[gcc r13-4524] libstdc++: Add nodiscard attribute to mutex try_lock functions
Jonathan Wakely
redi@gcc.gnu.org
Tue Dec 6 21:36:17 GMT 2022
https://gcc.gnu.org/g:af177d7280668e5b21560165dc828754618e6621
commit r13-4524-gaf177d7280668e5b21560165dc828754618e6621
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Dec 5 12:39:23 2022 +0000
libstdc++: Add nodiscard attribute to mutex try_lock functions
libstdc++-v3/ChangeLog:
* include/bits/std_mutex.h (mutex): Add nodiscard attribute to
try_lock member function.
* include/bits/unique_lock.h (unique_lock): Likewise for
try_lock, try_lock_until, try_lock_for member functions, and
owns_lock and mutex member functions.
* include/std/mutex (recursive_mutex): Likewise for try_lock
member function.
(timed_mutex, recursive_timed_mutex, try_lock): Likewise for
try_lock, try_lock_until, try_lock_for member functions.
(try_lock): Likewise for non-member function.
* include/std/shared_mutex (shared_mutex): Likewise for try_lock
and try_lock_shared member functions.
(shared_timed_mutex): Likewise for try_lock, try_lock_for,
try_lock_shared, try_lock_shared_for, try_lock_until, and
try_lock_shared_until member functions.
(shared_lock): Likewise for try_lock, try_lock, try_lock_for,
try_lock_until, owns_lock, and mutex member functions.
* testsuite/30_threads/recursive_timed_mutex/try_lock_until/clock_neg.cc:
Cast discarded value expression to void.
* testsuite/30_threads/shared_lock/locking/3.cc: Likewise.
* testsuite/30_threads/shared_lock/locking/4.cc: Likewise.
* testsuite/30_threads/shared_lock/locking/clock_neg.cc:
Likewise.
* testsuite/30_threads/shared_timed_mutex/try_lock_until/clock_neg.cc:
Likewise.
* testsuite/30_threads/timed_mutex/try_lock_until/clock_neg.cc:
Likewise.
* testsuite/30_threads/try_lock/4.cc: Likewise.
* testsuite/30_threads/unique_lock/cons/60497.cc: Likewise.
* testsuite/30_threads/unique_lock/locking/3.cc: Likewise.
* testsuite/30_threads/unique_lock/locking/clock_neg.cc:
Likewise.
Diff:
---
libstdc++-v3/include/bits/std_mutex.h | 1 +
libstdc++-v3/include/bits/unique_lock.h | 5 +++++
libstdc++-v3/include/std/mutex | 14 ++++++++++++++
libstdc++-v3/include/std/shared_mutex | 22 +++++++++++++++++++---
.../try_lock_until/clock_neg.cc | 4 ++--
.../testsuite/30_threads/shared_lock/locking/3.cc | 2 +-
.../testsuite/30_threads/shared_lock/locking/4.cc | 2 +-
.../30_threads/shared_lock/locking/clock_neg.cc | 4 ++--
.../shared_timed_mutex/try_lock_until/clock_neg.cc | 4 ++--
.../timed_mutex/try_lock_until/clock_neg.cc | 4 ++--
libstdc++-v3/testsuite/30_threads/try_lock/4.cc | 2 +-
.../testsuite/30_threads/unique_lock/cons/60497.cc | 2 +-
.../testsuite/30_threads/unique_lock/locking/3.cc | 2 +-
.../30_threads/unique_lock/locking/clock_neg.cc | 4 ++--
14 files changed, 54 insertions(+), 18 deletions(-)
diff --git a/libstdc++-v3/include/bits/std_mutex.h b/libstdc++-v3/include/bits/std_mutex.h
index b22e0e12793..68f5fb9ed65 100644
--- a/libstdc++-v3/include/bits/std_mutex.h
+++ b/libstdc++-v3/include/bits/std_mutex.h
@@ -117,6 +117,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__throw_system_error(__e);
}
+ _GLIBCXX_NODISCARD
bool
try_lock() noexcept
{
diff --git a/libstdc++-v3/include/bits/unique_lock.h b/libstdc++-v3/include/bits/unique_lock.h
index 9ed7ba25766..c6402d94e85 100644
--- a/libstdc++-v3/include/bits/unique_lock.h
+++ b/libstdc++-v3/include/bits/unique_lock.h
@@ -143,6 +143,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
}
+ _GLIBCXX_NODISCARD
bool
try_lock()
{
@@ -158,6 +159,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Clock, typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
{
@@ -173,6 +175,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Rep, typename _Period>
+ _GLIBCXX_NODISCARD
bool
try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
{
@@ -215,6 +218,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __ret;
}
+ _GLIBCXX_NODISCARD
bool
owns_lock() const noexcept
{ return _M_owns; }
@@ -222,6 +226,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
explicit operator bool() const noexcept
{ return owns_lock(); }
+ _GLIBCXX_NODISCARD
mutex_type*
mutex() const noexcept
{ return _M_device; }
diff --git a/libstdc++-v3/include/std/mutex b/libstdc++-v3/include/std/mutex
index b310c15687d..aca5f91e03c 100644
--- a/libstdc++-v3/include/std/mutex
