#include <fd_array.hh>

Inheritance diagram for gem5::FDArray:

Public Member Functions
	FDArray (std::string const &input, std::string const &output, std::string const &errout)
	Initialize the file descriptor array and set the standard file descriptors to defaults or values passed in with the process params.

void	updateFileOffsets ()
	Figure out the file offsets for all currently open files and save them the offsets during the calls to drain by the owning process.

void	restoreFileOffsets ()
	Restore all offsets for currently open files during the unserialize phase for the owning process class.

void	setFDEntry (int tgt_fd, std::shared_ptr< FDEntry > fdep)
	Put the pointer specified by fdep into the _fdArray entry indexed by tgt_fd.

std::shared_ptr< FDEntry >	operator[] (int tgt_fd)
	Treat this object like a normal array in using the subscript operator to pull entries out of it.

int	getSize () const
	Return the size of the _fdArray field.

int	allocFD (std::shared_ptr< FDEntry > fdp)
	Step through the file descriptor array and find the first available entry which is denoted as being free by being a 'nullptr'.

int	closeFDEntry (int tgt_fd)
	Try to close the host file descriptor.

void	serialize (CheckpointOut &cp) const override
	Serialize an object.

void	unserialize (CheckpointIn &cp, Process *process_ptr)

void	unserialize (CheckpointIn &cp) override
	Unserialize an object.

Public Member Functions inherited from gem5::Serializable
	Serializable ()

virtual	~Serializable ()

void	serializeSection (CheckpointOut &cp, const char *name) const
	Serialize an object into a new section.

void	serializeSection (CheckpointOut &cp, const std::string &name) const

void	unserializeSection (CheckpointIn &cp, const char *name)
	Unserialize an a child object.

void	unserializeSection (CheckpointIn &cp, const std::string &name)

Private Member Functions
int	openFile (std::string const &file_name, int flags, mode_t mode) const
	Help clarify our intention when opening files in the init and restoration code.

int	openInputFile (std::string const &file_name) const

int	openOutputFile (std::string const &file_name) const

std::shared_ptr< FDEntry >	getFDEntry (int tgt_fd)
	Return the file descriptor entry object associated with the index provided.

Private Attributes
std::array< std::shared_ptr< FDEntry >, _numFDs >	_fdArray

std::string	_input
	Hold param strings passed from the Process class which indicate the filename for each of the corresponding files or some keyword indicating the use of standard file descriptors.

std::string	_output

std::string	_errout

std::map< std::string, int >	_imap
	Hold strings which represent the default values which are checked against to initialize the standard file descriptors.

std::map< std::string, int >	_oemap

Static Private Attributes
static constexpr size_t	_numFDs {1024}
	Hold pointers to the file descriptor entries.

Additional Inherited Members
Static Public Member Functions inherited from gem5::Serializable
static const std::string &	currentSection ()
	Gets the fully-qualified name of the active section.

static void	generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
	Generate a checkpoint file so that the serialization can be routed to it.

Detailed Description

Definition at line 48 of file fd_array.hh.

Constructor & Destructor Documentation

◆ FDArray()

gem5::FDArray::FDArray	(	std::string const &	input,
		std::string const &	output,
		std::string const &	errout )

Initialize the file descriptor array and set the standard file descriptors to defaults or values passed in with the process params.

Parameters

input	Used to initialize the stdin file descriptor
output	Used to initialize the stdout file descriptor
errout	Used to initialize the stderr file descriptor

Search through the input options and setup the default fd if match is found; otherwise, open an input file and seek to location.

Search through the output/error options and setup the default fd if match is found; otherwise, open an output file and seek to location.

Definition at line 50 of file fd_array.cc.

Member Function Documentation

◆ allocFD()

int gem5::FDArray::allocFD ( std::shared_ptr< FDEntry > fdp )

Step through the file descriptor array and find the first available entry which is denoted as being free by being a 'nullptr'.

That file descriptor entry is the new target file descriptor entry that we return as the return parameter.

Parameters

fdp	Allocated beforehand and passed into this method; the fdp is meant to be a generic pointer capable of pointing to different types of file descriptors. Must cast the pointer to the correct type before dereferencing to access the needed fields.

Definition at line 285 of file fd_array.cc.

References fatal, and gem5::ArmISA::i.

◆ closeFDEntry()

int gem5::FDArray::closeFDEntry ( int tgt_fd )

Try to close the host file descriptor.

If successful, set the specified file descriptor entry object pointer to nullptr. Used to "close" the target file descriptor.

Parameters

tgt_fd Use target file descriptors to index the array.

Definition at line 334 of file fd_array.cc.

References gem5::ArmISA::status.

◆ getFDEntry()

std::shared_ptr< FDEntry > gem5::FDArray::getFDEntry ( int tgt_fd )

private

Return the file descriptor entry object associated with the index provided.

(The index is protected with bounds checking on the array size without the use of the array's at operator.)

Parameters

tgt_fd Use target file descriptors to index the array.

Definition at line 320 of file fd_array.cc.

Referenced by operator[]().

◆ getSize()

int gem5::FDArray::getSize ( ) const

inline

Return the size of the _fdArray field.

Definition at line 96 of file fd_array.hh.

References _fdArray.

◆ openFile()

int gem5::FDArray::openFile	(	std::string const &	file_name,
		int	flags,
		mode_t	mode ) const

private

Help clarify our intention when opening files in the init and restoration code.

These are helper functions which are not meant to be exposed to other objects or files.

Definition at line 298 of file fd_array.cc.

References fatal, flags, and gem5::ArmISA::mode.

◆ openInputFile()

int gem5::FDArray::openInputFile ( std::string const & file_name ) const

private

Definition at line 307 of file fd_array.cc.

◆ openOutputFile()

int gem5::FDArray::openOutputFile ( std::string const & file_name ) const

private

Definition at line 313 of file fd_array.cc.

References gem5::OutputDirectory::resolve(), and gem5::simout.

◆ operator[]()

std::shared_ptr< FDEntry > gem5::FDArray::operator[] ( int tgt_fd )

inline

Treat this object like a normal array in using the subscript operator to pull entries out of it.

Parameters

tgt_fd Use target file descriptors to index the array.

Definition at line 88 of file fd_array.hh.

References getFDEntry().

◆ restoreFileOffsets()

void gem5::FDArray::restoreFileOffsets ( )

Restore all offsets for currently open files during the unserialize phase for the owning process class.

Use this lambda to highlight what we mean to do with the seek. Notice that this either seeks correctly (sets the file location on the host) or it fails with a fatal. The error is fatal because it's not possible to guarantee that the simulation will proceed as it should have in the same way that it would have proceeded sans checkpoints.

Search through the input options and set fd if match is found; otherwise, open an input file and seek to location. Check if user has specified a different input file, and if so, use it instead of the file specified in the checkpoint. This also resets the file offset from the checkpointed value

Search through the output options and set fd if match is found; otherwise, open an output file and seek to location. Check if user has specified a different output file, and if so, use it instead of the file specified in the checkpoint. This also resets the file offset from the checkpointed value

Search through the error options and set fd if match is found; otherwise, open an error file and seek to location. Check if user has specified a different error file, and if so, use it instead of the file specified in the checkpoint. This also resets the file offset from the checkpointed value

Check which end of the pipe we are looking at; we only want to setup the pipe once so we arbitrarily choose the read end to be the end that sets up the pipe.

Reconstruct the ends of the pipe by reassigning the pipe that we created on the host. This one is the read end.

Grab the write end by referencing the read ends source and using that tgt_fd to index the array.

Yeah, how does one retain the entire driver state from this particular set of code? If you figure it out, add some code here to rectify the issue.

Assume that this has the mode of an output file so there's no need to worry about properly recording the mode. If you're reading this and this happens to be your issue, at least be happy that you've discovered the issue (and not mad at me). Onward ho!

Definition at line 126 of file fd_array.cc.

