GDB stub:

- Added CPU mutex functions gdbstub_mutex_init/destroy/lock/unlock, which govern access to NDS_ARM9 and NDS_ARM7 structs.
- Added locking and unlocking of the mutex to gdbstub.cpp/processPacket_gdb() and NDSSystem.cpp/NDS_exec()
Cocoa, CLI, GTK, Windows ports:
- Added mutex initialization and destruction to main() functions (cocoa/cocoa_core.mm, cli/main.cpp, gtk/main.cpp, windows/main.cpp)

desmume/src/NDSSystem.cpp

@@ -55,6 +55,10 @@
 #include "SPU.h"
 #include "wifi.h"
 
+#ifdef GDB_STUB
+#include "gdbstub.h"
+#endif
+
 //int xxctr=0;
 //#define LOG_ARM9
 //#define LOG_ARM7
@@ -1828,6 +1832,10 @@ void NDS_debug_step()
 template<bool FORCE>
 void NDS_exec(s32 nb)
 {
+	#ifdef GDB_STUB
+	gdbstub_mutex_lock();
+	#endif
+
 	LagFrameFlag=1;
 
 	sequencer.nds_vblankEnded = false;
@@ -1860,7 +1868,13 @@ void NDS_exec(s32 nb)
 					
 					while((NDS_ARM9.stalled || NDS_ARM7.stalled) && execute)
 					{
+					        #ifdef GDB_STUB
+					        gdbstub_mutex_unlock();
+					        #endif
 						driver->EMU_DebugIdleUpdate();
+					        #ifdef GDB_STUB
+					        gdbstub_mutex_lock();
+					        #endif
 						nds_debug_continuing[0] = nds_debug_continuing[1] = true;
 					}
 					
@@ -1961,6 +1975,10 @@ void NDS_exec(s32 nb)
 	DEBUG_Notify.NextFrame();
 	if (cheats)
 		cheats->process();
+
+        #ifdef GDB_STUB
+        gdbstub_mutex_unlock();
+        #endif
 }
 
 template<int PROCNUM> static void execHardware_interrupts_core()

desmume/src/cli/main.cpp

@@ -596,6 +596,8 @@ int main(int argc, char ** argv) {
   driver = new BaseDriver();
   
 #ifdef GDB_STUB
+  gdbstub_mutex_init();
+
   /*
    * Activate the GDB stubs
    * This has to come after NDS_Init() where the CPUs are set up.
@@ -826,6 +828,8 @@ int main(int argc, char ** argv) {
   
   destroyStub_gdb( arm7_gdb_stub);
   arm7_gdb_stub = NULL;
+
+  gdbstub_mutex_destroy();
 #endif
   
   SDL_Quit();

desmume/src/cocoa/cocoa_core.mm

@@ -371,6 +371,8 @@ volatile bool execute = true;
 #ifdef GDB_STUB
 	if (theState)
 	{
+        gdbstub_mutex_init();
+        
 		if ([self enableGdbStubARM9])
 		{
 			const uint16_t arm9Port = (uint16_t)[self gdbStubPortARM9];
@@ -422,6 +424,8 @@ volatile bool execute = true;
 		
 		destroyStub_gdb(gdbStubHandleARM7);
 		gdbStubHandleARM7 = NULL;
+
+        gdbstub_mutex_destroy();
 	}
 #endif
 	if (gdbStubHandleARM9 == NULL && gdbStubHandleARM7 == NULL)

desmume/src/gdbstub.h

@@ -25,6 +25,11 @@ typedef void *gdbstub_handle_t;
 struct armcpu_t;
 struct armcpu_memory_iface;
 
+void gdbstub_mutex_init();
+void gdbstub_mutex_destroy();
+void gdbstub_mutex_lock();
+void gdbstub_mutex_unlock();
+
 /*
  * The function interface
  */

desmume/src/gdbstub/gdbstub.cpp

@@ -35,6 +35,25 @@
 #include "../armcpu.h"
 #include "../MMU.h"
 