+++ b/libstdc++-v3/include/std/mutex
@@ -124,6 +124,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__throw_system_error(__e);
}
+ _GLIBCXX_NODISCARD
bool
try_lock() noexcept
{
@@ -253,6 +254,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__throw_system_error(__e);
}
+ _GLIBCXX_NODISCARD
bool
try_lock() noexcept
{
@@ -261,11 +263,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template <class _Rep, class _Period>
+ _GLIBCXX_NODISCARD
bool
try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
{ return _M_try_lock_for(__rtime); }
template <class _Clock, class _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
{ return _M_try_lock_until(__atime); }
@@ -328,6 +332,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__throw_system_error(__e);
}
+ _GLIBCXX_NODISCARD
bool
try_lock() noexcept
{
@@ -336,11 +341,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template <class _Rep, class _Period>
+ _GLIBCXX_NODISCARD
bool
try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
{ return _M_try_lock_for(__rtime); }
template <class _Clock, class _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
{ return _M_try_lock_until(__atime); }
@@ -395,6 +402,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_locked = true;
}
+ _GLIBCXX_NODISCARD
bool
try_lock()
{
@@ -406,6 +414,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Rep, typename _Period>
+ _GLIBCXX_NODISCARD
bool
try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
{
@@ -417,6 +426,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Clock, typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
{
@@ -478,6 +488,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
++_M_count;
}
+ _GLIBCXX_NODISCARD
bool
try_lock()
{
@@ -494,6 +505,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Rep, typename _Period>
+ _GLIBCXX_NODISCARD
bool
try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
{
@@ -510,6 +522,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Clock, typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
{
@@ -616,6 +629,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* Sequentially calls try_lock() on each argument.
*/
template<typename _L1, typename _L2, typename... _L3>
+ _GLIBCXX_NODISCARD
inline int
try_lock(_L1& __l1, _L2& __l2, _L3&... __l3)
{
diff --git a/libstdc++-v3/include/std/shared_mutex b/libstdc++-v3/include/std/shared_mutex
index cf74b32f185..7b70697f178 100644
--- a/libstdc++-v3/include/std/shared_mutex
+++ b/libstdc++-v3/include/std/shared_mutex
@@ -420,13 +420,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Exclusive ownership
void lock() { _M_impl.lock(); }
- bool try_lock() { return _M_impl.try_lock(); }
+ [[nodiscard]] bool try_lock() { return _M_impl.try_lock(); }
void unlock() { _M_impl.unlock(); }
// Shared ownership
void lock_shared() { _M_impl.lock_shared(); }
- bool try_lock_shared() { return _M_impl.try_lock_shared(); }
+ [[nodiscard]] bool try_lock_shared() { return _M_impl.try_lock_shared(); }
void unlock_shared() { _M_impl.unlock_shared(); }
#if _GLIBCXX_USE_PTHREAD_RWLOCK_T
@@ -473,10 +473,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Exclusive ownership
void lock() { _Base::lock(); }
- bool try_lock() { return _Base::try_lock(); }
+ _GLIBCXX_NODISCARD bool try_lock() { return _Base::try_lock(); }
void unlock() { _Base::unlock(); }
template<typename _Rep, typename _Period>
+ _GLIBCXX_NODISCARD
bool
try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
{
@@ -489,10 +490,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Shared ownership
void lock_shared() { _Base::lock_shared(); }
+ _GLIBCXX_NODISCARD
bool try_lock_shared() { return _Base::try_lock_shared(); }
void unlock_shared() { _Base::unlock_shared(); }
template<typename _Rep, typename _Period>
+ _GLIBCXX_NODISCARD
bool
try_lock_shared_for(const chrono::duration<_Rep, _Period>& __rtime)
{
@@ -507,6 +510,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Exclusive ownership
template<typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<chrono::system_clock,
_Duration>& __atime)
@@ -532,6 +536,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#ifdef _GLIBCXX_USE_PTHREAD_RWLOCK_CLOCKLOCK
template<typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<chrono::steady_clock,
_Duration>& __atime)
