From fe9bcb9b5bdf37212be9e16a5d3e02f295fce228 Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Thu, 7 Mar 2024 22:27:21 +1100
Subject: [PATCH] AP_Vehicle: cope with AP_Scheduler not being available

---
 libraries/AP_Vehicle/AP_Vehicle.cpp | 13 +++++++++++++
 libraries/AP_Vehicle/AP_Vehicle.h   |  8 +++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/libraries/AP_Vehicle/AP_Vehicle.cpp b/libraries/AP_Vehicle/AP_Vehicle.cpp
index 829383dd31..b05851bdfe 100644
--- a/libraries/AP_Vehicle/AP_Vehicle.cpp
+++ b/libraries/AP_Vehicle/AP_Vehicle.cpp
@@ -367,9 +367,11 @@ void AP_Vehicle::setup()
     networking.init();
 #endif
 
+#if AP_SCHEDULER_ENABLED
     // Register scheduler_delay_cb, which will run anytime you have
     // more than 5ms remaining in your call to hal.scheduler->delay
     hal.scheduler->register_delay_callback(scheduler_delay_callback, 5);
+#endif
 
 #if HAL_MSP_ENABLED
     // call MSP init before init_ardupilot to allow for MSP sensors
@@ -431,7 +433,11 @@ void AP_Vehicle::setup()
 
     // gyro FFT needs to be initialized really late
 #if HAL_GYROFFT_ENABLED
+#if AP_SCHEDULER_ENABLED
     gyro_fft.init(AP::scheduler().get_loop_rate_hz());
+#else
+    gyro_fft.init(1000);
+#endif
 #endif
 #if HAL_RUNCAM_ENABLED
     runcam.init();
@@ -520,8 +526,13 @@ void AP_Vehicle::setup()
 
 void AP_Vehicle::loop()
 {
+#if AP_SCHEDULER_ENABLED
     scheduler.loop();
     G_Dt = scheduler.get_loop_period_s();
+#else
+    hal.scheduler->delay(1);
+    G_Dt = 0.001;
+#endif
 
     if (!done_safety_init) {
         /*
@@ -548,6 +559,7 @@ void AP_Vehicle::loop()
     }
 }
 
+#if AP_SCHEDULER_ENABLED
 /*
   scheduler table - all regular tasks apart from the fast_loop()
   should be listed here.
@@ -708,6 +720,7 @@ void AP_Vehicle::scheduler_delay_callback()
     logger.EnableWrites(true);
 #endif
 }
+#endif  // AP_SCHEDULER_ENABLED
 
 // if there's been a watchdog reset, notify the world via a statustext:
 void AP_Vehicle::send_watchdog_reset_statustext()
diff --git a/libraries/AP_Vehicle/AP_Vehicle.h b/libraries/AP_Vehicle/AP_Vehicle.h
index 0ea6a802ca..8b22c9395d 100644
--- a/libraries/AP_Vehicle/AP_Vehicle.h
+++ b/libraries/AP_Vehicle/AP_Vehicle.h
@@ -127,10 +127,10 @@ public:
     // parameters for example.
     void notify_no_such_mode(uint8_t mode_number);
 
+#if AP_SCHEDULER_ENABLED
     void get_common_scheduler_tasks(const AP_Scheduler::Task*& tasks, uint8_t& num_tasks);
     // implementations *MUST* fill in all passed-in fields or we get
     // Valgrind errors
-#if AP_SCHEDULER_ENABLED
     virtual void get_scheduler_tasks(const AP_Scheduler::Task *&tasks, uint8_t &task_count, uint32_t &log_bit) = 0;
 #endif
 
@@ -310,8 +310,10 @@ protected:
     AP_CANManager can_mgr;
 #endif
 
+#if AP_SCHEDULER_ENABLED
     // main loop scheduler
     AP_Scheduler scheduler;
+#endif
 
     // IMU variables
     // Integration time; time last loop took to run
@@ -461,7 +463,9 @@ protected:
 #endif
 
     static const struct AP_Param::GroupInfo var_info[];
+#if AP_SCHEDULER_ENABLED
     static const struct AP_Scheduler::Task scheduler_tasks[];
+#endif
 
 #if OSD_ENABLED
     void publish_osd_info();
@@ -495,8 +499,10 @@ protected:
 
 private:
 
+#if AP_SCHEDULER_ENABLED
     // delay() callback that processing MAVLink packets
     static void scheduler_delay_callback();
+#endif
 
     // if there's been a watchdog reset, notify the world via a
     // statustext: