commit 3115a20d63f1a9ef155acfcb2013412298cbb2b4
author Austin Schuh <austin.linux@gmail.com> Mon May 27 21:02:14 2019 -0700
committer Austin Schuh <austin.linux@gmail.com> Wed Jun 12 19:28:01 2019 -0700
tree 73be5a91004d4ec715460e88b633141653d67118
parent 82c0c82f33318aa870d33f9b5efe7dad3f9bff67

Add SetRuntimeRealtimePriority

This lets us move the concept of priority into the event loop rather
than trying to manage it elsewhere.  Also add tests to confirm I got
them all.

Change-Id: Iba2651778e8d1eb88dedf71d0efdf05dfc999f2d

aos/events/shm-event-loop.cc

diff --git a/aos/events/shm-event-loop.cc b/aos/events/shm-event-loop.cc
index 11d9312..ee71b4c 100644
--- a/aos/events/shm-event-loop.cc
+++ b/aos/events/shm-event-loop.cc
@@ -6,6 +6,7 @@
 #include <chrono>
 #include <stdexcept>
 
+#include "aos/init.h"
 #include "aos/logging/logging.h"
 #include "aos/queue.h"
 
@@ -122,9 +123,13 @@
   }
 
   void Run() {
+    thread_state_->MaybeSetCurrentThreadRealtimePriority();
     thread_state_->WaitForStart();
 
-    if (!thread_state_->is_running()) return;
+    if (!thread_state_->is_running()) {
+      ::aos::UnsetCurrentThreadRealtimePriority();
+      return;
+    }
 
     const void *msg = nullptr;
     while (true) {
@@ -143,6 +148,7 @@
     }
 
     queue_->FreeMessage(msg);
+    ::aos::UnsetCurrentThreadRealtimePriority();
   }
 
  private:
@@ -180,6 +186,7 @@
   }
 
   void Run() {
+    thread_state_->MaybeSetCurrentThreadRealtimePriority();
     thread_state_->WaitForStart();
 
     while (true) {
@@ -196,6 +203,7 @@
         if (!thread_state_->is_running()) break;
       }
     }
+    ::aos::UnsetCurrentThreadRealtimePriority();
   }
 
  private:
@@ -256,11 +264,13 @@
 }
 
 void ShmEventLoop::Run() {
+  thread_state_->MaybeSetCurrentThreadRealtimePriority();
   set_is_running(true);
   for (const auto &run : on_run_) run();
   // TODO(austin): epoll event loop in main thread (if needed), and async safe
   // quit handler.
   thread_state_->Run();
+  ::aos::UnsetCurrentThreadRealtimePriority();
 }
 
 void ShmEventLoop::ThreadState::Run() {
@@ -275,6 +285,12 @@
   }
 }
 
+void ShmEventLoop::ThreadState::MaybeSetCurrentThreadRealtimePriority() {
+  if (priority_ != -1) {
+    ::aos::SetCurrentThreadRealtimePriority(priority_);
+  }
+}
+
 void ShmEventLoop::ThreadState::WaitForStart() {
   MutexLocker locker(&mutex_);
   while (!(loop_running_ || loop_finished_)) {