]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/kern/thread_act.c
xnu-792.17.14.tar.gz
[apple/xnu.git] / osfmk / kern / thread_act.c
index f7e5000ecb4f73201e36b75c997125ecbe65e487..eb8099a4d02d8b93742397df2adcfbd8e653dc5f 100644 (file)
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @OSF_FREE_COPYRIGHT@
  *
  *     Author: Bryan Ford, University of Utah CSS
  *
- *     Thread_Activation management routines
+ *     Thread management routines
  */
-
-#include <cpus.h>
-#include <task_swapper.h>
+#include <mach/mach_types.h>
 #include <mach/kern_return.h>
 #include <mach/alert.h>
-#include <kern/etap_macros.h>
+#include <mach_prof.h>
+#include <mach/rpc.h>
+#include <mach/thread_act_server.h>
+
+#include <kern/kern_types.h>
+#include <kern/ast.h>
 #include <kern/mach_param.h>
 #include <kern/zalloc.h>
 #include <kern/thread.h>
-#include <kern/thread_swap.h>
 #include <kern/task.h>
-#include <kern/task_swap.h>
-#include <kern/thread_act.h>
 #include <kern/sched_prim.h>
 #include <kern/misc_protos.h>
 #include <kern/assert.h>
 #include <kern/spl.h>
 #include <kern/syscall_subr.h>
 #include <kern/sync_lock.h>
-#include <kern/mk_sp.h>        /*** ??? fix so this can be removed ***/
 #include <kern/processor.h>
+#include <kern/timer.h>
 #include <mach_prof.h>
 #include <mach/rpc.h>
 
-/*
- * Debugging printf control
- */
-#if    MACH_ASSERT
-unsigned int   watchacts =       0 /* WA_ALL */
-                                   ;   /* Do-it-yourself & patchable */
-#endif
-
-/*
- * Track the number of times we need to swapin a thread to deallocate it.
- */
-int act_free_swapin = 0;
-boolean_t first_act;
-
-/*
- * Forward declarations for functions local to this file.
- */
-kern_return_t  act_abort( thread_act_t, boolean_t);
-void           special_handler(ReturnHandler *, thread_act_t);
-kern_return_t  act_set_state_locked(thread_act_t, int,
-                                       thread_state_t,
-                                       mach_msg_type_number_t);
-kern_return_t  act_get_state_locked(thread_act_t, int,
-                                       thread_state_t,
-                                       mach_msg_type_number_t *);
-void           act_set_astbsd(thread_act_t);
-void           act_set_apc(thread_act_t);
-void           act_user_to_kernel(thread_act_t);
-void           act_ulock_release_all(thread_act_t thr_act);
-
-void           install_special_handler_locked(thread_act_t);
-
-static void            act_disable(thread_act_t);
-
-struct thread_activation       pageout_act;
-
-static zone_t  thr_act_zone;
-
-/*
- * Thread interfaces accessed via a thread_activation:
- */
-
+void                   act_abort(thread_t);
+void                   act_set_apc(thread_t);
+void                   install_special_handler_locked(thread_t);
+void                   special_handler_continue(void);
 
 /*
  * Internal routine to terminate a thread.
@@ -121,39 +89,31 @@ static zone_t      thr_act_zone;
  */
 kern_return_t
 thread_terminate_internal(
-       register thread_act_t   act)
+       thread_t                        thread)
 {
-       kern_return_t   result;
-       thread_t                thread;
-
-       thread = act_lock_thread(act);
+       kern_return_t           result = KERN_SUCCESS;
 
-       if (!act->active) {
-               act_unlock_thread(act);
-               return (KERN_TERMINATED);
-       }
+       thread_mtx_lock(thread);
 
-       act_disable(act);
-       result = act_abort(act, FALSE);
+       if (thread->active) {
+               thread->active = FALSE;
 
-       /* 
-        * Make sure this thread enters the kernel
-        * Must unlock the act, but leave the shuttle
-        * captured in this act.
-        */
-       if (thread != current_thread()) {
-               act_unlock(act);
-
-               if (thread_stop(thread))
-                       thread_unstop(thread);
-               else
-                       result = KERN_ABORTED;
+               act_abort(thread);
 
-               act_lock(act);
+               if (thread->started)
+                       clear_wait(thread, THREAD_INTERRUPTED);
+               else {
+                       clear_wait(thread, THREAD_AWAKENED);
+                       thread->started = TRUE;
+               }
        }
+       else
+               result = KERN_TERMINATED;
 
-       clear_wait(thread, act->inited? THREAD_INTERRUPTED: THREAD_AWAKENED);
-       act_unlock_thread(act);
+       thread_mtx_unlock(thread);
+
+       if (thread != current_thread() && result == KERN_SUCCESS)
+               thread_wait(thread);
 
        return (result);
 }
@@ -163,19 +123,18 @@ thread_terminate_internal(
  */
 kern_return_t
 thread_terminate(
-       register thread_act_t   act)
+       thread_t                thread)
 {
        kern_return_t   result;
 
-       if (act == THR_ACT_NULL)
+       if (thread == THREAD_NULL)
                return (KERN_INVALID_ARGUMENT);
 
-       if (    (act->task == kernel_task       ||
-                        act->kernel_loaded                     )       &&
-                       act != current_act()                    )
+       if (    thread->task == kernel_task             &&
+                       thread != current_thread()                      )
                return (KERN_FAILURE);
 
-       result = thread_terminate_internal(act);
+       result = thread_terminate_internal(thread);
 
        /*
         * If a kernel thread is terminating itself, force an AST here.
@@ -183,10 +142,9 @@ thread_terminate(
         * code - and all threads finish their own termination in the
         * special handler APC.
         */
-       if (    act->task == kernel_task        ||
-                        act->kernel_loaded                     ) {
-               assert(act == current_act());
-               ast_taken(AST_APC, FALSE);
+       if (thread->task == kernel_task) {
+               ml_set_interrupts_enabled(FALSE);
+               ast_taken(AST_APC, TRUE);
                panic("thread_terminate");
        }
 
@@ -198,109 +156,92 @@ thread_terminate(
  * This is a recursive-style suspension of the thread, a count of
  * suspends is maintained.
  *
- * Called with act_lock held.
+ * Called with thread mutex held.
  */
 void
 thread_hold(
-       register thread_act_t   act)
+       register thread_t       thread)
 {
-       thread_t        thread = act->thread;
-
-       if (act->suspend_count++ == 0) {
-               install_special_handler(act);
-               if (    act->inited                                     &&
-                               thread != THREAD_NULL           &&
-                               thread->top_act == act          )
-                       thread_wakeup_one(&act->suspend_count);
+       if (thread->suspend_count++ == 0) {
+               install_special_handler(thread);
+               if (thread->started)
+                       thread_wakeup_one(&thread->suspend_count);
        }
 }
 
 /*
- * Decrement internal suspension count for thr_act, setting thread
+ * Decrement internal suspension count, setting thread
  * runnable when count falls to zero.
  *
- * Called with act_lock held.
+ * Called with thread mutex held.
  */
 void
 thread_release(
-       register thread_act_t   act)
+       register thread_t       thread)
 {
-       thread_t        thread = act->thread;
-
-       if (    act->suspend_count > 0          &&
-                       --act->suspend_count == 0       &&
-                       thread != THREAD_NULL           &&
-                       thread->top_act == act          ) {
-               if (!act->inited) {
+       if (    thread->suspend_count > 0               &&
+                       --thread->suspend_count == 0    ) {
+               if (thread->started)
+                       thread_wakeup_one(&thread->suspend_count);
+               else {
                        clear_wait(thread, THREAD_AWAKENED);
-                       act->inited = TRUE;
+                       thread->started = TRUE;
                }
-               else
-                       thread_wakeup_one(&act->suspend_count);
        }
 }
 
 kern_return_t
 thread_suspend(
-       register thread_act_t   act)
+       register thread_t       thread)
 {
-       thread_t        thread;
+       thread_t                        self = current_thread();
+       kern_return_t           result = KERN_SUCCESS;
 
-       if (act == THR_ACT_NULL)
+       if (thread == THREAD_NULL || thread->task == kernel_task)
                return (KERN_INVALID_ARGUMENT);
 