@@ -558,6 +563,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#endif
template<typename _Clock, typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
{
@@ -580,6 +586,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Shared ownership
template<typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_shared_until(const chrono::time_point<chrono::system_clock,
_Duration>& __atime)
@@ -619,6 +626,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#ifdef _GLIBCXX_USE_PTHREAD_RWLOCK_CLOCKLOCK
template<typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_shared_until(const chrono::time_point<chrono::steady_clock,
_Duration>& __atime)
@@ -645,6 +653,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#endif
template<typename _Clock, typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_shared_until(const chrono::time_point<_Clock,
_Duration>& __atime)
@@ -670,6 +679,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Exclusive ownership
template<typename _Clock, typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<_Clock, _Duration>& __abs_time)
{
@@ -694,6 +704,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Shared ownership
template <typename _Clock, typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_shared_until(const chrono::time_point<_Clock,
_Duration>& __abs_time)
@@ -776,6 +787,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_owns = true;
}
+ _GLIBCXX_NODISCARD
bool
try_lock()
{
@@ -784,6 +796,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Rep, typename _Period>
+ _GLIBCXX_NODISCARD
bool
try_lock_for(const chrono::duration<_Rep, _Period>& __rel_time)
{
@@ -792,6 +805,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Clock, typename _Duration>
+ _GLIBCXX_NODISCARD
bool
try_lock_until(const chrono::time_point<_Clock, _Duration>& __abs_time)
{
@@ -826,10 +840,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Getters
+ _GLIBCXX_NODISCARD
bool owns_lock() const noexcept { return _M_owns; }
explicit operator bool() const noexcept { return _M_owns; }
+ _GLIBCXX_NODISCARD
mutex_type* mutex() const noexcept { return _M_pm; }
private:
diff --git a/libstdc++-v3/testsuite/30_threads/recursive_timed_mutex/try_lock_until/clock_neg.cc b/libstdc++-v3/testsuite/30_threads/recursive_timed_mutex/try_lock_until/clock_neg.cc
index 541bd19f3cf..91f2c83be0d 100644
--- a/libstdc++-v3/testsuite/30_threads/recursive_timed_mutex/try_lock_until/clock_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/recursive_timed_mutex/try_lock_until/clock_neg.cc
@@ -33,7 +33,7 @@ void
test01()
{
std::recursive_timed_mutex m;
- m.try_lock_until(clok::now()); // { dg-error "here" }
+ (void) m.try_lock_until(clok::now()); // { dg-error "here" }
}
struct cloc
@@ -51,7 +51,7 @@ void
test02()
{
std::recursive_timed_mutex m;
- m.try_lock_until(cloc::now()); // { dg-error "here" }
+ (void) m.try_lock_until(cloc::now()); // { dg-error "here" }
}
// { dg-error "static assertion failed" "" { target *-*-* } 0 }
diff --git a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/3.cc b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/3.cc
index c7637d21993..8ad962baec3 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/3.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/3.cc
@@ -38,7 +38,7 @@ int main()
try
{
- l.try_lock_for(std::chrono::milliseconds(100));
+ (void) l.try_lock_for(std::chrono::milliseconds(100));
}
catch(const std::system_error&)
{
diff --git a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/4.cc b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/4.cc
index 126098dfeac..96388a1689d 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/4.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/4.cc
@@ -40,7 +40,7 @@ int main()
try
{
- l.try_lock_until(t);
+ (void) l.try_lock_until(t);
}
catch(const std::system_error&)
{
diff --git a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/clock_neg.cc b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/clock_neg.cc
index 3a6373b5926..d6df66efb17 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/clock_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/clock_neg.cc
@@ -34,7 +34,7 @@ test01()
{
std::shared_timed_mutex m;
std::shared_lock<std::shared_timed_mutex> l(m, std::defer_lock);
- l.try_lock_until(clok::now()); // { dg-error "here" }
