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Minor tweaks to Random.

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This commit is contained in:
Julian Storer 2011-07-06 10:40:37 +01:00
parent a7a4c287b7
commit a1abff979b
12 changed files with 67 additions and 64 deletions
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5
src/audio/dsp/juce_AudioDataConverters.cpp
View file

@ -504,6 +504,7 @@ public:
{
const int numSamples = 2048;
int32 original [numSamples], converted [numSamples], reversed [numSamples];
Random r;
{
AudioData::Pointer<F1, E1, AudioData::NonInterleaved, AudioData::NonConst> d (original);
@ -511,13 +512,13 @@ public:
for (int i = 0; i < numSamples / 2; ++i)
{
d.setAsFloat (Random::getSystemRandom().nextFloat() * 2.2f - 1.1f);
d.setAsFloat (r.nextFloat() * 2.2f - 1.1f);
if (! d.isFloatingPoint())
clippingFailed = d.getAsFloat() > 1.0f || d.getAsFloat() < -1.0f || clippingFailed;
++d;
d.setAsInt32 (Random::getSystemRandom().nextInt());
d.setAsInt32 (r.nextInt());
++d;
}

6
src/containers/juce_AbstractFifo.cpp
View file

@ -165,10 +165,11 @@ public:
void run()
{
int n = 0;
Random r;
while (! threadShouldExit())
{
int num = Random::getSystemRandom().nextInt (2000) + 1;
int num = r.nextInt (2000) + 1;
int start1, size1, start2, size2;
fifo.prepareToWrite (num, start1, size1, start2, size2);
@ -203,10 +204,11 @@ public:
WriteThread writer (fifo, buffer);
int n = 0;
Random r;
for (int count = 1000000; --count >= 0;)
{
int num = Random::getSystemRandom().nextInt (6000) + 1;
int num = r.nextInt (6000) + 1;
int start1, size1, start2, size2;
fifo.prepareToRead (num, start1, size1, start2, size2);

48
src/core/juce_Uuid.cpp
View file

@ -33,42 +33,36 @@ BEGIN_JUCE_NAMESPACE
#include "../io/network/juce_MACAddress.h"
#include "../memory/juce_MemoryBlock.h"
namespace
{
int64 getRandomSeedFromMACAddresses()
{
Array<MACAddress> result;
MACAddress::findAllAddresses (result);
Random r;
for (int i = 0; i < result.size(); ++i)
r.combineSeed (result[i].toInt64());
return r.nextInt64();
}
}
//==============================================================================
Uuid::Uuid()
{
// Mix up any available MAC addresses with some time-based pseudo-random numbers
// to make it very very unlikely that two UUIDs will ever be the same..
// The normal random seeding is pretty good, but we'll throw some MAC addresses
// into the mix too, to make it very very unlikely that two UUIDs will ever be the same..
static int64 macAddresses[2];
static bool hasCheckedMacAddresses = false;
static Random r1 (getRandomSeedFromMACAddresses());
if (! hasCheckedMacAddresses)
{
hasCheckedMacAddresses = true;
value.asInt64[0] = r1.nextInt64();
value.asInt64[1] = r1.nextInt64();
Array<MACAddress> result;
MACAddress::findAllAddresses (result);
for (int i = 0; i < numElementsInArray (macAddresses); ++i)
macAddresses[i] = result[i].toInt64();
}
value.asInt64[0] = macAddresses[0];
value.asInt64[1] = macAddresses[1];
// We'll use both a local RNG that is re-seeded, plus the shared RNG,
// whose seed will carry over between calls to this method.
Random r (macAddresses[0] ^ macAddresses[1]
^ Random::getSystemRandom().nextInt64());
Random r2;
for (int i = 4; --i >= 0;)
{
r.setSeedRandomly(); // calling this repeatedly improves randomness
value.asInt[i] ^= r.nextInt();
value.asInt[i] ^= Random::getSystemRandom().nextInt();
}
value.asInt[i] ^= r2.nextInt();
}
Uuid::~Uuid() noexcept

