kill.c

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/*-------------------------------------------------------------------------
 *
 * kill.c
 *    kill()
 *
 * Copyright (c) 1996-2024, PostgreSQL Global Development Group
 *
 *  This is a replacement version of kill for Win32 which sends
 *  signals that the backend can recognize.
 *
 * IDENTIFICATION
 *    src/port/kill.c
 *
 *-------------------------------------------------------------------------
 */
 
#include "c.h"
 
#ifdef WIN32
/* signal sending */
int
pgkill(int pid, int sig)
{
    char        pipename[128];
    BYTE        sigData = sig;
    BYTE        sigRet = 0;
    DWORD       bytes;
 
    /* we allow signal 0 here, but it will be ignored in pg_queue_signal */
    if (sig >= PG_SIGNAL_COUNT || sig < 0)
    {
        errno = EINVAL;
        return -1;
    }
    if (pid <= 0)
    {
        /* No support for process groups */
        errno = EINVAL;
        return -1;
    }
 
    /* special case for SIGKILL: just ask the system to terminate the target */
    if (sig == SIGKILL)
    {
        HANDLE      prochandle;
 
        if ((prochandle = OpenProcess(PROCESS_TERMINATE, FALSE, (DWORD) pid)) == NULL)
        {
            errno = ESRCH;
            return -1;
        }
        if (!TerminateProcess(prochandle, 255))
        {
            _dosmaperr(GetLastError());
            CloseHandle(prochandle);
            return -1;
        }
        CloseHandle(prochandle);
        return 0;
    }
    snprintf(pipename, sizeof(pipename), "\\\\.\\pipe\\pgsignal_%u", pid);
 
    if (CallNamedPipe(pipename, &sigData, 1, &sigRet, 1, &bytes, 1000))
    {
        if (bytes != 1 || sigRet != sig)
        {
            errno = ESRCH;
            return -1;
        }
        return 0;
    }
 
    switch (GetLastError())
    {
        case ERROR_BROKEN_PIPE:
        case ERROR_BAD_PIPE:
 
            /*
             * These arise transiently as a process is exiting.  Treat them
             * like POSIX treats a zombie process, reporting success.
             */
            return 0;
 
        case ERROR_FILE_NOT_FOUND:
            /* pipe fully gone, so treat the process as gone */
            errno = ESRCH;
            return -1;
        case ERROR_ACCESS_DENIED:
            errno = EPERM;
            return -1;
        default:
            errno = EINVAL;     /* unexpected */
            return -1;
    }
}
 
#endif