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_WINDOWS.c

@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <conio.h>
+#include <windows.h>
+#include "platform.h"
+
+#define NS_PER_SEC 1000000000
+#define MICRO_PER_MILLI 1000
+
+double ns_per_perfcount;
+
+//any platform-specific setup that must be done before sim starts here
+void platform_init()
+{
+  __int64 counts_per_sec;
+  QueryPerformanceFrequency((LARGE_INTEGER*)&countsPerSec);
+  ns_per_perfcount = (float)NS_PER_SEC / counts_per_sec;
+}
+
+//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;
+  __int64 counts;
+  uint32_t ns;
+  QueryPerformanceCounter((LARGE_INTEGER*)&counts);
+  ns = (counts*ns_per_perfcount);
+
+  if (gTimeBase== 0){gTimeBase=ns;}
+  return ns-gTimeBase;
+}
+
+//sleep in microseconds
+void platform_sleep(long  microsec)
+{
+  Sleep(microsec/MICRO_PER_MILLI);
+}
+
+  
+//create a thread
+plat_thread_t* platform_start_thread(plat_threadfunc_t threadfunc) {
+  plat_thread_t* th = malloc(sizeof(plat_thread_t));
+  th->tid = CreateThread(NULL,0,threadfunc,&th->exit,0);
+  if (!th->tid){
+	 free(th);
+	 return NULL;
+  }
+  return th;
+}
+
+//ask thread to exit nicely, wait
+void platform_stop_thread(plat_thread_t* th){
+  th->exit = 1;
+  WaitForSingleObject(th->tid,INFINITE);
+}
+
+//force-kill thread
+void platform_kill_thread(plat_thread_t* th){
+  th->exit = 1;
+  TerminateThread(th->tid);
+}
+
+//return char if one available.
+uint8_t platform_poll_stdin() {
+  return _kbhit();
+}