-       thread = act_lock_thread(act);
+       thread_mtx_lock(thread);
 
-       if (!act->active) {
-               act_unlock_thread(act);
-               return (KERN_TERMINATED);
-       }
-
-       if (    act->user_stop_count++ == 0             &&
-                       act->suspend_count++ == 0               ) {
-               install_special_handler(act);
-               if (    thread != current_thread()              &&
-                               thread != THREAD_NULL                   &&
-                               thread->top_act == act                  ) {
-                       assert(act->inited);
-                       thread_wakeup_one(&act->suspend_count);
-                       act_unlock_thread(act);
-
-                       thread_wait(thread);
+       if (thread->active) {
+               if (    thread->user_stop_count++ == 0          &&
+                               thread->suspend_count++ == 0            ) {
+                       install_special_handler(thread);
+                       if (thread != self)
+                               thread_wakeup_one(&thread->suspend_count);
                }
-               else
-                       act_unlock_thread(act);
        }
        else
-               act_unlock_thread(act);
+               result = KERN_TERMINATED;
 
-       return (KERN_SUCCESS);
+       thread_mtx_unlock(thread);
+
+       if (thread != self && result == KERN_SUCCESS)
+               thread_wait(thread);
+
+       return (result);
 }
 
 kern_return_t
 thread_resume(
-       register thread_act_t   act)
+       register thread_t       thread)
 {
-       kern_return_t   result = KERN_SUCCESS;
-       thread_t                thread;
+       kern_return_t           result = KERN_SUCCESS;
 
-       if (act == THR_ACT_NULL)
+       if (thread == THREAD_NULL || thread->task == kernel_task)
                return (KERN_INVALID_ARGUMENT);
 
-       thread = act_lock_thread(act);
+       thread_mtx_lock(thread);
 
-       if (act->active) {
-               if (act->user_stop_count > 0) {
-                       if (    --act->user_stop_count == 0             &&
-                                       --act->suspend_count == 0               &&
-                                       thread != THREAD_NULL                   &&
-                                       thread->top_act == act                  ) {
-                               if (!act->inited) {
+       if (thread->active) {
+               if (thread->user_stop_count > 0) {
+                       if (    --thread->user_stop_count == 0          &&
+                                       --thread->suspend_count == 0            ) {
+                               if (thread->started)
+                                       thread_wakeup_one(&thread->suspend_count);
+                               else {
                                        clear_wait(thread, THREAD_AWAKENED);
-                                       act->inited = TRUE;
+                                       thread->started = TRUE;
                                }
-                               else
-                                       thread_wakeup_one(&act->suspend_count);
                        }
                }
                else
@@ -309,26 +250,11 @@ thread_resume(
        else
                result = KERN_TERMINATED;
 
-       act_unlock_thread(act);
+       thread_mtx_unlock(thread);
 
        return (result);
 }
 
-/* 
- * This routine walks toward the head of an RPC chain starting at
- * a specified thread activation. An alert bit is set and a special 
- * handler is installed for each thread it encounters.
- *
- * The target thread act and thread shuttle are already locked.
- */
-kern_return_t
-post_alert( 
-       register thread_act_t   act,
-       unsigned                                alert_bits)
-{
-       panic("post_alert");
-}
-
 /*
  *     thread_depress_abort:
  *
@@ -336,25 +262,21 @@ post_alert(
  */
 kern_return_t
 thread_depress_abort(
-       register thread_act_t   thr_act)
+       register thread_t       thread)
 {
-    register thread_t          thread;
-       kern_return_t                   result;
+       kern_return_t           result;
 
-    if (thr_act == THR_ACT_NULL)
+    if (thread == THREAD_NULL)
                return (KERN_INVALID_ARGUMENT);
 
-    thread = act_lock_thread(thr_act);
-    /* if activation is terminating, this operation is not meaningful */
-    if (!thr_act->active) {
-               act_unlock_thread(thr_act);
+    thread_mtx_lock(thread);
 
-               return (KERN_TERMINATED);
-    }
-
-    result = _mk_sp_thread_depress_abort(thread, FALSE);
+       if (thread->active)
+               result = thread_depress_abort_internal(thread);
+       else
+               result = KERN_TERMINATED;
 
-    act_unlock_thread(thr_act);
+    thread_mtx_unlock(thread);
 
        return (result);
 }
@@ -362,422 +284,291 @@ thread_depress_abort(
 
 /*
  * Indicate that the activation should run its
- * special handler to detect the condition.
+ * special handler to detect a condition.
  *
- * Called with act_lock held.
+ * Called with thread mutex held.
  */
-kern_return_t
+void
 act_abort(
-       thread_act_t    act, 
-       boolean_t       chain_break )
+       thread_t        thread)
 {
-       thread_t        thread = act->thread;
        spl_t           s = splsched();
 
-       assert(thread->top_act == act);
-
        thread_lock(thread);
+
        if (!(thread->state & TH_ABORT)) {
                thread->state |= TH_ABORT;
-               install_special_handler_locked(act);
-       } else {
-               thread->state &= ~TH_ABORT_SAFELY;
+               install_special_handler_locked(thread);
        }
+       else
+               thread->state &= ~TH_ABORT_SAFELY;
+
        thread_unlock(thread);
        splx(s);
-
-       return (KERN_SUCCESS);
 }
        
 kern_return_t
 thread_abort(
-       register thread_act_t   act)
+       register thread_t       thread)
 {
-       kern_return_t   result;
-       thread_t                thread;
+       kern_return_t   result = KERN_SUCCESS;
 
-       if (act == THR_ACT_NULL)
+       if (thread == THREAD_NULL)
                return (KERN_INVALID_ARGUMENT);
 
-       thread = act_lock_thread(act);
+       thread_mtx_lock(thread);
 
-       if (!act->active) {
-               act_unlock_thread(act);
-               return (KERN_TERMINATED);
+       if (thread->active) {
+               act_abort(thread);
+               clear_wait(thread, THREAD_INTERRUPTED);
        }
+       else
+               result = KERN_TERMINATED;
 
-       result = act_abort(act, FALSE);
-       clear_wait(thread, THREAD_INTERRUPTED);
-       act_unlock_thread(act);
+       thread_mtx_unlock(thread);
 
        return (result);
 }
 
 kern_return_t
 thread_abort_safely(
-       thread_act_t    act)
+       thread_t                thread)
 {
-       thread_t                thread;
-       kern_return_t   ret;
-       spl_t                   s;
+       kern_return_t   result = KERN_SUCCESS;
 
-       if (    act == THR_ACT_NULL )
+       if (thread == THREAD_NULL)
                return (KERN_INVALID_ARGUMENT);
 
-       thread = act_lock_thread(act);
+       thread_mtx_lock(thread);
 
-       if (!act->active) {
-               act_unlock_thread(act);
-               return (KERN_TERMINATED);
-       }
+       if (thread->active) {
+               spl_t           s = splsched();
 
-       s = splsched();
-       thread_lock(thread);
-       if (!thread->at_safe_point ||
-               clear_wait_internal(thread, THREAD_INTERRUPTED) != KERN_SUCCESS) {
-               if (!(thread->state & TH_ABORT)) {
-                       thread->state |= (TH_ABORT|TH_ABORT_SAFELY);
-                       install_special_handler_locked(act);
+               thread_lock(thread);
+               if (!thread->at_safe_point ||
+                       clear_wait_internal(thread, THREAD_INTERRUPTED) != KERN_SUCCESS) {
+                       if (!(thread->state & TH_ABORT)) {
+                               thread->state |= (TH_ABORT|TH_ABORT_SAFELY);
+                               install_special_handler_locked(thread);
+                       }
                }
+               thread_unlock(thread);
+               splx(s);
        }
-       thread_unlock(thread);
-       splx(s);
+       else
+               result = KERN_TERMINATED;
                
-       act_unlock_thread(act);
+       thread_mtx_unlock(thread);
 
-       return (KERN_SUCCESS);
+       return (result);
 }
 
 /*** backward compatibility hacks ***/
 #include <mach/thread_info.h>
 #include <mach/thread_special_ports.h>
 #include <ipc/ipc_port.h>
-#include <mach/thread_act_server.h>
 
 kern_return_t
 thread_info(
-       thread_act_t                    thr_act,
+       thread_t                                thread,
        thread_flavor_t                 flavor,
        thread_info_t                   thread_info_out,
        mach_msg_type_number_t  *thread_info_count)
 {
-       register thread_t               thread;
        kern_return_t                   result;
 
