command: only spin on waitpid if it's non-blocking

1 files changed, 14 insertions, 11 deletions

diff --git a/src/Command.zig b/src/Command.zig
index 12dea7f3a..8fa8808a5 100644
--- a/src/Command.zig
+++ b/src/Command.zig
@@ -187,17 +187,20 @@ fn setupFd(src: File.Handle, target: i32) !void {
 
 /// Wait for the command to exit and return information about how it exited.
 pub fn wait(self: Command, block: bool) !Exit {
-    // We specify NOHANG because its not our fault if the process we launch
-    // for the tty doesn't properly waitpid its children. We don't want
-    // to hang the terminal over it.
-    // When NOHANG is specified, waitpid will return a pid of 0 if the process
-    // doesn't have a status to report. When that happens, it is as though the
-    // wait call has not been performed, so we need to keep trying until we get
-    // a non-zero pid back, otherwise we end up with zombie processes.
-    var res = std.os.WaitPidResult{ .pid = 0, .status = 0 };
-    while (res.pid == 0) {
-        res = std.os.waitpid(self.pid.?, if (block) 0 else std.c.W.NOHANG);
-    }
+    const res = if (block) std.os.waitpid(self.pid.?, 0) else res: {
+        // We specify NOHANG because its not our fault if the process we launch
+        // for the tty doesn't properly waitpid its children. We don't want
+        // to hang the terminal over it.
+        // When NOHANG is specified, waitpid will return a pid of 0 if the process
+        // doesn't have a status to report. When that happens, it is as though the
+        // wait call has not been performed, so we need to keep trying until we get
+        // a non-zero pid back, otherwise we end up with zombie processes.
+        while (true) {
+            const res = std.os.waitpid(self.pid.?, std.c.W.NOHANG);
+            if (res.pid != 0) break :res res;
+        }
+    };
+
     return Exit.init(res.status);
 }