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Reference documentation for deal.II version 9.1.0-pre
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Reference documentation for deal.II version 9.1.0-pre
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#include <deal.II/lac/vector_memory.h>
Classes | |
| struct | Pool |
Public Types | |
| using | size_type = types::global_dof_index |
Public Member Functions | |
| GrowingVectorMemory (const size_type initial_size=0, const bool log_statistics=false) | |
| virtual | ~GrowingVectorMemory () override |
| virtual VectorType * | alloc () override |
| virtual void | free (const VectorType *const) override |
| virtual std::size_t | memory_consumption () const |
 Public Member Functions inherited from VectorMemory< VectorType > | |
| virtual | ~VectorMemory () override=default |
| Public Member Functions inherited from Subscriptor | |
| Subscriptor () | |
| Subscriptor (const Subscriptor &) | |
| Subscriptor (Subscriptor &&) noexcept | |
| virtual | ~Subscriptor () |
| Subscriptor & | operator= (const Subscriptor &) |
| Subscriptor & | operator= (Subscriptor &&) noexcept |
| void | subscribe (const char *identifier=nullptr) const |
| void | unsubscribe (const char *identifier=nullptr) const |
| unsigned int | n_subscriptions () const |
| template<typename StreamType > | |
| void | list_subscribers (StreamType &stream) const |
| void | list_subscribers () const |
| template<class Archive > | |
| void | serialize (Archive &ar, const unsigned int version) |
Static Public Member Functions | |
| static void | release_unused_memory () |
| Static Public Member Functions inherited from VectorMemory< VectorType > | |
| static::ExceptionBase & | ExcNotAllocatedHere () |
| Static Public Member Functions inherited from Subscriptor | |
| static::ExceptionBase & | ExcInUse (int arg1, std::string arg2, std::string arg3) |
| static::ExceptionBase & | ExcNoSubscriber (std::string arg1, std::string arg2) |
Private Types | |
| using | entry_type = std::pair< bool, std::unique_ptr< VectorType >> |
Private Attributes | |
| size_type | total_alloc |
| size_type | current_alloc |
| bool | log_statistics |
Static Private Attributes | |
| static Pool | pool |
| static Threads::Mutex | mutex |
A pool based memory management class. See the documentation of the base class for a description of its purpose.
Each time a vector is requested from this class, it checks if it has one available and returns its address, or allocates a new one on the heap. If a vector is returned from its user, through the GrowingVectorMemory::free() member function, it doesn't return the allocated memory to the operating system memory subsystem, but keeps it around unused for later use if GrowingVectorMemory::alloc() is called again. The class therefore avoid the overhead of repeatedly allocating memory on the heap if temporary vectors are required and released frequently; on the other hand, it doesn't release once-allocated memory at the earliest possible time and may therefore lead to an increased overall memory consumption.
All GrowingVectorMemory objects of the same vector type use the same memory pool. (In other words: The pool of vectors from which this class draws is global, rather than a regular member variable of the current class that is destroyed at the time that the surrounding GrowingVectorMemory object is destroyed.) Therefore, functions can create such a GrowingVectorMemory object whenever needed without the performance penalty of creating a new memory pool every time. A drawback of this policy is that vectors once allocated are only released at the end of the program run.
Definition at line 320 of file vector_memory.h.
| using GrowingVectorMemory< VectorType >::size_type = types::global_dof_index |
Declare type for container size.
Definition at line 326 of file vector_memory.h.
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private |
A type that describes this entries of an array that represents the vectors stored by this object. The first component of the pair is be a flag telling whether the vector is used, the second a pointer to the vector itself.
Definition at line 403 of file vector_memory.h.
| GrowingVectorMemory< VectorType >::GrowingVectorMemory | ( | const size_type | initial_size = 0, |
| const bool | log_statistics = false |
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| ) |
Constructor. The argument allows to preallocate a certain number of vectors. The default is not to do this.
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overridevirtual |
Destructor. The destructor also checks that all vectors that have been allocated through the current object have all been released again. However, as discussed in the class documentation, this does not imply that their memory is returned to the operating system.
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overridevirtual |
Return a pointer to a new vector. The number of elements or their subdivision into blocks (if applicable) is unspecified and users of this function should reset vectors to their proper size. The same holds for the contents of vectors: they are unspecified. In other words, the place that calls this function will need to resize or reinitialize it appropriately.
new and delete explicitly in code invites bugs where memory is leaked (either because the corresponding delete is forgotten altogether, or because of exception safety issues), using the alloc() and free() functions explicitly invites writing code that accidentally leaks memory. You should consider using the VectorMemory::Pointer class instead, which provides the same kind of service that std::unique provides for arbitrary memory allocated on the heap. Implements VectorMemory< VectorType >.
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overridevirtual |
Return a vector and indicate that it is not going to be used any further by the instance that called alloc() to get a pointer to it.
For the present class, this means retaining the vector for later reuse by the alloc() method.
new and delete explicitly in code invites bugs where memory is leaked (either because the corresponding delete is forgotten altogether, or because of exception safety issues), using the alloc() and free() functions explicitly invites writing code that accidentally leaks memory. You should consider using the VectorMemory::Pointer class instead, which provides the same kind of service that std::unique provides for arbitrary memory allocated on the heap. Implements VectorMemory< VectorType >.
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static |
Release all vectors that are not currently in use.
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virtual |
Memory consumed by this class and all currently allocated vectors.
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staticprivate |
Array of allocated vectors.
Definition at line 441 of file vector_memory.h.
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private |
Overall number of allocations. Only used for bookkeeping and to generate output at the end of an object's lifetime.
Definition at line 447 of file vector_memory.h.
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private |
Number of vectors currently allocated in this object; used for detecting memory leaks.
Definition at line 453 of file vector_memory.h.
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private |
A flag controlling the logging of statistics by the destructor.
Definition at line 458 of file vector_memory.h.
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staticprivate |
Mutex to synchronize access to internal data of this object from multiple threads.
Definition at line 464 of file vector_memory.h.
1.8.11