C and C++ 基础

平衡堆栈？

玻璃小屋 — Wed, 20 Aug 2008 06:48:00 GMT

__declspec(naked) void f() {

__asm pushad

if(lpMessageBoxA) {

lpMessageBoxA(NULL, "this is f", "ok", MB_OK);

__asm {

popad

ret 10h

}

类的virtual成员函数编译情况~(7月凑数~)

玻璃小屋 — Fri, 11 Jul 2008 06:45:00 GMT

C++代码：

// Test32.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"

#include <stdio.h>

class Test
{
public:
    Test(){};
    ~Test(){};
    virtual inline int myyear(int a, int b) {return a*b;};
    int amyear(int a,int b){return a*b;};
};

class Test1 : Test
{
public:
    Test1(){};
    ~Test1(){};
    virtual inline int myyear(int a, int b) {return a-b;};
    int amyear(int a,int b){return a*b;};
};

int _cdecl main( int argc, char** argv )
{
    Test1 t;
    Test* pt = (Test*)&t;
    Test1* pTest1 = new Test1();
    Test* pTest = (Test*)new Test1();
    int a = pTest1->myyear(300,200);
    a = pTest1->amyear(300,200);
    a = pTest->myyear(300,200);
    a = pTest->amyear(300,200);
    a = t.myyear(300,200);
    a = t.amyear(300,200);
    a = pt->myyear(300,200);
    a = pt->amyear(300,200);
    a = (*pt).myyear(300,200);
    a = (*pt).amyear(300,200);
    delete pTest;

    return 0;
}

汇编代码：

; 34   :     int a = pTest1->myyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    mov    edx, DWORD PTR _pTest1$[ebp]
    mov    eax, DWORD PTR [edx]
    mov    ecx, DWORD PTR _pTest1$[ebp]
    mov    edx, DWORD PTR [eax]
    call    edx
    mov    DWORD PTR _a$[ebp], eax

; 35   :     a = pTest1->amyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    mov    ecx, DWORD PTR _pTest1$[ebp]
    call    ?amyear@Test1@@QAEHHH@Z            ; Test1::amyear
    mov    DWORD PTR _a$[ebp], eax

; 36   :     a = pTest->myyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    mov    eax, DWORD PTR _pTest$[ebp]
    mov    edx, DWORD PTR [eax]
    mov    ecx, DWORD PTR _pTest$[ebp]
    mov    eax, DWORD PTR [edx]
    call    eax
    mov    DWORD PTR _a$[ebp], eax

; 37   :     a = pTest->amyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    mov    ecx, DWORD PTR _pTest$[ebp]
    call    ?amyear@Test@@QAEHHH@Z            ; Test::amyear
    mov    DWORD PTR _a$[ebp], eax

; 38   :     a = t.myyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    lea    ecx, DWORD PTR _t$[ebp]
    call    ?myyear@Test1@@UAEHHH@Z            ; Test1::myyear
    mov    DWORD PTR _a$[ebp], eax

; 39   :     a = t.amyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    lea    ecx, DWORD PTR _t$[ebp]
    call    ?amyear@Test1@@QAEHHH@Z            ; Test1::amyear
    mov    DWORD PTR _a$[ebp], eax

; 40   :     a = pt->myyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    mov    ecx, DWORD PTR _pt$[ebp]
    mov    edx, DWORD PTR [ecx]
    mov    ecx, DWORD PTR _pt$[ebp]
    mov    eax, DWORD PTR [edx]
    call    eax
    mov    DWORD PTR _a$[ebp], eax

; 41   :     a = pt->amyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    mov    ecx, DWORD PTR _pt$[ebp]
    call    ?amyear@Test@@QAEHHH@Z            ; Test::amyear
    mov    DWORD PTR _a$[ebp], eax

; 42   :     a = (*pt).myyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    mov    ecx, DWORD PTR _pt$[ebp]
    mov    edx, DWORD PTR [ecx]
    mov    ecx, DWORD PTR _pt$[ebp]
    mov    eax, DWORD PTR [edx]
    call    eax
    mov    DWORD PTR _a$[ebp], eax

; 43   :     a = (*pt).amyear(300,200);

    push    200                    ; 000000c8H
    push    300                    ; 0000012cH
    mov    ecx, DWORD PTR _pt$[ebp]
    call    ?amyear@Test@@QAEHHH@Z            ; Test::amyear
    mov    DWORD PTR _a$[ebp], eax

CRITICAL_SECTION M$网站上的文章。

玻璃小屋 — Fri, 16 May 2008 02:52:00 GMT

http://www.microsoft.com/china/MSDN/library/enterprisedevelopment/softwaredev/ousCriticalSections.mspx

WSARecv 投递缓冲区也要对齐？？？不然就10014!

