C++, Comment déterminer si un processus Windows est en cours d'exécution ?

Question

Il s'agit des processus de Windows XP.

J'ai un processus en cours, appelons-le Processus1. Process1 crée un nouveau processus, Process2, et enregistre son id.

Maintenant, à un moment donné, le processus 1 veut que le processus 2 fasse quelque chose, il doit donc d'abord s'assurer que le processus 2 est toujours vivant et que l'utilisateur ne l'a pas tué.

Comment puis-je vérifier que ce processus est toujours en cours ? Depuis que je l'ai créé, j'ai l'ID du processus, je pense qu'il existe une fonction de bibliothèque du type IsProcessIDValid( id ) mais je ne la trouve pas sur MSDN.

Answer 1

Vous pouvez utiliser GetExitCodeProcess . Il retournera STILL_ACTIVE ( 259 ) si le processus est toujours en cours d'exécution (ou s'il est sorti avec ce code de sortie :( ).

Answer 2

Le handle du processus sera signalé s'il sort.

Ce qui suit fonctionnera donc (le traitement des erreurs a été supprimé pour des raisons de brièveté) :

BOOL IsProcessRunning(DWORD pid)
{
    HANDLE process = OpenProcess(SYNCHRONIZE, FALSE, pid);
    DWORD ret = WaitForSingleObject(process, 0);
    CloseHandle(process);
    return ret == WAIT_TIMEOUT;
}

Notez que les ID de processus peuvent être recyclés - il est préférable de mettre en cache le handle qui est retourné par l'appel CreateProcess.

Vous pouvez également utiliser les API de threadpool (SetThreadpoolWait sur Vista+, RegisterWaitForSingleObject sur les plateformes plus anciennes) pour recevoir un rappel lorsque le processus se termine.

EDIT : J'ai manqué la partie "vouloir faire quelque chose au processus" de la question originale. Vous pouvez utiliser cette technique s'il est acceptable d'avoir des données potentiellement périmées pendant une petite fenêtre ou si vous voulez faire échouer une opération sans même la tenter. Vous devrez toujours gérer le cas où l'action échoue parce que le processus est sorti.

Answer 3

#include <cstdio>
#include <windows.h>
#include <tlhelp32.h>

/*!
\brief Check if a process is running
\param [in] processName Name of process to check if is running
\returns \c True if the process is running, or \c False if the process is not running
*/
bool IsProcessRunning(const wchar_t *processName)
{
    bool exists = false;
    PROCESSENTRY32 entry;
    entry.dwSize = sizeof(PROCESSENTRY32);

    HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);

    if (Process32First(snapshot, &entry))
        while (Process32Next(snapshot, &entry))
            if (!wcsicmp(entry.szExeFile, processName))
                exists = true;

    CloseHandle(snapshot);
    return exists;
}

Answer 4

J'ai trouvé ceci aujourd'hui, il date de 2003. Il trouve un processus par nom, vous n'avez même pas besoin du pid.

\#include windows.h

\#include tlhelp32.h

\#include iostream.h

int FIND_PROC_BY_NAME(const char *);

int main(int argc, char *argv[])

{

//  Check whether a process is currently running, or not

char szName[100]="notepad.exe";   // Name of process to find

int isRunning;

    isRunning=FIND_PROC_BY_NAME(szName);

    // Note: isRunning=0 means process not found, =1 means yes, it is found in memor
    return isRunning;
}

int FIND_PROC_BY_NAME(const char *szToFind)

// Created: 12/29/2000  (RK)

// Last modified: 6/16/2003  (RK)

// Please report any problems or bugs to kochhar@physiology.wisc.edu

// The latest version of this routine can be found at:

//     http://www.neurophys.wisc.edu/ravi/software/killproc/

// Check whether the process "szToFind" is currently running in memory

// This works for Win/95/98/ME and also Win/NT/2000/XP

// The process name is case-insensitive, i.e. "notepad.exe" and "NOTEPAD.EXE"

// will both work (for szToFind)

// Return codes are as follows:

//   0   = Process was not found

//   1   = Process was found

//   605 = Unable to search for process

//   606 = Unable to identify system type

//   607 = Unsupported OS

//   632 = Process name is invalid

// Change history:

//  3/10/2002   - Fixed memory leak in some cases (hSnapShot and

//                and hSnapShotm were not being closed sometimes)

//  6/13/2003   - Removed iFound (was not being used, as pointed out

//                by John Emmas)

