Other Standard Facilities

The following classes are all defined within namespace HIPP::MPI.

Class Message: Probing and Matching

class Message

Memory management methods:

Method	Detail
default constructor	Available; noexcept; constructs a null value as returned by nullval().
copy constructor and operator=(&&)	Not Available.
move constructor and operator=(const &)	Available; noexcept.

typedef MPI_Message mpi_t;

explicit Message(mpi_t message) noexcept

Explicit construct a message object from MPI raw message object.

static Message nullval() noexcept

static Message no_proc_val() noexcept

bool is_null() const noexcept

bool is_no_proc() const noexcept

nullval() returns a null value (internally MPI_MESSAGE_NULL).

no_proc_val() returns a value of no-process (internally MPI_MESSAGE_NO_PROC).

is_null() tests whether this instance is a null value.

is_no_proc() tests whether this instance is a no-process value.

template<typename ...Args>
Status mrecv(Args&&... args)

template<typename ...Args>
Requests imrecv(Args&&... args)

Matched receiving calls.

Receive the message pointed by the message object into the buffer args. args may be any correct arguments that can be used to construct a datapacket object.

Class Info: the Hints to MPI Implementation

class Info

typedef std::pair<string, string> item_t

The type of info item, i.e., a key-value string pair.

Method	Detail
default constructor	Available; constructs an empty info object
copy constructor and operator=(&&)	Available; noexcept; shallow copy.
move constructor and operator=(const &)	Available; noexcept.

ostream &info(ostream &os = cout, int fmt_cntl = 1) const

friend ostream &operator<<(ostream &os, const Info &info)

Display some basic information of the info instance to os.

Parameters

fmt_cntl – Control the display format. 0 for inline information and 1 for a verbose, multiple-line information including all key-value pairs.

Returns

The os object is returned.

The overloaded << operator is equivalent to info() with the default fmt_cntl.

void free() noexcept

Free the current info object and set it to null value as returned by nullval(). free() can be called at any time, even for a pre-defined info object.

bool is_null() const

Inquiry whether the info object is a null value.

Info &set(const string &key, const string &val)

Add (or reset) a key-value pair.

Info &del(const string &key)

Aelete a key-value pair.

bool get(const string &key, string &val) const

string get(const string &key) const

item_t get(int n) const

vector<item_t> get() const

string operator[](const string &key) const

item_t operator[](int n) const

bool get_valuelen(const string &key, int &len) const

int get_nkeys() const

string get_nthkey(int n) const

Inquiry key-value pair, or pairs, or information of the pair.

get(key, val) returns the value into val corresponding to key. If the key is not set, return false, and val is not modified. Otherwise return true.

get(key) returns the value corresponding to key. If not set, throw an ErrLogic.

get(n) returns the n-th key-value pair. item_t is a std::pair<> instance with the first and second member corresponding to key and value, respectively.

get() returns a vector containing all key-value pairs.

operator[](key) and oprator[](n) are aliased to get(key) and get(n).

get_valuelen() returns the lengths of the value into len (not including the space of null-terminator) and return true if the key is set. Otherwise return false and len is not modified.

get_nkeys() gets number of keys.

get_nthkey() returns the n-th key.

Info dup()

static Info create()

static Info nullval() noexcept

Duplicate the info object, create a new empty info object, or get a null value object.

Memory Management

void *alloc_mem(aint_t size, const Info &info = Info::nullval())

void free_mem(void *base)

alloc_mem(size, info) allocates size bytes contiguous memory with hints info. The pointer to its starting address is returned.

The allocated memory must be free by free_mem() after using, otherwise causing memory leak.

Exception: both of the two functions throw an ErrMPI instance on failure. The error code is determined by MPI implementation.

void buffer_attach(void *buffer, int size)

std::pair<void*, int> buffer_detach()

Buffer management for buffered send operation.

buffer_attach(buffer, size) attaches a buffer with size bytes to be used for buffered mode send. User may use BSEND_OVERHEAD to properly determine the overhead associated with each message.

buffer_detach() detaches the buffer and returns its base address and size in bytes. This call will blocked until all messages currently in the buffer have been transmitted.

Timer

double wtime()

double wtick()

wtime() returns the wall-time in seconds. The zero-point is not changed in a process, but different nodes may have different zero-point.

wtick() returns the resolution of wtime() in seconds, i.e., the time between successive clock ticks.