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-rw-r--r--ChangeLog2
-rw-r--r--doc/mach.texi16
2 files changed, 11 insertions, 7 deletions
diff --git a/ChangeLog b/ChangeLog
index 51319fb..196bbd7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
2007-02-04 Thomas Schwinge <tschwinge@gnu.org>
+ * doc/mach.texi (thread_switch): Enhance a bit.
+
* doc/Makefrag.am ($(web)): Use ``mkdir -p''.
* doc/mach.texi: Fix unusual hyphens.
diff --git a/doc/mach.texi b/doc/mach.texi
index 13e0927..93c5eae 100644
--- a/doc/mach.texi
+++ b/doc/mach.texi
@@ -4550,14 +4550,15 @@ whose control port was presented.
The function @code{thread_switch} provides low-level access to the
scheduler's context switching code. @var{new_thread} is a hint that
implements hand-off scheduling. The operating system will attempt to
-switch directly to the new thread (by passing the normal logic that
+switch directly to the new thread (bypassing the normal logic that
selects the next thread to run) if possible. Since this is a hint, it
may be incorrect; it is ignored if it doesn't specify a thread on the
same host as the current thread or if that thread can't be switched to
-(i.e., not runnable or already running on another processor). In this
-case, the normal logic to select the next thread to run is used; the
-current thread may continue running if there is no other appropriate
-thread to run.
+(i.e., not runnable or already running on another processor or giving
+a plainly invalid hint, such as @code{MACH_PORT_NULL}). In this case,
+the normal logic to select the next thread to run is used; the current
+thread may continue running if there is no other appropriate thread to
+run.
Options for @var{option} are defined in @file{mach/thread_switch.h} and
specify the interpretation of @var{time}. The possible values for
@@ -4568,8 +4569,9 @@ specify the interpretation of @var{time}. The possible values for
No options, the time argument is ignored.
@item SWITCH_OPTION_WAIT
-The thread is blocked for the specified time. This can be aborted by
-@code{thread_abort}.
+The thread is blocked for the specified time (in milliseconds;
+specifying @code{0} will wait for the next tick). This can be aborted
+by @code{thread_abort}.
@item SWITCH_OPTION_DEPRESS
The thread's priority is depressed to the lowest possible value for the