This class is a simple wrapper around C++ standard library type std::shared_timed_mutex
. Thus, it is used to implement mutual exclusive access to resources by protecting critical code sections from being executed in parallel in concurrent threads, while allowing typical read-operations to continue to be executed in parallel.
With release-compilations, the only difference to using std::shared_timed_mutex
directly is that "spurious wake-ups" are detected and mitigated by this implementation.
When a pair of Acquire and Release invocations is performed within the same code block, then it is recommended to use a stack instantiation of class Owner to acquire and release objects of this class. Such a use is highly simplified with macros ALIB_LOCK and ALIB_LOCK_WITH.
The same is recommended for paired invocations of AcquireShared and ReleaseShared. Here, class OwnerShared is to be used, best using macros ALIB_LOCK_SHARED and ALIB_LOCK_SHARED_WITH.
This class does not allow nested calls to the method Acquire - method Release has to be invoked (from within the same thread that acquired this mutex), before any other thread can again gain access. Nested acquisitions constitute undefined behavior.
Definition at line 51 of file sharedtimedlock.inl.
Public Field Index: | |
DbgSharedLockAsserter | Dbg |
The debug tool instance. | |
std::atomic< int > | DbgWarningMaximumShared =10 |
Public Method Index: | |
~SharedTimedLock () override | |
Destructor. With debug-compilations, asserts that this lock is not acquired. | |
ALIB_DLL void | Acquire (ALIB_DBG_TAKE_CI) |
ALIB_DLL void | AcquireShared (ALIB_DBG_TAKE_CI) |
virtual ALIB_DLL bool | DCSIsAcquired () const override |
virtual ALIB_DLL bool | DCSIsSharedAcquired () const override |
ALIB_DLL void | Release (ALIB_DBG_TAKE_CI) |
ALIB_DLL void | ReleaseShared (ALIB_DBG_TAKE_CI) |
ALIB_DLL bool | TryAcquire (ALIB_DBG_TAKE_CI) |
ALIB_DLL bool | TryAcquireShared (ALIB_DBG_TAKE_CI) |
bool | TryAcquireSharedTimed (const Ticks &pointInTime, const CallerInfo &ci) |
ALIB_DLL bool | TryAcquireSharedTimed (const Ticks::Duration &waitDuration, const CallerInfo &ci) |
bool | TryAcquireSharedTimed (const Ticks::Duration::TDuration &waitDuration, const CallerInfo &ci) |
bool | TryAcquireSharedTimed (const Ticks::TTimePoint &pointInTime, const CallerInfo &ci) |
bool | TryAcquireTimed (const Ticks &pointInTime, const CallerInfo &ci) |
ALIB_DLL bool | TryAcquireTimed (const Ticks::Duration &waitDuration, const CallerInfo &ci) |
bool | TryAcquireTimed (const Ticks::Duration::TDuration &waitDuration, const CallerInfo &ci) |
bool | TryAcquireTimed (const Ticks::TTimePoint &pointInTime, const CallerInfo &ci) |
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virtual | ~AssociatedLock () |
Virtual Destructor. | |
Protected Field Index: | |
std::shared_timed_mutex | mutex |
The internal object to lock on. | |
DbgSharedLockAsserter alib::threads::SharedTimedLock::Dbg |
The debug tool instance.
Definition at line 63 of file sharedtimedlock.inl.
std::atomic<int> alib::threads::SharedTimedLock::DbgWarningMaximumShared =10 |
Warning-threshold of maximum number of parallel shared acquisitions.
Defaults to 10.
Definition at line 67 of file sharedtimedlock.inl.
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protected |
The internal object to lock on.
Definition at line 58 of file sharedtimedlock.inl.
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inlineoverride |
Destructor. With debug-compilations, asserts that this lock is not acquired.
Definition at line 71 of file sharedtimedlock.inl.
void alib::threads::SharedTimedLock::Acquire | ( | ALIB_DBG_TAKE_CI | ) |
Same as TryAcquireTimed(const Ticks::Duration&, const CallerInfo&) but misses the parameter waitTime. Using this method, the behavior is equivalent to that of sibling type Lock.
Definition at line 562 of file locks.cpp.
void alib::threads::SharedTimedLock::AcquireShared | ( | ALIB_DBG_TAKE_CI | ) |
Same as TryAcquireSharedTimed(const Ticks::Duration&, const CallerInfo&) but misses the parameter waitTime. Using this method, the behavior is equivalent to that of sibling type SharedLock.
Definition at line 658 of file locks.cpp.
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overridevirtual |
true
if the lock is acquired (in non-shared mode), false
otherwise. Implements alib::lang::DbgCriticalSections::AssociatedLock.