-       if (thr_act == THR_ACT_NULL)
+       if (thread == THREAD_NULL)
                return (KERN_INVALID_ARGUMENT);
 
-       thread = act_lock_thread(thr_act);
-       if (!thr_act->active) {
-               act_unlock_thread(thr_act);
+       thread_mtx_lock(thread);
 
-               return (KERN_TERMINATED);
-       }
-
-       result = thread_info_shuttle(thr_act, flavor,
-                                       thread_info_out, thread_info_count);
+       if (thread->active)
+               result = thread_info_internal(
+                                               thread, flavor, thread_info_out, thread_info_count);
+       else
+               result = KERN_TERMINATED;
 
-       act_unlock_thread(thr_act);
+       thread_mtx_unlock(thread);
 
        return (result);
 }
 
-/*
- *     Routine:        thread_get_special_port [kernel call]
- *     Purpose:
- *             Clones a send right for one of the thread's
- *             special ports.
- *     Conditions:
- *             Nothing locked.
- *     Returns:
- *             KERN_SUCCESS            Extracted a send right.
- *             KERN_INVALID_ARGUMENT   The thread is null.
- *             KERN_FAILURE            The thread is dead.
- *             KERN_INVALID_ARGUMENT   Invalid special port.
- */
-
 kern_return_t
-thread_get_special_port(
-       thread_act_t    thr_act,
-       int             which,
-       ipc_port_t      *portp)
+thread_get_state(
+       register thread_t               thread,
+       int                                             flavor,
+       thread_state_t                  state,                  /* pointer to OUT array */
+       mach_msg_type_number_t  *state_count)   /*IN/OUT*/
 {
-       ipc_port_t      *whichp;
-       ipc_port_t      port;
-       thread_t        thread;
-
-#if    MACH_ASSERT
-       if (watchacts & WA_PORT)
-           printf("thread_get_special_port(thr_act=%x, which=%x port@%x=%x\n",
-               thr_act, which, portp, (portp ? *portp : 0));
-#endif /* MACH_ASSERT */
-
-       if (!thr_act)
-               return KERN_INVALID_ARGUMENT;
-       thread = act_lock_thread(thr_act);
-       switch (which) {
-               case THREAD_KERNEL_PORT:
-                       whichp = &thr_act->ith_sself;
-                       break;
+       kern_return_t           result = KERN_SUCCESS;
 
-               default:
-                       act_unlock_thread(thr_act);
-                       return KERN_INVALID_ARGUMENT;
-       }
+       if (thread == THREAD_NULL)
+               return (KERN_INVALID_ARGUMENT);
 
-       if (!thr_act->active) {
-               act_unlock_thread(thr_act);
-               return KERN_FAILURE;
-       }
+       thread_mtx_lock(thread);
 
-       port = ipc_port_copy_send(*whichp);
-       act_unlock_thread(thr_act);
+       if (thread->active) {
+               if (thread != current_thread()) {
+                       thread_hold(thread);
 
-       *portp = port;
-       return KERN_SUCCESS;
-}
+                       thread_mtx_unlock(thread);
 
-/*
- *     Routine:        thread_set_special_port [kernel call]
- *     Purpose:
- *             Changes one of the thread's special ports,
- *             setting it to the supplied send right.
- *     Conditions:
- *             Nothing locked.  If successful, consumes
- *             the supplied send right.
- *     Returns:
- *             KERN_SUCCESS            Changed the special port.
- *             KERN_INVALID_ARGUMENT   The thread is null.
- *             KERN_FAILURE            The thread is dead.
- *             KERN_INVALID_ARGUMENT   Invalid special port.
- */
-
-kern_return_t
-thread_set_special_port(
-       thread_act_t    thr_act,
-       int             which,
-       ipc_port_t      port)
-{
-       ipc_port_t      *whichp;
-       ipc_port_t      old;
-       thread_t        thread;
-
-#if    MACH_ASSERT
-       if (watchacts & WA_PORT)
-               printf("thread_set_special_port(thr_act=%x,which=%x,port=%x\n",
-                       thr_act, which, port);
-#endif /* MACH_ASSERT */
-
-       if (thr_act == 0)
-               return KERN_INVALID_ARGUMENT;
-
-       thread = act_lock_thread(thr_act);
-       switch (which) {
-               case THREAD_KERNEL_PORT:
-                       whichp = &thr_act->ith_self;
-                       break;
-
-               default:
-                       act_unlock_thread(thr_act);
-                       return KERN_INVALID_ARGUMENT;
-       }
+                       if (thread_stop(thread)) {
+                               thread_mtx_lock(thread);
+                               result = machine_thread_get_state(
+                                                                               thread, flavor, state, state_count);
+                               thread_unstop(thread);
+                       }
+                       else {
+                               thread_mtx_lock(thread);
+                               result = KERN_ABORTED;
+                       }
 
-       if (!thr_act->active) {
-               act_unlock_thread(thr_act);
-               return KERN_FAILURE;
+                       thread_release(thread);
+               }
+               else
+                       result = machine_thread_get_state(
+                                                                       thread, flavor, state, state_count);
        }
+       else
+               result = KERN_TERMINATED;
 
-       old = *whichp;
-       *whichp = port;
-       act_unlock_thread(thr_act);
+       thread_mtx_unlock(thread);
 
-       if (IP_VALID(old))
-               ipc_port_release_send(old);
-       return KERN_SUCCESS;
+       return (result);
 }
 
 /*
- *  thread state should always be accessible by locking the thread
- *  and copying it.  The activation messes things up so for right
- *  now if it's not the top of the chain, use a special handler to
- *  get the information when the shuttle returns to the activation.
+ *     Change thread's machine-dependent state.  Called with nothing
+ *     locked.  Returns same way.
  */
 kern_return_t
-thread_get_state(
-       register thread_act_t   act,
+thread_set_state(
+       register thread_t               thread,
        int                                             flavor,
-       thread_state_t                  state,                  /* pointer to OUT array */
-       mach_msg_type_number_t  *state_count)   /*IN/OUT*/
+       thread_state_t                  state,
+       mach_msg_type_number_t  state_count)
 {
        kern_return_t           result = KERN_SUCCESS;
-       thread_t                        thread;
 
-       if (act == THR_ACT_NULL || act == current_act())
+       if (thread == THREAD_NULL)
                return (KERN_INVALID_ARGUMENT);
 
-       thread = act_lock_thread(act);
+       thread_mtx_lock(thread);
 
-       if (!act->active) {
-               act_unlock_thread(act);
-               return (KERN_TERMINATED);
-       }
+       if (thread->active) {
+               if (thread != current_thread()) {
+                       thread_hold(thread);
 
-       thread_hold(act);
+                       thread_mtx_unlock(thread);
 
-       for (;;) {
-               thread_t                        thread1;
-
-               if (    thread == THREAD_NULL           ||
-                               thread->top_act != act          )
-                       break;
-               act_unlock_thread(act);
+                       if (thread_stop(thread)) {
+                               thread_mtx_lock(thread);
+                               result = machine_thread_set_state(
+                                                                               thread, flavor, state, state_count);
+                               thread_unstop(thread);
+                       }
+                       else {
+                               thread_mtx_lock(thread);
+                               result = KERN_ABORTED;
+                       }
 
-               if (!thread_stop(thread)) {
-                       result = KERN_ABORTED;
-                       (void)act_lock_thread(act);
-                       thread = THREAD_NULL;
-                       break;
+                       thread_release(thread);
                }
-                       
-               thread1 = act_lock_thread(act);
-               if (thread1 == thread)
-                       break;
-
-               thread_unstop(thread);
-               thread = thread1;
+               else
+                       result = machine_thread_set_state(
+                                                                       thread, flavor, state, state_count);
        }
+       else
+               result = KERN_TERMINATED;
 
