//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// stdlib --
//
// Author           : Peter A. Buhr
// Created On       : Thu Jan 28 17:12:35 2016
// Last Modified By : Peter A. Buhr
// Last Modified On : Mon Apr 15 10:51:38 2024
// Update Count     : 815
//

#pragma once

#include "bits/defs.hfa"								// OPTIONAL_THREAD
#include "bits/align.hfa"								// libAlign
#include "bits/random.hfa"								// prng
#include <Exception.hfa>
#include <heap.hfa>

#include <stdlib.h>										// *alloc, strto*, ato*
#include <errno.h>

// Reduce includes by explicitly defining these routines.
extern "C" {
	void * memalign( size_t alignment, size_t size );	// malloc.h
	void * pvalloc( size_t size );						// malloc.h
	void * memset( void * dest, int fill, size_t size ); // string.h
	void * memcpy( void * dest, const void * src, size_t size ); // string.h
} // extern "C"

//---------------------------------------

#ifndef EXIT_FAILURE
#define	EXIT_FAILURE	1								// failing exit status
#define	EXIT_SUCCESS	0								// successful exit status
#endif // ! EXIT_FAILURE

//---------------------------------------

#include "common.hfa"

//---------------------------------------

static inline forall( T & | sized(T) ) {
	// CFA safe equivalents, i.e., implicit size specification

	T * malloc( void ) {
		if ( _Alignof(T) <= libAlign() ) return (T *)malloc( sizeof(T) ); // C allocation
		else return (T *)memalign( _Alignof(T), sizeof(T) );
	} // malloc

	T * aalloc( size_t dim ) {
		if ( _Alignof(T) <= libAlign() ) return (T *)aalloc( dim, sizeof(T) ); // C allocation
		else return (T *)amemalign( _Alignof(T), dim, sizeof(T) );
	} // aalloc

	T * calloc( size_t dim ) {
		if ( _Alignof(T) <= libAlign() ) return (T *)calloc( dim, sizeof(T) ); // C allocation
		else return (T *)cmemalign( _Alignof(T), dim, sizeof(T) );
	} // calloc

	T * resize( T * ptr, size_t size ) {				// CFA resize
		if ( _Alignof(T) <= libAlign() ) return (T *)resize( (void *)ptr, size ); // CFA resize
		else return (T *)resize( (void *)ptr, _Alignof(T), size ); // CFA resize
	} // resize

	T * realloc( T * ptr, size_t size ) {				// CFA realloc
		if ( _Alignof(T) <= libAlign() ) return (T *)realloc( (void *)ptr, size ); // C realloc
		else return (T *)realloc( (void *)ptr, _Alignof(T), size ); // CFA realloc
	} // realloc

	T * reallocarray( T * ptr, size_t dim ) {			// CFA reallocarray
		if ( _Alignof(T) <= libAlign() ) return (T *)reallocarray( (void *)ptr, dim, sizeof(T) ); // C reallocarray
		else return (T *)reallocarray( (void *)ptr, _Alignof(T), dim ); // CFA reallocarray
	} // realloc

	T * memalign( size_t align ) {
		return (T *)memalign( align, sizeof(T) );		// C memalign
	} // memalign

	T * amemalign( size_t align, size_t dim ) {
		return (T *)amemalign( align, dim, sizeof(T) );	// CFA amemalign
	} // amemalign

	T * cmemalign( size_t align, size_t dim  ) {
		return (T *)cmemalign( align, dim, sizeof(T) );	// CFA cmemalign
	} // cmemalign

	T * aligned_alloc( size_t align ) {
		return (T *)aligned_alloc( align, sizeof(T) );	// C aligned_alloc
	} // aligned_alloc

	int posix_memalign( T ** ptr, size_t align ) {
		return posix_memalign( (void **)ptr, align, sizeof(T) ); // C posix_memalign
	} // posix_memalign

	T * valloc( void ) {
		return (T *)valloc( sizeof(T) );				// C valloc
	} // valloc

	T * pvalloc( void ) {
		return (T *)pvalloc( sizeof(T) );				// C pvalloc
	} // pvalloc
} // distribution

/*
	FIX ME : fix alloc interface after Ticker Number 214 is resolved, define and add union to S_fill. Then, modify postfix-fill functions to support T * with nmemb, char, and T object of any size. Finally, change alloc_internal.
	Or, just follow the instructions below for that.