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overridevirtual |
true
if the lock is shared-acquired (by at least any thread). Otherwise, returns false
. Implements alib::lang::DbgCriticalSections::AssociatedLock.
void alib::threads::SharedTimedLock::Release | ( | ALIB_DBG_TAKE_CI | ) |
Releases ownership of this object. If this method is invoked on an object that is not acquired, in debug-compilations an assertion is raised. In release compilations, this leads to undefined behavior.
void alib::threads::SharedTimedLock::ReleaseShared | ( | ALIB_DBG_TAKE_CI | ) |
Releases shared ownership of this object. Invoking this method on an object that is not "shared acquired" by this thread constitutes undefined behavior.
In debug-compilations the overall sum (of any thread) of shared acquirements and releases is counted, and an error is raised if more releases than acquisitions are performed.
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nodiscard |
Tries to acquire this lock. Multiple (nested) successful calls to this method or method Acquire are not supported and lead to undefined behavior.
true
if the lock was not acquired by a different thread and thus, this call was successful. false
otherwise.
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nodiscard |
Tries to acquire this lock in shared mode. Multiple (nested) calls to this method or method AcquireShared from within the same thread are not supported and lead to undefined behavior.
true
if the lock was not acquired by a different thread and thus, this call was successful. false
otherwise.
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inlinenodiscard |
Same as overloaded sibling, but expects a point in time rather than an Ticks::Duration.
pointInTime | The point in time, when this method stops waiting. |
ci | Caller information. Use macro ALIB_COMMA_CALLER_PRUNED with invocations. |
true
if the lock was acquired, false
if the pointInTime was reached without successful acquisition. Definition at line 243 of file sharedtimedlock.inl.
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nodiscard |
Same as method TryAcquireShared(ALIB_DBG_TAKE_CI), but accepts a maximum wait time as first parameter.
waitDuration | The maximum time-span to wait. |
ci | Caller information. Use macro ALIB_COMMA_CALLER_PRUNED with invocations. |
true
if the lock was acquired, false
if the waitDuration expired without successful acquisition Definition at line 718 of file locks.cpp.
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inlinenodiscard |
Same as overloaded sibling, but expects a C++ standard library duration type rather than an Ticks::Duration.
waitDuration | The point in time, when this method stops waiting. |
ci | Caller information. Available only with debug-builds. |
true
if the lock was acquired, false
if the pointInTime was reached without successful acquisition. Definition at line 232 of file sharedtimedlock.inl.
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inlinenodiscard |
Same as overloaded sibling, but expects a C++ standard library point in time type rather than a Ticks::Duration value.
pointInTime | The point in time, when this method stops waiting. |
ci | Caller information. Use macro ALIB_COMMA_CALLER_PRUNED with invocations. |
true
if the lock was acquired, false
if the pointInTime was reached without successful acquisition. Definition at line 255 of file sharedtimedlock.inl.
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inlinenodiscard |
Same as overloaded sibling, but expects a point in time rather than an Ticks::Duration.
pointInTime | The point in time, when this method stops waiting. |
ci | Caller information. Use macro ALIB_COMMA_CALLER_PRUNED with invocations. |
true
if the lock was acquired, false
if the pointInTime was reached without successful acquisition. Definition at line 147 of file sharedtimedlock.inl.
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nodiscard |
A thread which invokes this method gets registered as the current owner of this object, until the same thread releases the ownership invoking Release. In the case that this object is already owned by another thread, the invoking thread is suspended until ownership can be gained. Multiple (nested) calls to this method are not supported and lead to undefined behavior.
waitDuration | The maximum time-span to wait. |
ci | Caller information. Use macro ALIB_COMMA_CALLER_PRUNED with invocations. |
true
if the lock was acquired, false
if the waitDuration expired without successful acquisition Definition at line 609 of file locks.cpp.
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inlinenodiscard |
Same as overloaded sibling, but expects a C++ standard library duration type rather than an Ticks::Duration.
waitDuration | The point in time, when this method stops waiting. |
ci | Caller information. Use macro ALIB_COMMA_CALLER_PRUNED with invocations. |
true
if the lock was acquired, false
if the pointInTime was reached without successful acquisition. Definition at line 136 of file sharedtimedlock.inl.
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inlinenodiscard |
Same as overloaded sibling, but expects a C++ standard library point in time type rather than an Ticks::Duration.
pointInTime | The point in time, when this method stops waiting. |
ci | Caller information. Use macro ALIB_COMMA_CALLER_PRUNED with invocations. |
true
if the lock was acquired, false
if the pointInTime was reached without successful acquisition. Definition at line 161 of file sharedtimedlock.inl.