenerator::global()->generate32();
+ int y = QRandomGenerator::global()->generate32();
+ int w = QRandomGenerator::global()->bounded(16384);
+ int h = QRandomGenerator::global()->bounded(16384);
+ \endcode
- QRandomGenerator does not need to be seeded and instead uses operating system
- or hardware facilities to generate random numbers. On some systems and with
- certain hardware, those facilities are true Random Number Generators.
- However, if they are true RNGs, those facilities have finite entropy source
- and thus may fail to produce any results if the entropy pool is exhausted.
+ \section1 System-wide random number generator
+
+ QRandomGenerator::system() may be used to access the system-wide random
+ number generator, which is cryptographically-safe on all systems that Qt
+ runs on. This function will use hardware facilities to generate random
+ numbers where available. On such systems, those facilities are true Random
+ Number Generators. However, if they are true RNGs, those facilities have
+ finite entropy sources and thus may fail to produce any results if their
+ entropy pool is exhausted.
If that happens, first the operating system then QRandomGenerator will fall
back to Pseudo Random Number Generators of decreasing qualities (Qt's
- fallback generator being the simplest). Therefore, QRandomGenerator should
- not be used for high-frequency random number generation, lest the entropy
- pool become empty. As a rule of thumb, this class should not be called upon
- to generate more than a kilobyte per second of random data (note: this may
- vary from system to system).
+ fallback generator being the simplest). Whether those generators are still
+ of cryptographic quality is implementation-defined. Therefore,
+ QRandomGenerator::system() should not be used for high-frequency random
+ number generation, lest the entropy pool become empty. As a rule of thumb,
+ this class should not be called upon to generate more than a kilobyte per
+ second of random data (note: this may vary from system to system).
If an application needs true RNG data in bulk, it should use the operating
- system facilities (such as \c{/dev/random} on Unix systems) directly and
- wait for entropy to become available. If true RNG is not required,
- applications should instead use a PRNG engines and can use QRandomGenerator to
- seed those.
+ system facilities (such as \c{/dev/random} on Linux) directly and wait for
+ entropy to become available. If the application requires PRNG engines of
+ cryptographic quality but not of true randomness,
+ QRandomGenerator::system() may still be used (see section below).
+
+ If neither a true RNG nor a cryptographically secure PRNG are required,
+ applications should instead use PRNG engines like QRandomGenerator's
+ deterministic mode and those from the C++ Standard Library.
+ QRandomGenerator::system() can be used to seed those.
+
+ \section2 Fallback quality
+
+ QRandomGenerator::system() uses the operating system facilities to obtain
+ random numbers, which attempt to collect real entropy from the surrounding
+ environment to produce true random numbers. However, it's possible that the
+ entropy pool becomes exhausted, in which case the operating system will
+ fall back to a pseudo-random engine for a time. Under no circumstances will
+ QRandomGenerator::system() block, waiting for more entropy to be collected.
+
+ The following operating systems guarantee that the results from their
+ random-generation API will be of at least cryptographically-safe quality,
+ even if the entropy pool is exhausted: Apple OSes (Darwin), BSDs, Linux,
+ Windows. Barring a system installation problem (such as \c{/dev/urandom}
+ not being readable by the current process), QRandomGenerator::system() will
+ therefore have the same guarantees.
+
+ On other operating systems, QRandomGenerator will fall back to a PRNG of
+ good numeric distribution, but it cannot guarantee proper seeding in all
+ cases. Please consult the OS documentation for more information.
+
+ Applications that require QRandomGenerator not to fall back to
+ non-cryptographic quality generators are advised to check their operating
+ system documentation or restrict their deployment to one of the above.
+
+ \section1 Reentrancy and thread-safety
+
+ QRandomGenerator is reentrant, meaning that multiple threads can operate on
+ this class at the same time, so long as they operate on different objects.
+ If multiple threads need to share one PRNG sequence, external locking by a
+ mutex is required.
+
+ The exceptions are the objects returned by QRandomGenerator::global() and
+ QRandomGenerator::system(): those objects are thread-safe and may be used
+ by any thread without external locking. Note that thread-safety does not
+ extend to copying those objects: they should always be used by reference.
\section1 Standard C++ Library compatibility
- QRandomGenerator is modeled after
- \c{\l{http://en.cppreference.com/w/cpp/numeric/random/random_device}{std::random_device}}
- and may be used in almost all contexts that the Standard Library can.
- QRandomGenerator attempts to use either the same engine that backs
- \c{std::random_device} or a better one. Note that \c{std::random_device} is
- also allowed to fail if the source entropy pool becomes exhausted, in which
- case it will throw an exception. QRandomGenerator never throws, but may abort
- program execution instead.
-
- Like the Standard Library class, QRandomGenerator can be used to seed Standard
- Library deterministic random engines from \c{<random>}, such as the
- Mersenne Twister. Unlike \c{std::random_device}, QRandomGenerator also
- implements the API of
- \c{\l{http://en.cppreference.com/w/cpp/numeric/random/seed_seq}{std::seed_seq}},
- allowing it to seed the deterministic engines directly.
-
- The following code can be used to create and seed the
- implementation-defined default deterministic PRNG, then use it to fill a
- block range:
-
- \code
- QRandomGenerator rd;
- std::default_random_engine rng(rd);
- std::generate(block.begin(), block.end(), rng);
+ QRandomGenerator is modeled after the requirements for random number
+ engines in the C++ Standard Library and may be used in almost all contexts
+ that the Standard Library engines can. Exceptions to the requirements are
+ the following:
- // equivalent to:
- for (auto &v : block)
- v = rng();
- \endcode
+ \list
+ \li QRandomGenerator does not support seeding from another seed
+ sequence-like class besides std::seed_seq itself;
+ \li QRandomGenerator is not comparable (but is copyable) or
+ streamable to \c{std::ostream} or from \c{std::istream}.
+ \endlist
QRandomGenerator is also compatible with the uniform distribution classes
\c{std::uniform_int_distribution} and \c{std:uniform_real_distribution}, as
@@ -535,57 +648,129 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
[1, 2.5):
\code
- QRandomGenerator64 rd;
std::uniform_real_distribution dist(1, 2.5);
- return dist(rd);
+ return dist(*QRandomGenerator::global());
\endcode
- Note the use of the QRandomGenerator64 class instead of QRandomGenerator to
- obtain 64 bits of random data in a single call, though it is not required
- to make the algorithm work (the Standard Library functions will make as
- many calls as required to obtain enough bits of random data for the desired
- range).
-
\sa QRandomGenerator64, qrand()
*/
/*!
- \fn QRandomGenerator::QRandomGenerator()
- \internal
- Defaulted constructor, does nothing.
+ \fn QRandomGenerator::QRandomGenerator(quint32 seedValue)
+
+ Initializes this QRandomGenerator object with the value \a seedValue as
+ the seed. Two objects constructed or reseeded with the same seed value will
+ produce the same number sequence.
