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| author | Richard Braun <rbraun@sceen.net> | 2018-01-30 20:44:24 +0100 |
|---|---|---|
| committer | Richard Braun <rbraun@sceen.net> | 2018-01-30 20:44:24 +0100 |
| commit | 9967e907feda967f237c30430f47357bc91332f5 (patch) | |
| tree | afad99fa69ba8cd0aa38c7bc695667520805d4c5 /kern/mutex.h | |
| parent | bc6e853d4b27055056eebfd871aaf0fc60405b0f (diff) | |
Fix condition variable broadcasting
The broadcast implementation is based on an invalid assumption, namely
that the first mutex_unlock call following condition_wait would be invoked
on the same mutex. Fixing this while guarding against the thundering herd
effect requires augmenting mutexes with a pointer to the condition
variable they may be associated with. Since the size of mutexes is
currently more important than broadcast scalability, the implementation
is simplified into one which suffers from the thundering herd effect.
Diffstat (limited to 'kern/mutex.h')
| -rw-r--r-- | kern/mutex.h | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/kern/mutex.h b/kern/mutex.h index 10872e6e..b4332dea 100644 --- a/kern/mutex.h +++ b/kern/mutex.h @@ -1,5 +1,5 @@ /* - * Copyright (c) 2013-2017 Richard Braun. + * Copyright (c) 2013-2018 Richard Braun. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -37,7 +37,6 @@ #include <kern/init.h> #include <kern/mutex_types.h> -#include <kern/thread.h> /* * Initialize a mutex. @@ -102,12 +101,6 @@ static inline void mutex_unlock(struct mutex *mutex) { mutex_impl_unlock(mutex); - - /* - * If this mutex was used along with a condition variable, wake up - * a potential pending waiter. - */ - thread_wakeup_last_cond(); } /* |