From 1ac831d4b13f3596843e5303f5bbed967b206455 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Wed, 6 Dec 2023 16:13:07 +0200
Subject: [PATCH] Kernel: Add API to block on semaphore until unblock or EINTR

---
 kernel/include/kernel/Thread.h | 3 +++
 kernel/kernel/Thread.cpp       | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/kernel/include/kernel/Thread.h b/kernel/include/kernel/Thread.h
index 30b3527bc8..7ae32ec15e 100644
--- a/kernel/include/kernel/Thread.h
+++ b/kernel/include/kernel/Thread.h
@@ -47,6 +47,9 @@ namespace Kernel
 		void handle_signal(int signal = 0);
 		bool add_signal(int signal);
 
+		// blocks semaphore and returns either on unblock, eintr or spuriously
+		[[nodiscard]] bool block_or_eintr(Semaphore&);
+
 		void set_return_rsp(uintptr_t& rsp) { m_return_rsp = &rsp; }
 		void set_return_rip(uintptr_t& rip) { m_return_rip = &rip; }
 		uintptr_t return_rsp() { ASSERT(m_return_rsp); return *m_return_rsp; }
diff --git a/kernel/kernel/Thread.cpp b/kernel/kernel/Thread.cpp
index 8ff9670918..01acffcfdd 100644
--- a/kernel/kernel/Thread.cpp
+++ b/kernel/kernel/Thread.cpp
@@ -330,6 +330,14 @@ namespace Kernel
 		return false;
 	}
 
+	bool Thread::block_or_eintr(Semaphore& semaphore)
+	{
+		if (is_interrupted_by_signal())
+			return true;
+		semaphore.block();
+		return is_interrupted_by_signal();
+	}
+
 	void Thread::validate_stack() const
 	{
 		if (stack_base() <= m_rsp && m_rsp <= stack_base() + stack_size())