+
+ \sa seed(), securelySeeded()
*/
/*!
- \typedef QRandomGenerator::result_type
+ \fn QRandomGenerator::QRandomGenerator(const quint32 (&seedBuffer)[N])
+ \overload
- A typedef to the type that operator()() returns. That is, quint32.
+ Initializes this QRandomGenerator object with the values found in the
+ array \a seedBuffer as the seed. Two objects constructed or reseeded with
+ the same seed value will produce the same number sequence.
- \sa operator()()
+ \sa seed(), securelySeeded()
*/
/*!
- \fn result_type QRandomGenerator::operator()()
+ \fn QRandomGenerator::QRandomGenerator(const quint32 *seedBuffer, qssize_t len)
+ \overload
- Generates a 32-bit random quantity and returns it.
+ Initializes this QRandomGenerator object with \a len values found in
+ the array \a seedBuffer as the seed. Two objects constructed or reseeded
+ with the same seed value will produce the same number sequence.
- \sa QRandomGenerator::generate(), QRandomGenerator::generate64()
+ This constructor is equivalent to:
+ \code
+ std::seed_seq sseq(seedBuffer, seedBuffer + len);
+ QRandomGenerator generator(sseq);
+ \endcode
+
+ \sa seed(), securelySeeded()
*/
/*!
- \fn double QRandomGenerator::entropy() const
+ \fn QRandomGenerator::QRandomGenerator(const quint32 *begin, const quin32 *end)
+ \overload
+
+ Initializes this QRandomGenerator object with the values found in the range
+ from \a begin to \a end as the seed. Two objects constructed or reseeded
+ with the same seed value will produce the same number sequence.
- Returns the estimate of the entropy in the random generator source.
+ This constructor is equivalent to:
+ \code
+ std::seed_seq sseq(begin, end);
+ QRandomGenerator generator(sseq);
+ \endcode
+
+ \sa seed(), securelySeeded()
+ */
+
+/*!
+ \fn QRandomGenerator::QRandomGenerator(std::seed_seq &sseq)
+ \overload
- This function exists to comply with the Standard Library requirements for
- \c{\l{http://en.cppreference.com/w/cpp/numeric/random/random_device}{std::random_device}}
- but it does not and cannot ever work. It is not possible to obtain a
- reliable entropy value in a shared entropy pool in a multi-tasking system,
- as other processes or threads may use that entropy. Any value non-zero
- value that this function could return would be obsolete by the time the
- user code reached it.
+ Initializes this QRandomGenerator object with the seed sequence \a
+ sseq as the seed. Two objects constructed or reseeded with the same seed
+ value will produce the same number sequence.
- Since QRandomGenerator attempts to use a hardware Random Number Generator,
- this function always returns 0.0.
+ \sa seed(), securelySeeded()
+ */
+
+/*!
+ \fn QRandomGenerator::QRandomGenerator(const QRandomGenerator &other)
+
+ Creates a copy of the generator state in the \a other object. If \a other is
+ QRandomGenerator::system() or a copy of that, this object will also read
+ from the operating system random-generating facilities. In that case, the
+ sequences generated by the two objects will be different.
+
+ In all other cases, the new QRandomGenerator object will start at the same
+ position in the deterministic sequence as the \a other object was. Both
+ objects will generate the same sequence from this point on.
+
+ For that reason, it is not adviseable to create a copy of
+ QRandomGenerator::global(). If one needs an exclusive deterministic
+ generator, consider instead using securelySeeded() to obtain a new object
+ that shares no relationship with the QRandomGenerator::global().
+ */
+
+/*!
+ \fn bool operator==(const QRandomGenerator &rng1, const QRandomGenerator &rng2)
+ \relates QRandomGenerator
+
+ Returns true if the two the two engines \a rng1 and \a rng2 are at the same
+ state or if they are both reading from the operating system facilities,
+ false otherwise.
+*/
+
+/*!
+ \fn bool operator!=(const QRandomGenerator &rng1, const QRandomGenerator &rng2)
+ \relates QRandomGenerator
+
+ Returns true if the two the two engines \a rng1 and \a rng2 are at
+ different states or if one of them is reading from the operating system
+ facilities and the other is not, false otherwise.
+*/
+
+/*!
+ \typedef QRandomGenerator::result_type
+
+ A typedef to the type that operator()() returns. That is, quint32.
+
+ \sa operator()()
+ */
+
+/*!
+ \fn result_type QRandomGenerator::operator()()
+
+ Generates a 32-bit random quantity and returns it.
+
+ \sa generate(), generate64()
*/
/*!
@@ -593,7 +778,7 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
Returns the minimum value that QRandomGenerator may ever generate. That is, 0.
- \sa max(), QRandomGenerator64::max()
+ \sa max(), QRandomGenerator64::min()
*/
/*!
@@ -606,13 +791,38 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
*/
/*!
+ \fn void QRandomGenerator::seed(quint32 seed)
+
+ Reseeds this object using the value \a seed as the seed.
+ */
+
+/*!
+ \fn void QRandomGenerator::seed(std::seed_seq &seed)
+ \overload
+
+ Reseeds this object using the seed sequence \a sseq as the seed.
+ */
+
+/*!
+ \fn void QRandomGenerator::discard(unsigned long long z)
+
+ Discards the next \a z entries from the sequence. This method is equivalent
+ to calling generate() \a z times and discarding the result, as in:
+
+ \code
+ while (z--)
+ generator.generate();
+ \endcode
+*/
+
+/*!
\fn void QRandomGenerator::generate(ForwardIterator begin, ForwardIterator end)
Generates 32-bit quantities and stores them in the range between \a begin
and \a end. This function is equivalent to (and is implemented as):
\code
- std::generate(begin, end, []() { return generate(); });
+ std::generate(begin, end, [this]() { return generate(); });
\endcode
This function complies with the requirements for the function
@@ -625,7 +835,7 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
quantities, one can write:
\code
- std::generate(begin, end, []() { return QRandomGenerator::generate64(); });
+ std::generate(begin, end, []() { return QRandomGenerator::global()->generate64(); });
\endcode
If the range refers to contiguous memory (such as an array or the data from
@@ -703,26 +913,26 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
*/
/*!
- \fn qreal QRandomGenerator::bounded(qreal sup)
+ \fn qreal QRandomGenerator::bounded(qreal highest)
Generates one random qreal in the range between 0 (inclusive) and \a
- sup (exclusive). This function is equivalent to and is implemented as:
+ highest (exclusive). This function is equivalent to and is implemented as:
\code
- return generateDouble() * sup;
+ return generateDouble() * highest;
\endcode
\sa generateDouble(), bounded()
*/
/*!