	1. Replace the current forall-block that contains defintions of S_fill and S_realloc with following:
		forall( T & | sized(T) ) {
			union  U_fill { char c; T * a; T t; };
			struct S_fill { char tag; U_fill(T) fill; };
			struct S_realloc { inline T *; };
		}

	2. Replace all current postfix-fill functions with following for updated S_fill:
		S_fill(T) ?`fill( char a ) { S_fill(T) ret = {'c'}; ret.fill.c = a; return ret; }
		S_fill(T) ?`fill( T a ) { S_fill(T) ret = {'t'}; memcpy(&ret.fill.t, &a, sizeof(T)); return ret; }
		S_fill(T) ?`fill( T a[], size_t nmemb ) { S_fill(T) ret = {'a', nmemb}; ret.fill.a = a; return ret; }

	3. Replace the alloc_internal$ function which is outside ttype forall-block with following function:
		T * alloc_internal$( void * Resize, T * Realloc, size_t Align, size_t Dim, S_fill(T) Fill) {
			T * ptr = NULL;
			size_t size = sizeof(T);
			size_t copy_end = 0;

			if(Resize) {
				ptr = (T*) (void *) resize( (int *)Resize, Align, Dim * size );
			} else if (Realloc) {
				if (Fill.tag != '0') copy_end = min(malloc_size( Realloc ), Dim * size);
				ptr = (T*) (void *) realloc( (int *)Realloc, Align, Dim * size );
			} else {
				ptr = (T*) (void *) memalign( Align, Dim * size );
			}

			if(Fill.tag == 'c') {
				memset( (char *)ptr + copy_end, (int)Fill.fill.c, Dim * size - copy_end );
			} else if(Fill.tag == 't') {
				for ( int i = copy_end; i <= Dim * size - size ; i += size ) {
					memcpy( (char *)ptr + i, &Fill.fill.t, size );
				}
			} else if(Fill.tag == 'a') {
				memcpy( (char *)ptr + copy_end, Fill.fill.a, min(Dim * size - copy_end, size * Fill.nmemb) );
			}

			return ptr;
		} // alloc_internal$
*/

typedef struct S_align { inline size_t;  } T_align;
typedef struct S_resize { inline void *;  }	T_resize;

forall( T & ) {
	struct S_fill { char tag; char c; size_t size; T * at; char t[50]; };
	struct S_realloc { inline T *; };
}

static inline T_align ?`align( size_t a ) { return (T_align){a}; }
static inline T_resize ?`resize( void * a )	{ return (T_resize){a}; }

extern "C" ssize_t write(int fd, const void *buf, size_t count);
static inline forall( T & | sized(T) ) {
	S_fill(T) ?`fill ( T t ) {
		S_fill(T) ret = { 't' };
		size_t size = sizeof(T);
		if ( size > sizeof(ret.t) ) {
			abort( "ERROR: const object of size greater than 50 bytes given for dynamic memory fill\n" );
		} // if
		memcpy( &ret.t, &t, size );
		return ret;
	}
	S_fill(T) ?`fill ( zero_t ) = void; // FIX ME: remove this once ticket 214 is resolved
	S_fill(T) ?`fill ( T * a ) { return (S_fill(T)){ 'T', '0', 0, a }; } // FIX ME: remove this once ticket 214 is resolved
	S_fill(T) ?`fill ( char c ) { return (S_fill(T)){ 'c', c };	}
	S_fill(T) ?`fill ( T a[], size_t nmemb ) { return (S_fill(T)){ 'a', '0', nmemb * sizeof(T), a }; }

	S_realloc(T) ?`realloc ( T * a ) { return (S_realloc(T)){a}; }

	T * alloc_internal$( void * Resize, T * Realloc, size_t Align, size_t Dim, S_fill(T) Fill ) {
		T * ptr = NULL;
		size_t size = sizeof(T);
		size_t copy_end = 0;

		if ( Resize ) {
			ptr = (T*)(void *)resize( (void *)Resize, Align, Dim * size );
		} else if ( Realloc ) {
			if ( Fill.tag != '0' ) copy_end = min(malloc_size( Realloc ), Dim * size );
			ptr = (T *)(void *)realloc( (void *)Realloc, Align, Dim * size );
		} else {
			ptr = (T *)(void *) memalign( Align, Dim * size );
		}

