Date: Thu, 28 Oct 2021 02:00:28 GMT
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org
Subject: git: 840680e601f1 - main - Wrap mutex(9), rwlock(9) and sx(9) macros into __extension__ ({}) instead of do {} while (0).
Message-ID: <202110280200.19S20S1h032148@gitrepo.freebsd.org>
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The branch main has been updated by glebius: URL: https://cgit.FreeBSD.org/src/commit/?id=840680e601f15b25abed3fad31399a9ce838f13a commit 840680e601f15b25abed3fad31399a9ce838f13a Author: Gleb Smirnoff <glebius@FreeBSD.org> AuthorDate: 2021-10-27 17:33:01 +0000 Commit: Gleb Smirnoff <glebius@FreeBSD.org> CommitDate: 2021-10-28 01:58:36 +0000 Wrap mutex(9), rwlock(9) and sx(9) macros into __extension__ ({}) instead of do {} while (0). This makes them real void expressions, and they can be used anywhere where a void function call can be used, for example in a conditional operator. Reviewed by: kib, mjg Differential revision: https://reviews.freebsd.org/D32696 --- sys/sys/mutex.h | 28 ++++++++++++++++------------ sys/sys/rwlock.h | 15 +++++++++------ sys/sys/sx.h | 5 +++-- 3 files changed, 28 insertions(+), 20 deletions(-) diff --git a/sys/sys/mutex.h b/sys/sys/mutex.h index f35cdd7413a6..04e2c823541a 100644 --- a/sys/sys/mutex.h +++ b/sys/sys/mutex.h @@ -236,14 +236,15 @@ void _thread_lock(struct thread *); */ /* Lock a normal mutex. */ -#define __mtx_lock(mp, tid, opts, file, line) do { \ +#define __mtx_lock(mp, tid, opts, file, line) __extension__ ({ \ uintptr_t _tid = (uintptr_t)(tid); \ uintptr_t _v = MTX_UNOWNED; \ \ if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__acquire) ||\ !_mtx_obtain_lock_fetch((mp), &_v, _tid))) \ _mtx_lock_sleep((mp), _v, (opts), (file), (line)); \ -} while (0) + (void)0; /* ensure void type for expression */ \ +}) /* * Lock a spin mutex. For spinlocks, we handle recursion inline (it @@ -252,7 +253,7 @@ void _thread_lock(struct thread *); * inlining this code is not too big a deal. */ #ifdef SMP -#define __mtx_lock_spin(mp, tid, opts, file, line) do { \ +#define __mtx_lock_spin(mp, tid, opts, file, line) __extension__ ({ \ uintptr_t _tid = (uintptr_t)(tid); \ uintptr_t _v = MTX_UNOWNED; \ \ @@ -260,7 +261,8 @@ void _thread_lock(struct thread *); if (__predict_false(LOCKSTAT_PROFILE_ENABLED(spin__acquire) || \ !_mtx_obtain_lock_fetch((mp), &_v, _tid))) \ _mtx_lock_spin((mp), _v, (opts), (file), (line)); \ -} while (0) + (void)0; /* ensure void type for expression */ \ +}) #define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__ ({ \ uintptr_t _tid = (uintptr_t)(tid); \ int _ret; \ @@ -277,7 +279,7 @@ void _thread_lock(struct thread *); _ret; \ }) #else /* SMP */ -#define __mtx_lock_spin(mp, tid, opts, file, line) do { \ +#define __mtx_lock_spin(mp, tid, opts, file, line) __extension__ ({ \ uintptr_t _tid = (uintptr_t)(tid); \ \ spinlock_enter(); \ @@ -287,7 +289,8 @@ void _thread_lock(struct thread *); KASSERT((mp)->mtx_lock == MTX_UNOWNED, ("corrupt spinlock")); \ (mp)->mtx_lock = _tid; \ } \ -} while (0) + (void)0; /* ensure void type for expression */ \ +}) #define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__ ({ \ uintptr_t _tid = (uintptr_t)(tid); \ int _ret; \ @@ -305,13 +308,14 @@ void _thread_lock(struct thread *); #endif /* SMP */ /* Unlock a normal mutex. */ -#define __mtx_unlock(mp, tid, opts, file, line) do { \ +#define __mtx_unlock(mp, tid, opts, file, line) __extension__ ({ \ uintptr_t _v = (uintptr_t)(tid); \ \ if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__release) ||\ !