{

    BOOL bResult,bResultm;
    DWORD aiPID[1000],iCb=1000,iNumProc,iV2000=0;
    DWORD iCbneeded,i;
    char szName[MAX_PATH],szToFindUpper[MAX_PATH];
    HANDLE hProc,hSnapShot,hSnapShotm;
    OSVERSIONINFO osvi;
    HINSTANCE hInstLib;
    int iLen,iLenP,indx;
    HMODULE hMod;
    PROCESSENTRY32 procentry;      
    MODULEENTRY32 modentry;

    // PSAPI Function Pointers.
     BOOL (WINAPI *lpfEnumProcesses)( DWORD *, DWORD cb, DWORD * );
     BOOL (WINAPI *lpfEnumProcessModules)( HANDLE, HMODULE *,
        DWORD, LPDWORD );
     DWORD (WINAPI *lpfGetModuleBaseName)( HANDLE, HMODULE,
        LPTSTR, DWORD );

      // ToolHelp Function Pointers.
      HANDLE (WINAPI *lpfCreateToolhelp32Snapshot)(DWORD,DWORD) ;
      BOOL (WINAPI *lpfProcess32First)(HANDLE,LPPROCESSENTRY32) ;
      BOOL (WINAPI *lpfProcess32Next)(HANDLE,LPPROCESSENTRY32) ;
      BOOL (WINAPI *lpfModule32First)(HANDLE,LPMODULEENTRY32) ;
      BOOL (WINAPI *lpfModule32Next)(HANDLE,LPMODULEENTRY32) ;

    // Transfer Process name into "szToFindUpper" and
    // convert it to upper case
    iLenP=strlen(szToFind);
    if(iLenP<1 || iLenP>MAX_PATH) return 632;
    for(indx=0;indx<iLenP;indx++)
        szToFindUpper[indx]=toupper(szToFind[indx]);
    szToFindUpper[iLenP]=0;

    // First check what version of Windows we're in
    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
    bResult=GetVersionEx(&osvi);
    if(!bResult)     // Unable to identify system version
        return 606;

    // At Present we only support Win/NT/2000 or Win/9x/ME
    if((osvi.dwPlatformId != VER_PLATFORM_WIN32_NT) &&
        (osvi.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS))
        return 607;

    if(osvi.dwPlatformId==VER_PLATFORM_WIN32_NT)
    {
        // Win/NT or 2000 or XP

         // Load library and get the procedures explicitly. We do
         // this so that we don't have to worry about modules using
         // this code failing to load under Windows 95, because
         // it can't resolve references to the PSAPI.DLL.
         hInstLib = LoadLibraryA("PSAPI.DLL");
         if(hInstLib == NULL)
            return 605;

         // Get procedure addresses.
         lpfEnumProcesses = (BOOL(WINAPI *)(DWORD *,DWORD,DWORD*))
            GetProcAddress( hInstLib, "EnumProcesses" ) ;
         lpfEnumProcessModules = (BOOL(WINAPI *)(HANDLE, HMODULE *,
            DWORD, LPDWORD)) GetProcAddress( hInstLib,
            "EnumProcessModules" ) ;
         lpfGetModuleBaseName =(DWORD (WINAPI *)(HANDLE, HMODULE,
            LPTSTR, DWORD )) GetProcAddress( hInstLib,
            "GetModuleBaseNameA" ) ;

         if( lpfEnumProcesses == NULL ||
            lpfEnumProcessModules == NULL ||
            lpfGetModuleBaseName == NULL)
            {
               FreeLibrary(hInstLib);
               return 605;
            }

        bResult=lpfEnumProcesses(aiPID,iCb,&iCbneeded);
        if(!bResult)
        {
            // Unable to get process list, EnumProcesses failed
            FreeLibrary(hInstLib);
            return 605;
        }

        // How many processes are there?
        iNumProc=iCbneeded/sizeof(DWORD);

        // Get and match the name of each process
        for(i=0;i<iNumProc;i++)
        {
            // Get the (module) name for this process

            strcpy(szName,"Unknown");
            // First, get a handle to the process
            hProc=OpenProcess(PROCESS_QUERY_INFORMATION|PROCESS_VM_READ,FALSE,
                aiPID[i]);
            // Now, get the process name
            if(hProc)
            {
               if(lpfEnumProcessModules(hProc,&hMod,sizeof(hMod),&iCbneeded) )
               {
                  iLen=lpfGetModuleBaseName(hProc,hMod,szName,MAX_PATH);
               }
            }
            CloseHandle(hProc);
            // Match regardless of lower or upper case
            if(strcmp(_strupr(szName),szToFindUpper)==0)
            {
                // Process found
                FreeLibrary(hInstLib);
                return 1;
            }
        }
    }

    if(osvi.dwPlatformId==VER_PLATFORM_WIN32_WINDOWS)
    {
        // Win/95 or 98 or ME

        hInstLib = LoadLibraryA("Kernel32.DLL");
        if( hInstLib == NULL )
            return FALSE ;

        // Get procedure addresses.
        // We are linking to these functions of Kernel32
        // explicitly, because otherwise a module using
        // this code would fail to load under Windows NT,
        // which does not have the Toolhelp32
        // functions in the Kernel 32.
        lpfCreateToolhelp32Snapshot=
            (HANDLE(WINAPI *)(DWORD,DWORD))
            GetProcAddress( hInstLib,
            "CreateToolhelp32Snapshot" ) ;
        lpfProcess32First=
            (BOOL(WINAPI *)(HANDLE,LPPROCESSENTRY32))
            GetProcAddress( hInstLib, "Process32First" ) ;
        lpfProcess32Next=
            (BOOL(WINAPI *)(HANDLE,LPPROCESSENTRY32))
            GetProcAddress( hInstLib, "Process32Next" ) ;
        lpfModule32First=
            (BOOL(WINAPI *)(HANDLE,LPMODULEENTRY32))
            GetProcAddress( hInstLib, "Module32First" ) ;
        lpfModule32Next=
            (BOOL(WINAPI *)(HANDLE,LPMODULEENTRY32))
            GetProcAddress( hInstLib, "Module32Next" ) ;
        if( lpfProcess32Next == NULL ||
            lpfProcess32First == NULL ||
            lpfModule32Next == NULL ||
            lpfModule32First == NULL ||
            lpfCreateToolhelp32Snapshot == NULL )
        {
            FreeLibrary(hInstLib);
            return 605;
        }

        // The Process32.. and Module32.. routines return names in all uppercase

        // Get a handle to a Toolhelp snapshot of all the systems processes.

        hSnapShot = lpfCreateToolhelp32Snapshot(
            TH32CS_SNAPPROCESS, 0 ) ;
        if( hSnapShot == INVALID_HANDLE_VALUE )
        {
            FreeLibrary(hInstLib);
            return 605;
        }

        // Get the first process' information.
        procentry.dwSize = sizeof(PROCESSENTRY32);
        bResult=lpfProcess32First(hSnapShot,&procentry);

        // While there are processes, keep looping and checking.
        while(bResult)
        {
            // Get a handle to a Toolhelp snapshot of this process.
            hSnapShotm = lpfCreateToolhelp32Snapshot(
                TH32CS_SNAPMODULE, procentry.th32ProcessID) ;
            if( hSnapShotm == INVALID_HANDLE_VALUE )
            {
                CloseHandle(hSnapShot);
                FreeLibrary(hInstLib);
                return 605;
            }
            // Get the module list for this process
            modentry.dwSize=sizeof(MODULEENTRY32);
            bResultm=lpfModule32First(hSnapShotm,&modentry);

            // While there are modules, keep looping and checking
            while(bResultm)
            {
                if(strcmp(modentry.szModule,szToFindUpper)==0)
                {
                    // Process found
                    CloseHandle(hSnapShotm);
                    CloseHandle(hSnapShot);
                    FreeLibrary(hInstLib);
                    return 1;
                }
                else
                {  // Look for next modules for this process
                    modentry.dwSize=sizeof(MODULEENTRY32);
                    bResultm=lpfModule32Next(hSnapShotm,&modentry);
                }
            }

            //Keep looking
            CloseHandle(hSnapShotm);
            procentry.dwSize = sizeof(PROCESSENTRY32);
            bResult = lpfProcess32Next(hSnapShot,&procentry);
        }
        CloseHandle(hSnapShot);
    }
    FreeLibrary(hInstLib);
    return 0;

}

Answer 5

Une autre façon de surveiller un processus enfant est de créer un fil de travail qui :

1. appeler CreateProcess()
2. appelez WaitForSingleObject() // le worker thread va maintenant attendre que le processus enfant termine son exécution. il est également possible de récupérer le code de retour (de la fonction main()).