		if ( Fill.tag == 'c' ) {
			memset( (char *)ptr + copy_end, (int)Fill.c, Dim * size - copy_end );
		} else if ( Fill.tag == 't' ) {
			for ( i; copy_end ~ Dim * size ~ size ) {
				#pragma GCC diagnostic push
				#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
				assert( size <= sizeof(Fill.t) );
				memcpy( (char *)ptr + i, &Fill.t, size );
				#pragma GCC diagnostic pop
			}
		} else if ( Fill.tag == 'a' ) {
			memcpy( (char *)ptr + copy_end, Fill.at, min(Dim * size - copy_end, Fill.size) );
		} else if ( Fill.tag == 'T' ) {
			memcpy( (char *)ptr + copy_end, Fill.at, Dim * size );
		}

		return ptr;
	} // alloc_internal$

	forall( TT... | { T * alloc_internal$( void *, T *, size_t, size_t, S_fill(T), TT ); } ) {
		T * alloc_internal$( void *, T *, size_t Align, size_t Dim, S_fill(T) Fill, T_resize Resize, TT rest ) {
	        return alloc_internal$( Resize, (T*)0p, Align, Dim, Fill, rest);
		}

		T * alloc_internal$( void *, T *, size_t Align, size_t Dim, S_fill(T) Fill, S_realloc(T) Realloc, TT rest ) {
	        return alloc_internal$( (void*)0p, Realloc, Align, Dim, Fill, rest);
		}

		T * alloc_internal$( void * Resize, T * Realloc, size_t, size_t Dim, S_fill(T) Fill, T_align Align, TT rest ) {
	        return alloc_internal$( Resize, Realloc, Align, Dim, Fill, rest);
		}

		T * alloc_internal$( void * Resize, T * Realloc, size_t Align, size_t Dim, S_fill(T), S_fill(T) Fill, TT rest ) {
	        return alloc_internal$( Resize, Realloc, Align, Dim, Fill, rest );
		}

	    T * alloc( TT all ) {
	    	return alloc_internal$( (void*)0p, (T*)0p, (_Alignof(T) > libAlign() ? _Alignof(T) : libAlign()), (size_t)1, (S_fill(T)){'0'}, all );
	    }

	    T * alloc( size_t dim, TT all ) {
	    	return alloc_internal$( (void*)0p, (T*)0p, (_Alignof(T) > libAlign() ? _Alignof(T) : libAlign()), dim, (S_fill(T)){'0'}, all );
	    }
	} // distribution TT
} // distribution T

static inline forall( T & | sized(T) ) {
	// CFA safe initialization/copy, i.e., implicit size specification, non-array types
	T * memset( T * dest, char fill ) {
		return (T *)memset( dest, fill, sizeof(T) );
	} // memset

	T * memcpy( T * dest, const T * src ) {
		return (T *)memcpy( dest, src, sizeof(T) );
	} // memcpy

	// CFA safe initialization/copy, i.e., implicit size specification, array types
	T * amemset( T dest[], char fill, size_t dim ) {
		return (T *)(void *)memset( dest, fill, dim * sizeof(T) ); // C memset
	} // amemset

	T * amemcpy( T dest[], const T src[], size_t dim ) {
		return (T *)(void *)memcpy( dest, src, dim * sizeof(T) ); // C memcpy
	} // amemcpy
} // distribution

// CFA deallocation for multiple objects
static inline forall( T & )							// FIX ME, problems with 0p in list
void free( T * ptr ) {
	free( (void *)ptr );								// C free
} // free
static inline forall( T &, TT... | { void free( TT ); } )
void free( T * ptr, TT rest ) {
	free( ptr );
	free( rest );
} // free

// CFA allocation/deallocation and constructor/destructor, non-array types
static inline forall( T & | sized(T), TT... | { void ?{}( T &, TT ); } )
T * new( TT p ) {
	return &(*(T *)malloc()){ p };						// run constructor
} // new

static inline forall( T & | { void ^?{}( T & ); } )
void delete( T * ptr ) {
	// special case for 0-sized object => always call destructor
	if ( ptr || sizeof(ptr) == 0 ) {					// ignore null but not 0-sized objects
		^(*ptr){};										// run destructor
	} // if
	free( ptr );										// always call free
} // delete
static inline forall( T &, TT... | { void ^?{}( T & ); void delete( TT ); } )
void delete( T * ptr, TT rest ) {
	delete( ptr );
	delete( rest );
} // delete