玻璃小屋 — Tue, 06 May 2008 17:23:00 GMT

如果把下面代码中背景色为绿色部分的 int iAlign = 4; 其中的 4 改为1或2，WSARecv就会返回 10014 错误。看来WSARecv 的投递的缓冲区也是要求对齐的。。正是因为这个问题。。浪费了我一天的时间调试我的内存池代码。。5555555555

#include <stdio.h>
#include "winsock2.h"

#define DATA_BUFSIZE 4096

void main() {
  //-----------------------------------------
  // Declare and initialize variables
  WSABUF DataBuf;
  char buffer[DATA_BUFSIZE];
  DWORD EventTotal = 0,
    RecvBytes = 0,
    Flags = 0,
    BytesTransferred = 0,
    CallBack = 0;
  WSAEVENT EventArray[WSA_MAXIMUM_WAIT_EVENTS];
  WSAOVERLAPPED AcceptOverlapped;
  SOCKET ListenSocket, AcceptSocket;

  //-----------------------------------------
  // Initialize Winsock
  WSADATA wsaData;
  WSAStartup(MAKEWORD(2,2), &wsaData);

  //-----------------------------------------
  // Create a listening socket bound to a local
  // IP address and the port specified
  ListenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  u_short port = 27015;
  char* ip;
  sockaddr_in service;
  service.sin_family = AF_INET;
  service.sin_port = htons(port);
  hostent* thisHost;
  thisHost = gethostbyname("");
  ip = inet_ntoa (*(struct in_addr *)*thisHost->h_addr_list);

  service.sin_addr.s_addr = inet_addr(ip);

  //-----------------------------------------
  // Bind the listening socket to the local IP address
  // and port number
  bind(ListenSocket, (SOCKADDR *) &service, sizeof(SOCKADDR));

  //-----------------------------------------
  // Set the socket to listen for incoming
  // connection requests
  listen(ListenSocket, 1);
  printf("Listening ");

  //-----------------------------------------
  // Accept and incoming connection request
  AcceptSocket = accept(ListenSocket, NULL, NULL);
  printf("Client Accepted ");

  //-----------------------------------------
  // Create an event handle and setup an overlapped structure.
  EventArray[EventTotal] = WSACreateEvent();
  ZeroMemory(&AcceptOverlapped, sizeof(WSAOVERLAPPED));
  AcceptOverlapped.hEvent = EventArray[EventTotal];
  DataBuf.len = DATA_BUFSIZE;
  DataBuf.buf = buffer;
  EventTotal++;

  LPWSABUF lpwsaBuf;

  //int iAlign = 1;
  int iAlign = 4;

  lpwsaBuf = (LPWSABUF) ((new CHAR[sizeof(WSABUF) + iAlign]) + iAlign);//pOverlapBuff->GetWSABuffer();
  lpwsaBuf->buf = new CHAR[52];
  lpwsaBuf->len = 52;

  //-----------------------------------------
  // Call WSARecv to receive data into DataBuf on
  // the accepted socket in overlapped I/O mode
  if (WSARecv(AcceptSocket, lpwsaBuf, 1, &RecvBytes, &Flags, &AcceptOverlapped, NULL) == SOCKET_ERROR)
  {
      if (WSAGetLastError() != WSA_IO_PENDING)
      {
          printf("Error occured at WSARecv() %d ",WSAGetLastError());
          closesocket(AcceptSocket);
          return;
      }
  }

  //-----------------------------------------
  // Process overlapped receives on the socket
  while (1) {
    DWORD Index;

    //-----------------------------------------
    // Wait for the overlapped I/O call to complete
    Index = WSAWaitForMultipleEvents(EventTotal, EventArray, FALSE, WSA_INFINITE, FALSE);

    //-----------------------------------------
    // Reset the signaled event
    WSAResetEvent(EventArray[Index - WSA_WAIT_EVENT_0]);

    //-----------------------------------------
    // Determine the status of the overlapped event
    WSAGetOverlappedResult(AcceptSocket, &AcceptOverlapped, &BytesTransferred, FALSE, &Flags);

    //-----------------------------------------
    // If the connection has been closed, close the accepted socket
    if (BytesTransferred == 0) {
      printf("Closing Socket %d ", AcceptSocket);
      closesocket(AcceptSocket);
      WSACloseEvent(EventArray[Index - WSA_WAIT_EVENT_0]);
      return;
    }

    //-----------------------------------------
    // If data has been received, echo the received data
    // from DataBuf back to the client
    if (WSASend(AcceptSocket, &DataBuf, 1, &RecvBytes, Flags, &AcceptOverlapped, NULL) == SOCKET_ERROR)
      printf("WSASend() is busted ");

    //-----------------------------------------
    // Reset the changed flags and overlapped structure
    Flags = 0;
    ZeroMemory(&AcceptOverlapped, sizeof(WSAOVERLAPPED));

    AcceptOverlapped.hEvent = EventArray[Index - WSA_WAIT_EVENT_0];

    //-----------------------------------------
    // Reset the data buffer
    DataBuf.len = DATA_BUFSIZE;
    DataBuf.buf = buffer;
  }
}