- \fn quint32 QRandomGenerator::bounded(quint32 sup)
+ \fn quint32 QRandomGenerator::bounded(quint32 highest)
\overload
Generates one random 32-bit quantity in the range between 0 (inclusive) and
- \a sup (exclusive). The same result may also be obtained by using
+ \a highest (exclusive). The same result may also be obtained by using
\c{\l{http://en.cppreference.com/w/cpp/numeric/random/uniform_int_distribution}{std::uniform_int_distribution}}
- with parameters 0 and \c{sup - 1}. That class can also be used to obtain
+ with parameters 0 and \c{highest - 1}. That class can also be used to obtain
quantities larger than 32 bits.
For example, to obtain a value between 0 and 255 (inclusive), one would write:
@@ -741,11 +951,11 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
*/
/*!
- \fn quint32 QRandomGenerator::bounded(int sup)
+ \fn quint32 QRandomGenerator::bounded(int highest)
\overload
Generates one random 32-bit quantity in the range between 0 (inclusive) and
- \a sup (exclusive). \a sup must not be negative.
+ \a highest (exclusive). \a highest must not be negative.
Note that this function cannot be used to obtain values in the full 32-bit
range of int. Instead, use generate() and cast to int.
@@ -754,13 +964,13 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
*/
/*!
- \fn quint32 QRandomGenerator::bounded(quint32 min, quint32 sup)
+ \fn quint32 QRandomGenerator::bounded(quint32 lowest, quint32 highest)
\overload
- Generates one random 32-bit quantity in the range between \a min (inclusive)
- and \a sup (exclusive). The same result may also be obtained by using
+ Generates one random 32-bit quantity in the range between \a lowest (inclusive)
+ and \a highest (exclusive). The same result may also be obtained by using
\c{\l{http://en.cppreference.com/w/cpp/numeric/random/uniform_int_distribution}{std::uniform_int_distribution}}
- with parameters \a min and \c{\a sup - 1}. That class can also be used to
+ with parameters \a lowest and \c{\a highest - 1}. That class can also be used to
obtain quantities larger than 32 bits.
For example, to obtain a value between 1000 (incl.) and 2000 (excl.), one
@@ -778,11 +988,11 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
*/
/*!
- \fn quint32 QRandomGenerator::bounded(int min, int sup)
+ \fn quint32 QRandomGenerator::bounded(int lowest, int highest)
\overload
- Generates one random 32-bit quantity in the range between \a min
- (inclusive) and \a sup (exclusive), both of which may be negative.
+ Generates one random 32-bit quantity in the range between \a lowest
+ (inclusive) and \a highest (exclusive), both of which may be negative.
Note that this function cannot be used to obtain values in the full 32-bit
range of int. Instead, use generate() and cast to int.
@@ -791,6 +1001,72 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
*/
/*!
+ \fn QRandomGenerator *QRandomGenerator::system()
+ \threadsafe
+
+ Returns a pointer to a shared QRandomGenerator that always uses the
+ facilities provided by the operating system to generate random numbers. The
+ system facilities are considered to be cryptographically safe on at least
+ the following operating systems: Apple OSes (Darwin), BSDs, Linux, Windows.
+ That may also be the case on other operating systems.
+
+ They are also possibly backed by a true hardware random number generator.
+ For that reason, the QRandomGenerator returned by this function should not
+ be used for bulk data generation. Instead, use it to seed QRandomGenerator
+ or a random engine from the <random> header.
+
+ The object returned by this function is thread-safe and may be used in any
+ thread without locks. It may also be copied and the resulting
+ QRandomGenerator will also access the operating system facilities, but they
+ will not generate the same sequence.
+
+ \sa securelySeeded(), global()
+*/
+
+/*!
+ \fn QRandomGenerator *QRandomGenerator::global()
+ \threadsafe
+
+ Returns a pointer to a shared QRandomGenerator that was seeded using
+ securelySeeded(). This function should be used to create random data
+ without the expensive creation of a securely-seeded QRandomGenerator
+ for a specific use or storing the rather large QRandomGenerator object.
+
+ For example, the following creates a random RGB color:
+
+ \code
+ return QColor::fromRgb(QRandomGenerator::global()->generate());
+ \endcode
+
+ Accesses to this object are thread-safe and it may therefore be used in any
+ thread without locks. The object may also be copied and the sequence
+ produced by the copy will be the same as the shared object will produce.
+ Note, however, that if there are other threads accessing the global object,
+ those threads may obtain samples at unpredictable intervals.
+
+ \sa securelySeeded(), system()
+*/
+
+/*!
+ \fn QRandomGenerator QRandomGenerator::securelySeeded()
+
+ Returns a new QRandomGenerator object that was securely seeded with
+ QRandomGenerator::system(). This function will obtain the ideal seed size
+ for the algorithm that QRandomGenerator uses and is therefore the
+ recommended way for creating a new QRandomGenerator object that will be
+ kept for some time.
+
+ Given the amount of data required to securely seed the deterministic
+ engine, this function is somewhat expensive and should not be used for
+ short-term uses of QRandomGenerator (using it to generate fewer than 2600
+ bytes of random data is effectively a waste of resources). If the use
+ doesn't require that much data, consider using QRandomGenerator::global()
+ and not storing a QRandomGenerator object instead.
+
+ \sa global(), system()
+ */
+
+/*!
\class QRandomGenerator64
\inmodule QtCore
\since 5.10
@@ -811,10 +1087,11 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
*/
/*!
- \fn QRandomGenerator64::QRandomGenerator64()
- \internal
- Defaulted constructor, does nothing.
- */
+ \fn QRandomGenerator64::QRandomGenerator64(const QRandomGenerator &other)
+ \internal
+
+ Creates a copy.
+*/
/*!
\typedef QRandomGenerator64::result_type
@@ -849,80 +1126,119 @@ static Q_NEVER_INLINE void fill(void *buffer, void *bufferEnd)
\sa QRandomGenerator::generate(), QRandomGenerator::generate64()
*/
-/*!
- \fn double QRandomGenerator64::entropy() const
+Q_DECL_CONSTEXPR QRandomGenerator::Storage::Storage()
+ : dummy(0)
+{
+ // nothing
+}
- Returns the estimate of the entropy in the random generator source.
+inline QRandomGenerator64::QRandomGenerator64(System s)
+ : QRandomGenerator(s)
+{
+}
- This function exists to comply with the Standard Library requirements for
- \c{\l{http://en.cppreference.com/w/cpp/numeric/random/random_device}{std::random_device}}
- but it does not and cannot ever work. It is not possible to obtain a
- reliable entropy value in a shared entropy pool in a multi-tasking system,
- as other processes or threads may use that entropy. Any value non-zero
- value that this function could return would be obsolete by the time the
- user code reached it.
+QRandomGenerator64 *QRandomGenerator64::system()
+{
+ auto self = SystemAndGlobalGenerators::system();
+ Q_ASSERT(self->type == SystemRNG);
+ return self;
+}
- Since QRandomGenerator64 attempts to use a hardware Random Number Generator,
- this function always returns 0.0.
