From a3703745eb21923b96e807b9163d303b8e4447b7 Mon Sep 17 00:00:00 2001
From: Malcolm Still <malcolm.still@gmail.com>
Date: Sat, 10 Jul 2021 21:56:41 +0100
Subject: [PATCH] Add waitid syscall on linux (#9335)

---
 lib/std/os/bits/linux.zig | 9 +++++++++
 lib/std/os/linux.zig      | 4 ++++
 2 files changed, 13 insertions(+)

diff --git a/lib/std/os/bits/linux.zig b/lib/std/os/bits/linux.zig
index 7501d54bbe..69fdbc84fb 100644
--- a/lib/std/os/bits/linux.zig
+++ b/lib/std/os/bits/linux.zig
@@ -204,6 +204,15 @@ pub const WEXITED = 4;
 pub const WCONTINUED = 8;
 pub const WNOWAIT = 0x1000000;
 
+// waitid id types
+pub const P = enum(c_uint) {
+    ALL = 0,
+    PID = 1,
+    PGID = 2,
+    PIDFD = 3,
+    _,
+};
+
 pub usingnamespace if (is_mips)
     struct {
         pub const SA_NOCLDSTOP = 1;
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 26f489a345..ef7c0ff077 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -710,6 +710,10 @@ pub fn waitpid(pid: pid_t, status: *u32, flags: u32) usize {
     return syscall4(.wait4, @bitCast(usize, @as(isize, pid)), @ptrToInt(status), flags, 0);
 }
 
+pub fn waitid(id_type: P, id: i32, infop: *siginfo_t, flags: u32) usize {
+    return syscall5(.waitid, @enumToInt(id_type), @bitCast(usize, @as(isize, id)), @ptrToInt(infop), flags, 0);
+}
+
 pub fn fcntl(fd: fd_t, cmd: i32, arg: usize) usize {
     return syscall3(.fcntl, @bitCast(usize, @as(isize, fd)), @bitCast(usize, @as(isize, cmd)), arg);
 }