diff --git a/include/server.h b/include/server.h
index 4e56dc42c51..fe14a9b778e 100644
--- a/include/server.h
+++ b/include/server.h
@@ -195,6 +195,15 @@ struct resume_thread_reply
 };
 
 
+/* Debugger support: freeze / unfreeze */
+struct debugger_request
+{
+    int          op;           /* operation type */
+};
+
+enum debugger_op { DEBUGGER_FREEZE_ALL, DEBUGGER_UNFREEZE_ALL };
+
+
 /* Queue an APC for a thread */
 struct queue_apc_request
 {
@@ -694,6 +703,7 @@ extern int CLIENT_InitServer(void);
 
 struct _THDB;
 extern int CLIENT_SetDebug( int level );
+extern int CLIENT_DebuggerRequest( int op );
 extern int CLIENT_InitThread(void);
 #endif  /* __WINE_SERVER__ */
 
diff --git a/include/server/request.h b/include/server/request.h
index 56ecfaae9f0..6167edd31d4 100644
--- a/include/server/request.h
+++ b/include/server/request.h
@@ -18,6 +18,7 @@ enum request
     REQ_SET_THREAD_INFO,
     REQ_SUSPEND_THREAD,
     REQ_RESUME_THREAD,
+    REQ_DEBUGGER,
     REQ_QUEUE_APC,
     REQ_CLOSE_HANDLE,
     REQ_GET_HANDLE_INFO,
@@ -80,6 +81,7 @@ DECL_HANDLER(get_thread_info);
 DECL_HANDLER(set_thread_info);
 DECL_HANDLER(suspend_thread);
 DECL_HANDLER(resume_thread);
+DECL_HANDLER(debugger);
 DECL_HANDLER(queue_apc);
 DECL_HANDLER(close_handle);
 DECL_HANDLER(get_handle_info);
@@ -139,6 +141,7 @@ static const struct handler {
     { (void(*)())req_set_thread_info, sizeof(struct set_thread_info_request) },
     { (void(*)())req_suspend_thread, sizeof(struct suspend_thread_request) },
     { (void(*)())req_resume_thread, sizeof(struct resume_thread_request) },
+    { (void(*)())req_debugger, sizeof(struct debugger_request) },
     { (void(*)())req_queue_apc, sizeof(struct queue_apc_request) },
     { (void(*)())req_close_handle, sizeof(struct close_handle_request) },
     { (void(*)())req_get_handle_info, sizeof(struct get_handle_info_request) },
diff --git a/include/server/thread.h b/include/server/thread.h
index af56773e411..bc77a37dc4e 100644
--- a/include/server/thread.h
+++ b/include/server/thread.h
@@ -59,6 +59,8 @@ extern void set_thread_info( struct thread *thread,
                              struct set_thread_info_request *req );
 extern int suspend_thread( struct thread *thread );
 extern int resume_thread( struct thread *thread );
+extern void suspend_all_threads( void );
+extern void resume_all_threads( void );
 extern int send_reply( struct thread *thread, int pass_fd,
                        int n, ... /* arg_1, len_1, ..., arg_n, len_n */ );
 extern int add_queue( struct object *obj, struct wait_queue_entry *entry );
diff --git a/scheduler/client.c b/scheduler/client.c
index d08652b7eeb..e013044a351 100644
--- a/scheduler/client.c
+++ b/scheduler/client.c
@@ -293,6 +293,9 @@ int CLIENT_InitServer(void)
         perror("fork");
         exit(1);
     case 0:  /* child */
+        close( fd[1] );
+        break;
+    default:  /* parent */
         close( fd[0] );
         sprintf( buffer, "%d", fd[1] );
 /*#define EXEC_SERVER*/
@@ -303,9 +306,6 @@ int CLIENT_InitServer(void)
 #endif
         create_initial_thread( fd[1] );
         exit(0);
-    default:  /* parent */
-        close( fd[1] );
-        break;
     }
     return fd[0];
 }
@@ -341,3 +341,17 @@ int CLIENT_SetDebug( int level )
     CLIENT_SendRequest( REQ_SET_DEBUG, -1, 1, &level, sizeof(level) );
     return CLIENT_WaitReply( NULL, NULL, 0 );
 }
+
+/***********************************************************************
+ *           CLIENT_DebuggerRequest
+ *
+ * Send a debugger support request. Return 0 if OK.
+ */
+int CLIENT_DebuggerRequest( int op )
+{
+    struct debugger_request req;
+    req.op = op;
+    CLIENT_SendRequest( REQ_DEBUGGER, -1, 1, &req, sizeof(req) );
+    return CLIENT_WaitReply( NULL, NULL, 0 );
+}
+
diff --git a/server/request.c b/server/request.c
index 25bd3534f5c..01d64c5ca71 100644
--- a/server/request.c
+++ b/server/request.c
@@ -315,6 +315,23 @@ DECL_HANDLER(set_thread_info)
     send_reply( current, -1, 0 );
 }
 