6
src/cryptography/juce_Primes.cpp
View file

@ -171,14 +171,14 @@ BigInteger Primes::createProbablePrime (const int bitLength,
{
randomSeeds = defaultSeeds;
numRandomSeeds = numElementsInArray (defaultSeeds);
Random r;
Random r1, r2;
for (int j = 10; --j >= 0;)
{
r.setSeedRandomly();
r1.setSeedRandomly();
for (int i = numRandomSeeds; --i >= 0;)
defaultSeeds[i] ^= r.nextInt() ^ Random::getSystemRandom().nextInt();
defaultSeeds[i] ^= r1.nextInt() ^ r2.nextInt();
}
}

3
src/gui/components/mouse/juce_DragAndDropContainer.cpp
View file

@ -359,6 +359,7 @@ void DragAndDropContainer::startDragging (const var& sourceDescription,
Point<int> relPos (sourceComponent->getLocalPoint (nullptr, lastMouseDown));
Point<int> clipped (dragImage.getBounds().getConstrainedPoint (relPos));
Random random;
for (int y = dragImage.getHeight(); --y >= 0;)
{
@ -373,7 +374,7 @@ void DragAndDropContainer::startDragging (const var& sourceDescription,
{
const float alpha = (distance > hi) ? 0
: (hi - distance) / (float) (hi - lo)
+ Random::getSystemRandom().nextFloat() * 0.008f;
+ random.nextFloat() * 0.008f;
dragImage.multiplyAlphaAt (x, y, alpha);
}

8
src/gui/components/windows/juce_ComponentPeer.cpp
View file

@ -135,9 +135,11 @@ void ComponentPeer::handlePaint (LowLevelGraphicsContext& contextToPaintTo)
// clearly when things are being repainted.
g.restoreState();
g.fillAll (Colour ((uint8) Random::getSystemRandom().nextInt (255),
(uint8) Random::getSystemRandom().nextInt (255),
(uint8) Random::getSystemRandom().nextInt (255),
static Random rng;
g.fillAll (Colour ((uint8) rng.nextInt (255),
(uint8) rng.nextInt (255),
(uint8) rng.nextInt (255),
(uint8) 0x50));
#endif

2
src/io/files/juce_File.cpp
View file

@ -890,7 +890,7 @@ String File::getRelativePathFrom (const File& dir) const
File File::createTempFile (const String& fileNameEnding)
{
const File tempFile (getSpecialLocation (tempDirectory)
.getChildFile ("temp_" + String (Random::getSystemRandom().nextInt()))
.getChildFile ("temp_" + String::toHexString (Random::getSystemRandom().nextInt()))
.withFileExtension (fileNameEnding));
if (tempFile.exists())

5
src/io/files/juce_TemporaryFile.cpp
View file

@ -36,7 +36,7 @@ BEGIN_JUCE_NAMESPACE
TemporaryFile::TemporaryFile (const String& suffix, const int optionFlags)
{
createTempFile (File::getSpecialLocation (File::tempDirectory),
"temp_" + String (Random::getSystemRandom().nextInt()),
"temp_" + String::toHexString (Random::getSystemRandom().nextInt()),
suffix,
optionFlags);
}
@ -48,7 +48,8 @@ TemporaryFile::TemporaryFile (const File& targetFile_, const int optionFlags)
jassert (targetFile != File::nonexistent);
createTempFile (targetFile.getParentDirectory(),
targetFile.getFileNameWithoutExtension() + "_temp" + String (Random::getSystemRandom().nextInt()),
targetFile.getFileNameWithoutExtension()
+ "_temp" + String::toHexString (Random::getSystemRandom().nextInt()),
targetFile.getFileExtension(),
optionFlags);
}