- */
+QRandomGenerator64 *QRandomGenerator64::global()
+{
+ auto self = SystemAndGlobalGenerators::globalNoInit();
-/*!
- \fn result_type QRandomGenerator64::min()
+ // Yes, this is a double-checked lock.
+ // We can return even if the type is not completely initialized yet:
+ // any thread trying to actually use the contents of the random engine
+ // will necessarily wait on the lock.
+ if (Q_LIKELY(self->type != SystemRNG))
+ return self;
- Returns the minimum value that QRandomGenerator64 may ever generate. That is, 0.
+ SystemAndGlobalGenerators::PRNGLocker locker(self);
+ if (self->type == SystemRNG)
+ SystemAndGlobalGenerators::securelySeed(self);
- \sa max(), QRandomGenerator::max()
- */
+ return self;
+}
-/*!
- \fn result_type QRandomGenerator64::max()
+QRandomGenerator64 QRandomGenerator64::securelySeeded()
+{
+ QRandomGenerator64 result(System{});
+ SystemAndGlobalGenerators::securelySeed(&result);
+ return result;
+}
- Returns the maximum value that QRandomGenerator64 may ever generate. That is,
- \c {std::numeric_limits<result_type>::max()}.
+/// \internal
+inline QRandomGenerator::QRandomGenerator(System)
+ : type(SystemRNG)
+{
+ // don't touch storage
+}
- \sa min(), QRandomGenerator::max()
- */
+QRandomGenerator::QRandomGenerator(const QRandomGenerator &other)
+ : type(other.type)
+{
+ Q_ASSERT(this != system());
+ Q_ASSERT(this != SystemAndGlobalGenerators::globalNoInit());
-/*!
- Generates one 32-bit random value and returns it.
+ if (type != SystemRNG) {
+ SystemAndGlobalGenerators::PRNGLocker lock(&other);
+ storage.engine() = other.storage.engine();
+ }
+}
- Note about casting to a signed integer: all bits returned by this function
- are random, so there's a 50% chance that the most significant bit will be
- set. If you wish to cast the returned value to int and keep it positive,
- you should mask the sign bit off:
+QRandomGenerator &QRandomGenerator::operator=(const QRandomGenerator &other)
+{
+ if (Q_UNLIKELY(this == system()) || Q_UNLIKELY(this == SystemAndGlobalGenerators::globalNoInit()))
+ qFatal("Attempted to overwrite a QRandomGenerator to system() or global().");
- \code
- int value = QRandomGenerator::generate() & std::numeric_limits<int>::max();
- \endcode
+ if ((type = other.type) != SystemRNG) {
+ SystemAndGlobalGenerators::PRNGLocker lock(&other);
+ storage.engine() = other.storage.engine();
+ }
+ return *this;
+}
- \sa generate64(), generateDouble()
- */
-quint32 QRandomGenerator::generate()
+QRandomGenerator::QRandomGenerator(std::seed_seq &sseq) Q_DECL_NOTHROW
+ : type(MersenneTwister)
{
- quint32 ret;
- fill(&ret, &ret + 1);
- return ret;
+ Q_ASSERT(this != system());
+ Q_ASSERT(this != SystemAndGlobalGenerators::globalNoInit());
+
+ new (&storage.engine()) RandomEngine(sseq);
}
-/*!
- Generates one 64-bit random value and returns it.
+QRandomGenerator::QRandomGenerator(const quint32 *begin, const quint32 *end)
+ : type(MersenneTwister)
+{
+ Q_ASSERT(this != system());
+ Q_ASSERT(this != SystemAndGlobalGenerators::globalNoInit());
- Note about casting to a signed integer: all bits returned by this function
- are random, so there's a 50% chance that the most significant bit will be
- set. If you wish to cast the returned value to qint64 and keep it positive,
- you should mask the sign bit off:
+ std::seed_seq s(begin, end);
+ new (&storage.engine()) RandomEngine(s);
+}
- \code
- qint64 value = QRandomGenerator::generate64() & std::numeric_limits<qint64>::max();
- \endcode
+void QRandomGenerator::discard(unsigned long long z)
+{
+ if (Q_UNLIKELY(type == SystemRNG))
+ return;
- \sa generate(), generateDouble(), QRandomGenerator64
- */
-quint64 QRandomGenerator::generate64()
+ SystemAndGlobalGenerators::PRNGLocker lock(this);
+ storage.engine().discard(z);
+}
+
+bool operator==(const QRandomGenerator &rng1, const QRandomGenerator &rng2)
{
- quint64 ret;
- fill(&ret, &ret + 1);
- return ret;
+ if (rng1.type != rng2.type)
+ return false;
+ if (rng1.type == SystemRNG)
+ return true;
+
+ // Lock global() if either is it (otherwise this locking is a no-op)
+ using PRNGLocker = QRandomGenerator::SystemAndGlobalGenerators::PRNGLocker;
+ PRNGLocker locker(&rng1 == QRandomGenerator::global() ? &rng1 : &rng2);
+ return rng1.storage.engine() == rng2.storage.engine();
}
/*!
@@ -931,9 +1247,19 @@ quint64 QRandomGenerator::generate64()
Fills the range pointed by \a buffer and \a bufferEnd with 32-bit random
values. The buffer must be correctly aligned.
