From ee80db4d9ac87dbb0eedc3a50ab7e5bafac6633d Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Sun, 21 Apr 2019 18:40:59 +0300
Subject: [PATCH] Introduce job_poll

---
 include/shell/job.h |  7 +++++++
 shell/job.c         | 30 +++++++++++++++++++++++++++---
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/include/shell/job.h b/include/shell/job.h
index 5051405..2189c61 100644
--- a/include/shell/job.h
+++ b/include/shell/job.h
@@ -43,6 +43,13 @@ bool job_terminated(struct mrsh_job *job);
  * have terminated.
  */
 bool job_stopped(struct mrsh_job *job);
+/**
+ * Polls the job's current status without blocking. Returns:
+ * - An integer >= 0 if the job has terminated
+ * - TASK_STATUS_STOPPED if the job is stopped
+ * - TASK_STATUS_WAIT if the job is running
+ */
+int job_poll(struct mrsh_job *job);
 /**
  * Wait for the completion of the job.
  */
diff --git a/shell/job.c b/shell/job.c
index ac9eebc..27355b5 100644
--- a/shell/job.c
+++ b/shell/job.c
@@ -184,8 +184,34 @@ bool job_set_foreground(struct mrsh_job *job, bool foreground, bool cont) {
 	return true;
 }
 
+int job_poll(struct mrsh_job *job) {
+	int proc_status = 0;
+	bool stopped = false;
+	for (size_t j = 0; j < job->processes.len; ++j) {
+		struct process *proc = job->processes.data[j];
+		proc_status = process_poll(proc);
+		if (proc_status == TASK_STATUS_WAIT) {
+			return TASK_STATUS_WAIT;
+		}
+		if (proc_status == TASK_STATUS_STOPPED) {
+			stopped = true;
+		}
+	}
+
+	if (stopped) {
+		return TASK_STATUS_STOPPED;
+	}
+	// All processes have terminated, return the last one's status
+	return proc_status;
+}
+
 int job_wait(struct mrsh_job *job) {
-	while (!job_stopped(job) && !job_terminated(job)) {
+	while (true) {
+		int status = job_poll(job);
+		if (status != TASK_STATUS_WAIT) {
+			return status;
+		}
+
 		int stat;
 		pid_t pid = waitpid(-1, &stat, WUNTRACED);
 		if (pid == -1) {
@@ -198,8 +224,6 @@ int job_wait(struct mrsh_job *job) {
 
 		update_job(job->state, pid, stat);
 	}
-
-	return 0; // TODO: return the job's status
 }
 
 bool init_job_child_process(struct mrsh_state *state) {
-- 
2.20.1