I'm having problems understanding why the Integer>>#atRandom sometimes return a number greater than the receiver. This problem only occurs when forking processes that generate random number using the above mentioned method. Obviously, all processes share the same RNG from the Collection class. Code below can reproduce (most of the time) the bug. | n | n := 3172918. 5 timesRepeat: [ [n timesRepeat: [ | alea |                            alea := n atRandom.                            (alea > n) ifTrue: [ self halt]]] forkAt: Processor userBackgroundPriority ]. I'm on Windows 10, Pharo4.0 Latest update: #40627. Pertinent System Reporter info below: Virtual Machine --------------- F:\Pharo4\Pharo4.0\Pharo.exe NBCoInterpreter NativeBoost-CogPlugin-HolgerHansPeterFreyther.21 uuid: e0df6e2d-5694-40e2-8035-dc217200b424 Sep 25 2014 NBCogit NativeBoost-CogPlugin-HolgerHansPeterFreyther.21 uuid: e0df6e2d-5694-40e2-8035-dc217200b424 Sep 25 2014 https://github.com/pharo-project/pharo-vm.git Commit: 81b5d19917dcb78f22482a780deec48c53738396 Date: 2014-09-20 14:36:18 +0200 By: Esteban Lorenzano <estebanlm@gmail.com> Jenkins build #14858 Win32 built on Sep 25 2014 17:47:04 Compiler: 4.6.2 VMMaker versionString https://github.com/pharo-project/pharo-vm.git Commit: 81b5d19917dcb78f22482a780deec48c53738396 Date: 2014-09-20 14:36:18 +0200 By: Esteban Lorenzano <estebanlm@gmail.com> Jenkins build #14858 NBCoInterpreter NativeBoost-CogPlugin-HolgerHansPeterFreyther.21 uuid: e0df6e2d-5694-40e2-8035-dc217200b424 Sep 25 2014 NBCogit NativeBoost-CogPlugin-HolgerHansPeterFreyther.21 uuid: e0df6e2d-5694-40e2-8035-dc217200b424 Sep 25 2014 Loaded VM Modules ----------------- B2DPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) BitBltPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) FT2Plugin Freetype-Plugin-IgorStasenko.64 (e) FilePlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) FloatArrayPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) JPEGReadWriter2Plugin VMMaker.oscog-jeanbaptistearnaud.783 (i) Kernel32 LargeIntegers v1.5 VMMaker.oscog-jeanbaptistearnaud.783 (i) LocalePlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) Matrix2x3Plugin VMMaker.oscog-jeanbaptistearnaud.783 (i) MiscPrimitivePlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) NativeBoostPlugin NativeBoost-CogPlugin-HolgerHansPeterFreyther.21 (i) SecurityPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) ZipPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) VM Built-in Modules ------------------- ADPCMCodecPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) AsynchFilePlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) B2DPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) B3DAcceleratorPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) BMPReadWriterPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) BitBltPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) CroquetPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) DSAPrims VMMaker.oscog-jeanbaptistearnaud.783 (i) DropPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) FFTPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) FilePlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) FloatArrayPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) FloatMathPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) HostWindowPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) IA32ABI VMMaker.oscog-jeanbaptistearnaud.783 (i) JPEGReadWriter2Plugin VMMaker.oscog-jeanbaptistearnaud.783 (i) JPEGReaderPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) JoystickTabletPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) Klatt VMMaker.oscog-jeanbaptistearnaud.783 (i) LargeIntegers v1.5 VMMaker.oscog-jeanbaptistearnaud.783 (i) LocalePlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) MIDIPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) Matrix2x3Plugin VMMaker.oscog-jeanbaptistearnaud.783 (i) MiscPrimitivePlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) Mpeg3Plugin VMMaker.oscog-jeanbaptistearnaud.783 (i) NativeBoostPlugin NativeBoost-CogPlugin-HolgerHansPeterFreyther.21 (i) RePlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) SecurityPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) SerialPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) SocketPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) SoundCodecPrims VMMaker.oscog-jeanbaptistearnaud.783 (i) SoundPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) StarSqueakPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) SurfacePlugin Sep 25 2014 (i) UUIDPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) Win32OSProcessPlugin VMConstruction-Plugins-OSProcessPlugin.oscog-EstebanLorenzano.43 (i) ZipPlugin VMMaker.oscog-jeanbaptistearnaud.783 (i) VM Configuration ---------------- F:\Pharo4\Pharo4.0\Pharo.ini [Global] DeferUpdate=1 ShowConsole=0 DynamicConsole=1 ReduceCPUUsage=0 ReduceCPUInBackground=0 3ButtonMouse=0 1ButtonMouse=0 UseDirectSound=1 PriorityBoost=0 B3DXUsesOpenGL=0 CaseSensitiveFileMode=0 Operating System/Hardware ------------------------- Win32 6.2 IX86 Hardware Details ---------------- Hardware information:    Manufacturer: Unknown    Model: Unknown    Number of processors: 4    Page size: 4096 Memory Information (upon launch):    Physical Memory Size: 2097151 kbytes    Physical Memory Free: 2097151 kbytes    Page File Size: 4194303 kbytes    Page File Free: 4194303 kbytes    Virtual Memory Size: 2097024 kbytes    Virtual Memory Free: 2015568 kbytes    Memory Load: 45 percent Processor 0: Intel(R) Core(TM) i5-6400 CPU @ 2.70GHz    Identifier: Intel64 Family 6 Model 94 Stepping 3    ~MHZ: 2712 Processor 1: Intel(R) Core(TM) i5-6400 CPU @ 2.70GHz    Identifier: Intel64 Family 6 Model 94 Stepping 3    ~MHZ: 2712 Processor 2: Intel(R) Core(TM) i5-6400 CPU @ 2.70GHz    Identifier: Intel64 Family 6 Model 94 Stepping 3    ~MHZ: 2712 Processor 3: Intel(R) Core(TM) i5-6400 CPU @ 2.70GHz    Identifier: Intel64 Family 6 Model 94 Stepping 3    ~MHZ: 2712 Graphics Hardware Details ------------------------- Display Information:    Graphics adapter name: Intel(R) HD Graphics 530    Primary monitor resolution: 1280 x 720 Device: ???    Adapter String: Intel(R) HD Graphics 530    Bios String: Intel Video BIOS    Chip Type: Intel(R) HD Graphics Family    DAC Type: Internal    Memory Size: 0x40000000 Driver Versions:    igdumdim64:  ----------------- Benoît St-Jean Yahoo! Messenger: bstjean Twitter: @BenLeChialeux Pinterest: benoitstjean Instagram: Chef_Benito IRC: lamneth Blogue: endormitoire.wordpress.com "A standpoint is an intellectual horizon of radius zero". (A. Einstein)