fixes

library/DFProcess-windows-SHM.cpp

@@ -92,6 +92,7 @@ bool SHMProcess::Private::isValidSV()
 bool SHMProcess::Private::waitWhile (DF_PINGPONG state)
 {
     uint32_t cnt = 0;
+    SCHED_YIELD // yield the CPU, valid only on single-core CPUs
     while (((shm_cmd *)my_shm)->pingpong == state)
     {
         if(cnt == 10000)

shmserver/shms-proto.cpp

@@ -46,6 +46,7 @@ void SHM_Act (void)
     uint32_t length;
     uint32_t address;
     check_again: // goto target!!!
+    SCHED_YIELD // yield the CPU, valid only on single-core CPUs
     if(numwaits == 10000)
     {
         // this tests if there's a process on the other side
@@ -58,6 +59,7 @@ void SHM_Act (void)
             full_barrier
             ((shm_cmd *)shm)->pingpong = DFPP_RUNNING;
             fprintf(stderr,"dfhack: Broke out of loop, other process disappeared.\n");
+            //MessageBox(0,"Broke out of loop, other process disappeared.","FUN", MB_OK);
         }
     }
     switch (((shm_cmd *)shm)->pingpong)
@@ -154,6 +156,7 @@ void SHM_Act (void)
         case DFPP_CL_ERROR:
         case DFPP_RUNNING:
             fprintf(stderr, "no. of waits: %d\n", numwaits);
+            //MessageBox(0,"Broke out of loop properly","FUN", MB_OK);
             break;
             
         default:

shmserver/shms-windows.cpp

@@ -643,7 +643,10 @@ extern "C" void SDL_Quit(void)
 static void (*_SDL_GL_SwapBuffers)(void) = 0;
 extern "C" void SDL_GL_SwapBuffers(void)
 {
+    if(!errorstate && ((shm_cmd *)shm)->pingpong != DFPP_RUNNING)
+    {
         SHM_Act();
+    }
     _SDL_GL_SwapBuffers();
 }
 

shmserver/shms.h

@@ -8,12 +8,26 @@
 #define SHM_SIZE SHM_HEADER+SHM_BODY
 
 
+// FIXME: add YIELD for linux, add single-core and multi-core compile targets for optimal speed
 #ifdef LINUX_BUILD
     // a full memory barrier! better be safe than sorry.
     #define full_barrier asm volatile("" ::: "memory"); __sync_synchronize();
+    #define SCHED_YIELD
 #else
+    // we need windows.h for Sleep()
+    #define _WIN32_WINNT 0x0501 // needed for INPUT struct
+    #define WINVER 0x0501                   // OpenThread(), PSAPI, Toolhelp32
+    #define WIN32_LEAN_AND_MEAN
+    #include <windows.h>
+    #define SCHED_YIELD Sleep(0);
     // FIXME: detect MSVC here and use the right barrier magic
-    #define full_barrier
+	#ifdef __MINGW32__
+		#define full_barrier asm volatile("" ::: "memory");
+	#else
+		#include <intrin.h>
+		#pragma intrinsic(_ReadWriteBarrier)
+		#define full_barrier _ReadWriteBarrier();
+	#endif
 #endif
 
 
@@ -82,12 +96,12 @@ enum DF_ERROR
 
 typedef struct
 {
-    uint32_t pingpong; // = 0
+    volatile uint32_t pingpong; // = 0
 } shm_cmd;
 
 typedef struct
 {
-    uint32_t pingpong;
+    volatile uint32_t pingpong;
     uint32_t address;
     uint32_t length;
 } shm_read;
@@ -97,25 +111,25 @@ typedef shm_read shm_bounce;
 
 typedef struct
 {
-    uint32_t pingpong;
+    volatile uint32_t pingpong;
 } shm_ret_data;
 
 typedef struct
 {
-    uint32_t pingpong;
+    volatile uint32_t pingpong;
     uint32_t address;
 } shm_read_small;
 
 typedef struct
 {
-    uint32_t pingpong;
+    volatile uint32_t pingpong;
     uint32_t address;
     uint32_t value;
 } shm_write_small;
 
 typedef struct
 {
-    uint32_t pingpong;
+    volatile uint32_t pingpong;
     uint32_t value;
 } shm_retval;