+/* debugger support operations */
+DECL_HANDLER(debugger)
+{
+    switch ( req->op )
+    {
+    case DEBUGGER_FREEZE_ALL:
+        suspend_all_threads();
+        break;
+
+    case DEBUGGER_UNFREEZE_ALL:
+        resume_all_threads();
+        break;
+    }
+
+    send_reply( current, -1, 0 );
+}
+
 /* suspend a thread */
 DECL_HANDLER(suspend_thread)
 {
diff --git a/server/thread.c b/server/thread.c
index bf8a2ca19bf..e86cd6d9f24 100644
--- a/server/thread.c
+++ b/server/thread.c
@@ -102,6 +102,7 @@ void create_initial_thread( int fd )
     initial_thread.process = create_initial_process(); 
     add_process_thread( initial_thread.process, &initial_thread );
     add_client( fd, &initial_thread );
+    grab_object( &initial_thread ); /* so that we never free it */
     select_loop();
 }
 
@@ -242,6 +243,24 @@ int resume_thread( struct thread *thread )
     return old_count;
 }
 
+/* suspend all threads but the current */
+void suspend_all_threads( void )
+{
+    struct thread *thread;
+    for ( thread = first_thread; thread; thread = thread->next )
+        if ( thread != current )
+            suspend_thread( thread );
+}
+
+/* resume all threads but the current */
+void resume_all_threads( void )
+{
+    struct thread *thread;
+    for ( thread = first_thread; thread; thread = thread->next )
+        if ( thread != current )
+            resume_thread( thread );
+}
+
 /* send a reply to a thread */
 int send_reply( struct thread *thread, int pass_fd, int n,
                 ... /* arg_1, len_1, ..., arg_n, len_n */ )
diff --git a/server/trace.c b/server/trace.c
index f1ab987e90c..260b16b22c9 100644
--- a/server/trace.c
+++ b/server/trace.c
@@ -160,6 +160,12 @@ static int dump_resume_thread_reply( struct resume_thread_reply *req, int len )
     return (int)sizeof(*req);
 }
 
+static int dump_debugger_request( struct debugger_request *req, int len )
+{
+    fprintf( stderr, " op=%d", req->op );
+    return (int)sizeof(*req);
+}
+
 static int dump_queue_apc_request( struct queue_apc_request *req, int len )
 {
     fprintf( stderr, " handle=%d,", req->handle );
@@ -663,6 +669,8 @@ static const struct dumper dumpers[REQ_NB_REQUESTS] =
       (void(*)())dump_suspend_thread_reply },
     { (int(*)(void *,int))dump_resume_thread_request,
       (void(*)())dump_resume_thread_reply },
+    { (int(*)(void *,int))dump_debugger_request,
+      (void(*)())0 },
     { (int(*)(void *,int))dump_queue_apc_request,
       (void(*)())0 },
     { (int(*)(void *,int))dump_close_handle_request,
@@ -762,6 +770,7 @@ static const char * const req_names[REQ_NB_REQUESTS] =
     "set_thread_info",
     "suspend_thread",
     "resume_thread",
+    "debugger",
     "queue_apc",
     "close_handle",
     "get_handle_info",