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boost::interprocess::file_lock
// In header: <boost/interprocess/sync/file_lock.hpp> class file_lock { public: // construct/copy/destruct () ; (); (); (file_lock &&) ; file_lock & (file_lock &&) ; ~(); // public member functions (file_lock &) ; (); (); template<typename TimePoint> (); template<typename TimePoint> (); template<typename Duration> (); (); (); (); (); (); template<typename TimePoint> (); template<typename TimePoint> (); template<typename Duration> (); (); (); };
A file lock, is a mutual exclusion utility similar to a mutex using a file. A file lock has sharable and exclusive locking capabilities and can be used with scoped_lock and sharable_lock classes. A file lock can't guarantee synchronization between threads of the same process so just use file locks to synchronize threads from different processes.
file_lock
public
construct/copy/destruct() ;
Constructs an empty file mapping. Does not throw
( name);
Opens a file lock. Throws interprocess_exception
if the file does not exist or there are no operating system resources.
( name);
Opens a file lock. Throws interprocess_exception
if the file does not exist or there are no operating system resources.
Note: This function is only available on operating systems with native wchar_t APIs (e.g. Windows).
(file_lock && moved) ;
Moves the ownership of "moved"'s file mapping object to *this. After the call, "moved" does not represent any file mapping object. Does not throw
file_lock & (file_lock && moved) ;
Moves the ownership of "moved"'s file mapping to *this. After the call, "moved" does not represent any file mapping. Does not throw
~();Closes a file lock. Does not throw.
file_lock
public member functions(file_lock & other) ;
Swaps two file_locks. Does not throw.
();
Requires: The calling thread does not own the mutex.
Effects: The calling thread tries to obtain exclusive ownership of the mutex, and if another thread has exclusive, or sharable ownership of the mutex, it waits until it can obtain the ownership. Throws: interprocess_exception
on error.
Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown.
();
Requires: The calling thread does not own the mutex.
Effects: The calling thread tries to acquire exclusive ownership of the mutex without waiting. If no other thread has exclusive, or sharable ownership of the mutex this succeeds. Returns: If it can acquire exclusive ownership immediately returns true. If it has to wait, returns false. Throws: interprocess_exception
on error.
Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown.
template<typename TimePoint> ( abs_time);
Requires: The calling thread does not own the mutex.
Effects: The calling thread tries to acquire exclusive ownership of the mutex waiting if necessary until no other thread has exclusive, or sharable ownership of the mutex or abs_time is reached. Returns: If acquires exclusive ownership, returns true. Otherwise returns false. Throws: interprocess_exception
on error.
Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown.
template<typename TimePoint> ( abs_time);
Same as timed_lock
, but this function is modeled after the standard library interface.
template<typename Duration> ( dur);
Same as timed_lock
, but this function is modeled after the standard library interface.
();
Precondition: The thread must have exclusive ownership of the mutex. Effects: The calling thread releases the exclusive ownership of the mutex. Throws: An exception derived from interprocess_exception
on error.
();
Requires: The calling thread does not own the mutex.
Effects: The calling thread tries to obtain sharable ownership of the mutex, and if another thread has exclusive ownership of the mutex, waits until it can obtain the ownership. Throws: interprocess_exception
on error.
Note: A program may deadlock if the thread that owns a mutex object calls this function. If the implementation can detect the deadlock, an exception could be thrown.
();
Same as lock_sharable
but with a std-compatible interface
();
Effects: The calling thread tries to acquire sharable ownership of the mutex without waiting. If no other thread has exclusive ownership of the mutex this succeeds. Returns: If it can acquire sharable ownership immediately returns true. If it has to wait, returns false. Throws: interprocess_exception
on error.
();
Same as try_lock_sharable
but with a std-compatible interface
template<typename TimePoint> ( abs_time);
Effects: The calling thread tries to acquire sharable ownership of the mutex waiting if necessary until no other thread has exclusive ownership of the mutex or abs_time is reached. Returns: If acquires sharable ownership, returns true. Otherwise returns false. Throws: interprocess_exception
on error.
template<typename TimePoint> ( abs_time);
Same as timed_lock_sharable
, but this function is modeled after the standard library interface.
template<typename Duration> ( dur);
Same as timed_lock_sharable
, but this function is modeled after the standard library interface.
();
Precondition: The thread must have sharable ownership of the mutex. Effects: The calling thread releases the sharable ownership of the mutex. Throws: An exception derived from interprocess_exception
on error.
();
Same as unlock_sharable
but with a std-compatible interface