// CFA allocation/deallocation and constructor/destructor, array types
forall( T & | sized(T), TT... | { void ?{}( T &, TT ); } ) T * anew( size_t dim, TT p );
forall( T & | sized(T) | { void ^?{}( T & ); } ) void adelete( T arr[] );
forall( T & | sized(T) | { void ^?{}( T & ); }, TT... | { void adelete( TT ); } ) void adelete( T arr[], TT rest );
//---------------------------------------

// Check if all string characters are a specific kind, e.g., checkif( s, isblank )
bool checkif( const char s[], int (* kind)( int ) );
bool checkif( const char s[], int (* kind)( int, locale_t ), locale_t locale );

//---------------------------------------

static inline {
	int strto( const char sptr[], char * eptr[], int base ) { return (int)strtol( sptr, eptr, base ); }
	unsigned int strto( const char sptr[], char * eptr[], int base ) { return (unsigned int)strtoul( sptr, eptr, base ); }
	long int strto( const char sptr[], char * eptr[], int base ) { return strtol( sptr, eptr, base ); }
	unsigned long int strto( const char sptr[], char * eptr[], int base ) { return strtoul( sptr, eptr, base ); }
	long long int strto( const char sptr[], char * eptr[], int base ) { return strtoll( sptr, eptr, base ); }
	unsigned long long int strto( const char sptr[], char * eptr[], int base ) { return strtoull( sptr, eptr, base ); }

	float strto( const char sptr[], char * eptr[] ) { return strtof( sptr, eptr ); }
	double strto( const char sptr[], char * eptr[] ) { return strtod( sptr, eptr ); }
	long double strto( const char sptr[], char * eptr[] ) { return strtold( sptr, eptr ); }
} // distribution

float _Complex strto( const char sptr[], char * eptr[] );
double _Complex strto( const char sptr[], char * eptr[] );
long double _Complex strto( const char sptr[], char * eptr[] );

ExceptionDecl( out_of_range );
ExceptionDecl( invalid_argument );

forall( T | { T strto( const char sptr[], char * eptr[], int ); } )
T convert( const char sptr[] );							// integrals
forall( T | { T strto( const char sptr[], char * eptr[] ); } )
T convert( const char sptr[] );							// floating-point (no base)

static inline {
	int ato( const char sptr[] ) { return (int)strtol( sptr, 0p, 10 ); }
	unsigned int ato( const char sptr[] ) { return (unsigned int)strtoul( sptr, 0p, 10 ); }
	long int ato( const char sptr[] ) { return strtol( sptr, 0p, 10 ); }
	unsigned long int ato( const char sptr[] ) { return strtoul( sptr, 0p, 10 ); }
	long long int ato( const char sptr[] ) { return strtoll( sptr, 0p, 10 ); }
	unsigned long long int ato( const char sptr[] ) { return strtoull( sptr, 0p, 10 ); }

	float ato( const char sptr[] ) { return strtof( sptr, 0p ); }
	double ato( const char sptr[] ) { return strtod( sptr, 0p ); }
	long double ato( const char sptr[] ) { return strtold( sptr, 0p ); }

	float _Complex ato( const char sptr[] ) { return strto( sptr, 0p ); }
	double _Complex ato( const char sptr[] ) { return strto( sptr, 0p ); }
	long double _Complex ato( const char sptr[] ) { return strto( sptr, 0p ); }
} // distribution

//---------------------------------------

forall( E | { int ?<?( E, E ); } ) {
	E * bsearch( E key, const E * vals, size_t dim );
	size_t bsearch( E key, const E * vals, size_t dim );
	E * bsearchl( E key, const E * vals, size_t dim );
	size_t bsearchl( E key, const E * vals, size_t dim );
	E * bsearchu( E key, const E * vals, size_t dim );
	size_t bsearchu( E key, const E * vals, size_t dim );
} // distribution

forall( K, E | { int ?<?( K, K ); K getKey( const E & ); } ) {
	E * bsearch( K key, const E * vals, size_t dim );
	size_t bsearch( K key, const E * vals, size_t dim );
	E * bsearchl( K key, const E * vals, size_t dim );
	size_t bsearchl( K key, const E * vals, size_t dim );
	E * bsearchu( K key, const E * vals, size_t dim );
	size_t bsearchu( K key, const E * vals, size_t dim );
} // distribution

forall( E | { int ?<?( E, E ); } ) {
	void qsort( E * vals, size_t dim );
} // distribution