-       if (result == KERN_SUCCESS)
-               result = act_machine_get_state(act, flavor, state, state_count);
-
-       if (    thread != THREAD_NULL           &&
-                       thread->top_act == act          )
-               thread_unstop(thread);
-
-       thread_release(act);
-       act_unlock_thread(act);
+       thread_mtx_unlock(thread);
 
        return (result);
 }
-
 /*
- *     Change thread's machine-dependent state.  Called with nothing
- *     locked.  Returns same way.
+ * Kernel-internal "thread" interfaces used outside this file:
+ */
+
+/* Initialize (or re-initialize) a thread state.  Called from execve
+ * with nothing locked, returns same way.
  */
 kern_return_t
-thread_set_state(
-       register thread_act_t   act,
-       int                                             flavor,
-       thread_state_t                  state,
-       mach_msg_type_number_t  state_count)
+thread_state_initialize(
+       register thread_t               thread)
 {
        kern_return_t           result = KERN_SUCCESS;
-       thread_t                        thread;
 
-       if (act == THR_ACT_NULL || act == current_act())
+       if (thread == THREAD_NULL)
                return (KERN_INVALID_ARGUMENT);
 
-       thread = act_lock_thread(act);
-
-       if (!act->active) {
-               act_unlock_thread(act);
-               return (KERN_TERMINATED);
-       }
+       thread_mtx_lock(thread);
 
-       thread_hold(act);
+       if (thread->active) {
+               if (thread != current_thread()) {
+                       thread_hold(thread);
 
-       for (;;) {
-               thread_t                        thread1;
+                       thread_mtx_unlock(thread);
 
-               if (    thread == THREAD_NULL           ||
-                               thread->top_act != act          )
-                       break;
-               act_unlock_thread(act);
+                       if (thread_stop(thread)) {
+                               thread_mtx_lock(thread);
+                               result = machine_thread_state_initialize( thread );
+                               thread_unstop(thread);
+                       }
+                       else {
+                               thread_mtx_lock(thread);
+                               result = KERN_ABORTED;
+                       }
 
-               if (!thread_stop(thread)) {
-                       result = KERN_ABORTED;
-                       (void)act_lock_thread(act);
-                       thread = THREAD_NULL;
-                       break;
+                       thread_release(thread);
                }
-
-               thread1 = act_lock_thread(act);
-               if (thread1 == thread)
-                       break;
-
-               thread_unstop(thread);
-               thread = thread1;
+               else
+            result = machine_thread_state_initialize( thread );
        }
+       else
+               result = KERN_TERMINATED;
 
-       if (result == KERN_SUCCESS)
-               result = act_machine_set_state(act, flavor, state, state_count);
-
-       if (    thread != THREAD_NULL           &&
-                       thread->top_act == act          )
-           thread_unstop(thread);
-
-       thread_release(act);
-       act_unlock_thread(act);
+       thread_mtx_unlock(thread);
 
        return (result);
 }
 
-/*
- * Kernel-internal "thread" interfaces used outside this file:
- */
 
 kern_return_t
 thread_dup(
-       register thread_act_t   target)
+       register thread_t       target)
 {
+       thread_t                        self = current_thread();
        kern_return_t           result = KERN_SUCCESS;
-       thread_act_t            self = current_act();
-       thread_t                        thread;
 
-       if (target == THR_ACT_NULL || target == self)
+       if (target == THREAD_NULL || target == self)
                return (KERN_INVALID_ARGUMENT);
 
-       thread = act_lock_thread(target);
-
-       if (!target->active) {
-               act_unlock_thread(target);
-               return (KERN_TERMINATED);
-       }
-
-       thread_hold(target);
+       thread_mtx_lock(target);
 
-       for (;;) {
-               thread_t                        thread1;
+       if (target->active) {
+               thread_hold(target);
 
-               if (    thread == THREAD_NULL           ||
-                               thread->top_act != target       )
-                       break;
-               act_unlock_thread(target);
+               thread_mtx_unlock(target);
 
-               if (!thread_stop(thread)) {
+               if (thread_stop(target)) {
+                       thread_mtx_lock(target);
+                       result = machine_thread_dup(self, target);
+                       thread_unstop(target);
+               }
+               else {
+                       thread_mtx_lock(target);
                        result = KERN_ABORTED;
-                       (void)act_lock_thread(target);
-                       thread = THREAD_NULL;
-                       break;
                }
 
-               thread1 = act_lock_thread(target);
-               if (thread1 == thread)
-                       break;
-
-               thread_unstop(thread);
-               thread = thread1;
+               thread_release(target);
        }
+       else
+               result = KERN_TERMINATED;
 
-       if (result == KERN_SUCCESS)
-               result = act_thread_dup(self, target);
-
-       if (    thread != THREAD_NULL           &&
-                       thread->top_act == target       )
-           thread_unstop(thread);
-
-       thread_release(target);
-       act_unlock_thread(target);
+       thread_mtx_unlock(target);
 
        return (result);
 }
@@ -791,29 +582,13 @@ thread_dup(
  */
 kern_return_t
 thread_setstatus(
-       register thread_act_t   act,
+       register thread_t               thread,
        int                                             flavor,
        thread_state_t                  tstate,
        mach_msg_type_number_t  count)
 {
-       kern_return_t           result = KERN_SUCCESS;
-       thread_t                        thread;
-
-       thread = act_lock_thread(act);
-
-       if (    act != current_act()                    &&
-                       (act->suspend_count == 0        ||
-                        thread == THREAD_NULL          ||
-                        (thread->state & TH_RUN)       ||
-                        thread->top_act != act)                )
-               result = KERN_FAILURE;
 
-       if (result == KERN_SUCCESS)
-               result = act_machine_set_state(act, flavor, tstate, count);
-
-       act_unlock_thread(act);
-
-       return (result);
+       return (thread_set_state(thread, flavor, tstate, count));
 }
 
