Send SIGCHLD to parent process

src/libos/src/process/do_exit.rs

@@ -1,10 +1,11 @@
+use crate::signal::constants::*;
 use std::intrinsics::atomic_store;
 
 use super::do_futex::futex_wake;
-use super::process::ProcessFilter;
+use super::process::{Process, ProcessFilter};
 use super::{table, TermStatus, ThreadRef, ThreadStatus};
 use crate::prelude::*;
-use crate::signal::SigNum;
+use crate::signal::{KernelSignal, SigNum};
 
 pub fn do_exit_group(status: i32) {
     let term_status = TermStatus::Exited(status as u8);
@@ -84,6 +85,9 @@ fn exit_process(thread: &ThreadRef, term_status: TermStatus) {
     let mut parent_inner = parent.inner();
     process.inner().exit(term_status);
 
+    //Send SIGCHLD to parent
+    send_sigchld_to(&parent);
+
     // Wake up the parent if it is waiting on this child
     let waiting_children = parent_inner.waiting_children_mut().unwrap();
     waiting_children.del_and_wake_one_waiter(|waiter_data| -> Option<pid_t> {
@@ -103,3 +107,9 @@ fn exit_process(thread: &ThreadRef, term_status: TermStatus) {
         Some(process.pid())
     });
 }
+
+fn send_sigchld_to(parent: &Arc<Process>) {
+    let signal = Box::new(KernelSignal::new(SigNum::from(SIGCHLD)));
+    let mut sig_queues = parent.sig_queues().lock().unwrap();
+    sig_queues.enqueue(signal);
+}

test/signal/main.c

@@ -325,6 +325,34 @@ int test_sigaltstack() {
     return 0;
 }
 
+// ============================================================================
+// Test SIGCHLD signal
+// ============================================================================
+int sigchld = 0;
+
+void proc_exit() {
+    sigchld = 1;
+}
+
+int test_sigchld() {
+    signal(SIGCHLD, proc_exit);
+
+    int ret, child_pid;
+    printf("Run a parent process has pid = %d and ppid = %d\n", getpid(), getppid());
+
+    ret = posix_spawn(&child_pid, "/bin/getpid", NULL, NULL, NULL, NULL);
+    if (ret < 0){
+        printf("ERROR: failed to spawn a child process\n");
+        return -1;
+    }
+    printf("Spawn a new proces successfully (pid = %d)\n", child_pid);
+
+    wait(NULL);
+    if (sigchld == 0) THROW_ERROR("Did not receive SIGCHLD");
+
+    return 0;
+}
+
 // ============================================================================
 // Test suite main
 // ============================================================================
@@ -336,6 +364,7 @@ static test_case_t test_cases[] = {
     TEST_CASE(test_kill),
     TEST_CASE(test_catch_fault),
     TEST_CASE(test_sigaltstack),
+    TEST_CASE(test_sigchld),
 };
 
 int main(int argc, const char* argv[]) {