13
src/io/streams/juce_MemoryInputStream.cpp
View file

@ -113,10 +113,11 @@ public:
void runTest()
{
beginTest ("Basics");
Random r;
int randomInt = Random::getSystemRandom().nextInt();
int64 randomInt64 = Random::getSystemRandom().nextInt64();
double randomDouble = Random::getSystemRandom().nextDouble();
int randomInt = r.nextInt();
int64 randomInt64 = r.nextInt64();
double randomDouble = r.nextDouble();
String randomString (createRandomWideCharString());
MemoryOutputStream mo;
@ -146,16 +147,16 @@ public:
for (int i = 0; i < numElementsInArray (buffer) - 1; ++i)
{
if (Random::getSystemRandom().nextBool())
if (r.nextBool())
{
do
{
buffer[i] = (juce_wchar) (1 + Random::getSystemRandom().nextInt (0x10ffff - 1));
buffer[i] = (juce_wchar) (1 + r.nextInt (0x10ffff - 1));
}
while (! CharPointer_UTF16::canRepresent (buffer[i]));
}
else
buffer[i] = (juce_wchar) (1 + Random::getSystemRandom().nextInt (0xff));
buffer[i] = (juce_wchar) (1 + r.nextInt (0xff));
}
return CharPointer_UTF32 (buffer);

7
src/maths/juce_Random.cpp
View file

@ -59,11 +59,14 @@ void Random::combineSeed (const int64 seedValue) noexcept
void Random::setSeedRandomly()
{
combineSeed ((int64) (pointer_sized_int) this);
static int64 globalSeed = 0;
combineSeed (globalSeed ^ (int64) (pointer_sized_int) this);
combineSeed (Time::getMillisecondCounter());
combineSeed (Time::getHighResolutionTicks());
combineSeed (Time::getHighResolutionTicksPerSecond());
combineSeed (Time::currentTimeMillis());
globalSeed ^= seed;
}
Random& Random::getSystemRandom() noexcept
@ -83,7 +86,7 @@ int Random::nextInt() noexcept
int Random::nextInt (const int maxValue) noexcept
{
jassert (maxValue > 0);
return (nextInt() & 0x7fffffff) % maxValue;
return (((unsigned int) nextInt()) * (uint64) maxValue) >> 32;
}
int64 Random::nextInt64() noexcept

21
src/maths/juce_Random.h
View file

@ -34,9 +34,6 @@
A random number generator.
You can create a Random object and use it to generate a sequence of random numbers.
As a handy shortcut to avoid having to create and seed one yourself, you can call
Random::getSystemRandom() to return a global RNG that is seeded randomly when the
app launches.
*/
class JUCE_API Random
{
@ -67,7 +64,7 @@ public:
int nextInt() noexcept;
/** Returns the next random number, limited to a given range.
The maxValue parameter may not be negative, or zero.
@returns a random integer between 0 (inclusive) and maxValue (exclusive).
*/
int nextInt (int maxValue) noexcept;
@ -104,14 +101,6 @@ public:
void fillBitsRandomly (BigInteger& arrayToChange, int startBit, int numBits);
//==============================================================================
/** To avoid the overhead of having to create a new Random object whenever
you need a number, this is a shared application-wide object that
can be used.
It's not thread-safe though, so threads should use their own Random object.
*/
static Random& getSystemRandom() noexcept;
/** Resets this Random object to a given seed value. */
void setSeed (int64 newSeed) noexcept;
@ -129,6 +118,14 @@ public:
*/
void setSeedRandomly();
/** The overhead of creating a new Random object is fairly small, but if you want to avoid
it, you can call this method to get a global shared Random object.
It's not thread-safe though, so threads should use their own Random object, otherwise
you run the risk of your random numbers becoming.. erm.. randomly corrupted..
*/
static Random& getSystemRandom() noexcept;
private:
//==============================================================================
int64 seed;

7
src/text/juce_String.cpp
View file

@ -2161,19 +2161,20 @@ public:
static String createRandomWideCharString()
{
juce_wchar buffer[50] = { 0 };
Random r;
for (int i = 0; i < numElementsInArray (buffer) - 1; ++i)
{
if (Random::getSystemRandom().nextBool())
if (r.nextBool())
{
do
{
buffer[i] = (juce_wchar) (1 + Random::getSystemRandom().nextInt (0x10ffff - 1));
buffer[i] = (juce_wchar) (1 + r.nextInt (0x10ffff - 1));
}
while (! CharPointer_UTF16::canRepresent (buffer[i]));
}
else
buffer[i] = (juce_wchar) (1 + Random::getSystemRandom().nextInt (0xff));
buffer[i] = (juce_wchar) (1 + r.nextInt (0xff));
}
return CharPointer_UTF32 (buffer);