From aca6c0c031f014312d289e1782efe9d6eefa00da Mon Sep 17 00:00:00 2001
From: Idan Horowitz <idan.horowitz@gmail.com>
Date: Thu, 24 Feb 2022 20:01:33 +0200
Subject: [PATCH] Kernel: Add Process::try_for_each_thread() for fallible
 iteration

This API will allow users to short circuit iteration and properly
propagate errors.
---
 Kernel/Process.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Kernel/Process.h b/Kernel/Process.h
index 1043901d34..affd3d9a2e 100644
--- a/Kernel/Process.h
+++ b/Kernel/Process.h
@@ -237,6 +237,7 @@ public:
     IterationDecision for_each_thread(Callback);
     template<IteratorFunction<Thread&> Callback>
     IterationDecision for_each_thread(Callback callback) const;
+    ErrorOr<void> try_for_each_thread(Function<ErrorOr<void>(Thread const&)>) const;
 
     // Non-breakable iteration functions
     template<VoidFunction<Process&> Callback>
@@ -939,6 +940,15 @@ inline IterationDecision Process::for_each_thread(Callback callback) const
     return IterationDecision::Continue;
 }
 
+inline ErrorOr<void> Process::try_for_each_thread(Function<ErrorOr<void>(Thread const&)> callback) const
+{
+    return thread_list().with([&](auto& thread_list) -> ErrorOr<void> {
+        for (auto& thread : thread_list)
+            TRY(callback(thread));
+        return {};
+    });
+}
+
 template<VoidFunction<Thread&> Callback>
 inline IterationDecision Process::for_each_thread(Callback callback)
 {