#include <locking_allocator.h>

Public Member Functions
void *	allocate (size_t num_elems, size_t elem_size)

bool	deallocate (void *p, size_t num_elems, size_t elem_size) noexcept

	mlock_allocator ()

	mlock_allocator (const mlock_allocator &)=delete

mlock_allocator &	operator= (const mlock_allocator &)=delete

	~mlock_allocator ()

Static Public Member Functions
static mlock_allocator &	instance ()

Detailed Description

Definition at line 19 of file locking_allocator.h.

Constructor & Destructor Documentation

◆ mlock_allocator() [1/2]

Botan::mlock_allocator::mlock_allocator ( const mlock_allocator & )

delete

◆ mlock_allocator() [2/2]

Botan::mlock_allocator::mlock_allocator ( )

Definition at line 46 of file locking_allocator.cpp.

                                 {
   const size_t mem_to_lock = OS::get_memory_locking_limit();
   const size_t page_size = OS::system_page_size();
 
   if(mem_to_lock > 0 && mem_to_lock % page_size == 0) {
      m_locked_pages = OS::allocate_locked_pages(mem_to_lock / page_size);
 
      if(!m_locked_pages.empty()) {
         m_pool = std::make_unique<Memory_Pool>(m_locked_pages, page_size);
      }
   }
}

References Botan::OS::allocate_locked_pages(), Botan::OS::get_memory_locking_limit(), and Botan::OS::system_page_size().

◆ ~mlock_allocator()

Botan::mlock_allocator::~mlock_allocator ( )

Definition at line 59 of file locking_allocator.cpp.

                                  {
   if(m_pool) {
      m_pool.reset();
      // OS::free_locked_pages scrubs the memory before free
      OS::free_locked_pages(m_locked_pages);
   }
}

References Botan::OS::free_locked_pages().

Member Function Documentation

◆ allocate()

void * Botan::mlock_allocator::allocate	(	size_t	num_elems,
		size_t	elem_size )

Definition at line 16 of file locking_allocator.cpp.

                                                                  {
   if(!m_pool) {
      return nullptr;
   }
 
   const auto n = BOTAN_CHECKED_MUL(num_elems, elem_size);
   if(!n.has_value()) {
      return nullptr;  // overflow!
   }
 
   return m_pool->allocate(n.value());
}

References BOTAN_CHECKED_MUL.

◆ deallocate()

bool Botan::mlock_allocator::deallocate	(	void *	p,
		size_t	num_elems,
		size_t	elem_size )

noexcept

Definition at line 29 of file locking_allocator.cpp.

                                                                                     {
   if(!m_pool) {
      return false;
   }
 
   /*
   We return nullptr in allocate if there was an overflow, so if an
   overflow occurs here we know the pointer was not allocated by this pool.
   */
   const auto n = BOTAN_CHECKED_MUL(num_elems, elem_size);
   if(!n.has_value()) {
      return false;
   }
 
   return m_pool->deallocate(p, n.value());
}

References BOTAN_CHECKED_MUL.

◆ instance()

mlock_allocator & Botan::mlock_allocator::instance ( )

static

Definition at line 74 of file locking_allocator.cpp.

                                           {
   return g_mlock_allocator;
}

Referenced by Botan::allocate_memory(), Botan::deallocate_memory(), and Botan::initialize_allocator().

◆ operator=()

mlock_allocator & Botan::mlock_allocator::operator= ( const mlock_allocator & )