Implement the waitid() SUSv4 function using wait6() system call.

PR:	standards/170346
Submitted by:	"Jukka A. Ukkonen" <jau@iki.fi>
MFC after:	1 month

1 files changed, 65 insertions, 0 deletions

diff --git a/lib/libc/gen/waitid.c b/lib/libc/gen/waitid.c
new file mode 100644
index 0000000..795b208
--- /dev/null
+++ b/lib/libc/gen/waitid.c
@@ -0,0 +1,65 @@
+/*-
+ * Copyright (c) 2012 Jukka A. Ukkonen
+ * All rights reserved.
+ *
+ * This software was developed by Jukka Ukkonen for FreeBSD.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <stddef.h>
+#include <string.h>
+#include <signal.h>
+#include <errno.h>
+#include "un-namespace.h"
+
+int
+__waitid(idtype_t idtype, id_t id, siginfo_t *info, int flags)
+{
+	int status;
+	pid_t ret;
+
+	ret = _wait6(idtype, id, &status, flags, NULL, info);
+
+	/*
+	 * According to SUSv4, waitid() shall not return a PID when a
+	 * process is found, but only 0.  If a process was actually
+	 * found, siginfo_t fields si_signo and si_pid will be
+	 * non-zero.  In case WNOHANG was set in the flags and no
+	 * process was found those fields are set to zero using
+	 * memset() below.
+	 */
+	if (ret == 0 && info != NULL)
+		memset(info, 0, sizeof(*info));
+	else if (ret > 0)
+		ret = 0;
+	return (ret);
+}
+
+__weak_reference(__waitid, waitid);
+__weak_reference(__waitid, _waitid);