From 024d3b71e728ee7247be8df92acee5dcc0672b0d Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Thu, 21 Aug 2014 07:49:49 +1000
Subject: [PATCH] HAL_Linux: use a semaphore in suspend_timer_procs()
this is the start of multi-core aware code
---
libraries/AP_HAL_Linux/Scheduler.cpp | 37 +++++++++++-----------------
libraries/AP_HAL_Linux/Scheduler.h | 5 ++--
2 files changed, 18 insertions(+), 24 deletions(-)
diff --git a/libraries/AP_HAL_Linux/Scheduler.cpp b/libraries/AP_HAL_Linux/Scheduler.cpp
index 7e51e64b1..70b59f05c 100644
--- a/libraries/AP_HAL_Linux/Scheduler.cpp
+++ b/libraries/AP_HAL_Linux/Scheduler.cpp
@@ -198,19 +198,14 @@ void LinuxScheduler::register_timer_failsafe(AP_HAL::Proc failsafe, uint32_t per
void LinuxScheduler::suspend_timer_procs()
{
- _timer_suspended = true;
- while (_in_timer_proc) {
- delay_microseconds(20);
+ if (!_timer_semaphore.take(0)) {
+ printf("Failed to take timer semaphore\n");
}
}
void LinuxScheduler::resume_timer_procs()
{
- _timer_suspended = false;
- if (_timer_event_missed == true) {
- _run_timers(false);
- _timer_event_missed = false;
- }
+ _timer_semaphore.give();
}
void LinuxScheduler::_run_timers(bool called_from_timer_thread)
@@ -220,16 +215,16 @@ void LinuxScheduler::_run_timers(bool called_from_timer_thread)
}
_in_timer_proc = true;
- if (!_timer_suspended) {
- // now call the timer based drivers
- for (int i = 0; i < _num_timer_procs; i++) {
- if (_timer_proc[i] != NULL) {
- _timer_proc[i]();
- }
+ if (!_timer_semaphore.take(0)) {
+ printf("Failed to take timer semaphore in _run_timers\n");
+ }
+ // now call the timer based drivers
+ for (int i = 0; i < _num_timer_procs; i++) {
+ if (_timer_proc[i] != NULL) {
+ _timer_proc[i]();
}
- } else if (called_from_timer_thread) {
- _timer_event_missed = true;
}
+ _timer_semaphore.give();
// and the failsafe, if one is setup
if (_failsafe != NULL) {
@@ -272,12 +267,10 @@ void LinuxScheduler::_run_io(void)
}
_in_io_proc = true;
- if (!_timer_suspended) {
- // now call the IO based drivers
- for (int i = 0; i < _num_io_procs; i++) {
- if (_io_proc[i] != NULL) {
- _io_proc[i]();
- }
+ // now call the IO based drivers
+ for (int i = 0; i < _num_io_procs; i++) {
+ if (_io_proc[i] != NULL) {
+ _io_proc[i]();
}
}
diff --git a/libraries/AP_HAL_Linux/Scheduler.h b/libraries/AP_HAL_Linux/Scheduler.h
index dc11ceddc..ddc48365d 100644
--- a/libraries/AP_HAL_Linux/Scheduler.h
+++ b/libraries/AP_HAL_Linux/Scheduler.h
@@ -3,6 +3,7 @@
#define __AP_HAL_LINUX_SCHEDULER_H__
#include <AP_HAL_Linux.h>
+#include "Semaphores.h"
#if CONFIG_HAL_BOARD == HAL_BOARD_LINUX
#include <sys/time.h>
@@ -56,8 +57,6 @@ private:
bool _initialized;
volatile bool _timer_pending;
- volatile bool _timer_suspended;
-
AP_HAL::MemberProc _timer_proc[LINUX_SCHEDULER_MAX_TIMER_PROCS];
uint8_t _num_timer_procs;
volatile bool _in_timer_proc;
@@ -83,6 +82,8 @@ private:
void _setup_realtime(uint32_t size);
uint64_t stopped_clock_usec;
+
+ LinuxSemaphore _timer_semaphore;
};
#endif // CONFIG_HAL_BOARD
--
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