beremiz

Runtime: Add RealTime checkbox in Linux target options to enable PREEMPT_RT scheduling.

2023-02-21, Edouard Tisserant
929276eea252
Parents 549763a28934
Children c9a1a8ede8d9
Runtime: Add RealTime checkbox in Linux target options to enable PREEMPT_RT scheduling.
4 files changed, 76 insertions(+), 5 deletions(-)
  • +2 -1
    targets/Linux/XSD
  • +5 -1
    targets/Linux/__init__.py
  • +60 -3
    targets/Linux/plc_Linux_main.c
  • +9 -0
    targets/beremiz.h
    • --- a/targets/Linux/XSD Tue Feb 21 11:38:45 2023 +0100
    +++ b/targets/Linux/XSD Tue Feb 21 11:47:11 2023 +0100
    @@ -1,6 +1,7 @@
    <xsd:element name="Linux">
    <xsd:complexType>
    + <xsd:attribute name="RealTime" type="xsd:boolean" use="optional" default="false"/>
    %(toolchain_gcc)s
    </xsd:complexType>
    - </xsd:element>
    \ No newline at end of file
    + </xsd:element>
    --- a/targets/Linux/__init__.py Tue Feb 21 11:38:45 2023 +0100
    +++ b/targets/Linux/__init__.py Tue Feb 21 11:47:11 2023 +0100
    @@ -32,7 +32,11 @@
    extension = ".so"
    def getBuilderCFLAGS(self):
    - return toolchain_gcc.getBuilderCFLAGS(self) + ["-fPIC"]
    + additional_cflags = ["-fPIC"]
    + build_for_realtime = self.CTRInstance.GetTarget().getcontent().getRealTime()
    + if build_for_realtime:
    + additional_cflags.append("-DREALTIME_LINUX")
    + return toolchain_gcc.getBuilderCFLAGS(self) + additional_cflags
    def getBuilderLDFLAGS(self):
    return toolchain_gcc.getBuilderLDFLAGS(self) + ["-shared", "-lrt"]
    --- a/targets/Linux/plc_Linux_main.c Tue Feb 21 11:38:45 2023 +0100
    +++ b/targets/Linux/plc_Linux_main.c Tue Feb 21 11:47:11 2023 +0100
    @@ -11,6 +11,9 @@
    #include <pthread.h>
    #include <locale.h>
    #include <semaphore.h>
    +#ifdef REALTIME_LINUX
    +#include <sys/mman.h>
    +#endif
    static unsigned long __debug_tick;
    @@ -105,10 +108,60 @@
    pthread_exit(0);
    }
    +#define _LogError(text,...) \
    + {\
    + char mstr[256];\
    + snprintf(mstr, 255, text, ##__VA_ARGS__);\
    + LogMessage(LOG_CRITICAL, mstr, strlen(mstr));\
    + }
    #define maxval(a,b) ((a>b)?a:b)
    int startPLC(int argc,char **argv)
    {
    + int ret;
    + pthread_attr_t *pattr = NULL;
    +
    +#ifdef REALTIME_LINUX
    + struct sched_param param;
    + pthread_attr_t attr;
    +
    + /* Lock memory */
    + ret = mlockall(MCL_CURRENT|MCL_FUTURE);
    + if(ret == -1) {
    + _LogError("mlockall failed: %m\n");
    + return ret;
    + }
    +
    + /* Initialize pthread attributes (default values) */
    + ret = pthread_attr_init(&attr);
    + if (ret) {
    + _LogError("init pthread attributes failed\n");
    + return ret;
    + }
    +
    + /* Set scheduler policy and priority of pthread */
    + ret = pthread_attr_setschedpolicy(&attr, SCHED_FIFO);
    + if (ret) {
    + _LogError("pthread setschedpolicy failed\n");
    + return ret;
    + }
    + param.sched_priority = PLC_THREAD_PRIORITY;
    + ret = pthread_attr_setschedparam(&attr, &param);
    + if (ret) {
    + _LogError("pthread setschedparam failed\n");
    + return ret;
    + }
    +
    + /* Use scheduling parameters of attr */
    + ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
    + if (ret) {
    + _LogError("pthread setinheritsched failed\n");
    + return ret;
    + }
    +
    + pattr = &attr;
    +#endif
    +
    PLC_shutdown = 0;
    pthread_mutex_init(&debug_wait_mutex, NULL);
    @@ -119,7 +172,7 @@
    pthread_mutex_lock(&debug_wait_mutex);
    pthread_mutex_lock(&python_wait_mutex);
    - if( __init(argc,argv) == 0 ){
    + if((ret = __init(argc,argv)) == 0 ){
    /* Signal to wakeup PLC thread when period changes */
    signal(SIGUSR1, PLCThreadSignalHandler);
    @@ -132,9 +185,13 @@
    period_ns = common_ticktime__;
    clock_gettime(CLOCK_MONOTONIC, &next_abs_time);
    - pthread_create(&PLC_thread, NULL, (void*) &PLC_thread_proc, NULL);
    + ret = pthread_create(&PLC_thread, pattr, (void*) &PLC_thread_proc, NULL);
    + if (ret) {
    + _LogError("create pthread failed\n");
    + return ret;
    + }
    }else{
    - return 1;
    + return ret;
    }
    return 0;
    }
    --- a/targets/beremiz.h Tue Feb 21 11:38:45 2023 +0100
    +++ b/targets/beremiz.h Tue Feb 21 11:47:11 2023 +0100
    @@ -32,4 +32,13 @@
    int unblock_RT_to_nRT_signal(void* handle);
    void nRT_reschedule(void);
    +
    +#ifdef REALTIME_LINUX
    +
    +#ifndef PLC_THREAD_PRIORITY
    +#define PLC_THREAD_PRIORITY 80
    #endif
    +
    +#endif
    +
    +#endif