_mtx_release_lock_fetch((mp), &_v))) \ _mtx_unlock_sleep((mp), _v, (opts), (file), (line)); \ -} while (0) + (void)0; /* ensure void type for expression */ \ +}) /* * Unlock a spin mutex. For spinlocks, we can handle everything @@ -324,7 +328,7 @@ void _thread_lock(struct thread *); * releasing a spin lock. This includes the recursion cases. */ #ifdef SMP -#define __mtx_unlock_spin(mp) do { \ +#define __mtx_unlock_spin(mp) __extension__ ({ \ if (mtx_recursed((mp))) \ (mp)->mtx_recurse--; \ else { \ @@ -332,9 +336,9 @@ void _thread_lock(struct thread *); _mtx_release_lock_quick((mp)); \ } \ spinlock_exit(); \ -} while (0) +}) #else /* SMP */ -#define __mtx_unlock_spin(mp) do { \ +#define __mtx_unlock_spin(mp) __extension__ ({ \ if (mtx_recursed((mp))) \ (mp)->mtx_recurse--; \ else { \ @@ -342,7 +346,7 @@ void _thread_lock(struct thread *); (mp)->mtx_lock = MTX_UNOWNED; \ } \ spinlock_exit(); \ -} while (0) +}) #endif /* SMP */ /* diff --git a/sys/sys/rwlock.h b/sys/sys/rwlock.h index 4e7768595737..99e885e07aaf 100644 --- a/sys/sys/rwlock.h +++ b/sys/sys/rwlock.h @@ -103,23 +103,25 @@ */ /* Acquire a write lock. */ -#define __rw_wlock(rw, tid, file, line) do { \ +#define __rw_wlock(rw, tid, file, line) __extension__ ({ \ uintptr_t _tid = (uintptr_t)(tid); \ uintptr_t _v = RW_UNLOCKED; \ \ if (__predict_false(LOCKSTAT_PROFILE_ENABLED(rw__acquire) || \ !_rw_write_lock_fetch((rw), &_v, _tid))) \ _rw_wlock_hard((rw), _v, (file), (line)); \ -} while (0) + (void)0; /* ensure void type for expression */ \ +}) /* Release a write lock. */ -#define __rw_wunlock(rw, tid, file, line) do { \ +#define __rw_wunlock(rw, tid, file, line) __extension__ ({ \ uintptr_t _v = (uintptr_t)(tid); \ \ if (__predict_false(LOCKSTAT_PROFILE_ENABLED(rw__release) || \ !_rw_write_unlock_fetch((rw), &_v))) \ _rw_wunlock_hard((rw), _v, (file), (line)); \ -} while (0) + (void)0; /* ensure void type for expression */ \ +}) /* * Function prototypes. Routines that start with _ are not part of the @@ -231,12 +233,13 @@ void __rw_assert(const volatile uintptr_t *c, int what, const char *file, #define rw_try_upgrade(rw) _rw_try_upgrade((rw), LOCK_FILE, LOCK_LINE) #define rw_try_wlock(rw) _rw_try_wlock((rw), LOCK_FILE, LOCK_LINE) #define rw_downgrade(rw) _rw_downgrade((rw), LOCK_FILE, LOCK_LINE) -#define rw_unlock(rw) do { \ +#define rw_unlock(rw) __extension__ ({ \ if (rw_wowned(rw)) \ rw_wunlock(rw); \ else \ rw_runlock(rw); \ -} while (0) + (void)0; /* ensure void type for expression */ \ +}) #define rw_sleep(chan, rw, pri, wmesg, timo) \ _sleep((chan), &(rw)->lock_object, (pri), (wmesg), \ tick_sbt * (timo), 0, C_HARDCLOCK) diff --git a/sys/sys/sx.h b/sys/sys/sx.h index 1e6b9f3f8a46..bd164a96558b 100644 --- a/sys/sys/sx.h +++ b/sys/sys/sx.h @@ -253,12 +253,13 @@ __sx_xunlock(struct sx *sx, struct thread *td, const char *file, int line) (((sx)->sx_lock & ~(SX_LOCK_FLAGMASK & ~SX_LOCK_SHARED)) == \ (uintptr_t)curthread) -#define sx_unlock_(sx, file, line) do { \ +#define sx_unlock_(sx, file, line) __extension__ ({ \ if (sx_xlocked(sx)) \ sx_xunlock_(sx, file, line); \ else \ sx_sunlock_(sx, file, line); \ -} while (0) + (void)0; /* ensure void type for expression */ \ +}) #define sx_unlock(sx) sx_unlock_((sx), LOCK_FILE, LOCK_LINE)
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