From 9f1216fa2f17f520851b5c920acf71d13b62bf03 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Mr=C3=A1zek?= <peterix@gmail.com>
Date: Mon, 11 Jan 2010 18:57:57 +0000
Subject: [PATCH] fixes

---
 library/DFProcess-windows-SHM.cpp |  1 +
 shmserver/shms-proto.cpp          |  3 +++
 shmserver/shms-windows.cpp        |  5 ++++-
 shmserver/shms.h                  | 28 +++++++++++++++++++++-------
 tools/expbench.cpp                |  2 +-
 5 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/library/DFProcess-windows-SHM.cpp b/library/DFProcess-windows-SHM.cpp
index 41a21e1b5..5209e5afb 100644
--- a/library/DFProcess-windows-SHM.cpp
+++ b/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)
diff --git a/shmserver/shms-proto.cpp b/shmserver/shms-proto.cpp
index 4cdbee007..4e00275ae 100644
--- a/shmserver/shms-proto.cpp
+++ b/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:
diff --git a/shmserver/shms-windows.cpp b/shmserver/shms-windows.cpp
index 42b5365a8..f9a867cdc 100644
--- a/shmserver/shms-windows.cpp
+++ b/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)
 {
-    SHM_Act();
+    if(!errorstate && ((shm_cmd *)shm)->pingpong != DFPP_RUNNING)
+    {
+        SHM_Act();
+    }
     _SDL_GL_SwapBuffers();
 }
 
diff --git a/shmserver/shms.h b/shmserver/shms.h
index 15183563a..bf547a338 100644
--- a/shmserver/shms.h
+++ b/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;
 
diff --git a/tools/expbench.cpp b/tools/expbench.cpp
index 0672501b1..7f083e49b 100644
--- a/tools/expbench.cpp
+++ b/tools/expbench.cpp
@@ -32,7 +32,7 @@ int main (void)
     for(uint32_t i = 0; i< 1000;i++)
     {
         if(!DF.InitMap())
-			break;
+            break;
         DF.getSize(x_max,y_max,z_max);
         if((i % 10) == 0)
         {