Total rework of simulator for dev branch. Create separate thread for interrupt processes. Tick-accurate simulation of timers. Non-blocking character input for running in realtime mode. Decouple hardware sim from grbl code as much as possible. Expanded command line options. Provisions for cross-platform solution.

sim/platform_LINUX.c

@@ -0,0 +1,116 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <termios.h>
+#include <time.h>
+#include <sys/time.h>
+#include "platform.h"
+
+#define MS_PER_SEC 1000000
+
+
+//any platform-specific setup that must be done before sim starts here
+void platform_init()
+{
+}
+
+//cleanup int here;
+void platform_terminate()
+{
+}
+
+//returns a free-running 32 bit nanosecond counter which rolls over
+uint32_t platform_ns() 
+{
+  static uint32_t gTimeBase = 0;
+  struct timespec ts;
+  clock_gettime(CLOCK_MONOTONIC,&ts);
+  if (gTimeBase== 0){gTimeBase=ts.tv_nsec;}
+  return ts.tv_nsec-gTimeBase;
+}
+
+//sleep in microseconds
+void platform_sleep(long  microsec)
+{
+  struct timespec ts={0};
+  while (microsec >= MS_PER_SEC){
+	 ts.tv_sec++;
+	 microsec-=MS_PER_SEC;
+  }
+  ts.tv_nsec = microsec*1000;
+  nanosleep(&ts,NULL);
+}
+
+#define SIM_ECHO_TERMINAL 1 //use this to make grbl_sim act like a serial terminal with local echo on.
+
+//set terminal to allow kbhit detection
+void enable_kbhit(int dir)
+{
+  static struct termios oldt, newt;
+ 
+  if ( dir == 1 )
+  {
+    tcgetattr( STDIN_FILENO, &oldt);
+    newt = oldt;
+	 newt.c_lflag &= ~( ICANON  ); 
+	 if (!SIM_ECHO_TERMINAL) {
+		newt.c_lflag &= ~( ECHO );
+	 }
+    tcsetattr( STDIN_FILENO, TCSANOW, &newt);
+  }
+  else
+    tcsetattr( STDIN_FILENO, TCSANOW, &oldt);
+}
+ 
+//detect key pressed
+int kbhit (void)
+{
+  struct timeval tv={0};
+  fd_set rdfs={{0}};
+  int retval;
+
+  /* tv.tv_sec = 0; */
+  /* tv.tv_usec = 0; */
+ 
+  /* FD_ZERO(&rdfs); */
+  FD_SET (STDIN_FILENO, &rdfs);
+ 
+  select(STDIN_FILENO+1, &rdfs, NULL, NULL, &tv);
+  retval = FD_ISSET(STDIN_FILENO, &rdfs);
+
+  return retval;
+}
+
+
+
+plat_thread_t* platform_start_thread(plat_threadfunc_t threadfunc) {
+  plat_thread_t* th = malloc(sizeof(plat_thread_t));
+  if (pthread_create(&th->tid, NULL, threadfunc, &th->exit)){
+	 free(th);
+	 return NULL;
+  }
+  return th;
+}
+
+//ask thread to exit nicely, wait
+void platform_stop_thread(plat_thread_t* th){
+  th->exit = 1;
+  pthread_join(th->tid,NULL);  
+}
+
+//force-kill thread
+void platform_kill_thread(plat_thread_t* th){
+  th->exit = 1;
+  pthread_cancel(th->tid); 
+}
+
+//return char if one available.
+uint8_t platform_poll_stdin() {
+  uint8_t char_in=0;
+  enable_kbhit(1);
+  if ( kbhit()) {
+	 char_in = getchar();
+  }
+  enable_kbhit(0);
+  return char_in;
+}