 /*
@@ -823,610 +598,117 @@ thread_setstatus(
  */
 kern_return_t
 thread_getstatus(
-       register thread_act_t   act,
+       register thread_t               thread,
        int                                             flavor,
        thread_state_t                  tstate,
        mach_msg_type_number_t  *count)
 {
-       kern_return_t           result = KERN_SUCCESS;
-       thread_t                        thread;
-
-       thread = act_lock_thread(act);
-
-       if (    act != current_act()                    &&
-                       (act->suspend_count == 0        ||
-                        thread == THREAD_NULL          ||
-                        (thread->state & TH_RUN)       ||
-                        thread->top_act != act)                )
-               result = KERN_FAILURE;
-
-       if (result == KERN_SUCCESS)
-               result = act_machine_get_state(act, flavor, tstate, count);
-
-       act_unlock_thread(act);
-
-       return (result);
-}
-
-/*
- * Kernel-internal thread_activation interfaces used outside this file:
- */
-
-/*
- * act_init()  - Initialize activation handling code
- */
-void
-act_init()
-{
-       thr_act_zone = zinit(
-                       sizeof(struct thread_activation),
-                       ACT_MAX * sizeof(struct thread_activation), /* XXX */
-                       ACT_CHUNK * sizeof(struct thread_activation),
-                       "activations");
-       first_act = TRUE;
-       act_machine_init();
-}
-
-
-/*
- * act_create  - Create a new activation in a specific task.
- */
-kern_return_t
-act_create(task_t task,
-           thread_act_t *new_act)
-{
-       thread_act_t thr_act;
-       int rc;
-       vm_map_t map;
-
-       if (first_act) {
-               thr_act = &pageout_act;
-               first_act = FALSE;
-       } else
-               thr_act = (thread_act_t)zalloc(thr_act_zone);
-       if (thr_act == 0)
-               return(KERN_RESOURCE_SHORTAGE);
-
-#if    MACH_ASSERT
-       if (watchacts & WA_ACT_LNK)
-               printf("act_create(task=%x,thr_act@%x=%x)\n",
-                       task, new_act, thr_act);
-#endif /* MACH_ASSERT */
-
-       /* Start by zeroing everything; then init non-zero items only */
-       bzero((char *)thr_act, sizeof(*thr_act));
-
-       if (thr_act == &pageout_act)
-               thr_act->thread = &pageout_thread;
-
-#ifdef MACH_BSD
-       {
-               /*
-                * Take care of the uthread allocation
-                * do it early in order to make KERN_RESOURCE_SHORTAGE
-                * handling trivial
-                * uthread_alloc() will bzero the storage allocated.
-                */
-               extern void *uthread_alloc(task_t, thread_act_t);
-
-               thr_act->uthread = uthread_alloc(task, thr_act);
-               if(thr_act->uthread == 0) {
-                       /* Put the thr_act back on the thr_act zone */
-                       zfree(thr_act_zone, (vm_offset_t)thr_act);
-                       return(KERN_RESOURCE_SHORTAGE);
-               }
-       }
-#endif /* MACH_BSD */
-
-       /*
-        * Start with one reference for the caller and one for the
-        * act being alive.
-        */
-       act_lock_init(thr_act);
-       thr_act->ref_count = 2;
-
-       /* Latch onto the task.  */
-       thr_act->task = task;
-       task_reference(task);
-
-       /* special_handler will always be last on the returnhandlers list.  */
-       thr_act->special_handler.next = 0;
-       thr_act->special_handler.handler = special_handler;
-
-#if    MACH_PROF
-       thr_act->act_profiled = FALSE;
-       thr_act->act_profiled_own = FALSE;
-       thr_act->profil_buffer = NULLPROFDATA;
-#endif
-
-       /* Initialize the held_ulocks queue as empty */
-       queue_init(&thr_act->held_ulocks);
-
-       /* Inherit the profiling status of the parent task */
-       act_prof_init(thr_act, task);
-
-       ipc_thr_act_init(task, thr_act);
-       act_machine_create(task, thr_act);
-
-       /*
-        * If thr_act created in kernel-loaded task, alter its saved
-        * state to so indicate
-        */
-       if (task->kernel_loaded) {
-               act_user_to_kernel(thr_act);
-       }
-
-       /* Cache the task's map and take a reference to it */
-       map = task->map;
-       thr_act->map = map;
-
-       /* Inline vm_map_reference cause we don't want to increment res_count */
-       mutex_lock(&map->s_lock);
-       map->ref_count++;
-       mutex_unlock(&map->s_lock);
-
-       *new_act = thr_act;
-       return KERN_SUCCESS;
-}
-
-/*
- * act_free    - called when an thr_act's ref_count drops to zero.
- *
- * This can only happen after the activation has been reaped, and
- * all other references to it have gone away.  We can now release
- * the last critical resources, unlink the activation from the
- * task, and release the reference on the thread shuttle itself.
- *
- * Called with activation locked.
- */
-#if    MACH_ASSERT
-int    dangerous_bzero = 1;    /* paranoia & safety */
-#endif
-
-void
-act_free(thread_act_t thr_act)
-{
-       task_t          task;
-       thread_t        thr;
-       vm_map_t        map;
-       unsigned int    ref;
-       void * task_proc;
-
-#if    MACH_ASSERT
-       if (watchacts & WA_EXIT)
-               printf("act_free(%x(%d)) thr=%x tsk=%x(%d) %sactive\n",
-                       thr_act, thr_act->ref_count, thr_act->thread,
-                       thr_act->task,
-                       thr_act->task ? thr_act->task->ref_count : 0,
-                       thr_act->active ? " " : " !");
-#endif /* MACH_ASSERT */
-
-       assert(!thr_act->active);
-
-       task = thr_act->task;
-       task_lock(task);
-
-       task_proc = task->bsd_info;
-       if (thr = thr_act->thread) {
-               time_value_t    user_time, system_time;
-
-               thread_read_times(thr, &user_time, &system_time);
-               time_value_add(&task->total_user_time, &user_time);
-               time_value_add(&task->total_system_time, &system_time);
-       
-               /* Unlink the thr_act from the task's thr_act list,
-                * so it doesn't appear in calls to task_threads and such.
-                * The thr_act still keeps its ref on the task, however.
-                */
-               queue_remove(&task->thr_acts, thr_act, thread_act_t, thr_acts);
-               thr_act->thr_acts.next = NULL;
-               task->thr_act_count--;
-               task->res_act_count--;
-               task_unlock(task);
-               task_deallocate(task);
-               thread_deallocate(thr);
-               act_machine_destroy(thr_act);
-       } else {
-               /*
-                * Must have never really gotten started
-                * no unlinking from the task and no need
-                * to free the shuttle.
-                */
-               task_unlock(task);
-               task_deallocate(task);
-       }
-
-       act_prof_deallocate(thr_act);
-       ipc_thr_act_terminate(thr_act);
-
-       /*
-        * Drop the cached map reference.
-        * Inline version of vm_map_deallocate() because we
-        * don't want to decrement the map's residence count here.
-        */
-       map = thr_act->map;
-       mutex_lock(&map->s_lock);
-       ref = --map->ref_count;
-       mutex_unlock(&map->s_lock);
-       if (ref == 0)
-               vm_map_destroy(map);
-
-#ifdef MACH_BSD 
-       {
-               /*
-                * Free uthread BEFORE the bzero.
-                * Not doing so will result in a leak.
-                */
-               extern void uthread_free(task_t, void *, void *);
-
-               void *ut = thr_act->uthread;
-               thr_act->uthread = 0;
-               uthread_free(task, ut, task_proc);
-       }
-#endif  /* MACH_BSD */   
-
-#if    MACH_ASSERT
-       if (dangerous_bzero)    /* dangerous if we're still using it! */
-               bzero((char *)thr_act, sizeof(*thr_act));
-#endif /* MACH_ASSERT */
-       /* Put the thr_act back on the thr_act zone */
-       zfree(thr_act_zone, (vm_offset_t)thr_act);
-}
-
-
-/*
- * act_attach  - Attach an thr_act to the top of a thread ("push the stack").
- *
- * The thread_shuttle must be either the current one or a brand-new one.
- * Assumes the thr_act is active but not in use.
- *
- * Already locked: thr_act plus "appropriate" thread-related locks
- * (see act_lock_thread()).
- */
-void 
-act_attach(
-       thread_act_t    thr_act,
-       thread_t        thread,
-       unsigned        init_alert_mask)
-{
-        thread_act_t    lower;
-
-#if    MACH_ASSERT
-       assert(thread == current_thread() || thread->top_act == THR_ACT_NULL);
-       if (watchacts & WA_ACT_LNK)
-               printf("act_attach(thr_act %x(%d) thread %x(%d) mask %d)\n",
-                      thr_act, thr_act->ref_count, thread, thread->ref_count,
-                      init_alert_mask);
-#endif /* MACH_ASSERT */
-
-       /* 
-        *      Chain the thr_act onto the thread's thr_act stack.  
-        *      Set mask and auto-propagate alerts from below.
-        */
-       thr_act->ref_count++;
-       thr_act->thread = thread;
-       thr_act->higher = THR_ACT_NULL;  /*safety*/
-       thr_act->alerts = 0;
-       thr_act->alert_mask = init_alert_mask;
-       lower = thr_act->lower = thread->top_act;
-
-        if (lower != THR_ACT_NULL) {
-                lower->higher = thr_act;
-                thr_act->alerts = (lower->alerts & init_alert_mask);
-        }
-
-       thread->top_act = thr_act;
-}
-
-/*
- *     act_detach      
- *
- *     Remove the current thr_act from the top of the current thread, i.e.
- *     "pop the stack". Assumes already locked: thr_act plus "appropriate"
- *     thread-related locks (see act_lock_thread).
- */
-void 
-act_detach(
-       thread_act_t    cur_act)
-{
-       thread_t        cur_thread = cur_act->thread;
-
-#if    MACH_ASSERT
-       if (watchacts & (WA_EXIT|WA_ACT_LNK))
-               printf("act_detach: thr_act %x(%d), thrd %x(%d) task=%x(%d)\n",
-                      cur_act, cur_act->ref_count,
-                      cur_thread, cur_thread->ref_count,
-                      cur_act->task,
-                      cur_act->task ? cur_act->task->ref_count : 0);
-#endif /* MACH_ASSERT */
-
-       /* Unlink the thr_act from the thread's thr_act stack */
-       cur_thread->top_act = cur_act->lower;
-       cur_act->thread = 0;
-       cur_act->ref_count--;
-       assert(cur_act->ref_count > 0);
-
-#if    MACH_ASSERT
-       cur_act->lower = cur_act->higher = THR_ACT_NULL; 
-       if (cur_thread->top_act)
-               cur_thread->top_act->higher = THR_ACT_NULL;
-#endif /* MACH_ASSERT */
-
-       return;
-}
-
-
-/*
- * Synchronize a thread operation with migration.
- * Called with nothing locked.
- * Returns with thr_act locked.
- */
-thread_t
-act_lock_thread(
-       thread_act_t thr_act)
-{
-
-       /*
-        * JMM - We have moved away from explicit RPC locks
-        * and towards a generic migration approach.  The wait
-        * queue lock will be the point of synchronization for
-        * the shuttle linkage when this is rolled out.  Until
-        * then, just lock the act.
-        */
-       act_lock(thr_act);
-       return (thr_act->thread);
-}
-
-/*
- * Unsynchronize with migration (i.e., undo an act_lock_thread() call).
- * Called with thr_act locked, plus thread locks held that are
- * "correct" for thr_act's state.  Returns with nothing locked.
- */
-void
-act_unlock_thread(thread_act_t thr_act)
-{
-       act_unlock(thr_act);
-}
-
-/*
- * Synchronize with migration given a pointer to a shuttle (instead of an
- * activation).  Called with nothing locked; returns with all
- * "appropriate" thread-related locks held (see act_lock_thread()).
- */
-thread_act_t
-thread_lock_act(
-       thread_t        thread)
-{
-       thread_act_t    thr_act;
-
-       while (1) {
-               thr_act = thread->top_act;
-               if (!thr_act)
-                       break;
-               if (!act_lock_try(thr_act)) {
-                       mutex_pause();
-                       continue;
-               }
-               break;
-       }
-       return (thr_act);
-}
-
-/*
- * Unsynchronize with an activation starting from a pointer to
- * a shuttle.
- */
-void
-thread_unlock_act(
-       thread_t        thread)
-{
-       thread_act_t    thr_act;
-
-       if (thr_act = thread->top_act) {
-               act_unlock(thr_act);
-       }
+       return (thread_get_state(thread, flavor, tstate, count));
 }
 
