From 44904f00c81f1dea3743a092c0976c2e2ec32d0f Mon Sep 17 00:00:00 2001
From: Jianfeng Jiang <jiangjianfeng.jjf@antgroup.com>
Date: Wed, 15 Mar 2023 17:02:20 +0800
Subject: [PATCH] Add syscall pause

---
 .../libs/jinux-std/src/syscall/mod.rs         |  4 ++++
 .../libs/jinux-std/src/syscall/pause.rs       | 20 +++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 src/services/libs/jinux-std/src/syscall/pause.rs

diff --git a/src/services/libs/jinux-std/src/syscall/mod.rs b/src/services/libs/jinux-std/src/syscall/mod.rs
index 61181833..edd8e796 100644
--- a/src/services/libs/jinux-std/src/syscall/mod.rs
+++ b/src/services/libs/jinux-std/src/syscall/mod.rs
@@ -34,6 +34,7 @@ use crate::syscall::mmap::sys_mmap;
 use crate::syscall::mprotect::sys_mprotect;
 use crate::syscall::munmap::sys_munmap;
 use crate::syscall::open::{sys_open, sys_openat};
+use crate::syscall::pause::sys_pause;
 use crate::syscall::poll::sys_poll;
 use crate::syscall::prctl::sys_prctl;
 use crate::syscall::prlimit64::sys_prlimit64;
@@ -96,6 +97,7 @@ mod mmap;
 mod mprotect;
 mod munmap;
 mod open;
+mod pause;
 mod poll;
 mod prctl;
 mod prlimit64;
@@ -177,6 +179,7 @@ define_syscall_nums!(
     SYS_MADVISE = 28,
     SYS_DUP = 32,
     SYS_DUP2 = 33,
+    SYS_PAUSE = 34,
     SYS_GETPID = 39,
     SYS_CLONE = 56,
     SYS_FORK = 57,
@@ -306,6 +309,7 @@ pub fn syscall_dispatch(
         SYS_MADVISE => syscall_handler!(3, sys_madvise, args),
         SYS_DUP => syscall_handler!(1, sys_dup, args),
         SYS_DUP2 => syscall_handler!(2, sys_dup2, args),
+        SYS_PAUSE => syscall_handler!(0, sys_pause),
         SYS_GETPID => syscall_handler!(0, sys_getpid),
         SYS_CLONE => syscall_handler!(5, sys_clone, args, context.clone()),
         SYS_FORK => syscall_handler!(0, sys_fork, context.clone()),
diff --git a/src/services/libs/jinux-std/src/syscall/pause.rs b/src/services/libs/jinux-std/src/syscall/pause.rs
new file mode 100644
index 00000000..ab5ce360
--- /dev/null
+++ b/src/services/libs/jinux-std/src/syscall/pause.rs
@@ -0,0 +1,20 @@
+use crate::{prelude::*, process::posix_thread::posix_thread_ext::PosixThreadExt, thread::Thread};
+
+use super::SyscallReturn;
+
+pub fn sys_pause() -> Result<SyscallReturn> {
+    loop {
+        let current_thread = current_thread!();
+        // check sig_queue of current thread and process,
+        // if there's any pending signal, break loop
+        let posix_thread = current_thread.as_posix_thread().unwrap();
+        if !posix_thread.sig_queues().lock().empty() || !current!().sig_queues().lock().empty() {
+            break;
+        }
+        // there's no pending signal, yield execution
+        // FIXME: set current thread interruptible here
+        Thread::yield_now();
+    }
+    // handle signal before returning to user space
+    return_errno_with_message!(Errno::ERESTART, "catch signal")
+}