kern/thread: add the thread_delay function

2 files changed, 20 insertions, 0 deletions

diff --git a/kern/thread.c b/kern/thread.c
index 73e1cfb8..043f14de 100644
--- a/kern/thread.c
+++ b/kern/thread.c
@@ -2555,6 +2555,21 @@ thread_timedsleep(struct spinlock *interlock, const void *wchan_addr,
     return thread_sleep_common(interlock, wchan_addr, wchan_desc, true, ticks);
 }
 
+void
+thread_delay(uint64_t ticks, bool absolute)
+{
+    thread_preempt_disable();
+
+    if (!absolute) {
+        /* Add a tick to avoid quantization errors */
+        ticks += clock_get_time() + 1;
+    }
+
+    thread_timedsleep(NULL, thread_self(), "delay", ticks);
+
+    thread_preempt_enable();
+}
+
 void __init
 thread_run_scheduler(void)
 {
diff --git a/kern/thread.h b/kern/thread.h
index 04eea2b5..e84300c9 100644
--- a/kern/thread.h
+++ b/kern/thread.h
@@ -231,6 +231,11 @@ int thread_timedsleep(struct spinlock *interlock, const void *wchan_addr,
 int thread_wakeup(struct thread *thread);
 
 /*
+ * Suspend execution of the calling thread.
+ */
+void thread_delay(uint64_t ticks, bool absolute);
+
+/*
  * Start running threads on the local processor.
  *
  * Interrupts must be disabled when calling this function.