*/
-void QRandomGenerator::fillRange_helper(void *buffer, void *bufferEnd)
+void QRandomGenerator::_fillRange(void *buffer, void *bufferEnd)
{
- fill(buffer, bufferEnd);
+ // Verify that the pointers are properly aligned for 32-bit
+ Q_ASSERT(quintptr(buffer) % sizeof(quint32) == 0);
+ Q_ASSERT(quintptr(bufferEnd) % sizeof(quint32) == 0);
+ quint32 *begin = static_cast<quint32 *>(buffer);
+ quint32 *end = static_cast<quint32 *>(bufferEnd);
+
+ if (type == SystemRNG || Q_UNLIKELY(uint(qt_randomdevice_control) & (UseSystemRNG|SetRandomData)))
+ return SystemGenerator::self().generate(begin, end);
+
+ SystemAndGlobalGenerators::PRNGLocker lock(this);
+ std::generate(begin, end, [this]() { return storage.engine()(); });
}
#if defined(Q_OS_ANDROID) && (__ANDROID_API__ < 21)
diff --git a/src/corelib/global/qrandom.h b/src/corelib/global/qrandom.h
index 049495d4e8..bde64646a4 100644
--- a/src/corelib/global/qrandom.h
+++ b/src/corelib/global/qrandom.h
@@ -42,6 +42,7 @@
#include <QtCore/qglobal.h>
#include <algorithm> // for std::generate
+#include <random> // for std::mt19937
QT_BEGIN_NAMESPACE
@@ -51,19 +52,43 @@ class QRandomGenerator
template <typename UInt> using IfValidUInt =
typename std::enable_if<std::is_unsigned<UInt>::value && sizeof(UInt) >= sizeof(uint), bool>::type;
public:
- static QRandomGenerator system() { return {}; }
- static QRandomGenerator global() { return {}; }
- QRandomGenerator() = default;
-
- // ### REMOVE BEFORE 5.10
- QRandomGenerator *operator->() { return this; }
- static quint32 get32() { return generate(); }
- static quint64 get64() { return generate64(); }
- static qreal getReal() { return generateDouble(); }
-
- static Q_CORE_EXPORT quint32 generate();
- static Q_CORE_EXPORT quint64 generate64();
- static double generateDouble()
+ QRandomGenerator(quint32 seedValue = 1)
+ : QRandomGenerator(&seedValue, 1)
+ {}
+ template <qssize_t N> QRandomGenerator(const quint32 (&seedBuffer)[N])
+ : QRandomGenerator(seedBuffer, seedBuffer + N)
+ {}
+ QRandomGenerator(const quint32 *seedBuffer, qssize_t len)
+ : QRandomGenerator(seedBuffer, seedBuffer + len)
+ {}
+ Q_CORE_EXPORT QRandomGenerator(std::seed_seq &sseq) Q_DECL_NOTHROW;
+ Q_CORE_EXPORT QRandomGenerator(const quint32 *begin, const quint32 *end);
+
+ // copy constructor & assignment operator (move unnecessary)
+ Q_CORE_EXPORT QRandomGenerator(const QRandomGenerator &other);
+ Q_CORE_EXPORT QRandomGenerator &operator=(const QRandomGenerator &other);
+
+ friend Q_CORE_EXPORT bool operator==(const QRandomGenerator &rng1, const QRandomGenerator &rng2);
+ friend bool operator!=(const QRandomGenerator &rng1, const QRandomGenerator &rng2)
+ {
+ return !(rng1 == rng2);
+ }
+
+ quint32 generate()
+ {
+ quint32 ret;
+ fillRange(&ret, 1);
+ return ret;
+ }
+
+ quint64 generate64()
+ {
+ quint32 buf[2];
+ fillRange(buf);
+ return buf[0] | (quint64(buf[1]) << 32);
+ }
+
+ double generateDouble()
{
// IEEE 754 double precision has:
// 1 bit sign
@@ -77,87 +102,161 @@ public:
return double(x) / double(limit);
}
- static qreal bounded(qreal sup)
+ double bounded(double highest)
{
- return generateDouble() * sup;
+ return generateDouble() * highest;
}
- static quint32 bounded(quint32 sup)
+ quint32 bounded(quint32 highest)
{
quint64 value = generate();
- value *= sup;
+ value *= highest;
value /= (max)() + quint64(1);
return quint32(value);
}
- static int bounded(int sup)
+ int bounded(int highest)
{
- return int(bounded(quint32(sup)));
+ return int(bounded(quint32(highest)));
}
- static quint32 bounded(quint32 min, quint32 sup)
+ quint32 bounded(quint32 lowest, quint32 highest)
{
- return bounded(sup - min) + min;
+ return bounded(highest - lowest) + lowest;
}
- static int bounded(int min, int sup)
+ int bounded(int lowest, int highest)
{
- return bounded(sup - min) + min;
+ return bounded(highest - lowest) + lowest;
}
template <typename UInt, IfValidUInt<UInt> = true>
- static void fillRange(UInt *buffer, qssize_t count)
+ void fillRange(UInt *buffer, qssize_t count)
{
- fillRange_helper(buffer, buffer + count);
+ _fillRange(buffer, buffer + count);
}
template <typename UInt, size_t N, IfValidUInt<UInt> = true>
- static void fillRange(UInt (&buffer)[N])
+ void fillRange(UInt (&buffer)[N])
{
- fillRange_helper(buffer, buffer + N);
+ _fillRange(buffer, buffer + N);
}
// API like std::seed_seq
template <typename ForwardIterator>
void generate(ForwardIterator begin, ForwardIterator end)
{
- auto generator = static_cast<quint32 (*)()>(&QRandomGenerator::generate);
- std::generate(begin, end, generator);
+ std::generate(begin, end, [this]() { return generate(); });
}
void generate(quint32 *begin, quint32 *end)
{
- fillRange_helper(begin, end);
+ _fillRange(begin, end);
}
- // API like std::random_device
+ // API like std:: random engines
typedef quint32 result_type;
result_type operator()() { return generate(); }
- double entropy() const Q_DECL_NOTHROW { return 0.0; }
+ void seed(quint32 s = 1) { *this = { s }; }
+ void seed(std::seed_seq &sseq) Q_DECL_NOTHROW { *this = { sseq }; }
+ Q_CORE_EXPORT void discard(unsigned long long z);
static Q_DECL_CONSTEXPR result_type min() { return (std::numeric_limits<result_type>::min)(); }
static Q_DECL_CONSTEXPR result_type max() { return (std::numeric_limits<result_type>::max)(); }
+ static inline Q_DECL_CONST_FUNCTION QRandomGenerator *system();
+ static inline Q_DECL_CONST_FUNCTION QRandomGenerator *global();
+ static inline QRandomGenerator securelySeeded();
+
+protected:
+ enum System {};
+ QRandomGenerator(System);
+
private:
- static Q_CORE_EXPORT void fillRange_helper(void *buffer, void *bufferEnd);
+ Q_CORE_EXPORT void _fillRange(void *buffer, void *bufferEnd);
+
+ friend class QRandomGenerator64;
+ struct SystemGenerator;
+ struct SystemAndGlobalGenerators;
+ typedef std::mt19937 RandomEngine;
+
+ union Storage {
+ uint dummy;
+#ifdef Q_COMPILER_UNRESTRICTED_UNIONS
+ RandomEngine twister;
+ RandomEngine &engine() { return twister; }
+ const RandomEngine &engine() const { return twister; }
+#else
+ std::aligned_storage<sizeof(RandomEngine), Q_ALIGNOF(RandomEngine)>::type buffer;
+ RandomEngine &engine() { return reinterpret_cast<RandomEngine &>(buffer); }
+ const RandomEngine &engine() const { return reinterpret_cast<const RandomEngine &>(buffer); }
+#endif
+
+ Q_STATIC_ASSERT_X(std::is_trivially_destructible<RandomEngine>::value,
+ "std::mersenne_twister not trivially destructible as expected");
+ Q_DECL_CONSTEXPR Storage();
+ };
+ uint type;
+ Storage storage;
};
-class QRandomGenerator64
+class QRandomGenerator64 : public QRandomGenerator
{
+ QRandomGenerator64(System);
public:
- static QRandomGenerator64 system() { return {}; }
- static QRandomGenerator64 global() { return {}; }
- QRandomGenerator64() = default;
+ // unshadow generate() overloads, since we'll override.