//---------------------------------------

extern "C" {											// override C version
	void srandom( unsigned int seed );
	long int random( void );							// GENERATES POSITIVE AND NEGATIVE VALUES
	// For positive values, use unsigned int, e.g., unsigned int r = random() % 100U;
} // extern "C"

static inline {
	long int random( long int l, long int u ) { if ( u < l ) [u, l] = [l, u]; return lrand48() % (u - l + 1) + l; } // [l,u]
	long int random( long int u ) { return random( 0, u - 1 ); } // [0,u)
	unsigned long int random( void ) { return lrand48(); }
	unsigned long int random( unsigned long int u ) { return lrand48() % u; } // [0,u)
	unsigned long int random( unsigned long int l, unsigned long int u ) { if ( u < l ) [u, l] = [l, u]; return lrand48() % (u - l + 1) + l; } // [l,u]

	char random( void ) { return (unsigned long int)random(); }
	char random( char u ) { return (unsigned long int)random( (unsigned long int)u ); } // [0,u)
	char random( char l, char u ) { return random( (unsigned long int)l, (unsigned long int)u ); } // [l,u)
	int random( void ) { return (long int)random(); }
	int random( int u ) { return (long int)random( (long int)u ); } // [0,u]
	int random( int l, int u ) { return random( (long int)l, (long int)u ); } // [l,u)
	unsigned int random( void ) { return (unsigned long int)random(); }
	unsigned int random( unsigned int u ) { return (unsigned long int)random( (unsigned long int)u ); } // [0,u]
	unsigned int random( unsigned int l, unsigned int u ) { return random( (unsigned long int)l, (unsigned long int)u ); } // [l,u)
} // distribution

float random( void );									// [0.0, 1.0)
double random( void );									// [0.0, 1.0)
float _Complex random( void );							// [0.0, 1.0)+[0.0, 1.0)i
double _Complex random( void );							// [0.0, 1.0)+[0.0, 1.0)i
long double _Complex random( void );					// [0.0, 1.0)+[0.0, 1.0)i

//---------------------------------------

// Sequential Pseudo Random-Number Generator : generate repeatable sequence of values that appear random.
//
// Declaration :
//   PRNG sprng = { 1009 } - set starting seed versus random seed
//
// Interface :
//   set_seed( sprng, 1009 ) - set starting seed for ALL kernel threads versus random seed
//   get_seed( sprng ) - read seed
//   prng( sprng ) - generate random value in range [0,UINT_MAX]
//   prng( sprng, u ) - generate random value in range [0,u)
//   prng( sprng, l, u ) - generate random value in range [l,u]
//   calls( sprng ) - number of generated random value so far
//
// Examples : generate random number between 5-21
//   prng( sprng ) % 17 + 5;	values 0-16 + 5 = 5-21
//   prng( sprng, 16 + 1 ) + 5;
//   prng( sprng, 5, 21 );
//   calls( sprng );

forall( PRNG &, R )
trait basic_prng {
	void set_seed( PRNG & prng, R seed );				// set seed
	R get_seed( PRNG & prng );							// get seed
	R prng( PRNG & prng );
	void ?{}( PRNG & prng );							// random seed
	void ?{}( PRNG & prng, R seed );					// fixed seed
}; // basic_prng

static inline forall( PRNG &, R | basic_prng( PRNG, R ) | { R ?%?( R, R ); } ) {
	R prng( PRNG & prng, R u ) { return prng( prng ) % u; } // [0,u)
}
static inline forall( PRNG &, R | basic_prng( PRNG, R ) | { R ?+?( R, R ); R ?-?( R, R ); R ?%?( R, R ); void ?{}( R &, one_t ); } ) {
	R prng( PRNG & prng, R l, R u ) { return prng( prng, u - l + (R){1} ) + l; } // [l,u]
}

struct PRNG32 {
	uint32_t callcnt;									// call count
	uint32_t seed;										// current seed
	PRNG_STATE_32_T state;								// random state
}; // PRNG32

