PLMD::PlumedHandle Class Reference

Tiny local class to load a PLUMED kernel. More...

#include <PlumedHandle.h>

Classes
class	DlHandle
	Automatically dlclosing auxiliary class. More...

Public Member Functions
	PlumedHandle ()
	Default constructor. More...
	PlumedHandle (PlumedHandle &&)=default
	Move constructor. More...
virtual	~PlumedHandle ()
	Destructor. More...
void	cmd (const char *key, const void *ptr=nullptr)
	Execute cmd. More...

Static Public Member Functions
static PlumedHandle	dlopen (const char *path)
	Construct a PlumedHandle given the path to a kernel. More...

Private Member Functions
	PlumedHandle (const char *path)
	Constructor using the path to a kernel. More...

Private Attributes
const plumed_cmd_pointer	cmd_ =nullptr
	Pointer to cmd function. More...
const plumed_create_pointer	create_ =nullptr
	Pointer to create function. More...
const plumed_finalize_pointer	finalize_ =nullptr
	Pointer to finalize function. More...
DlHandle	handle
	Pointer to dlsym handle used to open the kernel. More...
std::unique_ptr< PlumedMain >	local
	Pointer to PlumedMain. More...
void *const	p =nullptr
	Pointer to the plumed object. More...
plumed_symbol_table_type *const	symbol_ =nullptr
	Pointer to symbol table. More...

Detailed Description

Tiny local class to load a PLUMED kernel.

Maps command to either a loaded PLUMED kernel or to the present one. It is a simplified version of the interface located at wrapper/Plumed.h. Differences are:

• It does not use the PLUMED_KERNEL env var. Indeed, it would not make sense to use it, since this class is meant to load different kernels.
• It does not implement interoperability with C/FORTRAN interfaces.
• It does not implement global versions (e.g. PLMD::Plumed::gcmd).
• It does not implement PLMD::Plumed::ginitialized. If it cannot be loaded, it crashes in its constructor. This will make sure that once constructed the object is usable.

The mechanism for loading the kernel is anyway very similar to the one in wrapper/Plumed.c. In particular, it can load both kernels from PLUMED <=2.4 and >=2.5, and it tries to load the libplumed.so object if the libplumedKernel.so object does not load correctly. It can also be created without passing any kernel path. In that case it refers to the current one (the one to which this class belongs).

The following syntax creates a handle referring to the current kernel

PlumedHandle p;
// Alternatively:
// auto p=PlumedHandle();
p.cmd("init");

The following syntax instead creates a handle referring to a loaded kernel

PlumedHandle p(PlumedHandle::dlopen("/path/to/libplumedkernel.so");
// Alternatively:
// auto p=PlumedHandle::dlopen("/path/to/libplumedkernel.so");
p.cmd("init");

Notice that if there are problems loading the kernel an exception is thrown. Thus, once constructed the object is guaranteed to be functional.

Constructor & Destructor Documentation

PlumedHandle() [1/3]

PLMD::PlumedHandle::PlumedHandle ( const char *  path )

explicitprivate

Constructor using the path to a kernel.

I keep it private to avoid confusion wrt the similar constructor of PLMD::Plumed that accepts a string (conversion from FORTRAN).

PlumedHandle() [2/3]

PLMD::PlumedHandle::PlumedHandle

(

)

Default constructor.

Maps following commands to the current kernel.

~PlumedHandle()

PLMD::PlumedHandle::~PlumedHandle ( )

virtual

Destructor.

In case a kernel was dlopened, it dlcloses it. I make it virtual for future extensibility, though this is not necessary now.

PlumedHandle() [3/3]

PLMD::PlumedHandle::PlumedHandle ( PlumedHandle &&  )

default

Move constructor.

Member Function Documentation

cmd()

void PLMD::PlumedHandle::cmd	(	const char *	key,
		const void *	ptr = nullptr
	)

Execute cmd.

dlopen()

PlumedHandle PLMD::PlumedHandle::dlopen ( const char *  path )

static

Construct a PlumedHandle given the path to a kernel.

It just uses the private constructor PlumedHandle(const char* path).

Member Data Documentation

cmd_

const plumed_cmd_pointer PLMD::PlumedHandle::cmd_ =nullptr

private

Pointer to cmd function.

Used when kernel is dlopened.

create_

const plumed_create_pointer PLMD::PlumedHandle::create_ =nullptr

private

Pointer to create function.

Used when kernel is dlopened.

finalize_

const plumed_finalize_pointer PLMD::PlumedHandle::finalize_ =nullptr

private

Pointer to finalize function.

Used when kernel is dlopened.

handle

DlHandle PLMD::PlumedHandle::handle

private

Pointer to dlsym handle used to open the kernel.

Null when using current kernel.

local

std::unique_ptr<PlumedMain> PLMD::PlumedHandle::local

private

Pointer to PlumedMain.

Used when using the current kernel in order to avoid unneeded indirections.

p

void* const PLMD::PlumedHandle::p =nullptr

private

Pointer to the plumed object.

Used when kernel is dlopened.

symbol_

plumed_symbol_table_type* const PLMD::PlumedHandle::symbol_ =nullptr

private

Pointer to symbol table.

Used for kernels>=2.5. We store it here since it is needed in constructor to initialize create_/cmd_/finalize_. Later on we might use the additional version information that it carries.

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The documentation for this class was generated from the following files:

• tools/PlumedHandle.h
• tools/PlumedHandle.cpp