Brl.Random - threadsafe #20
Description
MarkCWM in the syntaxbomb.com forums just brought up an old thread (in which I replied...;-)
Grable enhanced brl.random to be threadsafe there.
Strict
Rem
bbdoc: Math/Random numbers
End Rem
Module BRL.Random
ModuleInfo "Version: 1.09"
ModuleInfo "Author: Mark Sibly, Floyd"
ModuleInfo "License: zlib/libpng"
ModuleInfo "Copyright: Blitz Research Ltd"
ModuleInfo "Modserver: BRL"
ModuleInfo "History: 1.09 [grable]"
ModuleInfo "History: Made seed==0 get seed from main thread (so threads start with main thread seed)"
ModuleInfo "History: 1.08 [grable]"
ModuleInfo "History: Added RndSeedMain() to get seed of main thread"
ModuleInfo "History: 1.07 [grable]"
ModuleInfo "History: Now thread-safe, each thread has its own seed"
ModuleInfo "History: 1.05 Release"
ModuleInfo "History: Fixed Rand() with negative min value bug"
Private
Const RND_A=48271,RND_M=2147483647,RND_Q=44488,RND_R=3399
?Not Threaded
Global rnd_state=$1234
?Threaded
Extern "C"
Function bbThreadAllocData:Int()
Function bbThreadSetData( index:Int, data:Int )
' Function bbThreadGetData:Int( index:Int )
Function bbThreadGetMain:Int Ptr()
Function bbThreadGetCurrent:Int Ptr()
EndExtern
' reimplemented to allow 0
Function bbThreadGetData:Int( index:Int)
' Return bbThreadGetCurrent()[2 + index]
Local slots:Int Ptr = bbThreadGetCurrent() + 2
Local rnd_state:Int = slots[index]
If rnd_state = 0 Then
slots[index] = rnd_state_init
Return rnd_state_init
EndIf
Return rnd_state
EndFunction
Function bbThreadGetMainData:Int( index:Int)
Return bbThreadGetMain()[2 + index]
EndFunction
Global rnd_state_init:Int = $1234
Global rnd_state_index:Int = bbThreadAllocData()
bbThreadSetData rnd_state_index, rnd_state_init
?
Public
Rem
bbdoc: Generate random float
returns: A random float in the range 0 (inclusive) to 1 (exclusive)
End Rem
Function RndFloat#()
?Threaded
Local rnd_state:Int = bbThreadGetData(rnd_state_index)
?
rnd_state=RND_A*(rnd_state Mod RND_Q)-RND_R*(rnd_state/RND_Q)
If rnd_state<0 rnd_state=rnd_state+RND_M
?Threaded
bbThreadSetData( rnd_state_index, rnd_state)
?
Return (rnd_state & $ffffff0) / 268435456# 'divide by 2^28
End Function
Rem
bbdoc: Generate random double
returns: A random double in the range 0 (inclusive) to 1 (exclusive)
End Rem
Function RndDouble!()
Const TWO27! = 134217728.0 '2 ^ 27
Const TWO29! = 536870912.0 '2 ^ 29
?Threaded
Local rnd_state:Int = bbThreadGetData(rnd_state_index)
?
rnd_state=RND_A*(rnd_state Mod RND_Q)-RND_R*(rnd_state/RND_Q)
If rnd_state<0 rnd_state=rnd_state+RND_M
Local r_hi! = rnd_state & $1ffffffc
rnd_state=RND_A*(rnd_state Mod RND_Q)-RND_R*(rnd_state/RND_Q)
If rnd_state<0 rnd_state=rnd_state+RND_M
Local r_lo! = rnd_state & $1ffffff8
?Threaded
bbThreadSetData( rnd_state_index, rnd_state)
?
Return (r_hi + r_lo/TWO27)/TWO29
End Function
Rem
bbdoc: Generate random double
returns: A random double in the range min (inclusive) to max (exclusive)
about:
The optional parameters allow you to use Rnd in 3 ways:
[ @Format | @Result
* &Rnd() | Random double in the range 0 (inclusive) to 1 (exclusive)
* &Rnd(_x_) | Random double in the range 0 (inclusive) to n (exclusive)
* &Rnd(_x,y_) | Random double in the range x (inclusive) to y (exclusive)
]
End Rem
Function Rnd!( min_value!=1,max_value!=0 )
If max_value>min_value Return RndDouble()*(max_value-min_value)+min_value
Return RndDouble()*(min_value-max_value)+max_value
End Function
Rem
bbdoc: Generate random integer
returns: A random integer in the range min (inclusive) to max (inclusive)
about:
The optional parameter allows you to use #Rand in 2 ways:
[ @Format | @Result
* &Rand(x) | Random integer in the range 1 to x (inclusive)
* &Rand(x,y) | Random integer in the range x to y (inclusive)
]
End Rem
Function Rand( min_value,max_value=1 )
Local range=max_value-min_value
If range>0 Return Int( RndDouble()*(1+range) )+min_value
Return Int( RndDouble()*(1-range) )+max_value
End Function
Rem
bbdoc: Set random number generator seed
End Rem
Function SeedRnd( seed )
?Not Threaded
rnd_state=seed & $7fffffff 'enforces rnd_state >= 0
?Threaded
Local rnd_state:Int = seed & $7fffffff 'enforces rnd_state >= 0
?
If rnd_state=0 Or rnd_state=RND_M rnd_state=$1234 'disallow 0 and M
?Threaded
If bbThreadGetCurrent() = bbThreadGetMain() Then rnd_state_init = rnd_state
bbThreadSetData( rnd_state_index, rnd_state)
?
End Function
Rem
bbdoc: Get random number generator seed
returns: The current random number generator seed
about: Use in conjunction with SeedRnd, RndSeed allows you to reproduce sequences of random
numbers.
End Rem
Function RndSeed()
?Not Threaded
Return rnd_state
?Threaded
Return bbThreadGetData(rnd_state_index)
?
End Function
?Threaded
Rem
bbdoc: Get random number generator seed of Main thread
returns: The current random number generator seed of the Main thread
about: Use in conjunction with SeedRnd, RndSeedMain allows you to reproduce sequences of random
numbers.
End Rem
Function RndSeedMain()
Return bbThreadGetMainData(rnd_state_index)
End Function
?