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[newlib-cygwin] Fix thread priority handling
- From: Corinna Vinschen <corinna at sourceware dot org>
- To: cygwin-cvs at sourceware dot org
- Date: 20 May 2016 16:01:25 -0000
- Subject: [newlib-cygwin] Fix thread priority handling
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=4b51e4c142445c133d6075d2a68ce98e8ec6058b
commit 4b51e4c142445c133d6075d2a68ce98e8ec6058b
Author: Corinna Vinschen <corinna@vinschen.de>
Date: Fri May 20 17:45:24 2016 +0200
Fix thread priority handling
So far pthread::postcreate() only sets the thread priority at all, only
if the inherit-scheduler attribute is PTHREAD_EXPLICIT_SCHED. This
completely ignores the PTHREAD_INHERIT_SCHED case, since in contrast
to POSIX, a thread does not inherit its priority from the creating
thread, but always starts with THREAD_PRIORITY_NORMAL.
pthread_getschedparam() only returns what's stored in the thread attributes,
not the actual thread priority.
This patch fixes both problems.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Diff:
---
winsup/cygwin/thread.cc | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 350879a..1feee5b 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -37,6 +37,7 @@ details. */
extern "C" void __fp_lock_all ();
extern "C" void __fp_unlock_all ();
extern "C" bool valid_sched_parameters(const struct sched_param *);
+extern "C" int sched_get_thread_priority(HANDLE thread);
extern "C" int sched_set_thread_priority(HANDLE thread, int priority);
static inline verifyable_object_state
verifyable_object_isvalid (void const * objectptr, thread_magic_t magic,
@@ -531,12 +532,15 @@ pthread::postcreate ()
valid = true;
InterlockedIncrement (&MT_INTERFACE->threadcount);
- /* FIXME: set the priority appropriately for system contention scope */
- if (attr.inheritsched == PTHREAD_EXPLICIT_SCHED)
- {
- /* FIXME: set the scheduling settings for the new thread */
- /* sched_thread_setparam (win32_obj_id, attr.schedparam); */
- }
+
+ /* Per POSIX the new thread inherits the sched priority from its caller
+ thread if PTHREAD_INHERIT_SCHED is set.
+ FIXME: set the priority appropriately for system contention scope */
+ if (attr.inheritsched == PTHREAD_INHERIT_SCHED)
+ attr.schedparam.sched_priority
+ = sched_get_thread_priority (GetCurrentThread ());
+ if (attr.schedparam.sched_priority)
+ sched_set_thread_priority (win32_obj_id, attr.schedparam.sched_priority);
}
void
@@ -2601,9 +2605,7 @@ pthread_getschedparam (pthread_t thread, int *policy,
if (!pthread::is_good_object (&thread))
return ESRCH;
*policy = SCHED_FIFO;
- /* we don't return the current effective priority, we return the current
- requested priority */
- *param = thread->attr.schedparam;
+ param->sched_priority = sched_get_thread_priority (thread->win32_obj_id);
return 0;
}