static inline {
	void set_seed( PRNG32 & prng, uint32_t seed_ ) with( prng ) { seed = seed_; PRNG_SET_SEED_32( state, seed ); }
	uint32_t get_seed( PRNG32 & prng ) __attribute__(( warn_unused_result )) with( prng ) { return seed; }
	void ?{}( PRNG32 & prng, uint32_t seed ) with( prng ) { callcnt = 0; set_seed( prng, seed ); } // fixed seed
	void ?{}( PRNG32 & prng ) with( prng ) { ?{}( prng, rdtscl() ); } // random seed
	uint32_t prng( PRNG32 & prng ) __attribute__(( warn_unused_result )) with( prng ) { callcnt += 1; return PRNG_NAME_32( state ); } // [0,UINT_MAX]
	uint32_t prng( PRNG32 & prng, uint32_t u ) __attribute__(( warn_unused_result )) { return prng( prng ) % u; } // [0,u)
	uint32_t prng( PRNG32 & prng, uint32_t l, uint32_t u ) __attribute__(( warn_unused_result )) { return prng( prng, u - l + 1 ) + l; } // [l,u]
	uint32_t calls( PRNG32 & prng ) __attribute__(( warn_unused_result )) with( prng ) { return callcnt; }
	void copy( PRNG32 & dst, PRNG32 & src ) { dst = src; } // checkpoint PRNG state, use autogen assignment
} // distribution
void ?{}( PRNG32 &, PRNG32 & ) = void;					// no copy, remove autogen copy constructor
PRNG32 & ?=?( PRNG32 &, const PRNG32 ) = void;			// no assignment, remove autogen assignment

struct PRNG64 {
	uint64_t callcnt;									// call count
	uint64_t seed;										// current seed
	PRNG_STATE_64_T state;								// random state
}; // PRNG64

static inline {
	void set_seed( PRNG64 & prng, uint64_t seed_ ) with( prng ) { seed = seed_; PRNG_SET_SEED_64( state, seed ); }
	uint64_t get_seed( PRNG64 & prng ) __attribute__(( warn_unused_result )) with( prng ) { return seed; }
	void ?{}( PRNG64 & prng, uint64_t seed ) with( prng ) { callcnt = 0; set_seed( prng, seed ); } // fixed seed
	void ?{}( PRNG64 & prng ) with( prng ) { ?{}( prng, rdtscl() ); } // random seed
	uint64_t prng( PRNG64 & prng ) __attribute__(( warn_unused_result )) with( prng ) { callcnt += 1; return PRNG_NAME_64( state ); } // [0,UINT_MAX]
	uint64_t prng( PRNG64 & prng, uint64_t u ) __attribute__(( warn_unused_result )) { return prng( prng ) % u; } // [0,u)
	uint64_t prng( PRNG64 & prng, uint64_t l, uint64_t u ) __attribute__(( warn_unused_result )) { return prng( prng, u - l + 1 ) + l; } // [l,u]
	uint64_t calls( PRNG64 & prng ) __attribute__(( warn_unused_result )) with( prng ) { return callcnt; }
	void copy( PRNG64 & dst, PRNG64 & src ) { dst = src; } // checkpoint PRNG state, use autogen assignment
} // distribution
void ?{}( PRNG64 &, PRNG64 & ) = void;					// no copy, remove autogen copy constructor
PRNG64 & ?=?( PRNG64 &, const PRNG64 ) = void;			// no assignment, remove autogen assignment

// Set default random-generator size.
#if defined( __x86_64__ ) || defined( __aarch64__ )		// 64-bit architecture
#define PRNG PRNG64
#else													// 32-bit architecture
#define PRNG PRNG32
#endif // __x86_64__

// Concurrent Pseudo Random-Number Generator : generate repeatable sequence of values that appear random.
//
// Interface :
//   set_seed( 1009 ) - fixed seed for all kernel threads versus random seed
//   get_seed() - read seed
//   prng() - generate random value in range [0,UINT_MAX]
//   prng( u ) - generate random value in range [0,u)
//   prng( l, u ) - generate random value in range [l,u]
//
// Examples : generate random number between 5-21
//   prng() % 17 + 5;	values 0-16 + 5 = 5-21
//   prng( 16 + 1 ) + 5;
//   prng( 5, 21 );

// Harmonize with concurrency/thread.hfa.
void set_seed( size_t seed_ ) OPTIONAL_THREAD;			// set global seed
size_t get_seed() __attribute__(( warn_unused_result )); // get global seed
size_t prng( void ) __attribute__(( warn_unused_result )) OPTIONAL_THREAD; // [0,UINT_MAX]
static inline {
	size_t prng( size_t u ) __attribute__(( warn_unused_result )) { return prng() % u; } // [0,u)
	size_t prng( size_t l, size_t u ) __attribute__(( warn_unused_result )) { return prng( u - l + 1 ) + l; } // [l,u]
} // distribution

//---------------------------------------

extern bool threading_enabled( void ) OPTIONAL_THREAD;

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// tab-width: 4 //
// End: //