+ using QRandomGenerator::generate;
+ quint64 generate() { return generate64(); }
- static quint64 generate() { return QRandomGenerator::generate64(); }
-
- // API like std::random_device
typedef quint64 result_type;
- result_type operator()() { return QRandomGenerator::generate64(); }
- double entropy() const Q_DECL_NOTHROW { return 0.0; }
+ result_type operator()() { return generate64(); }
+
+#ifndef Q_QDOC
+ QRandomGenerator64(quint32 seedValue = 1)
+ : QRandomGenerator(seedValue)
+ {}
+ template <qssize_t N> QRandomGenerator64(const quint32 (&seedBuffer)[N])
+ : QRandomGenerator(seedBuffer)
+ {}
+ QRandomGenerator64(const quint32 *seedBuffer, qssize_t len)
+ : QRandomGenerator(seedBuffer, len)
+ {}
+ QRandomGenerator64(std::seed_seq &sseq) Q_DECL_NOTHROW
+ : QRandomGenerator(sseq)
+ {}
+ QRandomGenerator64(const quint32 *begin, const quint32 *end)
+ : QRandomGenerator(begin, end)
+ {}
+ QRandomGenerator64(const QRandomGenerator &other) : QRandomGenerator(other) {}
+
+ void discard(unsigned long long z)
+ {
+ Q_ASSERT_X(z * 2 > z, "QRandomGenerator64::discard",
+ "Overflow. Are you sure you want to skip over 9 quintillion samples?");
+ QRandomGenerator::discard(z * 2);
+ }
+
static Q_DECL_CONSTEXPR result_type min() { return (std::numeric_limits<result_type>::min)(); }
static Q_DECL_CONSTEXPR result_type max() { return (std::numeric_limits<result_type>::max)(); }
+ static Q_DECL_CONST_FUNCTION Q_CORE_EXPORT QRandomGenerator64 *system();
+ static Q_DECL_CONST_FUNCTION Q_CORE_EXPORT QRandomGenerator64 *global();
+ static Q_CORE_EXPORT QRandomGenerator64 securelySeeded();
+#endif // Q_QDOC
};
+inline QRandomGenerator *QRandomGenerator::system()
+{
+ return QRandomGenerator64::system();
+}
+
+inline QRandomGenerator *QRandomGenerator::global()
+{
+ return QRandomGenerator64::global();
+}
+
+QRandomGenerator QRandomGenerator::securelySeeded()
+{
+ return QRandomGenerator64::securelySeeded();
+}
QT_END_NAMESPACE
diff --git a/src/corelib/global/qrandom_p.h b/src/corelib/global/qrandom_p.h
index 6ac2904e1b..917a91098e 100644
--- a/src/corelib/global/qrandom_p.h
+++ b/src/corelib/global/qrandom_p.h
@@ -52,11 +52,12 @@
//
#include "qglobal_p.h"
+#include <private/qsimd_p.h>
QT_BEGIN_NAMESPACE
enum QRandomGeneratorControl {
- SkipMemfill = 1,
+ UseSystemRNG = 1,
SkipSystemRNG = 2,
SkipHWRNG = 4,
SetRandomData = 8,
@@ -65,6 +66,11 @@ enum QRandomGeneratorControl {
RandomDataMask = 0xfffffff0
};
+enum RNGType {
+ SystemRNG = 0,
+ MersenneTwister = 1
+};
+
#if defined(QT_BUILD_INTERNAL) && defined(QT_BUILD_CORE_LIB)
Q_CORE_EXPORT QBasicAtomicInteger<uint> qt_randomdevice_control = Q_BASIC_ATOMIC_INITIALIZER(0U);
#elif defined(QT_BUILD_INTERNAL)
@@ -73,6 +79,16 @@ extern Q_CORE_EXPORT QBasicAtomicInteger<uint> qt_randomdevice_control;
enum { qt_randomdevice_control = 0 };
#endif
+inline bool qt_has_hwrng()
+{
+#if defined(Q_PROCESSOR_X86) && QT_COMPILER_SUPPORTS_HERE(RDRND)
+ return qCpuHasFeature(RDRND);
+#else
+ return false;
+#endif
+}
+
+
QT_END_NAMESPACE
#endif // QRANDOM_P_H
diff --git a/src/corelib/io/qfileselector.cpp b/src/corelib/io/qfileselector.cpp
index 9db67f2f9b..0ba8b124f7 100644
--- a/src/corelib/io/qfileselector.cpp
+++ b/src/corelib/io/qfileselector.cpp
@@ -146,7 +146,7 @@ QFileSelectorPrivate::QFileSelectorPrivate()
Selectors normally available are
\list
\li platform, any of the following strings which match the platform the application is running
- on (list not exhaustive): android, ios, osx, darwin, mac, linux, wince, unix, windows.
+ on (list not exhaustive): android, ios, osx, darwin, mac, macos, linux, qnx, unix, windows.
On Linux, if it can be determined, the name of the distribution too, like debian,
fedora or opensuse.
\li locale, same as QLocale().name().
@@ -373,8 +373,8 @@ QStringList QFileSelectorPrivate::platformSelectors()
# endif
#elif defined(Q_OS_UNIX)
ret << QStringLiteral("unix");
-# if !defined(Q_OS_ANDROID)
- // we don't want "linux" for Android
+# if !defined(Q_OS_ANDROID) && !defined(Q_OS_QNX)
+ // we don't want "linux" for Android or two instances of "qnx" for QNX
ret << QSysInfo::kernelType();
# ifdef Q_OS_MAC
ret << QStringLiteral("mac"); // compatibility, since kernelType() is "darwin"
diff --git a/src/corelib/io/qfilesystemwatcher_win.cpp b/src/corelib/io/qfilesystemwatcher_win.cpp
index cdb79e7c97..9e43d11e71 100644
--- a/src/corelib/io/qfilesystemwatcher_win.cpp
+++ b/src/corelib/io/qfilesystemwatcher_win.cpp
@@ -308,7 +308,7 @@ void QWindowsRemovableDriveListener::addPath(const QString &p)
notify.dbch_size = sizeof(notify);
notify.dbch_devicetype = DBT_DEVTYP_HANDLE;
notify.dbch_handle = volumeHandle;
- QEventDispatcherWin32 *winEventDispatcher = static_cast<QEventDispatcherWin32 *>(QCoreApplication::eventDispatcher());
+ QEventDispatcherWin32 *winEventDispatcher = static_cast<QEventDispatcherWin32 *>(QAbstractEventDispatcher::instance());
re.devNotify = RegisterDeviceNotification(winEventDispatcher->internalHwnd(),
&notify, DEVICE_NOTIFY_WINDOW_HANDLE);
// Empirically found: The notifications also work when the handle is immediately
@@ -336,7 +336,7 @@ QWindowsFileSystemWatcherEngine::QWindowsFileSystemWatcherEngine(QObject *parent
: QFileSystemWatcherEngine(parent)
{
#ifndef Q_OS_WINRT
- if (QAbstractEventDispatcher *eventDispatcher = QCoreApplication::eventDispatcher()) {
+ if (QAbstractEventDispatcher *eventDispatcher = QAbstractEventDispatcher::instance()) {
m_driveListener = new QWindowsRemovableDriveListener(this);
eventDispatcher->installNativeEventFilter(m_driveListener);
parent->setProperty("_q_driveListener",
diff --git a/src/corelib/io/qiodevice.cpp b/src/corelib/io/qiodevice.cpp
index 82fc34c537..0a3e83206b 100644
--- a/src/corelib/io/qiodevice.cpp
+++ b/src/corelib/io/qiodevice.cpp
@@ -775,6 +775,7 @@ bool QIODevice::open(OpenMode mode)
d->writeBuffers.clear();
d->setReadChannelCount(isReadable() ? 1 : 0);
d->setWriteChannelCount(isWritable() ? 1 : 0);
+ d->errorString.clear();
#if defined QIODEVICE_DEBUG
printf("%p QIODevice::open(0x%x)\n", this, quint32(mode));
#endif
@@ -801,7 +802,6 @@ void QIODevice::close()
emit aboutToClose();
#endif
d->openMode = NotOpen;
- d->errorString.clear();
d->pos = 0;
d->transactionStarted = false;
d->transactionPos = 0;
diff --git a/src/corelib/io/qprocess_win.cpp b/src/corelib/io/qprocess_win.cpp
index fbbfac26f6..6ab806d9fe 100644
--- a/src/corelib/io/qprocess_win.cpp
+++ b/src/corelib/io/qprocess_win.cpp
@@ -1,7 +1,7 @@
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
-** Copyright (C) 2016 Intel Corporation.
