src/port/kill.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * kill.c
   4  *        kill()
   5  *
   6  * Copyright (c) 1996-2020, PostgreSQL Global Development Group
   7  *
   8  *      This is a replacement version of kill for Win32 which sends
   9  *      signals that the backend can recognize.
  10  *
  11  * IDENTIFICATION
  12  *        src/port/kill.c
  13  *
  14  *-------------------------------------------------------------------------
  15  */
  16
  17 #include "c.h"
  18
  19 #ifdef WIN32
  20 /* signal sending */
  21 int
  22 pgkill(int pid, int sig)
  23 {
  24         char            pipename[128];
  25         BYTE            sigData = sig;
  26         BYTE            sigRet = 0;
  27         DWORD           bytes;
  28
  29         /* we allow signal 0 here, but it will be ignored in pg_queue_signal */
  30         if (sig >= PG_SIGNAL_COUNT || sig < 0)
  31         {
  32                 errno = EINVAL;
  33                 return -1;
  34         }
  35         if (pid <= 0)
  36         {
  37                 /* No support for process groups */
  38                 errno = EINVAL;
  39                 return -1;
  40         }
  41
  42         /* special case for SIGKILL: just ask the system to terminate the target */
  43         if (sig == SIGKILL)
  44         {
  45                 HANDLE          prochandle;
  46
  47                 if ((prochandle = OpenProcess(PROCESS_TERMINATE, FALSE, (DWORD) pid)) == NULL)
  48                 {
  49                         errno = ESRCH;
  50                         return -1;
  51                 }
  52                 if (!TerminateProcess(prochandle, 255))
  53                 {
  54                         _dosmaperr(GetLastError());
  55                         CloseHandle(prochandle);
  56                         return -1;
  57                 }
  58                 CloseHandle(prochandle);
  59                 return 0;
  60         }
  61         snprintf(pipename, sizeof(pipename), "\\\\.\\pipe\\pgsignal_%u", pid);
  62
  63         if (CallNamedPipe(pipename, &sigData, 1, &sigRet, 1, &bytes, 1000))
  64         {
  65                 if (bytes != 1 || sigRet != sig)
  66                 {
  67                         errno = ESRCH;
  68                         return -1;
  69                 }
  70                 return 0;
  71         }
  72
  73         switch (GetLastError())
  74         {
  75                 case ERROR_BROKEN_PIPE:
  76                 case ERROR_BAD_PIPE:
  77
  78                         /*
  79                          * These arise transiently as a process is exiting.  Treat them
  80                          * like POSIX treats a zombie process, reporting success.
  81                          */
  82                         return 0;
  83
  84                 case ERROR_FILE_NOT_FOUND:
  85                         /* pipe fully gone, so treat the process as gone */
  86                         errno = ESRCH;
  87                         return -1;
  88                 case ERROR_ACCESS_DENIED:
  89                         errno = EPERM;
  90                         return -1;
  91                 default:
  92                         errno = EINVAL;         /* unexpected */
  93                         return -1;
  94         }
  95 }
  96
  97 #endif