X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/8f6c56a50524aa785f7e596d52dddfb331e18961..d41d1dae2cd00cc08c7982087d1c445180cad9f5:/osfmk/kern/syscall_subr.c?ds=inline

diff --git a/osfmk/kern/syscall_subr.c b/osfmk/kern/syscall_subr.c
index c74f325ad..3daf1ec38 100644
--- a/osfmk/kern/syscall_subr.c
+++ b/osfmk/kern/syscall_subr.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2009 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
@@ -74,6 +74,25 @@
 #include <mach/mach_host_server.h>
 #include <mach/mach_syscalls.h>
 
+
+#ifdef MACH_BSD
+extern void workqueue_thread_yielded(void);
+#endif /* MACH_BSD */
+
+
+/* Called from commpage to take a delayed preemption when exiting
+ * the "Preemption Free Zone" (PFZ).
+ */
+kern_return_t
+pfz_exit(
+__unused	struct pfz_exit_args *args)
+{
+	/* For now, nothing special to do.  We'll pick up the ASTs on kernel exit. */
+
+	return (KERN_SUCCESS);
+}
+
+
 /*
  *	swtch and swtch_pri both attempt to context switch (logic in
  *	thread_block no-ops the context switch if nothing would happen).
@@ -96,8 +115,7 @@ swtch_continue(void)
 
     disable_preemption();
 	myprocessor = current_processor();
-	result =		myprocessor->runq.count > 0					||
-				myprocessor->processor_set->runq.count > 0;
+	result = myprocessor->runq.count > 0 || rt_runq.count > 0;
 	enable_preemption();
 
 	thread_syscall_return(result);
@@ -113,8 +131,7 @@ swtch(
 
 	disable_preemption();
 	myprocessor = current_processor();
-	if (		myprocessor->runq.count == 0				&&
-			myprocessor->processor_set->runq.count == 0			) {
+	if (myprocessor->runq.count == 0 &&	rt_runq.count == 0) {
 		mp_enable_preemption();
 
 		return (FALSE);
@@ -127,8 +144,7 @@ swtch(
 
 	disable_preemption();
 	myprocessor = current_processor();
-	result =		myprocessor->runq.count > 0					||
-				myprocessor->processor_set->runq.count > 0;
+	result = myprocessor->runq.count > 0 || rt_runq.count > 0;
 	enable_preemption();
 
 	return (result);
@@ -144,8 +160,7 @@ swtch_pri_continue(void)
 
     disable_preemption();
 	myprocessor = current_processor();
-	result =		myprocessor->runq.count > 0					||
-				myprocessor->processor_set->runq.count > 0;
+	result = myprocessor->runq.count > 0 || rt_runq.count > 0;
 	mp_enable_preemption();
 
 	thread_syscall_return(result);
@@ -161,8 +176,7 @@ __unused	struct swtch_pri_args *args)
 
 	disable_preemption();
 	myprocessor = current_processor();
-	if (	myprocessor->runq.count == 0					&&
-			myprocessor->processor_set->runq.count == 0			) {
+	if (myprocessor->runq.count == 0 && rt_runq.count == 0) {
 		mp_enable_preemption();
 
 		return (FALSE);
@@ -179,8 +193,7 @@ __unused	struct swtch_pri_args *args)
 
 	disable_preemption();
 	myprocessor = current_processor();
-	result =	myprocessor->runq.count > 0						||
-				myprocessor->processor_set->runq.count > 0;
+	result = myprocessor->runq.count > 0 || rt_runq.count > 0;
 	enable_preemption();
 
 	return (result);
@@ -227,6 +240,8 @@ thread_switch(
 	    return (KERN_INVALID_ARGUMENT);
     }
 
+    workqueue_thread_yielded();
+
 	/*
 	 * Translate the port name if supplied.
 	 */
@@ -242,7 +257,7 @@ thread_switch(
 			ipc_port_release(port);
 
 			if (thread == self) {
-				thread_deallocate_internal(thread);
+				(void)thread_deallocate_internal(thread);
 				thread = THREAD_NULL;
 			}
 		}
@@ -263,9 +278,9 @@ thread_switch(
 		thread_lock(thread);
 
 		/*
-		 *	Check if the thread is in the right pset,
-		 *	is not bound to a different processor,
-		 *	and that realtime is not involved.
+		 *	Check that the thread is not bound
+		 *	to a different processor, and that realtime
+		 *	is not involved.
 		 *
 		 *	Next, pull it off its run queue.  If it
 		 *	doesn't come, it's not eligible.
@@ -273,16 +288,15 @@ thread_switch(
 		processor = current_processor();
 		if (processor->current_pri < BASEPRI_RTQUEUES			&&
 			thread->sched_pri < BASEPRI_RTQUEUES				&&
-			thread->processor_set == processor->processor_set	&&
 			(thread->bound_processor == PROCESSOR_NULL	||
 			 thread->bound_processor == processor)				&&
-			run_queue_remove(thread) != RUN_QUEUE_NULL			) {
+				run_queue_remove(thread)							) {
 			/*
 			 *	Hah, got it!!
 			 */
 			thread_unlock(thread);
 
-			thread_deallocate_internal(thread);
+			(void)thread_deallocate_internal(thread);
 
 			if (option == SWITCH_OPTION_WAIT)
 				assert_wait_timeout((event_t)assert_wait_timeout, THREAD_ABORTSAFE,
@@ -338,7 +352,6 @@ thread_depress_abstime(
 
 		self->sched_pri = DEPRESSPRI;
 		myprocessor->current_pri = self->sched_pri;
-		self->sched_mode &= ~TH_MODE_PREEMPT;
 		self->sched_mode |= TH_MODE_DEPRESS;
 
 		if (interval != 0) {
@@ -434,7 +447,6 @@ thread_poll_yield(
 			if (!(self->sched_mode & TH_MODE_ISDEPRESSED)) {
 				self->sched_pri = DEPRESSPRI;
 				myprocessor->current_pri = self->sched_pri;
-				self->sched_mode &= ~TH_MODE_PREEMPT;
 			}
 			self->computation_epoch = abstime;
 			self->computation_metered = 0;
@@ -445,9 +457,33 @@ thread_poll_yield(
 				self->depress_timer_active++;
 			thread_unlock(self);
 
-			if ((preempt = csw_check(self, myprocessor)) != AST_NONE)
+			if ((preempt = csw_check(myprocessor)) != AST_NONE)
 				ast_on(preempt);
 		}
 	}
 	splx(s);
 }
+
+
+void
+thread_yield_internal(
+	mach_msg_timeout_t	ms)
+{
+	processor_t	myprocessor;
+
+	disable_preemption();
+	myprocessor = current_processor();
+	if (myprocessor->runq.count == 0 && rt_runq.count == 0) {
+		mp_enable_preemption();
+
+		return;
+	}
+	enable_preemption();
+
+	thread_depress_ms(ms);
+
+	thread_block_reason(THREAD_CONTINUE_NULL, NULL, AST_YIELD);
+
+	thread_depress_abort_internal(current_thread());
+}
+