 /*
- * switch_act
+ * install_special_handler:
  *
- * If a new activation is given, switch to it. If not,
- * switch to the lower activation (pop). Returns the old
- * activation. This is for migration support.
- */
-thread_act_t
-switch_act( 
-       thread_act_t act)
-{
-       thread_t        thread;
-       thread_act_t    old, new;
-       unsigned        cpu;
-       spl_t           spl;
-
-
-       disable_preemption();
-
-       cpu = cpu_number();
-       thread  = current_thread();
-
-       /*
-        *      Find the old and new activation for switch.
-        */
-       old = thread->top_act;
-
-       if (act) {
-               new = act;
-                new->thread = thread;
-       }
-       else {
-               new = old->lower;
-       }
-
-       assert(new != THR_ACT_NULL);
-       assert(cpu_to_processor(cpu)->cpu_data->active_thread == thread);
-       active_kloaded[cpu] = (new->kernel_loaded) ? new : 0;
-
-       /* This is where all the work happens */
-       machine_switch_act(thread, old, new, cpu);
-
-       /*
-        *      Push or pop an activation on the chain.
-        */
-       if (act) {
-               act_attach(new, thread, 0);
-       }
-       else {
-               act_detach(old);
-       }
-
-        enable_preemption();
-
-       return(old);
-}
-
-/*
- * install_special_handler
  *     Install the special returnhandler that handles suspension and
  *     termination, if it hasn't been installed already.
  *
- * Already locked: RPC-related locks for thr_act, but not
- * scheduling lock (thread_lock()) of the associated thread.
+ *     Called with the thread mutex held.
  */
 void
 install_special_handler(
-       thread_act_t    thr_act)
+       thread_t                thread)
 {
-       spl_t           spl;
-       thread_t        thread = thr_act->thread;
-
-#if    MACH_ASSERT
-       if (watchacts & WA_ACT_HDLR)
-           printf("act_%x: install_special_hdlr(%x)\n",current_act(),thr_act);
-#endif /* MACH_ASSERT */
+       spl_t           s = splsched();
 
-       spl = splsched();
        thread_lock(thread);
-       install_special_handler_locked(thr_act);
+       install_special_handler_locked(thread);
        thread_unlock(thread);
-       splx(spl);
+       splx(s);
 }
 
 /*
- * install_special_handler_locked
+ * install_special_handler_locked:
+ *
  *     Do the work of installing the special_handler.
  *
- * Already locked: RPC-related locks for thr_act, plus the
- * scheduling lock (thread_lock()) of the associated thread.
+ *     Called with the thread mutex and scheduling lock held.
  */
 void
 install_special_handler_locked(
-       thread_act_t                            act)
+       thread_t                                thread)
 {
-       thread_t                thread = act->thread;
        ReturnHandler   **rh;
 
        /* The work handler must always be the last ReturnHandler on the list,
           because it can do tricky things like detach the thr_act.  */
-       for (rh = &act->handlers; *rh; rh = &(*rh)->next)
+       for (rh = &thread->handlers; *rh; rh = &(*rh)->next)
                continue;
-       if (rh != &act->special_handler.next)
-               *rh = &act->special_handler;
-
-       if (act == thread->top_act) {
-               /*
-                * Temporarily undepress, so target has
-                * a chance to do locking required to
-                * block itself in special_handler().
-                */
-               if (thread->sched_mode & TH_MODE_ISDEPRESSED)
-                       compute_priority(thread, TRUE);
-       }
 
-       thread_ast_set(act, AST_APC);
-       if (act == current_act())
-               ast_propagate(act->ast);
+       if (rh != &thread->special_handler.next)
+               *rh = &thread->special_handler;
+
+       /*
+        * Temporarily undepress, so target has
+        * a chance to do locking required to
+        * block itself in special_handler().
+        */
+       if (thread->sched_mode & TH_MODE_ISDEPRESSED)
+               compute_priority(thread, TRUE);
+
+       thread_ast_set(thread, AST_APC);
+
+       if (thread == current_thread())
+               ast_propagate(thread->ast);
        else {
                processor_t             processor = thread->last_processor;
 
-               if (    processor != PROCESSOR_NULL                                             &&
-                               processor->state == PROCESSOR_RUNNING                   &&
-                               processor->cpu_data->active_thread == thread    )
+               if (    processor != PROCESSOR_NULL                                     &&
+                               processor->state == PROCESSOR_RUNNING           &&
+                               processor->active_thread == thread                      )
                        cause_ast_check(processor);
        }
 }
 
-kern_return_t
-thread_apc_set(
-       thread_act_t                    act,
-       thread_apc_handler_t    apc)
-{
-       extern thread_apc_handler_t     bsd_ast;
-
-       assert(apc == bsd_ast);
-       return (KERN_FAILURE);
-}
-
-kern_return_t
-thread_apc_clear(
-       thread_act_t                    act,
-       thread_apc_handler_t    apc)
-{
-       extern thread_apc_handler_t     bsd_ast;
-
-       assert(apc == bsd_ast);
-       return (KERN_FAILURE);
-}
-
 /*
  * Activation control support routines internal to this file:
  */
 
-/*
- * act_execute_returnhandlers()        - does just what the name says
- *
- * This is called by system-dependent code when it detects that
- * thr_act->handlers is non-null while returning into user mode.
- */
 void
 act_execute_returnhandlers(void)
 {
-       thread_act_t    act = current_act();
-
-#if    MACH_ASSERT
-       if (watchacts & WA_ACT_HDLR)
-               printf("execute_rtn_hdlrs: act=%x\n", act);
-#endif /* MACH_ASSERT */
+       thread_t        thread = current_thread();
 
-       thread_ast_clear(act, AST_APC);
+       thread_ast_clear(thread, AST_APC);
        spllo();
 
        for (;;) {
                ReturnHandler   *rh;
-               thread_t                thread = act_lock_thread(act);
+
+               thread_mtx_lock(thread);
 
                (void)splsched();
                thread_lock(thread);
-               rh = act->handlers;
-               if (!rh) {
+
+               rh = thread->handlers;
+               if (rh != NULL) {
+                       thread->handlers = rh->next;
+
                        thread_unlock(thread);
                        spllo();
-                       act_unlock_thread(act);
-                       return;
-               }
-               act->handlers = rh->next;
-               thread_unlock(thread);
-               spllo();
-               act_unlock_thread(act);
 
