2 files changed, 38 insertions(+), 2 deletions(-)

M os/exec/process+freebsd.ha
M os/exec/process+linux.ha

@@ 111,7 111,7 @@ export fn waitall() (uint | error | !(process, exit_status)) = {
 export fn peek(proc: *process) (status | void | error) = {
 	let ru: rt::rusage = rt::rusage { ... };
 	let st: status = status { ... };
-	match (rt::wait4(*proc, &st.status, 0, &ru)) {
+	match (rt::wait4(*proc, &st.status, rt::WNOHANG, &ru)) {
 	case let err: rt::errno =>
 		return errors::errno(err);
 	case let pid: int =>


@@ 126,6 126,24 @@ export fn peek(proc: *process) (status | void | error) = {
 	return st;
 };
 
+// Waits for the first child process to complete, then returns its process info
+// and status
+export fn peekany() ((process, status) | void | error) = {
+	let ru: rt::rusage = rt::rusage { ... };
+	let st: status = status { ... };
+	match (rt::wait4(-1, &st.status, rt::WNOHANG, &ru)) {
+	case let err: rt::errno =>
+		return errors::errno(err);
+	case let pid: int =>
+		switch (pid) {
+		case 0 =>
+			return;
+		case =>
+			return (pid, st);
+		};
+	};
+};
+
 // The exit status code of a process.
 export type exited = int;
 

@@ 97,7 97,7 @@ export fn waitall() (uint | error | !(process, exit_status)) = {
 export fn peek(proc: *process) (status | void | error) = {
 	let ru: rt::rusage = rt::rusage { ... };
 	let st: status = status { ... };
-	match (rt::wait4(*proc, &st.status, 0, &ru)) {
+	match (rt::wait4(*proc, &st.status, rt::WNOHANG, &ru)) {
 	case let err: rt::errno =>
 		return errors::errno(err);
 	case let pid: int =>


@@ 112,6 112,24 @@ export fn peek(proc: *process) (status | void | error) = {
 	return st;
 };
 
+// Waits for the first child process to complete, then returns its process info
+// and status
+export fn peekany() ((process, status) | void | error) = {
+	let ru: rt::rusage = rt::rusage { ... };
+	let st: status = status { ... };
+	match (rt::wait4(-1, &st.status, rt::WNOHANG, &ru)) {
+	case let err: rt::errno =>
+		return errors::errno(err);
+	case let pid: int =>
+		switch (pid) {
+		case 0 =>
+			return;
+		case =>
+			return (pid, st);
+		};
+	};
+};
+
 // The exit status code of a process.
 export type exited = int;