+ (void) l.try_lock_until(clok::now()); // { dg-error "here" }
}
struct cloc
@@ -53,7 +53,7 @@ test02()
{
std::shared_timed_mutex m;
std::shared_lock<std::shared_timed_mutex> l(m, std::defer_lock);
- l.try_lock_until(cloc::now()); // { dg-error "here" }
+ (void) l.try_lock_until(cloc::now()); // { dg-error "here" }
}
// { dg-error "static assertion failed" "" { target *-*-* } 0 }
diff --git a/libstdc++-v3/testsuite/30_threads/shared_timed_mutex/try_lock_until/clock_neg.cc b/libstdc++-v3/testsuite/30_threads/shared_timed_mutex/try_lock_until/clock_neg.cc
index ac401235f6c..f948101a884 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_timed_mutex/try_lock_until/clock_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_timed_mutex/try_lock_until/clock_neg.cc
@@ -33,7 +33,7 @@ void
test01()
{
std::shared_timed_mutex m;
- m.try_lock_until(clok::now()); // { dg-error "here" }
+ (void) m.try_lock_until(clok::now()); // { dg-error "here" }
}
struct cloc
@@ -51,7 +51,7 @@ void
test02()
{
std::shared_timed_mutex m;
- m.try_lock_shared_until(cloc::now()); // { dg-error "here" }
+ (void) m.try_lock_shared_until(cloc::now()); // { dg-error "here" }
}
// { dg-error "static assertion failed" "" { target *-*-* } 0 }
diff --git a/libstdc++-v3/testsuite/30_threads/timed_mutex/try_lock_until/clock_neg.cc b/libstdc++-v3/testsuite/30_threads/timed_mutex/try_lock_until/clock_neg.cc
index 36424747b4d..71c83c514bc 100644
--- a/libstdc++-v3/testsuite/30_threads/timed_mutex/try_lock_until/clock_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/timed_mutex/try_lock_until/clock_neg.cc
@@ -33,7 +33,7 @@ void
test01()
{
std::timed_mutex m;
- m.try_lock_until(clok::now()); // { dg-error "here" }
+ (void) m.try_lock_until(clok::now()); // { dg-error "here" }
}
struct cloc
@@ -51,7 +51,7 @@ void
test02()
{
std::timed_mutex m;
- m.try_lock_until(cloc::now()); // { dg-error "here" }
+ (void) m.try_lock_until(cloc::now()); // { dg-error "here" }
}
// { dg-error "static assertion failed" "" { target *-*-* } 0 }
diff --git a/libstdc++-v3/testsuite/30_threads/try_lock/4.cc b/libstdc++-v3/testsuite/30_threads/try_lock/4.cc
index cfb5a74734f..96afa55a68d 100644
--- a/libstdc++-v3/testsuite/30_threads/try_lock/4.cc
+++ b/libstdc++-v3/testsuite/30_threads/try_lock/4.cc
@@ -125,7 +125,7 @@ void test03()
unreliable_lock::count = 0;
try
{
- std::try_lock(l1, l2, l3);
+ (void) std::try_lock(l1, l2, l3);
VERIFY( false );
}
catch (int e)
diff --git a/libstdc++-v3/testsuite/30_threads/unique_lock/cons/60497.cc b/libstdc++-v3/testsuite/30_threads/unique_lock/cons/60497.cc
index c3cb6214d63..a8a8db4318a 100644
--- a/libstdc++-v3/testsuite/30_threads/unique_lock/cons/60497.cc
+++ b/libstdc++-v3/testsuite/30_threads/unique_lock/cons/60497.cc
@@ -50,5 +50,5 @@ void test02()
void test03()
{
test_type l1, l2, l3;
- std::try_lock(l1, l2, l3);
+ (void) std::try_lock(l1, l2, l3);
}
diff --git a/libstdc++-v3/testsuite/30_threads/unique_lock/locking/3.cc b/libstdc++-v3/testsuite/30_threads/unique_lock/locking/3.cc
index 3cb787b3154..ecc5b82f1c1 100644
--- a/libstdc++-v3/testsuite/30_threads/unique_lock/locking/3.cc
+++ b/libstdc++-v3/testsuite/30_threads/unique_lock/locking/3.cc
@@ -38,7 +38,7 @@ int main()
try
{
- l.try_lock_for(std::chrono::milliseconds(100));
+ (void) l.try_lock_for(std::chrono::milliseconds(100));
}
catch(const std::system_error&)
{
diff --git a/libstdc++-v3/testsuite/30_threads/unique_lock/locking/clock_neg.cc b/libstdc++-v3/testsuite/30_threads/unique_lock/locking/clock_neg.cc
index 68157f6ad26..b633e5fcc58 100644
--- a/libstdc++-v3/testsuite/30_threads/unique_lock/locking/clock_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/unique_lock/locking/clock_neg.cc
@@ -34,7 +34,7 @@ test01()
{
std::timed_mutex m;
std::unique_lock<std::timed_mutex> l(m, std::defer_lock);
- l.try_lock_until(clok::now()); // { dg-error "here" }
+ (void) l.try_lock_until(clok::now()); // { dg-error "here" }
}
struct cloc
@@ -53,7 +53,7 @@ test02()
{
std::recursive_timed_mutex m;
std::unique_lock<std::recursive_timed_mutex> l(m, std::defer_lock);
- l.try_lock_until(cloc::now()); // { dg-error "here" }
+ (void) l.try_lock_until(cloc::now()); // { dg-error "here" }
}
// { dg-error "static assertion failed" "" { target *-*-* } 0 }
More information about the Libstdc++-cvs
mailing list