advanced operating systems moving to c++ 2015-10-28 · giuseppe massari advanced operating systems...

Advanced Operating SystemsMoving to C++

Giuseppe Massarigiuseppemassaripolimiit

Advanced Operating SystemsGiuseppe Massari

442Outline

C++ Programs Memory allocation Passing parameters to functions

Classes Constructors and assignments Object pointers Qualifiers

Standard Template Library (STL) Templates Example vectorltgt listltgt

Memory management From raw to smart pointers


443Program memory

Memory layout Once loaded in the main memory a program is typicallydivided into segments

TEXT Program instructions

DATA Initialized variables

BSS Uninitialized or zeroed variables

STACK Local variables and return address of functions

HEAP Dynamically allocated data ie allocateddeshyallocated at runshytime


444Program memory

Memory allocation In C programs dynamic memory allocation and deshyallocation is performed through malloc() and free() functions

In C++ programs operators new and delete are usedFor dynamic array allocation new hellip[] delete[]

newdelete call class constructor and destructor respectivelyDo not mix mallocfree with newdelete usage

Do not use mallocfree with C++ objects since they do not call the class constructordestructor

char buff = malloc(buff_size)char buff = malloc(buff_size) free(buff)free(buff)

char buff = new char[5]

Object obj = new Object()



delete[] buff

delete obj

delete[] buff

delete obj


445Program memory

Memory allocation Example

static resultunsigned int count = 20

int main()

int numchar buff = new char[4]

hellipdelete[] valuereturn 0


int main()



result

count

main numbuff

ldquordquo


446Memory allocation common errors

Memory leak Memory allocated but NOT released Application continuously increase memory consumption

Reducing the availability for other applications Performance slow down

Operating system may reshymap the virtual memory page to the hard drive Application or even the system may stop working

Unpredictable behaviour when system memory resource limits are reached

Sources We forgotten the related delete call for some new We changed the value of a pointer variable

No other variables point to the previously dynamically allocated data

Such data becomes unreachable



Memory corruption Memory location alteration without an explicit assignment

Attempt of freeing an already freed memory location (dangling pointer)

Attempt of accessing a freed (or not allocated yet) memory location

int main() char buff = new char[4]delete[] buffhellipdelete[] buff


$ program Error in `program double free or corruption 0x00000000011a5040

Aborted (core dumped)



int main() char buffcout ltlt buff ltlt endl


$ programSegmentation fault(core dumped)



448Functions

Passing parameters By value

Passed variablesobjects are COPIED into the called function stack

By address (C approach)Caller passes the address of the objectvariable to the callee (NO COPY)

Callee can modify the content of the variableobject

By reference (C++ approach)Same effect of passing by address (NO COPY)


void func(Object var)void func(Object var) func(var) callfunc(var) call

void func(Object var)void func(Object var) func(ampvar) callfunc(ampvar) call

void func(Object amp var)void func(Object amp var) func(var) callfunc(var) call


449Outline






4410Classes

Syntax A C++ class can include a public and private sections (keywords public and private) to set the visibility level of member data (attributes) and member functions (methods)

Good practice member definition and member implementation placed into separated files

Definition header file (rarr h hh) Implementation rarr cpp cc Member function implementation syntaxltfunction typegt ClassNameFunctionName()

Accessor methods (Get()) are tagged with the keyword const

The class definition is closed by a semicolon ()


4411Classes

Syntax

ifndef PEOPLE_H_define PEOPLE_H_

include ltstringgt

class People public

People()int Walk()void Talk() const

privatestdstring nameint step_count

endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh

include ltiostreamgtinclude peopleh

PeoplePeople()name(ldquoguyrdquo)step_count(0)

int PeopleWalk() return ++step_count

void PeopleTalk() conststdcout ltlt name

ltlt ldquo made rdquo ltlt step_countltlt ldquo stepsrdquo ltlt stdendl

peoplecpp






peoplecpp


4412Classes

Constructors A function having the same class name but not returning any type Called every time an instance of a class is created If not provided the compiler will generate the code for one A class can have multiple constructors with different argument lists

class People public

People()People(stdstring _name)hellip


hellip

peopleh

class People public



hellip

peopleh

PeoplePeople()name(ldquoGuyrdquo)step_count(0)

PeoplePeople(stdstring _name)name(_name)step_count(0)

peoplecpp



peoplecpp


4413Classes

Constructors Called when we instantiate an object by declaring a variable of the class type or we dynamically allocate an object of the class type(see later)

int main()

People who1People who2()People simon(ldquoSimonrdquo)

who1Talk()who2Talk()simonTalk()

Guy made 0 stepsGuy made 0 stepsSimon made 0 steps


People() version is called

People(stdstring) version is called

Output


4414Classes

Destructors Called when the object is going out of scope or it is explicitly deleted

Syntax ~ClassName() (no arguments)Very often qualified as ldquovirtualrdquo to prevent derived class from invoking thebase class destructor

Commonly includes the implementation of end of life actions eg cleanshyup code memory deallocation

class People public

People()People(stdstring _name)virtual ~People()

hellip peopleh

class People public


hellip peopleh

hellip People~People()

stdcout ltlt nameltlt ldquo im dyingrdquoltlt stdendl

hellip peoplecpp



hellip peoplecpp


4415Classes

Copy constructors Special constructors having an object of the same class as argument If not implemented the compiler will automatically generate one The default implementation is a membershywise copy of the object

Membershywise copy can be expensiveWhat if member data are further complex objects

Depending on the class definition it may also lead to undesired behaviours

What if member data are pointers Pointer object ldquocomplexrdquo class types

PeoplePeople( const People amp other )

name = othernamestep_count = otherstep_count




4416Classes

Copy constructors Example

Fred is created starting from Simon(do we want Fred to have the same Simons information)

Default copy constructor is called (membershywise copy)

int main()

People simon(ldquoSimonrdquo)

for(int i=0 ilt3 ++i)simonWalk()

simonTalk()

People fred(simon)fredTalk()

int main()



simonTalk()


Simon made 3 stepsSimon made 3 steps


freds member data have been initialized to the same value of object simon

Output


4417Classes

Copy constructors Creating a ldquoPeoplerdquo object starting from another one

Do we want the ldquonew personrdquo Fred to start with the number of steps of the Simon

Overload of the copy constructor implementing our custom versionSet step_count to zero since we are constructing a new object that hasnever walked before

Desired behaviour Just copy the name of the other person


name = othernamestep_count = 0




4418Classes


We create a second ldquoSimonrdquo object

Custom copy constructor initializes the object using the same of the first Simon

int main()

People simon1(ldquoSimonrdquo)


simonTalk()

People simon2(simon1)simon2Talk()

int main()



simonTalk()




simon2 has the same name of simon1 but since it has just born it has never walked before

Output


4419Classes

Object assignment Assignment operation is provided by the compiler Also in this case the default implementation is the membershywise copy of the object

Conversely from other OO languages (eg Java) the object variables content is a value and not a reference

We can overload the assignment operator (ldquo=rdquo) tooSyntax similar to member function implementation but replacing the function name with operatorltoperator_symbolgt

People amp Peopleoperator=( const People amp other )





4420Classes

Object assignment Conversely from other OO languages (eg Java) the object variables content is a value and not a reference

An assignment operation lead to a copy of the entire object

int main()

People simon(ldquoSimonrdquo)People fred

fred = simonsimonWalk()simonTalk()

fredTalk()

int main()



fredTalk()



Member data name value hasbeen copied

Walk() has updated only simon status

Output


4421Classes

Object pointers Pointers allows multiple variables to jointly access the same object

Assignment operation copies the pointervalue ie the memory address

int main() People joe1 =

new People(ldquoJoerdquo)People joe2

joe2 = joe1joe1-gtWalk()joe1-gtTalk()joe2-gtTalk()

delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040

Joe made 1 stepsJoe made 1 steps



4422Classes

Constant members Data or function members qualified with const keyword Constshyqualified variable are used to store data that should not be altered

Qualifier const applies to whatever is on its immediate left If there is nothing there applies to whatever is its immediate right

k is a variable pointer to a constant integerconst int k alternative syntax which does the sameint const k k is constant pointer to an integer variableint const k k is a constant pointer to a constant integerint const const k



4423Classes

Constant members The const keyword can be used also in functions To specify a ldquoreadshyonlyrdquo function ie that does not change the object status (member data values)

To pass (by reference) arguments (typically objects) that we donot want to be modified

Function TalkWith() cannot access not const member functions of other To prevent alteration of returned variable of pointer types

Alteration attempts are detected at compileshytime

void Talk() constvoid Talk() const

void TalkWith(const People amp other)void TalkWith(const People amp other)

const People GetParent() constconst People GetParent() const


4424Classes

Static members The static keyword can be used in a class definition for different purposes depending on if it is applied to data or functions

Static member data are variables shared among all the instancesMember data initialization cannot be performed in the class

Static member functions do not require a class instanceFunctions though to be meaningful at classshylevel instead of instanceshylevel

They cannot access non static members since not ldquobelongingrdquo to any instance

stdcoutltlt MyClassGetCount()ltlt stdendl


class MyClass myclasshstatic int count


myclasscpp Initializationint MyClasscount = 0


class MyClass myclasshpublic

static int GetCount()




4425Classes

Static members Example

class People public

People()hellip

static int GetPopulation()private

hellip static int population

peopleh

class People public

People()hellip



peopleh

Initint Peoplepopulation = 0

PeoplePeople()name(ldquoguyrdquo)step_count(0) population++

People~People() population--

int PeopleGetPopulation() return population

peoplecpp





peoplecpp

int main() People joestdcout ltlt

PeopleGetPopulation()hellip




4426Outline






4427Standard Template Library (STL)

Template A way of making functions or classes more abstract Focus on the behaviour of the function (or the class) without knowing variables data type

A single function class implementation to cover several data type cases

Avoid code replications (simply due to variables data type) Data type resolution performed at compileshytime

Compilers generate additional code Large use of template may strongly increase the executable size Longer compilation times

Debugging is complicated by hard to read compiler messages

Template code is commonly placed in header files Modify a template class may lead to entire project reshybuild



Template functions Example of global function performing addition between two variables of a generic type

hellip templateltclass TgtT add(T a1 T a2) return a1 + a2hellip int main()

int i1 i2float f1 f2hellip cout ltlt addltintgt(i1 i2)

ltlt endlcout ltlt addltfloatgt(f1 f2)

ltlt endlreturn 0




ltlt endlreturn 0

The compiler will generatetwo versions of function add()

int add(int a1 int a2) return a1 + a2


float add(float a1 float a2) return a1 + a2




Template classes A class including generic type members

ifndef MATH_H_define MATH_H_namespace aos

template ltclass Tgtclass Math public

T add(T a1 T a2)T mul(T m1 T m2)T div(T m1 T m2)

namespace aosendif MATH_H_

mathh





mathh

include mathhnamespace aos

template ltclass TgtT MathltTgtadd(T a1 T a2)

return a1 + a2template ltclass TgtT MathltTgtmul(T m1 T m2)

return m1 m2template ltclass TgtT MathltTgtdiv(T d1 T d2)

return d1 d2template class Mathltintgttemplate class Mathltfloatgt namespace aos









Two instances are used to work on integer and floating points data

include ltiostreamgtinclude mathhusing namespace std

int main() aosMathltintgt mIaosMathltfloatgt mF Integer operationscout ltlt Add ltlt mIadd(6 10) ltlt endlcout ltlt Mul ltlt mImul(12 2) ltlt endlcout ltlt Div ltlt mIdiv(7 3) ltlt endl Floating point operationscout ltlt Div ltlt mFdiv(7 3) ltlt endlreturn 0



Add 16Mul 24Div 2Div 233333




STL A powerful set of C++ template classes Provides generalshypurpose templateshybased classes and functions Implement commonly used algorithms and data structure Containers are the most noticeable example of data structures

List queues stack map set hellip

Used to manage a collection of object of a certain class

The differ for functionality typology (sequential associative unordered) and complexity of accessing and manipulation operations

Iterators are used to step through the elements of the containers Algorithms includes function manipulating containers

Search copy sort transform

For a complete list httpwwwcpluspluscomreferencestl



vector Sequence containers representing dynamic arrays (mutable size)

Contiguous of storage of elements with random access

int main() People claire(Claire)People john(John)vectorltPeoplegt citizens Container of Peoplecitizenspush_back(john) Add to vectorcitizenspush_back(claire) Add to vectorvectorltPeoplegtiterator itfor(it = citizensbegin() it = citizensend() ++it)

cout ltlt Name ltlt it-gtGetName() ltlt endlcout ltlt ldquoCitizen 1 isrdquo ltlt citizens[1]GetName() ltlt endlreturn 0



Name JohnName ClaireCitizen 1 is Claire




list Sequence containers implementing doubleshylinked lists

Constant time insert and erase operations on the object collection

int main() People claire(Claire)People john(John)listltPeoplegt citizens Container of Peoplecitizenspush_back(john) Add to vectorcitizenspush_back(claire) Add to vectorlistltPeoplegtiterator itfor(it = citizensbegin() it = citizensend() ++it)

cout ltlt Name ltlt it-gtGetName() ltlt endlreturn 0



Name JohnName Claire



4434Outline






4435Memory management

Raw pointers Using (raw) pointers is a powerful CC++ feature but in general difficult to handle and errorshyprone

Consider the following example

This ends in a ldquoSegmentation faultrdquo since ldquoalexrdquo is deallocated multiple times

int main() People joe = new People(ldquoJoerdquo)People ann = new People(ldquoAnnrdquo)People alex = new People(ldquoAlexrdquo)joe-gtSetChild(alex)ann-gtSetChild(alex)

delete joedelete anndelete alexreturn 0



class People public

virtual ~People()void SetChild(

People _child)private

People child

class People public



People child

People~People() delete child




Smart pointers To solve the problem we should start from the concept of ownership To own a dynamically allocated object means to be the entity in charge of deallocating it

Smart pointers is a feature introduced in C++ since standard C++11 to simplify the memory management in C++ programs

Concept of ownership introduced and exploited

Limited garbage collection facilities Base idea To wrap raw pointers in stack allocated objects that could control the lifeshycycle of the dynamically allocated object

We are going to focus on just two class of smart pointerUnique pointers (class unique_ptrltgt)

Shared pointers (class shared_ptrltgt)



Shared pointers Pointers of type shared allows us to keep track of the number of shared ownership ie references to the objects

Reference counting based mechanismAssignments and scope exit alter the reference counters

If the count is decreased to zero the object is automatically deallocated This facility does not come for free

Reference counting mechanism requires a little additional memory overhead

Shared pointers can rely the developer from the burden of using explicit newdelete constructs

include ltmemorygtusing namespace stdint main()

shared_ptrltPeoplegt jack = make_sharedltPeoplegt(Jack)hellip





Shared pointers Similarly to pointer variables

Object ldquojackrdquo (of class shared_ptrltgt) is allocated onto the stack

Members of the pointed object are accessed by using the ldquo-gtrdquo operator shared_ptrltgt member function get()returns the raw pointer value

Using ldquordquo operator to access shared_ptrltgt member functions

hellip shared_ptrltPeoplegt jack

= make_sharedltPeoplegt(Jack) cout ltlt Name = ltlt jack-gtGetName() ltlt endl cout ltlt Raw ptr = ltlt jackget() ltlt endl hellip



Name = JackRaw pointer = 0x22440c8


mainjack

0x22440c8



Shared pointers Example an assignment operation and a scope exit


hellip shared_ptrltPeoplegt jack = make_sharedltPeoplegt(Jack)cout ltlt Jack refcount = ltlt jackuse_count() ltlt endl

shared_ptrltPeoplegt jack2jack2 = jackcout ltlt Jack refcount = ltlt jackuse_count() ltlt endl

cout ltlt Jack refcount = ltlt jackuse_count() ltlt endl return 0





Jack refcount = 1Jack refcount = 2 jack2 = jackJack refcount = 1 jack2 out of scope =gt jack refcount decreaseJack im dying People object ldquoJackrdquo destruction




Shared pointers The previous ldquoparentsrdquo example can be rewritten as follows using shared pointers (changing also SetChild() signature)

No need of explicit delete (objects deallocated at main function exit) No multiple deallocation thanks to reference counting


shared_ptrltPeoplegt jack = make_sharedltPeoplegt(Jack)shared_ptrltPeoplegt ann = make_sharedltPeoplegt(Ann)shared_ptrltPeoplegt alex = make_sharedltPeoplegt(Alex)jack-gtSetChild(alex)ann-gtSetChild(alex)return 0





Unique pointers Do not share the ownership of a pointed object

Unique pointer means unique ownership

Only one object responsible of memory deallocation Copy assignments not allowed only move assignments are


unique_ptrltPeoplegt jason(new People(Jason))unique_ptrltPeoplegt lauracout ltlt Jason = ltlt jasonget() ltlt endl laura = stdmove(jason)cout ltlt Jason = ltlt jasonget() ltlt endl cout ltlt Laura = ltlt lauraget() ltlt endl



Jason = 0x15fd040Jason = 0Laura = 0x15fd040




Objects and containers Containers can be used to store objects (stack allocated)

An object copy is performed when a new object is added to the collection Containers can be used to store pointers to objects (heap allocated)

For dynamically allocated objects keep in mind the potential pitfalls about memory management

clear() calls objects destructors but what about raw pointers

int main() vectorltPeople gt citizens Using raw pointersPeople p1 = new People(p1)People p2 = new People(p2)citizenspush_back(p1)citizenspush_back(p2)citizensclear() Clear the containerreturn 0




Objects and containers We may used smart (eg shared) pointers also in containers

Insertremove operations affect shared pointers reference counting Destroying the vector the reference counters are decreased

int main() vectorltshared_ptrltPeoplegtgt citizens Using shared pointersshared_ptrltPeoplegt p1 = make_sharedltPeoplegt(p1)shared_ptrltPeoplegt p2 = make_sharedltPeoplegt(p2)citizenspush_back(p1)citizenspush_back(p2)cout ltlt p1 use count = ltlt p1use_count() ltlt endlreturn 0


p1 use count = 2p1 im dyingp2 im dyingp3 im dying



4444References

Web links httpwwwcpluspluscom httpencppreferencecomw httpwwwhorstmanncomccj2ccjapp3html httpwwwcprogrammingcomtutorialconstructor_destructor_orderinghtml

httpwwwyolinuxcomTUTORIALSC++MemoryCorruptionAndMemoryLeakshtml

httpduramechocomComputerInformationWhyHowCppConsthtml

httpwwwtutorialspointcomcpluspluscpp_stl_tutorialhtm


442Outline






443Program memory








444Program memory










delete[] buff

delete obj

delete[] buff

delete obj


445Program memory



int main()




int main()



result

count

main numbuff

ldquordquo


























448Functions











449Outline






4410Classes







4411Classes

Syntax


include ltstringgt

class People public



endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh






peoplecpp






peoplecpp


4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






443Program memory








444Program memory










delete[] buff

delete obj

delete[] buff

delete obj


445Program memory



int main()




int main()



result

count

main numbuff

ldquordquo


























448Functions











449Outline






4410Classes







4411Classes

Syntax


include ltstringgt

class People public



endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh






peoplecpp






peoplecpp


4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






444Program memory










delete[] buff

delete obj

delete[] buff

delete obj


445Program memory



int main()




int main()



result

count

main numbuff

ldquordquo


























448Functions











449Outline






4410Classes







4411Classes

Syntax


include ltstringgt

class People public



endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh






peoplecpp






peoplecpp


4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






445Program memory



int main()




int main()



result

count

main numbuff

ldquordquo


























448Functions











449Outline






4410Classes







4411Classes

Syntax


include ltstringgt

class People public



endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh






peoplecpp






peoplecpp


4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






























448Functions











449Outline






4410Classes







4411Classes

Syntax


include ltstringgt

class People public



endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh






peoplecpp






peoplecpp


4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






449Outline






4410Classes







4411Classes

Syntax


include ltstringgt

class People public



endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh






peoplecpp






peoplecpp


4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4410Classes







4411Classes

Syntax


include ltstringgt

class People public



endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh






peoplecpp






peoplecpp


4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4411Classes

Syntax


include ltstringgt

class People public



endif PEOPLE_H_

peopleh


include ltstringgt

class People public



endif PEOPLE_H_

peopleh






peoplecpp






peoplecpp


4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4412Classes


class People public



hellip

peopleh

class People public



hellip

peopleh



peoplecpp



peoplecpp


4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4413Classes


int main()







Output


4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4414Classes




class People public


hellip peopleh

class People public


hellip peopleh



hellip peoplecpp



hellip peoplecpp


4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4415Classes










4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4416Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4417Classes










4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4418Classes




int main()



simonTalk()


int main()



simonTalk()





Output


4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4419Classes









4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4420Classes



int main()



fredTalk()

int main()



fredTalk()





Output


4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4421Classes






delete joe2return 0




delete joe2return 0

mainjoe2joe1

ldquordquo0x8ed040




4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4422Classes






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4423Classes









4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4424Classes
















4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4425Classes


class People public

People()hellip



peopleh

class People public

People()hellip



peopleh





peoplecpp





peoplecpp






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References






4426Outline



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References



















ltlt endlreturn 0




ltlt endlreturn 0













mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References












mathh





mathh



















































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References













































4434Outline














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References














class People public



People child

class People public



People child


































mainjack

0x22440c8


















































4444References




































mainjack

0x22440c8


















































4444References






















































4444References





advanced operating systems moving to c++ 2015-10-28 · giuseppe massari advanced operating systems...

Documents