/thirdparty/breakpad/client/mac/handler/protected_memory_allocator.h
http://github.com/tomahawk-player/tomahawk · C++ Header · 85 lines · 21 code · 12 blank · 52 comment · 0 complexity · 668d9432f2f6a44b80190bb94496a98b MD5 · raw file
- // Copyright (c) 2006, Google Inc.
- // All rights reserved.
- //
- // Redistribution and use in source and binary forms, with or without
- // modification, are permitted provided that the following conditions are
- // met:
- //
- // * Redistributions of source code must retain the above copyright
- // notice, this list of conditions and the following disclaimer.
- // * Redistributions in binary form must reproduce the above
- // copyright notice, this list of conditions and the following disclaimer
- // in the documentation and/or other materials provided with the
- // distribution.
- // * Neither the name of Google Inc. nor the names of its
- // contributors may be used to endorse or promote products derived from
- // this software without specific prior written permission.
- //
- // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- //
- // ProtectedMemoryAllocator
- //
- // A very simple allocator class which allows allocation, but not deallocation.
- // The allocations can be made read-only with the Protect() method.
- // This class is NOT useful as a general-purpose memory allocation system,
- // since it does not allow deallocation. It is useful to use for a group
- // of allocations which are created in the same time-frame and destroyed
- // in the same time-frame. It is useful for making allocations of memory
- // which will not need to change often once initialized. This memory can then
- // be protected from memory smashers by calling the Protect() method.
- #ifndef PROTECTED_MEMORY_ALLOCATOR_H__
- #define PROTECTED_MEMORY_ALLOCATOR_H__
- #include <mach/mach.h>
- //
- class ProtectedMemoryAllocator {
- public:
- ProtectedMemoryAllocator(vm_size_t pool_size);
- ~ProtectedMemoryAllocator();
-
- // Returns a pointer to an allocation of size n within the pool.
- // Fails by returning NULL is no more space is available.
- // Please note that the pointers returned from this method should not
- // be freed in any way (for example by calling free() on them ).
- char * Allocate(vm_size_t n);
-
- // Returns the base address of the allocation pool.
- char * GetBaseAddress() { return (char*)base_address_; }
- // Returns the size of the allocation pool, including allocated
- // plus free space.
- vm_size_t GetTotalSize() { return pool_size_; }
- // Returns the number of bytes already allocated in the pool.
- vm_size_t GetAllocatedSize() { return next_alloc_offset_; }
- // Returns the number of bytes available for allocation.
- vm_size_t GetFreeSize() { return pool_size_ - next_alloc_offset_; }
-
- // Makes the entire allocation pool read-only including, of course,
- // all allocations made from the pool.
- kern_return_t Protect();
- // Makes the entire allocation pool read/write.
- kern_return_t Unprotect();
-
- private:
- vm_size_t pool_size_;
- vm_address_t base_address_;
- vm_size_t next_alloc_offset_;
- bool valid_;
- };
- #endif // PROTECTED_MEMORY_ALLOCATOR_H__