+** Copyright (C) 2017 Intel Corporation.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtCore module of the Qt Toolkit.
@@ -48,6 +48,7 @@
#include <qdir.h>
#include <qelapsedtimer.h>
#include <qfileinfo.h>
+#include <qrandom.h>
#include <qregexp.h>
#include <qwineventnotifier.h>
#include <private/qsystemlibrary_p.h>
@@ -99,10 +100,8 @@ static void qt_create_pipe(Q_PIPE *pipe, bool isInputPipe)
wchar_t pipeName[256];
unsigned int attempts = 1000;
forever {
- // ### The user must make sure to call qsrand() to make the pipe names less predictable.
- // ### Replace the call to qrand() with a secure version, once we have it in Qt.
_snwprintf(pipeName, sizeof(pipeName) / sizeof(pipeName[0]),
- L"\\\\.\\pipe\\qt-%X", qrand());
+ L"\\\\.\\pipe\\qt-%X", QRandomGenerator::global()->generate());
DWORD dwOpenMode = FILE_FLAG_OVERLAPPED;
DWORD dwOutputBufferSize = 0;
diff --git a/src/corelib/io/qstorageinfo_unix.cpp b/src/corelib/io/qstorageinfo_unix.cpp
index 0911083bac..cdaa6329f9 100644
--- a/src/corelib/io/qstorageinfo_unix.cpp
+++ b/src/corelib/io/qstorageinfo_unix.cpp
@@ -544,6 +544,38 @@ void QStorageInfoPrivate::initRootPath()
}
}
+#ifdef Q_OS_LINUX
+// udev encodes the labels with ID_LABEL_FS_ENC which is done with
+// blkid_encode_string(). Within this function some 1-byte utf-8
+// characters not considered safe (e.g. '\' or ' ') are encoded as hex
+static QString decodeFsEncString(const QString &str)
+{
+ QString decoded;
+ decoded.reserve(str.size());
+
+ int i = 0;
+ while (i < str.size()) {
+ if (i <= str.size() - 4) { // we need at least four characters \xAB
+ if (str.at(i) == QLatin1Char('\\') &&
+ str.at(i+1) == QLatin1Char('x')) {
+ bool bOk;
+ const int code = str.midRef(i+2, 2).toInt(&bOk, 16);
+ // only decode characters between 0x20 and 0x7f but not
+ // the backslash to prevent collisions
+ if (bOk && code >= 0x20 && code < 0x80 && code != '\\') {
+ decoded += QChar(code);
+ i += 4;
+ continue;
+ }
+ }
+ }
+ decoded += str.at(i);
+ ++i;
+ }
+ return decoded;
+}
+#endif
+
static inline QString retrieveLabel(const QByteArray &device)
{
#ifdef Q_OS_LINUX
@@ -557,7 +589,7 @@ static inline QString retrieveLabel(const QByteArray &device)
it.next();
QFileInfo fileInfo(it.fileInfo());
if (fileInfo.isSymLink() && fileInfo.symLinkTarget() == devicePath)
- return fileInfo.fileName();
+ return decodeFsEncString(fileInfo.fileName());
}
#elif defined Q_OS_HAIKU
fs_info fsInfo;
diff --git a/src/corelib/io/qtemporaryfile.cpp b/src/corelib/io/qtemporaryfile.cpp
index 5865d9e19a..b8d3e859cf 100644
--- a/src/corelib/io/qtemporaryfile.cpp
+++ b/src/corelib/io/qtemporaryfile.cpp
@@ -165,7 +165,7 @@ QFileSystemEntry::NativePath QTemporaryFileName::generateNext()
Char *rIter = placeholderEnd;
while (rIter != placeholderStart) {
- quint32 rnd = QRandomGenerator::generate();
+ quint32 rnd = QRandomGenerator::global()->generate();
auto applyOne = [&]() {
quint32 v = rnd & ((1 << BitsPerCharacter) - 1);
rnd >>= BitsPerCharacter;
diff --git a/src/corelib/io/qurl.cpp b/src/corelib/io/qurl.cpp
index a499dc2d30..cf7ed130ba 100644
--- a/src/corelib/io/qurl.cpp
+++ b/src/corelib/io/qurl.cpp
@@ -1037,6 +1037,7 @@ inline void QUrlPrivate::setAuthority(const QString &auth, int from, int end, QU
{
sectionIsPresent &= ~Authority;
sectionIsPresent |= Host;
+ port = -1;
// we never actually _loop_
while (from != end) {
@@ -1061,10 +1062,8 @@ inline void QUrlPrivate::setAuthority(const QString &auth, int from, int end, QU
}
}
- if (colonIndex == end - 1) {
- // found a colon but no digits after it
- port = -1;
- } else if (uint(colonIndex) < uint(end)) {
+ if (uint(colonIndex) < uint(end) - 1) {
+ // found a colon with digits after it
unsigned long x = 0;
for (int i = colonIndex + 1; i < end; ++i) {
ushort c = auth.at(i).unicode();
@@ -1083,8 +1082,6 @@ inline void QUrlPrivate::setAuthority(const QString &auth, int from, int end, QU
if (mode == QUrl::StrictMode)
break;
}
- } else {
- port = -1;
}
setHost(auth, from, qMin<uint>(end, colonIndex), mode);
@@ -1644,8 +1641,7 @@ inline QUrlPrivate::ErrorCode QUrlPrivate::validityError(QString *source, int *p
if (path.isEmpty())
return NoError;
if (path.at(0) == QLatin1Char('/')) {
- if (sectionIsPresent & QUrlPrivate::Authority || port != -1 ||
- path.length() == 1 || path.at(1) != QLatin1Char('/'))
+ if (hasAuthority() || path.length() == 1 || path.at(1) != QLatin1Char('/'))
return NoError;
if (source) {
*source = path;
@@ -2474,6 +2470,8 @@ void QUrl::setPort(int port)
}
d->port = port;
+ if (port != -1)
+ d->sectionIsPresent |= QUrlPrivate::Host;
}
/*!
