From d0b65674e6990cc2cfc2f4d3a2503a212df8578c Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Thu, 8 Jun 2023 19:57:38 +0200
Subject: [PATCH] kernel: Fix 0-delay sleeps blocking the thread forever

---
 kernel/src/sys/usleep.cpp       | 3 +++
 kernel/src/thread/Scheduler.cpp | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/src/sys/usleep.cpp b/kernel/src/sys/usleep.cpp
index 970b887b..dbf853ae 100644
--- a/kernel/src/sys/usleep.cpp
+++ b/kernel/src/sys/usleep.cpp
@@ -6,6 +6,9 @@ Result<u64> sys_usleep(Registers*, SyscallArgs args)
 {
     useconds_t us = (useconds_t)args[0];
 
+    // FIXME: Allow usleep() to use a more precise resolution.
+    if (us < 1000) return 0;
+
     kernel_sleep(us / 1000);
 
     return 0;
diff --git a/kernel/src/thread/Scheduler.cpp b/kernel/src/thread/Scheduler.cpp
index a40af402..4e331010 100644
--- a/kernel/src/thread/Scheduler.cpp
+++ b/kernel/src/thread/Scheduler.cpp
@@ -271,7 +271,7 @@ namespace Scheduler
         {
             if (thread->state == ThreadState::Sleeping)
             {
-                if (--thread->sleep_ticks_left == 0) thread->wake_up();
+                if (thread->sleep_ticks_left == 0 || --thread->sleep_ticks_left == 0) thread->wake_up();
             }
         }