spades Namespace Reference

Solver for PArallel Discrete Event Simulation. More...

Namespaces
namespace	constants
	SPADES constants.
namespace	ic
	SPADES initial conditions.
namespace	io
	IO functionality for SPADES.
namespace	particles
	SPADES particles.

Classes
struct	Factory
class	SPADES
	Main SPADES class. More...

Functions
amrex::Real	random_exponential (const amrex::Real lambda)
	Exponential distribution.
void	goto_next_line (std::istream &is)
	Skip to the next line in stream.
void	read_file (const std::string &filename, amrex::Vector< char > &charBuf, bool bExitOnError)
	Read and broadcast file to all ranks.
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE amrex::Long	pairing_function (const amrex::Long k1, const amrex::Long k2)
	Cantor pairing function.
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE amrex::Real	random_exponential (const amrex::Real lambda, amrex::RandomEngine const &engine)
	Exponential distribution.
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE std::uint64_t	max_representation (const int nbits)
	Maximum unsigned integer representation given a number of bits.
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE std::uint64_t	bitmask (const int nbits)
	bitmask given a number of bits

Detailed Description

Solver for PArallel Discrete Event Simulation.

Function Documentation

bitmask()

AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE std::uint64_t spades::bitmask

(

const int

nbits

)

bitmask given a number of bits

Parameters

nbits

[in] number of bits

Returns

bitmask

{
    AMREX_ASSERT(nbits < 64);
    // Shift 1 by nbits (create power of 2)
    // Subtract 1 to fill all lower nbits with 1s
    // bitmask(16): 0xFFFF
    return (1ULL << nbits) - 1;
}

goto_next_line()

void spades::goto_next_line

(

std::istream &

is

)

Skip to the next line in stream.

Parameters

is	[in, out] stream

{
    constexpr std::streamsize bl_ignore_max{100000};
    is.ignore(bl_ignore_max, '\n');
}

Here is the caller graph for this function:

max_representation()

AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE std::uint64_t spades::max_representation

(

const int

nbits

)

Maximum unsigned integer representation given a number of bits.

Parameters

nbits

[in] number of bits

Returns

maximum integer representation

{
    AMREX_ASSERT(nbits < 64);
    std::uint64_t result = 2;
    for (int i = 0; i < nbits; i++) {
        result *= 2;
    }
    return result;
}

pairing_function()

AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE amrex::Long spades::pairing_function	(	const amrex::Long	k1,
		const amrex::Long	k2 )

Cantor pairing function.

Parameters

k1	[in] first number
k2	[in] second number

Returns

value of the Cantor pairing function

{
    return (k1 + k2) * (k1 + k2 + 1) / 2 + k2;
}

random_exponential() [1/2]

amrex::Real spades::random_exponential

(

const amrex::Real

lambda

)

Exponential distribution.

Parameters

lambda

[in] rate parameter

Returns

sample from an exponential distribution

{
 
    return std::log(1 - amrex::Random()) / (-lambda);
}

Here is the caller graph for this function:

random_exponential() [2/2]

AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE amrex::Real spades::random_exponential	(	const amrex::Real	lambda,
		amrex::RandomEngine const &	engine )

Exponential distribution.

Parameters

lambda	[in] rate parameter
engine	[in] random number generator

Returns

sample from an exponential distribution

{
    return std::log(1 - amrex::Random(engine)) / (-lambda);
}

read_file()

void spades::read_file	(	const std::string &	filename,
		amrex::Vector< char > &	charBuf,
		bool	bExitOnError )

Read and broadcast file to all ranks.

Equivalent to amrex::ParallelDescriptor::ReadAndBcastFile but for all ranks.

Parameters

filename	[in] file to read
charBuf	[out] character buffer
bExitOnError	[in] exit if error

{
    enum { IO_Buffer_Size = 262144 * 8 };
 
#ifdef BL_SETBUF_SIGNED_CHAR
    using Setbuf_Char_Type = signed char;
#else
    using Setbuf_Char_Type = char;
#endif
 
    amrex::Vector<Setbuf_Char_Type> io_buffer(IO_Buffer_Size);
 
    amrex::Long file_length(0);
    amrex::Long file_length_padded(0);
 
    std::ifstream iss;
 
    iss.rdbuf()->pubsetbuf(io_buffer.dataPtr(), io_buffer.size());
    iss.open(filename.c_str(), std::ios::in);
    if (!iss.good()) {
        if (bExitOnError) {
            amrex::FileOpenFailed(filename);
        } else {
            file_length = -1;
        }
    } else {
        iss.seekg(0, std::ios::end);
        file_length = static_cast<std::streamoff>(iss.tellg());
        iss.seekg(0, std::ios::beg);
    }
 
    if (file_length == -1) {
        return;
    }
 
    file_length_padded = file_length + 1;
    charBuf.resize(file_length_padded);
 
    iss.read(charBuf.dataPtr(), file_length);
    iss.close();
 
    charBuf[file_length] = '\0';
}

Here is the caller graph for this function: