so-05 introducao a win32

8/12/2019 SO-05 Introducao a Win32

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Introduo WIN32

Mark E. Russinovich, David A. Solomon, Microsoft WindowsInternals, Fourth Edition, Microsoft Press, 2005 [cap. 2]

Jeffrey Richter, Christophe Nasarre, Windows via C/C++, Fifth

Edition, Microsoft Press, 2008 [cap. 1, 2 e 3]

Microsoft, Microsoft Developers Network(MSDN)


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205 Introduo Win 32 APIISEL - DEETC - ASO LEIC SO 2

Sumrio

Arquitectura Windows

Caracteres e Strings

Objectos do Kernel Tratamento de erros


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Arquitectura Windows

Mark E. Russinovich, David A. Solomon, Microsoft WindowsInternals, Fourth Edition, Microsoft Press, 2005 [cap. 2]


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Requirements drove the

specification of Windows

The following requirements drove the specification of Windows

NT back in 1989: Provide a true 32-bit, preemptive, reentrant, virtual memory operating

system

Run on multiple hardware architectures and platforms

Run and scale well on symmetric multiprocessing systems Be a great distributed computing platform, both as a network client and as

a server

Run most existing 16-bit MS-DOS and Microsoft Windows 3.1

applications Meet government requirements for POSIX 1003.1 compliance

Meet government and industry requirements for operating system security

Be easily adaptable to the global market by supporting Unicode


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Design goals

Extensibility - The code must be written to comfortably grow and change asmarket requirements change

Portability - The system must be able to run on multiple hardwarearchitectures and must be able to move with relative ease to new ones asmarket demands dictate

Reliability and robustness - The system should protect itself from both

internal malfunction and external tampering. Applications should not be ableto harm the operating system or other applications

Compatibility - Although Windows NT should extend existing technology,its user interface and APIs should be compatible with older versions of

Windows and with MS-DOS. It should also interoperate well with othersystems such as UNIX, OS/2, and NetWare

Performance - Within the constraints of the other design goals, the systemshould be as fast and responsive as possible on each hardware platform


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Architecture overview


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Such as the logon process and the session manager, that are not Windows services. That is,

they are not started by the service control manager

Such as the logon process and the session manager, that are not Windows services. That is,

they are not started by the service control manager


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That host Windows services, such as the Task Scheduler and Spooler services. Services generally

have the requirement that they run independently of user logons. Many Windows server

applications, such as Microsoft SQL Server and Microsoft Exchange Server, also include

components that run as services.

That host Windows services, such as the Task Scheduler and Spooler services. Services generally

have the requirement that they run independently of user logons. Many Windows server

applications, such as Microsoft SQL Server and Microsoft Exchange Server, also include

components that run as services.


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Which can be one of six types:

Windows 32-bit, Windows 64-bit,

Windows 3.1 16-bit, MS-DOS 16-bit,

POSIX 32-bit, or OS/2 32-bit.

Which can be one of six types:

Windows 32-bit, Windows 64-bit,

Windows 3.1 16-bit, MS-DOS 16-bit,

POSIX 32-bit, or OS/2 32-bit.


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Which implement part of the support for the operating system environment, or personality

presented to the user and programmer.Windows NT originally shipped with three environment subsystems: Windows, POSIX, and OS/2.

OS/2 was dropped as of Windows 2000.

As of Windows XP, only the Windows subsystem is shipped in the base productan enhanced

POSIX subsystem is available as part of the free Services for Unix product.

Which implement part of the support for the operating system environment, or personality

presented to the user and programmer.

Windows NT originally shipped with three environment subsystems: Windows, POSIX, and OS/2.

OS/2 was dropped as of Windows 2000.

As of Windows XP, only the Windows subsystem is shipped in the base productan enhanced

POSIX subsystem is available as part of the free Services for Unix product.


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Under Windows, user applications don't call the native Windows operating system services

directly;

Rather, they go through one or more subsystem dynamic-link libraries (DLLs)The role of the subsystem DLLs is to translate a documented function into the appropriate

internal (and generally undocumented) Windows system service calls.

This translation might or might not involve sending a message to the environment subsystem

process that is serving the user application.

Under Windows, user applications don't call the native Windows operating system services

directly;

Rather, they go through one or more subsystem dynamic-link libraries (DLLs)

The role of the subsystem DLLs is to translate a documented function into the appropriate

internal (and generally undocumented) Windows system service calls.

This translation might or might not involve sending a message to the environment subsystem

process that is serving the user application.


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The Windows executive contains the base operating system services, such as memory

management, process and thread management, security, I/O, networking, and

interprocess communication.

The Windows executive contains the base operating system services, such as memory

management, process and thread management, security, I/O, networking, and

interprocess communication.


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The Windows kernel consists of low-level operating system functions, such as thread

scheduling, interrupt and exception dispatching, and multiprocessor synchronization.

It also provides a set of routines and basic objects that the rest of the executive uses to

implement higher-level constructs.

The Windows kernel consists of low-level operating system functions, such as thread

scheduling, interrupt and exception dispatching, and multiprocessor synchronization.

It also provides a set of routines and basic objects that the rest of the executive uses to

implement higher-level constructs.


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Device drivers include both hardware device drivers that translate user I/O function calls into

specific hardware device I/O requests as well as file system and network drivers.

Device drivers include both hardware device drivers that translate user I/O function calls into

specific hardware device I/O requests as well as file system and network drivers.


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The hardware abstraction layer (HAL) is a layer of code that isolates the kernel, device drivers,

and the rest of the Windows executive from platform-specific hardware differences (such as

differences between motherboards).

The hardware abstraction layer (HAL) is a layer of code that isolates the kernel, device drivers,

and the rest of the Windows executive from platform-specific hardware differences (such as

differences between motherboards).


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The windowing and graphics system implements the graphical user interface (GUI) functions

(better known as the Windows USER and GDI functions), such as dealing with windows, user

interface controls, and drawing.

The windowing and graphics system implements the graphical user interface (GUI) functions

(better known as the Windows USER and GDI functions), such as dealing with windows, user

interface controls, and drawing.


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kernel32.dll

advapi32.dll

user32.dll

gdi32.dll

Ntoskrnl.exe

Ntkrnlpa.exe

(32-bit systems only)

with support for Physical

Address Extension (PAE),

which allows addressing of upto 64 GB of physical memory

hal.dll

win32k.sys

csrss.exe (windows)os2ss.exe (OS/2)psxss.exe (Posix)


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Subsystem DLLs


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Environment subsystems

A informao de iniciao dos subsistemas guardada na chave do registry

HKLM\SYSTEM\Current-ControlSet\Control\Session Manager\SubSystems

A informao de iniciao dos subsistemas guardada na chave do registry

HKLM\SYSTEM\Current-ControlSet\Control\Session Manager\SubSystems


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Architecture


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Architecture

Ntdll.dll is a special system supportlibrary primarily for the use ofsubsystem DLLs. It contains two

types of functions:

Group of functions provides theinterface to the Windowsexecutive system services that

can be called from user mode (e.g.NtCreateFile, NtSetEvent)

Internal support functions usedby subsystems, subsystem DLLs,and other native images (e.g. image

loader, the heap manager, Windowssubsystem process communicationfunctions


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Architecture System Processes


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Idle processcontains one thread per CPU toaccount for idle CPU time

System process is the homefor a special kind of thread thatruns only in kernel mode - akernel-mode system thread


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Session manager (smss.exe)

The first user-mode process created in the system. The

kernel-mode system thread that performs the final phaseof the initialization of the executive and kernel createsthe actual smss process

The Session Manager is responsible for a number ofimportant steps in starting Windows, such as opening

additional page files, performing delayed file rename anddelete operations, and creating system environmentvariables. It also launches the subsystem processes(normally just csrss.exe) and the Winlogon process


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Windows logon process (Winlogon.exe)

Handles interactive user logons and logoffs Winlogon is notified of a user logon request when the

secure attention sequence (SAS) keystrokecombination is entered. The default SAS on Windows isthe combination Ctrl+Alt+Delete. The reason for the SASis to protect users from password-capture programs thatsimulate the logon process, because this keyboardsequence cannot be intercepted by a user modeapplication

Once the username and password have been captured,they are sent to the local security authentication serverprocess lsass.exe

Upon a successful authentication Winlogon create theinitial process(es) in the user's session (default isuserinit.exe)*

* registry key HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon


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Userinit

performs some initialization of the user environment

(such as running the login script and applying group

policies) looks in the registry at the Shell value * and creates a

process to run the system-defined shell (by default,

Explorer.exe)

Then Userinit exits (This is the reason Explorer.exe is

shown with no parent)

Winlogon is active not only during user logon and logoffbut also whenever it intercepts the SAS from the

keyboard

* registry key HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon


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Service control manager (Services.exe)

This process (and the child service processes it creates(e.g. service host process - Svchost.exe) is a specialsystem process that is responsible for starting, stopping,and interacting with service processes

Processes that can be configured to start automatically atsystem boot time without requiring an interactive logon

Service programs are really just Windows images that call

special Windows functions to interact with the servicecontrol manager to perform such actions as registeringthe service's successful startup, responding to statusrequests, pausing and shutting down the service


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Services listing installed services

Services are defined in the registry under

HKLM\SYSTEM\CurrentControlSet\Services

Administrative Tools from Control Panel and the select Services


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Services listing installed services

Detailed properties about a service right

clicked on the service and select

properties


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Services Process Explorer

Double-click on a service-hosting process


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WIN 32


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Verses mais ligeiras do Windows (desktop use) Windows 1.0-1985, 2.0-1987 , 3.0-1990, 3.1-1992 Windows for Workgroups 3.11, 1994 Windows 95, Windows 98, Windows ME in 2000

Verses do Windows baseadas no NT (New Technology) Windows NT 3.1, Workstation, Advanced Server, 1993, Windows NT 3.5, Workstation, Server, 1994 Windows NT 3.51 , Workstation, Server, 1995 Windows NT 4.0 Workstation, Server, Server Enterprise, 1996 Windows 2000 Professional, Server,Advanced ServereData Center Server editions,

2000 Windows XPHome, Professional,Media Centere 64-bits editions, 2001 Windows Server 2003 (.net), Standard,Enterprise,Datacenter, Web e Small Business

editions, 2003

Windows Vista, Starter, Home Basic, Home Premium, Professional, Small Business,Enterprise, Ultimate (x64 editions will be available too), ~2006 Windows Longhorn Server (codename), ~2007

Windows CE 1.0-1996, 2.0-1997, 3.0-2000, 4.0-2002, 5.0-2004, 6.0-2006

Verses do Windows


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Windows 95 NT/2000Windows 3.x

Win32s

Win32

Win32s - uma extenso API de 16 bits do Windows 3.x para correr aplicaes de 32bits.

Windows CE implementa parte da Win32 API mas com muitas limitaes visto quedever correr em mquinas sem disco e com pouca memria.

Windows 95 uma implementao da Win32 API mas com limitaes visto que devercorrer em mquinas com 386 e 4Mb.

Windows NT/2000/XP/Vista - implementam a totalidade da API Win32.

Windows CEWindows 98 XP/server/Vista

Implementaes da Win32


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Caracteres e Strings

Representao de texto

Cdi ASCII


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Cdigo ASCII

American Standard Code for Information Interchange (ANSIX3.4-1986)

Cdigo de representao de caracteres a 8 bits apenas 256smbolos

Ento como representar todos os caracteres e smbolos de todo omundo incluindo as escritas modernas mas tambm antigas, porexemplo o chins, japons, rabe, hebreu, etc

Soluo 1: Representar alguns caracteres a 16 bits (DBCS Double ByteCharacter Strings)

Soluo 2: Codificao UNICODE

Cdi ASCII


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Cdigo ASCII

Cdi ASCII t did


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Cdigo ASCII estendido

U i d


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Unicode

Proposto inicialmente pela Apple e Xerox em 1988

Em 1991 foi criado um consrcio para desenvolver e promover o Unicode. Noconsrcio estavam empresas como Apple, Compaq, Hewlett-Packard, IBM, Microsoft,Oracle, Silicon Graphics, Sybase, Unisys e Xerox (lista completa emhttp://www.unicode.org)

Unicode define 1.114.112code points de 0hex at 10FFFFhex

habitual indicar um Unicodecode point escrevendo U+

capacidade para representar os caracteres das vrias lnguas e outros smbolos, como

por exemplo smbolos matemticos e tcnicosPlane Range Description Abbreviation

0 0000FFFF Basic Multilingual Plane BMP

1 100001FFFF Supplementary Multilingual Plane SMP

2 200002FFFF Supplementary Ideographic Plane SIP

3 to 13 30000DFFFF currently unassigned

14 E0000EFFFF Supplementary Special-purpose Plane SSP

15 F0000FFFFF Supplementary Private Use Area-A

16 10000010FFFF Supplementary Private Use Area-B

U i d


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Unicode

Esto definidos standards para a representao dosUnicode (Unicode Transformation Format - UTF)

UTF-8 Codificao a 1 byte, a 2 bytes, a 3 bytes ou a 4 bytes

UTF-16

codificao a 2 bytes 16 bits no suficiente para todos os caracteres Unicode nessas

situaes o UTF-16 usa surrogates (uma forma de utilizar 4

bytes na codificao).

O Windows utiliza este tipo de codificao

UTF-32

Codifica todos os caracteres a 4 bytes

Unicode


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Cdigo a 16 bits

Partes mostradas:Basic LatinLatin SupplementLatin Extended-A

GreekArabic

Musical SymbolsArrows

Geometric Shapes

BasicLatin

Latin

Supplement

Unicode

Source:http://www.unicode.org/Public/5.0.0/charts/CodeCharts.pdf

Unicode


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Greek

A

rabic

La

tinExtended-A

Unicode

Unicode


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Music

alSymbols

Arrows

Geome

tricShapes

Unicode

ASCII/Unicode na Win32


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O sistema operativo Windows 95 e suas evolues, Windows 98 e ME,no suportam Unicode nativo

Se um aplicao utilizar cdigo Unicode quando faz uma chamada de sistema as

strings so em primeiro lugar convertidas para ASCII, feita a chamada desistemas e as strings de resposta so convertidas novamente para Unicode

O Windows NT e suas evolues, 2000, XP, 2003 (.NET), Vista, suportamnativamente o Unicode continuando, no entanto, a suportar o ASCII

Se um aplicao utilizar cdigo ASCII quando faz uma chamada de sistema as

strings so em primeiro lugar convertidas para Unicode, feita a chamada de

sistemas e as strings de resposta so convertidas novamente para ASCII

O Windows CE s suporta Unicode

A concepo de cdigo na disciplina de S.O. assume o compromisso defazer cdigo que possa ser compilado nas vrias famlias do sistemaoperativo Windows

Caracteres a 8 e 16 bits no ANSI C


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Caracteres a 8 e 16 bits no ANSI C

Declarao de carateres a 8 bits:char c = s ;char *st r = Ol a;char a[ ] = ol a" ;

Declarao de caracteres a 16 bits (wide char):wchar _t c = s ; / / wchar _t def i ni do em wchar . hwchar _t *st r = LOl a;wchar _t a[ ] = LOl a;

No Windows um wchar_t representa um caracter Unicode de 16 bits no formato UTF-16

A biblioteca de Run-Time C contm verses de funes paracaracteres a 8 e 16 bits, exemplos:8bits 16bits

st r l en wcsl en

st r cpy wcscpy

st r cmp wcscmp

pr i nt f wpr i nt f

sscanf swscanf

Vai-se utilizar compilao

condicional para se obter as

verses 8 e 16 bits

ASCII/Unicode - RT/C


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Utilizao do tipo genrico de caracter TCHAR Definido no ficheiro de definies tchar.h (no compatvel com ANSI C)

As definies do ficheiro tchar.h so expandias em funo da definio do smbolo

_UNICODE

A definio do smbolo _UNICODE deve aparecer antes dos includes ou atravs das opes

do compilador

#def i ne _UNI CODE / / par a c r un- t i me header f i l es

Smbolo _UNICODE definido Sim: uso das verses com suporte de caracteres wide (16 bits)

No: uso das verses com suporte de caracteres single (8 bits)

Macros de utilizao condicional TCHAR para caracter (expande para wchar_t ou char)

_TEXT() ou _T para caracteres ou strings (expande para L( ) ou no)

Exemplos: TCHAR c0 = _T( s ) , c1 = _TEXT( s ) ;

TCHAR *st r 0 = _T( Ol a) ;

TCHAR *st r 1 = _TEXT( Ol a) ;




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ASCII/Unicode RT/C

Macros para as funes da biblioteca ANSI que expandempara as verses de 8 ou 16 bits exemplos: 8bits 16bits tchar.h (condicional)

st r l en wcsl en _t csl en

pr i nt f wpr i nt f _t pr i nt f

sscanf swscanf _st scanf

Funo Main genrica _tmain expande para

main (8 bits) ou

wmain (16bits))

Nota: a funo wsprintf no

suporta a formatao defloats

#ifdef _UNICODE

#define _tcslen wcslen

#else

#define _tcslen strlen

#endif

ASCII/Unicode - Exemplo


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/ / Li st Ar gs. cpp : Pr i nt t he ar gument s on t he consol e.

#define _UNICODE / / f or c r un- t i me header f i l es

#i ncl ude / / f or _t pr i nt f def i ni t i on _TEXT#i ncl ude / / f or pr i nt f and wpr i nt f

i nt _t mai n( i nt ar gc, TCHAR* argv[ ] ){

_t pr i nt f ( _TEXT( "Li st agem dos ar gument os: \ n") ) ;f or ( i nt i =0; i


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A Microsoft definiu os seus prprios tipos de caracteres, utilizadosna Win32 API, para separar dos tipos da linguagem C

Estas definies encontram-se em WinNT.h

t ypedef char CHAR; / / An 8-bit character

t ypedef wchar _t WCHAR; / / A 16-bit character

/ / Pointer to 8-bit character(s)

t ypedef CHAR *PCHAR;t ypedef CHAR *PSTR;t ypedef CONST CHAR *PCSTR;

// Pointer to 16-bit character(s)

t ypedef WCHAR *PWCHAR;t ypedef WCHAR *PWSTR;t ypedef CONST WCHAR *PCWSTR;



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A escrita de cdigo genrica possvel atravs de tipos que expandempara as verses ASCII ou UNICODE em funo da definio do smbolode compilao UNICODE

Essas definies encontram-se em WinNT.h#i f def UNICODEt ypedef WCHAR PTCH;t ypedef WCHAR *PTSTR;t ypedef CONST WCHAR *PCTSTR;

#def i ne __TEXT( quot e) L##quot e#el set ypedef CHAR PTCH;t ypedef CHAR *PTSTR;t ypedef CONST CHAR *PCTSTR;#def i ne __TEXT( quot e) quot e#endi f

#def i ne TEXT( quot e) __TEXT( quot e)



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A API possui funes que tm como argumento strings. Geralmente, so fornecidasduas verses da mesma funo

HWND WINAPI CreateWindowExW(

DWORD dwExStyle,

PCWSTR pClassName, // A Unicode stringPCWSTR pWindowName, // A Unicode string

...);

HWND WINAPI CreateWindowExA(

DWORD dwExStyle,

PCSTR pClassName, // An ANSI stringPCSTR pWindowName, // An ANSI string

...);

No entanto podemos utilizar uma macro genrica que expande para uma das funesanteriores em funo da definio do smbolo UNICODE

#ifdef UNICODE

#define CreateWindowEx CreateWindowExW

#else

#define CreateWindowEx CreateWindowExA

#endif

Funes de stringseguras RT/C


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u es de st ing segu as /C

Muitas das funes de manipulao de strings da biblioteca de run-timeC no possuem um argumento para o programador indicar a dimensomxima do buffer

Assim as funes no consegue determinar se est a corromper amemria (aceder fora da memria associada ao buffer -overrun buffer),e.g strcat, strcpy,

Este comportamento pode ser explorado por cdigo malicioso (e.g. virus) A Microsoft disponibiliza um novo conjunto de funes que substituem as

funes originais consideradas inseguras e definidas em StrSafe.h As novas funes possuem o sufixo _s, basicamente possuem um novo

argumento indicando a dimenso mxima do buffer e procedem validao de todos os seus argumentos (apontadores diferente de nulos,ausncia deoverrun buffer)

PTSTR_tcscpy ( PTSTR st r Dest i nat i on, PCTSTR st r Sour ce) ;errno_t_tcscpy_s( PTSTR st r Dest i nat i on,

si ze_t number Of Char act er s, PCTSTR st r Sour ce) ;

Funes de stringseguras RT/C


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g g /

Esto definidas outro conjunto de funes na biblioteca de RT/Cque oferecem um melhor controlo nas operaes sobre as strings

Ao contrrio das funes anteriores estas deixam no buffer a

informao que for possvel colocar (truncation) Existem funes que no seu nome tm:

Cch (count of characters) em que as dimenses so indicadas emcaracteres e deve-se usar a macro _countof() para obter esse valor

HRESULT StringCchCopy(PTSTR pszDest,size_t cchDest, PCTSTR pszSrc);

HRESULT StringCchCopyEx(PTSTR pszDest, size_t cchDest,PCTSTR pszSrc, PTSTR *ppszDestEnd,size_t *pcchRemaining, DWORD dwFlags);

Cb (Count of bytes) em que as dimenses so indicadas em bytesdevendo-se utilizar o operador sizeof

HRESULT StringCbCopy(LPTSTR pszDest,

size_t cbDest, LPCTSTR pszSrc );


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Aplicaes Win32

Windows.h


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O ficheiro faz o import dos seguintes ficheiros (deinclude):

WinDEF.h Definio de tipos bsicos

WinNT.h Definio de tipos para suporte UNICODE

WinBASE.h Interface das funes do Kernel

WinUSER.h Funes da Interface com utilizador (user interface)

WinGDI.h Funes da interface grfica (Graphics Device Interface)

Criao de um projecto no Visual Studio 2005


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para uma aplicao em modo de consola

Criao de um projecto no Visual Studio 2005


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para uma aplicao em modo de consola

_tmain macroque expande paramain ou wmain

_TCHARmacro

que expande parachar ou wchar_t

Ol Mundo


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Localizao Locale

Escrita na consola adequada ao Local

Localizao


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"Locale" Refere a localizao (Pas/Regio e Lngua) para o qual podemosconfigurar certos aspectos do nosso programa. Categorias dependentes da localizao:

Formatao de datas;

Formatao de valores monetrios;

Impresso de caracteres prprios da lngua.

Alterao do locale _tsetlocale(int category, TCHAR *)

macro que expande para setlocale()[8bits] ou _wsetlocale()[16bits]

Categorias (ver MSDN para detalhes): LC_ALL (Afecta todas as categorias)

LC_COLLATE

LC_CTYPE

LC_MONETARY

LC_NUMERIC

LC_TIME

Local: "portuguese_portugal"

TCHAR *act ual Local e =_tsetlocale(LC_ALL,_T("portuguese_portugal"));

Exemplo


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Exemplo sem Localizao


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Tratamento de erros

Tratamento de erros


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As chamadas de sistema na situao de erro devolvem um valor quepermite aplicao verificar o sucesso ou insucesso do servio;

Na situao de erro o sistema mantm o cdigo do ltimo erro que

ocorreu (no contexto de cada tarefa);

Este cdigo descreve de uma forma detalhada a situao que o provocou;

As aplicaes podem obter este cdigo atravs da funo GetLastError()

Atravs da funo FormatMessage() possvel converter o cdigo do erronuma informao textual (dependente da lngua do sistema operativo)

De forma a facilitar a apresentao dos erros foram definidas asseguintes funes de apoio aos exemplos: ReportErrorSystem() eFatalErrorSystem() definidas nos ficheiros SesError.h e SesError.cpp

Funes para apresentao de erros


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Estas funes tm uma utilizao idntica funo printf() da linguagem C, masapresentam o seu output numa MessageBox.

Ambas mostram o ltimo erro de sistema, mas a funo FatalErrorSystem tambm

termina o prprio processo.

void ReportErrorUser( const char *fmtStr, ... );void FatalErrorUser( const char *fmtStr, ... );

Existem definidas mais duas funes semelhantes s anteriores sem

apresentarem o cdigo de erro nem a informao textual do erro:

void ReportErrorSystem( const char *fmtStr, ... );

void FatalErrorSystem( const char *fmtStr, ... );

Um exemplo utilizao FatalErrorSystem


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int _tmain(int argc, _TCHAR* argv[])

{

HANDLE hFile = CreateFile(TEXT("DummyFile"), 0, 0, NULL, OPEN_EXISTING, 0, NULL);

if (hFile == INVALID_HANDLE_VALUE)

FatalErrorSystem(TEXT("Erro na abertura do ficheiro %s"), TEXT("DummyFile"));

return 0;

}

No caso de ocorrer um erroeste vai ser apresentado na

janela seguinte

Cdigo do erro (GetLastError)

Descrio textual (FormatMessage)

Converso do cdigo de erro


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O Visual Studio possui o utilitrio Error Lookup (menu Tools -> Error Lookup) que

permite determinar a mensagem de erro associada a um cdigo de erro

O Visual Studio possui o utilitrio Error Lookup (menu Tools -> Error Lookup) que

permite determinar a mensagem de erro associada a um cdigo de erro


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Objectos do Kernel

Objectos do Kernel(kernel objects)


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Caractersticas dos objectos do kernel: so manipulados pelas funes da WIN32 API e controlados pelo

SO

so referenciados por um HANDLE

tm um descritor de segurana associado, ...

tm um contador de referncias

File, Mailslot, pipe,...

Mutex, Semaphore, Event, ...Process, Thread

Exemplos de objectos

Kernel

O Kernelproporciona : partilha, proteco, acesso/nome,...

(kernel objects)

Uso de Objectos do Kernel


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Um objecto s eliminado do sistema quando o seunmero de referncias for zero.

Exempl o: HANDLE CreateMut ex( , Mut exName) ;

Criar um objecto Kernel

Partilhar um objecto j existente

Eliminar uma referncia (handle) para o objecto

BOOL CloseHandle( HANDLE hobj ect ) ;

Exempl o: HANDLE OpenMut ex( access_per mi ssi ons, , Mut exName) ;

Objectos do kernelnum processo


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Processo Thr ead 0

Fi l e

Flags: herana, ...

HANDLE ht hr ead0

Thr ead 1

HANDLE ht hr ead1

HANDLE hf i l e

Tabela dehandles deobjectos dokernelOs HANDLEsso simples referncias para

entradas da tabela de handlesdo processo

Permisses de acesso

Partilha de objectos


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Processo BProcesso A

Thr ead B

Handle 0

Handle 1

Handle 2

Handletable

Handle 0

Handle 1

Handle 2

Handletable

Partilha por:acesso ao objecto usando o nome

passagem do handle ao outro processo:

por herana

por evocao da funo Dupl i cat eHandl e

Thr ead A

Mut ex

Refs = 2

Thr ead B

Win32 Data Types


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BOOL Bool ean var i abl e ( shoul d be TRUE or FALSE) .CALLBACK Cal l i ng convent i on f or cal l back f unct i ons.WI NAPI Cal l i ng convent i on f or t he Wi n32 API .WNDPROC Poi nt er t o an appl i cat i on- def i ned wi ndow pr ocedur e.DLGPROC Poi nt er t o an appl i cat i on- def i ned di al og box cal l back pr ocedur eDWORD 32- bi t unsi gned i nt eger .HANDLE Handl e t o an obj ect .HMENU Handl e t o a menu.LPARAM, WPARAM Message par amet er s.

WCHAR 16- bi t Uni code char act er .WORD 16- bi t unsi gned i nt eger .LPCSTR Pt r t o a const ant nul l - t er mi nat ed st r i ng of 8- bi t Wi ndows ( ANSI ) char s.LPCWSTR Pt r t o a const ant nul l - t er mi nat ed st r i ng of 16- bi t Uni code char act er s.LPVOI D Poi nt er t o any t ype.LPDWORD Poi nt er t o a DWORD.

LRESULT Si gned r esul t of message pr ocess i ng.PCWSTR Pt r t o a const ant nul l - t er mi nat ed st r i ng of 16- bi t Uni code char act er s.PHANDLE Poi nt er t o a HANDLE.

Alguns exemplos

so-05 introducao a win32

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