-#if    MACH_ASSERT
-               if (watchacts & WA_ACT_HDLR)
-                   printf( (rh == &act->special_handler) ?
-                       "\tspecial_handler\n" : "\thandler=%x\n", rh->handler);
-#endif /* MACH_ASSERT */
+                       thread_mtx_unlock(thread);
 
-               /* Execute it */
-               (*rh->handler)(rh, act);
+                       /* Execute it */
+                       (*rh->handler)(rh, thread);
+               }
+               else
+                       break;
        }
+
+       thread_unlock(thread);
+       spllo();
+
+       thread_mtx_unlock(thread);
 }
 
 /*
@@ -1441,12 +723,13 @@ act_execute_returnhandlers(void)
 void
 special_handler_continue(void)
 {
-       thread_act_t            self = current_act();
+       thread_t                thread = current_thread();
 
-       if (self->suspend_count > 0)
-               install_special_handler(self);
+       thread_mtx_lock(thread);
+
+       if (thread->suspend_count > 0)
+               install_special_handler(thread);
        else {
-               thread_t                thread = self->thread;
                spl_t                   s = splsched();
 
                thread_lock(thread);
@@ -1461,6 +744,8 @@ special_handler_continue(void)
                splx(s);
        }
 
+       thread_mtx_unlock(thread);
+
        thread_exception_return();
        /*NOTREACHED*/
 }
@@ -1471,13 +756,12 @@ special_handler_continue(void)
  */
 void
 special_handler(
-       ReturnHandler   *rh,
-       thread_act_t    self)
+       __unused ReturnHandler  *rh,
+       thread_t                                thread)
 {
-       thread_t                thread = act_lock_thread(self);
-       spl_t                   s;
+       spl_t           s;
 
-       assert(thread != THREAD_NULL);
+       thread_mtx_lock(thread);
 
        s = splsched();
        thread_lock(thread);
@@ -1485,322 +769,80 @@ special_handler(
        thread_unlock(thread);
        splx(s);
 
-       /*
-        * If someone has killed this invocation,
-        * invoke the return path with a terminated exception.
-        */
-       if (!self->active) {
-               act_unlock_thread(self);
-               act_machine_return(KERN_TERMINATED);
-       }
-
        /*
         * If we're suspended, go to sleep and wait for someone to wake us up.
         */
-       if (self->suspend_count > 0) {
-               if (self->handlers == NULL) {
-                       assert_wait(&self->suspend_count, THREAD_ABORTSAFE);
-                       act_unlock_thread(self);
-                       thread_block(special_handler_continue);
-                       /* NOTREACHED */
-               }
-
-               act_unlock_thread(self);
-
-               special_handler_continue();
-               /*NOTREACHED*/
-       }
-
-       act_unlock_thread(self);
-}
-
-/*
- * Update activation that belongs to a task created via kernel_task_create().
- */
-void
-act_user_to_kernel(
-       thread_act_t    thr_act)
-{
-       pcb_user_to_kernel(thr_act);
-       thr_act->kernel_loading = TRUE;
-}
-
-/*
- * Already locked: activation (shuttle frozen within)
- *
- * Mark an activation inactive, and prepare it to terminate
- * itself.
- */
-static void
-act_disable(
-       thread_act_t    thr_act)
-{
-
-#if    MACH_ASSERT
-       if (watchacts & WA_EXIT) {
-               printf("act_%x: act_disable_tl(thr_act=%x(%d))%sactive",
-                              current_act(), thr_act, thr_act->ref_count,
-                                       (thr_act->active ? " " : " !"));
-               printf("\n");
-               (void) dump_act(thr_act);
-       }
-#endif /* MACH_ASSERT */
+       if (thread->active) {
+               if (thread->suspend_count > 0) {
+                       if (thread->handlers == NULL) {
+                               assert_wait(&thread->suspend_count, THREAD_ABORTSAFE);
+                               thread_mtx_unlock(thread);
+                               thread_block((thread_continue_t)special_handler_continue);
+                               /*NOTREACHED*/
+                       }
 
-       thr_act->active = 0;
+                       thread_mtx_unlock(thread);
 
-       /* Drop the thr_act reference taken for being active.
-        * (There is still at least one reference left:
-        * the one we were passed.)
-        * Inline the deallocate because thr_act is locked.
-        */
-       act_locked_act_deallocate(thr_act);
-}
-
-/*
- * act_alert   - Register an alert from this activation.
- *
- * Each set bit is propagated upward from (but not including) this activation,
- * until the top of the chain is reached or the bit is masked.
- */
-kern_return_t
-act_alert(thread_act_t thr_act, unsigned alerts)
-{
-       thread_t thread = act_lock_thread(thr_act);
-
-#if    MACH_ASSERT
-       if (watchacts & WA_ACT_LNK)
-               printf("act_alert %x: %x\n", thr_act, alerts);
-#endif /* MACH_ASSERT */
-
-       if (thread) {
-               thread_act_t act_up = thr_act;
-               while ((alerts) && (act_up != thread->top_act)) {
-                       act_up = act_up->higher;
-                       alerts &= act_up->alert_mask;
-                       act_up->alerts |= alerts;
+                       special_handler_continue();
+                       /*NOTREACHED*/
                }
-               /*
-                * XXXX If we reach the top, and it is blocked in glue
-                * code, do something to kick it.  XXXX
-                */
        }
-       act_unlock_thread(thr_act);
-
-       return KERN_SUCCESS;
-}
-
-kern_return_t act_alert_mask(thread_act_t thr_act, unsigned alert_mask)
-{
-       panic("act_alert_mask NOT YET IMPLEMENTED\n");
-       return KERN_SUCCESS;
-}
-
-typedef struct GetSetState {
-       struct ReturnHandler rh;
-       int flavor;
-       void *state;
-       int *pcount;
-       int result;
-} GetSetState;
-
-/* Local Forward decls */
-kern_return_t get_set_state(
-                       thread_act_t thr_act, int flavor,
-                       thread_state_t state, int *pcount,
-                       void (*handler)(ReturnHandler *rh, thread_act_t thr_act));
-void get_state_handler(ReturnHandler *rh, thread_act_t thr_act);
-void set_state_handler(ReturnHandler *rh, thread_act_t thr_act);
-
-/*
- * get_set_state(thr_act ...)
- *
- * General code to install g/set_state handler.
- * Called with thr_act's act_lock() and "appropriate"
- * thread-related locks held.  (See act_lock_thread().)
- */
-kern_return_t
-get_set_state(
-       thread_act_t            act,
-       int                                     flavor,
-       thread_state_t          state,
-       int                                     *pcount,
-       void                            (*handler)(
-                                                       ReturnHandler   *rh,
-                                                       thread_act_t     act))
-{
-       GetSetState                     gss;
-
-       /* Initialize a small parameter structure */
-       gss.rh.handler = handler;
-       gss.flavor = flavor;
-       gss.state = state;
-       gss.pcount = pcount;
-       gss.result = KERN_ABORTED;      /* iff wait below is interrupted */
-
-       /* Add it to the thr_act's return handler list */
-       gss.rh.next = act->handlers;
-       act->handlers = &gss.rh;
-
-       act_set_apc(act);
-
-#if    MACH_ASSERT
-       if (watchacts & WA_ACT_HDLR) {
-           printf("act_%x: get_set_state(act=%x flv=%x state=%x ptr@%x=%x)",
-                   current_act(), act, flavor, state,
-                   pcount, (pcount ? *pcount : 0));
-           printf((handler == get_state_handler ? "get_state_hdlr\n" :
-                   (handler == set_state_handler ? "set_state_hdlr\n" :
-                       "hndler=%x\n")), handler); 
-       }
-#endif /* MACH_ASSERT */
-
-       assert(act->thread);
-       assert(act != current_act());
-
-       for (;;) {
-               wait_result_t           result;
-
-               if (    act->inited                                             &&
-                               act->thread->top_act == act             )
-                               thread_wakeup_one(&act->suspend_count);
-
-               /*
-                * Wait must be interruptible to avoid deadlock (e.g.) with
-                * task_suspend() when caller and target of get_set_state()
-                * are in same task.
-                */
-               result = assert_wait(&gss, THREAD_ABORTSAFE);
-               act_unlock_thread(act);
-
-               if (result == THREAD_WAITING)
-                       result = thread_block(THREAD_CONTINUE_NULL);
-
-               assert(result != THREAD_WAITING);
-
-               if (gss.result != KERN_ABORTED) {
-                       assert(result != THREAD_INTERRUPTED);
-                       break;
-               }
-
-               /* JMM - What about other aborts (like BSD signals)? */
-               if (current_act()->handlers)
-                       act_execute_returnhandlers();
+       else {
+               thread_mtx_unlock(thread);
 
