Use an all-permissive copyright notice, recommended by RMS.

[gnulib.git] / lib / wait-process.c

diff --git a/lib/wait-process.c b/lib/wait-process.c
index 138f25c..0af9a18 100644 (file)
--- a/lib/wait-process.c
+++ b/lib/wait-process.c
@@ -101,6 +101,18 @@
 #define SIZEOF(a) (sizeof(a) / sizeof(a[0]))
 
 
+#if defined _MSC_VER || defined __MINGW32__
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+/* The return value of spawnvp() is really a process handle as returned
+   by CreateProcess().  Therefore we can kill it using TerminateProcess.  */
+#define kill(pid,sig) TerminateProcess ((HANDLE) (pid), sig)
+
+#endif
+
+
 /* Type of an entry in the slaves array.
    The 'used' bit determines whether this entry is currently in use.
    (If pid_t was an atomic type like sig_atomic_t, we could just set the
@@ -131,7 +143,7 @@ static size_t slaves_allocated = SIZEOF (static_slaves);
 
 /* The cleanup action.  It gets called asynchronously.  */
 static void
-cleanup_slaves ()
+cleanup_slaves (void)
 {
   for (;;)
     {
@@ -240,9 +252,95 @@ unregister_slave_subprocess (pid_t child)
    return 127.  */
 int
 wait_subprocess (pid_t child, const char *progname,
-                bool null_stderr,
+                bool ignore_sigpipe, bool null_stderr,
                 bool slave_process, bool exit_on_error)
 {
+#if HAVE_WAITID && defined WNOWAIT && 0
+  /* Commented out because waitid() with WNOWAIT doesn't work: On Solaris 7
+     and OSF/1 4.0, it returns -1 and sets errno = ECHILD, and on HP-UX 10.20
+     it just hangs.  */
+  /* Use of waitid() with WNOWAIT avoids a race condition: If slave_process is
+     true, and this process sleeps a very long time between the return from
+     waitpid() and the execution of unregister_slave_subprocess(), and
+     meanwhile another process acquires the same PID as child, and then - still
+     before unregister_slave_subprocess() - this process gets a fatal signal,
+     it would kill the other totally unrelated process.  */
+  siginfo_t info;
+  for (;;)
+    {
+      if (waitid (P_PID, child, &info, slave_process ? WNOWAIT : 0) < 0)
+       {
+# ifdef EINTR
+         if (errno == EINTR)
+           continue;
+# endif
+         if (exit_on_error || !null_stderr)
+           error (exit_on_error ? EXIT_FAILURE : 0, errno,
+                  _("%s subprocess"), progname);
+         return 127;
+       }
+
+      /* info.si_code is set to one of CLD_EXITED, CLD_KILLED, CLD_DUMPED,
+        CLD_TRAPPED, CLD_STOPPED, CLD_CONTINUED.  Loop until the program
+        terminates.  */
+      if (info.si_code == CLD_EXITED
+         || info.si_code == CLD_KILLED || info.si_code == CLD_DUMPED)
+       break;
+    }
+
+  /* The child process has exited or was signalled.  */
+
+  if (slave_process)
+    {
+      /* Unregister the child from the list of slave subprocesses, so that
+        later, when we exit, we don't kill a totally unrelated process which
+        may have acquired the same pid.  */
+      unregister_slave_subprocess (child);
+
+      /* Now remove the zombie from the process list.  */
+      for (;;)
+       {
+         if (waitid (P_PID, child, &info, 0) < 0)
+           {
+# ifdef EINTR
+             if (errno == EINTR)
+               continue;
+# endif
+             if (exit_on_error || !null_stderr)
+               error (exit_on_error ? EXIT_FAILURE : 0, errno,
+                      _("%s subprocess"), progname);
+             return 127;
+           }
+         break;
+       }
+    }
+
+  switch (info.si_code)
+    {
+    case CLD_KILLED:
+    case CLD_DUMPED:
+# ifdef SIGPIPE
+      if (info.si_status == SIGPIPE && ignore_sigpipe)
+       return 0;
+# endif
+      if (exit_on_error || !null_stderr)
+       error (exit_on_error ? EXIT_FAILURE : 0, 0,
+              _("%s subprocess got fatal signal %d"),
+              progname, info.si_status);
+      return 127;
+    case CLD_EXITED:
+      if (info.si_status == 127)
+       {
+         if (exit_on_error || !null_stderr)
+           error (exit_on_error ? EXIT_FAILURE : 0, 0,
+                  _("%s subprocess failed"), progname);
+         return 127;
+       }
+      return info.si_status;
+    default:
+      abort ();
+    }
+#else
   /* waitpid() is just as portable as wait() nowadays.  */
   WAIT_T status;
 
@@ -253,11 +351,11 @@ wait_subprocess (pid_t child, const char *progname,
 
       if (result != child)
        {
-#ifdef EINTR
+# ifdef EINTR
          if (errno == EINTR)
            continue;
-#endif
-#if 0 /* defined ECHILD */
+# endif
+# if 0 /* defined ECHILD */
          if (errno == ECHILD)
            {
              /* Child process nonexistent?! Assume it terminated
@@ -265,7 +363,7 @@ wait_subprocess (pid_t child, const char *progname,
              *(int *) &status = 0;
              break;
            }
-#endif
+# endif
          if (exit_on_error || !null_stderr)
            error (exit_on_error ? EXIT_FAILURE : 0, errno,
                   _("%s subprocess"), progname);
@@ -288,6 +386,10 @@ wait_subprocess (pid_t child, const char *progname,
 
   if (WIFSIGNALED (status))
     {
+# ifdef SIGPIPE
+      if (WTERMSIG (status) == SIGPIPE && ignore_sigpipe)
+       return 0;
+# endif
       if (exit_on_error || !null_stderr)
        error (exit_on_error ? EXIT_FAILURE : 0, 0,
               _("%s subprocess got fatal signal %d"),
@@ -302,4 +404,5 @@ wait_subprocess (pid_t child, const char *progname,
       return 127;
     }
   return WEXITSTATUS (status);
+#endif
 }