+// For cpu_mutex
+#ifdef HOST_WINDOWS
+#include <windows.h>
+#else
+#include <pthread.h>
+#if defined HOST_LINUX
+#include <unistd.h>
+#elif defined HOST_BSD || defined HOST_DARWIN
+#include <sys/sysctl.h>
+#endif
+#endif // HOST_WINDOWS
+
+#ifndef HOST_WINDOWS
+// to access the CPUs in any way, a thread has to get a lock on this first
+pthread_mutex_t cpu_mutex;
+#else
+HANDLE cpu_mutex;
+#endif
+
 #ifdef __GNUC__
 #define UNUSED_PARM( parm) parm __attribute__((unused))
 #else
@@ -134,9 +153,53 @@ enum target_signal
     TARGET_SIGNAL_PRIO = 44,
   };
 
+// Try defining/undefining this, if you have problems with the GDB stub on Windows.
+#define USE_MUTEX_ON_WINDOWS
 
+void gdbstub_mutex_init()
+{
+    #ifndef HOST_WINDOWS
+    pthread_mutex_init(&cpu_mutex, NULL);
+    #else
+#ifdef USE_MUTEX_ON_WINDOWS
+    cpu_mutex = CreateMutex(NULL, FALSE, NULL);
+#endif
+    #endif
+}
 
+void gdbstub_mutex_destroy()
+{
+    #ifndef HOST_WINDOWS
+    pthread_mutex_destroy(&cpu_mutex);
+    #else
+#ifdef USE_MUTEX_ON_WINDOWS
+    CloseHandle(cpu_mutex);
+#endif
+    #endif
+}
 
+void gdbstub_mutex_lock()
+{
+#ifndef HOST_WINDOWS
+    pthread_mutex_lock(&cpu_mutex);
+#else
+#ifdef USE_MUTEX_ON_WINDOWS
+    // Maybe we should check the return value, but then again what could we do about it anyway.
+    WaitForSingleObject(cpu_mutex, INFINITE);
+#endif
+#endif
+}
+
+void gdbstub_mutex_unlock()
+{
+#ifndef HOST_WINDOWS
+    pthread_mutex_unlock(&cpu_mutex);
+#else
+#ifdef USE_MUTEX_ON_WINDOWS
+    ReleaseMutex(cpu_mutex);
+#endif
+#endif
+}
 
 static void
 causeQuit_gdb( struct gdb_stub_state *stub) {
@@ -527,6 +590,7 @@ processPacket_gdb( SOCKET_TYPE sock, const uint8_t *packet,
   uint32_t send_size = 0;
 
   DEBUG_LOG("Processing packet %c\n", packet[0]);
+  gdbstub_mutex_lock();
 
   switch( packet[0]) {
   case 3:
@@ -899,6 +963,8 @@ processPacket_gdb( SOCKET_TYPE sock, const uint8_t *packet,
     break;
   }
 
+  gdbstub_mutex_unlock();
+
   if ( send_reply) {
     return putpacket( sock, out_packet, send_size);
   }

desmume/src/gtk/main.cpp

@@ -2919,6 +2919,8 @@ common_gtk_main( class configured_features *my_config)
      * where the cpus are set up.
      */
 #ifdef GDB_STUB
+    gdbstub_mutex_init();
+    
     gdbstub_handle_t arm9_gdb_stub = NULL;
     gdbstub_handle_t arm7_gdb_stub = NULL;
     
@@ -3277,6 +3279,8 @@ common_gtk_main( class configured_features *my_config)
 	
     destroyStub_gdb( arm7_gdb_stub);
 	arm7_gdb_stub = NULL;
+
+    gdbstub_mutex_destroy();
 #endif
 
     return EXIT_SUCCESS;

desmume/src/windows/main.cpp

@@ -3257,6 +3257,8 @@ int _main()
 	NDS_Init();
 	
 #ifdef GDB_STUB
+    gdbstub_mutex_init();
+
 	// Activate the GDB stubs. This has to come after the NDS_Init() where the CPUs are set up.
 	gdbstub_handle_t arm9_gdb_stub = NULL;
 	gdbstub_handle_t arm7_gdb_stub = NULL;
@@ -3460,6 +3462,8 @@ int _main()
 	
 	destroyStub_gdb(arm7_gdb_stub);
 	arm7_gdb_stub = NULL;
+
+    gdbstub_mutex_destroy();
 #endif
 	
 	NDS_DeInit();