hare

commit 7e8a3466c36d1d53856f85e59d5f503eec1a6943
parent 4380d79c06d7a596d762b121b0d329c791569466
Author: Bor Grošelj Simić <bor.groseljsimic@telemach.net>
Date:   Fri, 25 Feb 2022 01:46:13 +0100

implement os::exec::peek{,any}

Signed-off-by: Bor Grošelj Simić <bor.groseljsimic@telemach.net>

Diffstat:
M
os/exec/process+freebsd.ha
 | 
20
+++++++++++++++++++-
M
os/exec/process+linux.ha
 | 
20
+++++++++++++++++++-

2 files changed, 38 insertions(+), 2 deletions(-)
diff --git a/os/exec/process+freebsd.ha b/os/exec/process+freebsd.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;
 
diff --git a/os/exec/process+linux.ha b/os/exec/process+linux.ha
@@ -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;