diff --git a/src/corelib/kernel/qfunctions_winrt.h b/src/corelib/kernel/qfunctions_winrt.h
index 9b33f8b120..d0c44be683 100644
--- a/src/corelib/kernel/qfunctions_winrt.h
+++ b/src/corelib/kernel/qfunctions_winrt.h
@@ -44,6 +44,7 @@
#ifdef Q_OS_WIN
+#include <QtCore/QCoreApplication>
#include <QtCore/QThread>
#include <QtCore/QAbstractEventDispatcher>
#include <QtCore/QElapsedTimer>
diff --git a/src/corelib/kernel/qwineventnotifier.cpp b/src/corelib/kernel/qwineventnotifier.cpp
index 362111a2c8..24de491326 100644
--- a/src/corelib/kernel/qwineventnotifier.cpp
+++ b/src/corelib/kernel/qwineventnotifier.cpp
@@ -199,8 +199,11 @@ void QWinEventNotifier::setEnabled(bool enable)
d->enabled = enable;
QAbstractEventDispatcher *eventDispatcher = d->threadData->eventDispatcher.load();
- if (!eventDispatcher) // perhaps application is shutting down
+ if (!eventDispatcher) { // perhaps application is shutting down
+ if (!enable && d->waitHandle != nullptr)
+ d->unregisterWaitObject();
return;
+ }
if (Q_UNLIKELY(thread() != QThread::currentThread())) {
qWarning("QWinEventNotifier: Event notifiers cannot be enabled or disabled from another thread");
return;
diff --git a/src/corelib/statemachine/qstatemachine.cpp b/src/corelib/statemachine/qstatemachine.cpp
index eb425bcd4f..e58ddaff44 100644
--- a/src/corelib/statemachine/qstatemachine.cpp
+++ b/src/corelib/statemachine/qstatemachine.cpp
@@ -411,7 +411,7 @@ QStateMachinePrivate::~QStateMachinePrivate()
qDeleteAll(internalEventQueue);
qDeleteAll(externalEventQueue);
- for (QHash<int, DelayedEvent>::const_iterator it = delayedEvents.begin(), eit = delayedEvents.end(); it != eit; ++it) {
+ for (QHash<int, DelayedEvent>::const_iterator it = delayedEvents.cbegin(), eit = delayedEvents.cend(); it != eit; ++it) {
delete it.value().event;
}
}
diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h
index 541f6af546..3dff363541 100644
--- a/src/corelib/thread/qmutex.h
+++ b/src/corelib/thread/qmutex.h
@@ -67,6 +67,12 @@ class QMutexData;
class Q_CORE_EXPORT QBasicMutex
{
public:
+#ifdef Q_COMPILER_CONSTEXPR
+ constexpr QBasicMutex()
+ : d_ptr(nullptr)
+ {}
+#endif
+
// BasicLockable concept
inline void lock() QT_MUTEX_LOCK_NOEXCEPT {
if (!fastTryLock())
diff --git a/src/corelib/thread/qsemaphore.h b/src/corelib/thread/qsemaphore.h
index c41f258577..2639085e99 100644
--- a/src/corelib/thread/qsemaphore.h
+++ b/src/corelib/thread/qsemaphore.h
@@ -74,8 +74,6 @@ private:
class QSemaphoreReleaser
{
- QSemaphore *m_sem = nullptr;
- int m_n;
public:
QSemaphoreReleaser() = default;
explicit QSemaphoreReleaser(QSemaphore &sem, int n = 1) Q_DECL_NOTHROW
@@ -109,6 +107,10 @@ public:
m_sem = nullptr;
return old;
}
+
+private:
+ QSemaphore *m_sem = nullptr;
+ int m_n;
};
#endif // QT_NO_THREAD
diff --git a/src/corelib/tools/qdatetimeparser.cpp b/src/corelib/tools/qdatetimeparser.cpp
index 978b663444..dd277f7753 100644
--- a/src/corelib/tools/qdatetimeparser.cpp
+++ b/src/corelib/tools/qdatetimeparser.cpp
@@ -1090,7 +1090,6 @@ QDateTimeParser::scanString(const QDateTime &defaultValue,
int dayofweek = defaultDate.dayOfWeek();
Qt::TimeSpec tspec = defaultValue.timeSpec();
int zoneOffset = 0; // In seconds; local - UTC
- QString zoneName;
QTimeZone timeZone;
switch (tspec) {
case Qt::OffsetFromUTC: // timeZone is ignored
diff --git a/src/corelib/tools/qhash.cpp b/src/corelib/tools/qhash.cpp
index ded9ad354e..501f0d345f 100644
--- a/src/corelib/tools/qhash.cpp
+++ b/src/corelib/tools/qhash.cpp
@@ -339,6 +339,7 @@ static void qt_initialize_qhash_seed()
*/
int qGlobalQHashSeed()
{
+ qt_initialize_qhash_seed();
return qt_qhash_seed.load();
}
diff --git a/src/corelib/tools/qversionnumber.cpp b/src/corelib/tools/qversionnumber.cpp
index 0f237bce87..b96e48252e 100644
--- a/src/corelib/tools/qversionnumber.cpp
+++ b/src/corelib/tools/qversionnumber.cpp
@@ -388,7 +388,7 @@ QVersionNumber QVersionNumber::commonPrefix(const QVersionNumber &v1,
/*!
\fn QString QVersionNumber::toString() const
- Returns a string with all of the segments delimited by a '.'.
+ Returns a string with all of the segments delimited by a period (\c{.}).
\sa majorVersion(), minorVersion(), microVersion(), segments()
*/
@@ -409,7 +409,7 @@ QString QVersionNumber::toString() const
#if QT_STRINGVIEW_LEVEL < 2
/*!
Constructs a QVersionNumber from a specially formatted \a string of
- non-negative decimal numbers delimited by '.'.
+ non-negative decimal numbers delimited by a period (\c{.}).
Once the numerical segments have been parsed, the remainder of the string
is considered to be the suffix string. The start index of that string will be
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-30 20:10:46 +0000