-               act_lock_thread(act);
+               thread_terminate_self();
+               /*NOTREACHED*/
        }
 
-#if    MACH_ASSERT
-       if (watchacts & WA_ACT_HDLR)
-           printf("act_%x: get_set_state returns %x\n",
-                           current_act(), gss.result);
-#endif /* MACH_ASSERT */
-
-       return (gss.result);
-}
-
-void
-set_state_handler(ReturnHandler *rh, thread_act_t thr_act)
-{
-       GetSetState *gss = (GetSetState*)rh;
-
-#if    MACH_ASSERT
-       if (watchacts & WA_ACT_HDLR)
-               printf("act_%x: set_state_handler(rh=%x,thr_act=%x)\n",
-                       current_act(), rh, thr_act);
-#endif /* MACH_ASSERT */
-
-       gss->result = act_machine_set_state(thr_act, gss->flavor,
-                                               gss->state, *gss->pcount);
-       thread_wakeup((event_t)gss);
-}
-
-void
-get_state_handler(ReturnHandler *rh, thread_act_t thr_act)
-{
-       GetSetState *gss = (GetSetState*)rh;
-
-#if    MACH_ASSERT
-       if (watchacts & WA_ACT_HDLR)
-               printf("act_%x: get_state_handler(rh=%x,thr_act=%x)\n",
-                       current_act(), rh, thr_act);
-#endif /* MACH_ASSERT */
-
-       gss->result = act_machine_get_state(thr_act, gss->flavor,
-                       gss->state, 
-                       (mach_msg_type_number_t *) gss->pcount);
-       thread_wakeup((event_t)gss);
+       thread_mtx_unlock(thread);
 }
 
 kern_return_t
-act_get_state_locked(thread_act_t thr_act, int flavor, thread_state_t state,
-                                       mach_msg_type_number_t *pcount)
-{
-#if    MACH_ASSERT
-    if (watchacts & WA_ACT_HDLR)
-       printf("act_%x: act_get_state_L(thr_act=%x,flav=%x,st=%x,pcnt@%x=%x)\n",
-               current_act(), thr_act, flavor, state, pcount,
-               (pcount? *pcount : 0));
-#endif /* MACH_ASSERT */
-
-    return(get_set_state(thr_act, flavor, state, (int*)pcount, get_state_handler));
-}
-
-kern_return_t
-act_set_state_locked(thread_act_t thr_act, int flavor, thread_state_t state,
-                                       mach_msg_type_number_t count)
-{
-#if    MACH_ASSERT
-    if (watchacts & WA_ACT_HDLR)
-       printf("act_%x: act_set_state_L(thr_act=%x,flav=%x,st=%x,pcnt@%x=%x)\n",
-               current_act(), thr_act, flavor, state, count, count);
-#endif /* MACH_ASSERT */
-
-    return(get_set_state(thr_act, flavor, state, (int*)&count, set_state_handler));
-}
-
-kern_return_t
-act_set_state(thread_act_t thr_act, int flavor, thread_state_t state,
-                                       mach_msg_type_number_t count)
+act_set_state(
+       thread_t                                thread,
+       int                                             flavor,
+       thread_state_t                  state,
+       mach_msg_type_number_t  count)
 {
-    if (thr_act == THR_ACT_NULL || thr_act == current_act())
-           return(KERN_INVALID_ARGUMENT);
+    if (thread == current_thread())
+           return (KERN_INVALID_ARGUMENT);
 
-    act_lock_thread(thr_act);
-    return(act_set_state_locked(thr_act, flavor, state, count));
+    return (thread_set_state(thread, flavor, state, count));
     
 }
 
 kern_return_t
-act_get_state(thread_act_t thr_act, int flavor, thread_state_t state,
-                                       mach_msg_type_number_t *pcount)
+act_get_state(
+       thread_t                                thread,
+       int                                             flavor,
+       thread_state_t                  state,
+       mach_msg_type_number_t  *count)
 {
-    if (thr_act == THR_ACT_NULL || thr_act == current_act())
-           return(KERN_INVALID_ARGUMENT);
+    if (thread == current_thread())
+           return (KERN_INVALID_ARGUMENT);
 
-    act_lock_thread(thr_act);
-    return(act_get_state_locked(thr_act, flavor, state, pcount));
+    return (thread_get_state(thread, flavor, state, count));
 }
 
 void
 act_set_astbsd(
-       thread_act_t    act)
+       thread_t        thread)
 {
-       spl_t                   s = splsched();
+       spl_t           s = splsched();
        
-       if (act == current_act()) {
-               thread_ast_set(act, AST_BSD);
-               ast_propagate(act->ast);
+       if (thread == current_thread()) {
+               thread_ast_set(thread, AST_BSD);
+               ast_propagate(thread->ast);
        }
        else {
-               thread_t                thread = act->thread;
                processor_t             processor;
 
                thread_lock(thread);
-               thread_ast_set(act, AST_BSD);
+               thread_ast_set(thread, AST_BSD);
                processor = thread->last_processor;
-               if (    processor != PROCESSOR_NULL                                             &&
-                               processor->state == PROCESSOR_RUNNING                   &&
-                               processor->cpu_data->active_thread == thread    )
+               if (    processor != PROCESSOR_NULL                                     &&
+                               processor->state == PROCESSOR_RUNNING           &&
+                               processor->active_thread == thread                      )
                        cause_ast_check(processor);
                thread_unlock(thread);
        }
@@ -1810,77 +852,26 @@ act_set_astbsd(
 
 void
 act_set_apc(
-       thread_act_t    act)
+       thread_t        thread)
 {
-       spl_t                   s = splsched();
+       spl_t           s = splsched();
        
-       if (act == current_act()) {
-               thread_ast_set(act, AST_APC);
-               ast_propagate(act->ast);
+       if (thread == current_thread()) {
+               thread_ast_set(thread, AST_APC);
+               ast_propagate(thread->ast);
        }
        else {
-               thread_t                thread = act->thread;
                processor_t             processor;
 
                thread_lock(thread);
-               thread_ast_set(act, AST_APC);
+               thread_ast_set(thread, AST_APC);
                processor = thread->last_processor;
-               if (    processor != PROCESSOR_NULL                                             &&
-                               processor->state == PROCESSOR_RUNNING                   &&
-                               processor->cpu_data->active_thread == thread    )
+               if (    processor != PROCESSOR_NULL                                     &&
+                               processor->state == PROCESSOR_RUNNING           &&
+                               processor->active_thread == thread                      )
                        cause_ast_check(processor);
                thread_unlock(thread);
        }
        
        splx(s);
 }
-
-void
-act_ulock_release_all(thread_act_t thr_act)
-{
-       ulock_t ulock;
-
-       while (!queue_empty(&thr_act->held_ulocks)) {
-               ulock = (ulock_t) queue_first(&thr_act->held_ulocks);
-               (void) lock_make_unstable(ulock, thr_act);
-               (void) lock_release_internal(ulock, thr_act);
-       }
-}
-
-/*
- * Provide routines (for export to other components) of things that
- * are implemented as macros insternally.
- */
-thread_act_t
-thread_self(void)
-{
-       thread_act_t self = current_act_fast();
-
-       act_reference(self);
-       return self;
-}
-
-thread_act_t
-mach_thread_self(void)
-{
-       thread_act_t self = current_act_fast();
-
-       act_reference(self);
-       return self;
-}
-
-#undef act_reference
-void
-act_reference(
-       thread_act_t thr_act)
-{
-       act_reference_fast(thr_act);
-}
-
-#undef act_deallocate
-void
-act_deallocate(
-       thread_act_t thr_act) 
-{
-       act_deallocate_fast(thr_act);
-}