References fatal, and warn.

◆ serialize()

void gem5::FDArray::serialize ( CheckpointOut & cp ) const

overridevirtual

Serialize an object.

Output an object's state into the current checkpoint section.

Parameters

cp	Checkpoint state

Implements gem5::Serializable.

Definition at line 355 of file fd_array.cc.

References gem5::csprintf(), gem5::ArmISA::fd, and gem5::paramOut().

◆ setFDEntry()

void gem5::FDArray::setFDEntry	(	int	tgt_fd,
		std::shared_ptr< FDEntry >	fdep )

Put the pointer specified by fdep into the _fdArray entry indexed by tgt_fd.

Parameters

tgt_fd	Use target file descriptors to index the array.
fdep	Incoming pointer used to set the entry pointed to by tgt_fd.

Definition at line 327 of file fd_array.cc.

◆ unserialize() [1/2]

void gem5::FDArray::unserialize ( CheckpointIn & cp )

inlineoverridevirtual

Unserialize an object.

Read an object's state from the current checkpoint section.

Parameters

cp	Checkpoint state

Implements gem5::Serializable.

Definition at line 123 of file fd_array.hh.

References unserialize().

◆ unserialize() [2/2]

void gem5::FDArray::unserialize	(	CheckpointIn &	cp,
		Process *	process_ptr )

Definition at line 371 of file fd_array.cc.

References gem5::Process::checkPathRedirect(), gem5::csprintf(), flags, gem5::ArmISA::mode, panic, and gem5::paramIn().

Referenced by unserialize().

◆ updateFileOffsets()

void gem5::FDArray::updateFileOffsets ( )

Figure out the file offsets for all currently open files and save them the offsets during the calls to drain by the owning process.

It only makes sense to check the offsets if the file descriptor type is 'File' (which indicates that this file is backed by a file on the host). If the type is File, then record the offset.

Use lseek with SEEK_CUR with offset 0 to figure out where the offset currently resides and pass that back to our setter.

Definition at line 103 of file fd_array.cc.

Member Data Documentation

◆ _errout

std::string gem5::FDArray::_errout

private

Definition at line 160 of file fd_array.hh.

◆ _fdArray

std::array<std::shared_ptr<FDEntry>, _numFDs> gem5::FDArray::_fdArray

private

Definition at line 151 of file fd_array.hh.

Referenced by getSize().

◆ _imap

std::map<std::string, int> gem5::FDArray::_imap

private

Hold strings which represent the default values which are checked against to initialize the standard file descriptors.

If the string provided doesn't hit against these maps, then a file is opened on the host instead of using the host's standard file descriptors.

Definition at line 168 of file fd_array.hh.

◆ _input

std::string gem5::FDArray::_input

private

Hold param strings passed from the Process class which indicate the filename for each of the corresponding files or some keyword indicating the use of standard file descriptors.

Definition at line 158 of file fd_array.hh.

◆ _numFDs

size_t gem5::FDArray::_numFDs {1024}

staticconstexprprivate

Hold pointers to the file descriptor entries.

The array size is statically defined by the operating system.

Definition at line 150 of file fd_array.hh.

◆ _oemap

std::map<std::string, int> gem5::FDArray::_oemap

private

Definition at line 169 of file fd_array.hh.

◆ _output

std::string gem5::FDArray::_output

private

Definition at line 159 of file fd_array.hh.

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

sim/fd_array.hh
sim/fd_array.cc

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ FDArray()

Member Function Documentation

◆ allocFD()

◆ closeFDEntry()

◆ getFDEntry()

◆ getSize()

◆ openFile()

◆ openInputFile()

◆ openOutputFile()

◆ operator[]()

◆ restoreFileOffsets()

◆ serialize()

◆ setFDEntry()

◆ unserialize() [1/2]

◆ unserialize() [2/2]

◆ updateFileOffsets()

Member Data Documentation

◆ _errout

◆ _fdArray

◆ _imap

◆ _input

◆ _numFDs

◆ _oemap

◆ _output