| Message ID | 20240217105904.1912368-2-fabio.maria.de.francesco@linux.intel.com |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add cond_guard() to conditional guards | expand |
On Sat, 17 Feb 2024 11:59:02 +0100 "Fabio M. De Francesco" <fabio.maria.de.francesco@linux.intel.com> wrote: > Add cond_guard() macro to conditional guards. > > cond_guard() is a guard to be used with the conditional variants of locks, > like down_read_trylock() or mutex_lock_interruptible(). > > It takes a statement (or statement-expression) that is passed as its > second argument. That statement (or statement-expression) is executed if > waiting for a lock is interrupted or if a _trylock() fails in case of > contention. > > Usage example: > > cond_guard(mutex_intr, return -EINTR, &mutex); > > Consistent with other usage of _guard(), locks are unlocked at the exit of > the scope where cond_guard() is called. This macro can be called multiple > times in the same scope. > > Cc: Dave Jiang <dave.jiang@intel.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Suggested-by: Dan Williams <dan.j.williams@intel.com> > Suggested-by: Ira Weiny <ira.weiny@intel.com> > Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: Fabio M. De Francesco <fabio.maria.de.francesco@linux.intel.com> Looks good. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
On 2/17/24 3:59 AM, Fabio M. De Francesco wrote: > Add cond_guard() macro to conditional guards. > > cond_guard() is a guard to be used with the conditional variants of locks, > like down_read_trylock() or mutex_lock_interruptible(). > > It takes a statement (or statement-expression) that is passed as its > second argument. That statement (or statement-expression) is executed if > waiting for a lock is interrupted or if a _trylock() fails in case of > contention. > > Usage example: > > cond_guard(mutex_intr, return -EINTR, &mutex); > > Consistent with other usage of _guard(), locks are unlocked at the exit of > the scope where cond_guard() is called. This macro can be called multiple > times in the same scope. > > Cc: Dave Jiang <dave.jiang@intel.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Suggested-by: Dan Williams <dan.j.williams@intel.com> > Suggested-by: Ira Weiny <ira.weiny@intel.com> > Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: Fabio M. De Francesco <fabio.maria.de.francesco@linux.intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> > --- > include/linux/cleanup.h | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h > index c2d09bc4f976..602afb85da34 100644 > --- a/include/linux/cleanup.h > +++ b/include/linux/cleanup.h > @@ -134,6 +134,19 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ > * an anonymous instance of the (guard) class, not recommended for > * conditional locks. > * > + * cond_guard(name, fail, args...): > + * a guard to be used with the conditional variants of locks, like > + * down_read_trylock() or mutex_lock_interruptible(). 'fail' is a > + * statement or statement-expression that is executed if waiting for a > + * lock is interrupted or if a _trylock() fails in case of contention. > + * > + * Example: > + * > + * cond_guard(mutex_intr, return -EINTR, &mutex); > + * > + * This macro can be called multiple times in the same scope, for it > + * declares unique instances of type 'name'. > + * > * scoped_guard (name, args...) { }: > * similar to CLASS(name, scope)(args), except the variable (with the > * explicit name 'scope') is declard in a for-loop such that its scope is > @@ -165,6 +178,13 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ > > #define __guard_ptr(_name) class_##_name##_lock_ptr > > +#define __cond_guard(__unique, _name, _fail, args...) \ > + CLASS(_name, __unique)(args); \ > + if (!__guard_ptr(_name)(&__unique)) _fail; \ > + else { } > +#define cond_guard(_name, _fail, args...) \ > + __cond_guard(__UNIQUE_ID(scope), _name, _fail, args) > + > #define scoped_guard(_name, args...) \ > for (CLASS(_name, scope)(args), \ > *done = NULL; __guard_ptr(_name)(&scope) && !done; done = (void *)1)
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index c2d09bc4f976..602afb85da34 100644 --- a/include/linux/cleanup.h +++ b/include/linux/cleanup.h @@ -134,6 +134,19 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * an anonymous instance of the (guard) class, not recommended for * conditional locks. * + * cond_guard(name, fail, args...): + * a guard to be used with the conditional variants of locks, like + * down_read_trylock() or mutex_lock_interruptible(). 'fail' is a + * statement or statement-expression that is executed if waiting for a + * lock is interrupted or if a _trylock() fails in case of contention. + * + * Example: + * + * cond_guard(mutex_intr, return -EINTR, &mutex); + * + * This macro can be called multiple times in the same scope, for it + * declares unique instances of type 'name'. + * * scoped_guard (name, args...) { }: * similar to CLASS(name, scope)(args), except the variable (with the * explicit name 'scope') is declard in a for-loop such that its scope is @@ -165,6 +178,13 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ #define __guard_ptr(_name) class_##_name##_lock_ptr +#define __cond_guard(__unique, _name, _fail, args...) \ + CLASS(_name, __unique)(args); \ + if (!__guard_ptr(_name)(&__unique)) _fail; \ + else { } +#define cond_guard(_name, _fail, args...) \ + __cond_guard(__UNIQUE_ID(scope), _name, _fail, args) + #define scoped_guard(_name, args...) \ for (CLASS(_name, scope)(args), \ *done = NULL; __guard_ptr(_name)(&scope) && !done; done = (void *)1)
Add cond_guard() macro to conditional guards. cond_guard() is a guard to be used with the conditional variants of locks, like down_read_trylock() or mutex_lock_interruptible(). It takes a statement (or statement-expression) that is passed as its second argument. That statement (or statement-expression) is executed if waiting for a lock is interrupted or if a _trylock() fails in case of contention. Usage example: cond_guard(mutex_intr, return -EINTR, &mutex); Consistent with other usage of _guard(), locks are unlocked at the exit of the scope where cond_guard() is called. This macro can be called multiple times in the same scope. Cc: Dave Jiang <dave.jiang@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Suggested-by: Dan Williams <dan.j.williams@intel.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Fabio M. De Francesco <fabio.maria.de.francesco@linux.intel.com> --- include/linux/cleanup.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)