utils::command::osal::IOsal Interface Reference

This class is a high level interface added to ease testability of component that use Executor. It decouples Excecutor and syscalls used to handle requests thus behaving like an OS abstraction layer. More...

#include "utils/command/executor/IOsal.h"

Inheritance diagram for utils::command::osal::IOsal:

Public Types
enum	ProcessId : unsigned int { CHILD = (1u << 0u), PARENT = (1u << 1u) }
	An id to inform caller about the current process type after a new process has been created. More...

Public Member Functions
	IOsal ()=default
virtual	~IOsal ()=default
	IOsal (const IOsal &)=delete
IOsal &	operator= (const IOsal &)=delete
	IOsal (IOsal &&)=delete
IOsal &	operator= (IOsal &&)=delete
virtual ProcessId	createProcess () const =0
	creates a new process by duplicating the calling process. More...
virtual void	waitChildProcess () const =0
	Wait for any child process whose process group ID is equal to that of the calling process. More...
virtual void	executeProgram (const char *pathname, char *const argv[], char *const envp[]) const =0
	Execute the program referred to by pathname. More...
virtual void	reseedPRNG () const =0
	Initialize the Random Number Generator for a new sequence of pseudo-random integers to be returned by rand() More...
virtual void	sanitizeFiles () const =0
	Close all opened file descriptors except those related to the standard streams (stdin, stdout, stderr). These are reopened to /dev/null if not already opened. More...
virtual void	dropPrivileges () const =0
	Permanently drop the privileges of the process. More...

Detailed Description

This class is a high level interface added to ease testability of component that use Executor. It decouples Excecutor and syscalls used to handle requests thus behaving like an OS abstraction layer.

Note

Copy contructor, copy-assignment operator, move constructor and move-assignment operator are defined to be compliant with the "Rule of five"

See also

https://en.cppreference.com/w/cpp/language/rule_of_three

Author

Boubacar DIENE bouba.nosp@m.car..nosp@m.diene.nosp@m.@gma.nosp@m.il.co.nosp@m.m

Date

May 2020

Member Enumeration Documentation

ProcessId

enum utils::command::osal::IOsal::ProcessId : unsigned int

An id to inform caller about the current process type after a new process has been created.

Enumerator
CHILD	In child process
PARENT	In parent process

Constructor & Destructor Documentation

IOsal() [1/3]

utils::command::osal::IOsal::IOsal ( )

default

Class constructor

~IOsal()

virtual utils::command::osal::IOsal::~IOsal ( )

virtualdefault

Class destructor

IOsal() [2/3]

utils::command::osal::IOsal::IOsal ( const IOsal &  )

delete

Class copy constructor

IOsal() [3/3]

utils::command::osal::IOsal::IOsal ( IOsal &&  )

delete

Class move constructor

Member Function Documentation

createProcess()

virtual ProcessId utils::command::osal::IOsal::createProcess ( ) const

pure virtual

creates a new process by duplicating the calling process.

It can basically be a wrapper of fork() call in linux.

Returns

An id of type ProcessId

Implemented in utils::command::osal::Linux.

dropPrivileges()

virtual void utils::command::osal::IOsal::dropPrivileges ( ) const

pure virtual

Permanently drop the privileges of the process.

Implemented in utils::command::osal::Linux.

executeProgram()

virtual void utils::command::osal::IOsal::executeProgram ( const char *  pathname, char *const  argv[], char *const  envp[]  ) const

pure virtual

Execute the program referred to by pathname.

It can basically be a wrapper of a exec()-like function. It is expected it does not return unless an error is encountered.

Parameters

pathname	Either a binary executable, or a script starting with a line of the form: "#! interpreter [optional-arg]"
argv	An array of argument strings passed to the new program. By convention, the first of these strings should contain the filename associated with the file being executed.
envp	An array of strings of the form key=value, which are passed as environment to the new program.

Implemented in utils::command::osal::Linux.

operator=() [1/2]

IOsal& utils::command::osal::IOsal::operator= ( const IOsal &  )

delete

Class copy-assignment operator

operator=() [2/2]

IOsal& utils::command::osal::IOsal::operator= ( IOsal &&  )

delete

Class move-assignment operator

reseedPRNG()

virtual void utils::command::osal::IOsal::reseedPRNG ( ) const

pure virtual

Initialize the Random Number Generator for a new sequence of pseudo-random integers to be returned by rand()

Implemented in utils::command::osal::Linux.

sanitizeFiles()

virtual void utils::command::osal::IOsal::sanitizeFiles ( ) const

pure virtual

Close all opened file descriptors except those related to the standard streams (stdin, stdout, stderr). These are reopened to /dev/null if not already opened.

Implemented in utils::command::osal::Linux.

waitChildProcess()

virtual void utils::command::osal::IOsal::waitChildProcess ( ) const

pure virtual

Wait for any child process whose process group ID is equal to that of the calling process.

It can basically be a wrapper of waitpid() call in linux with a pid equal to 0.

Note

This method raises an exception when the child process failed

Implemented in utils::command::osal::Linux.

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The documentation for this interface was generated from the following file:

• /workdir/src/utils/command/executor/IOsal.h