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// 

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// met:

// 

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// in the documentation and/or other materials provided with the

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// this software without specific prior written permission.

// 

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// ---

// Author: Sanjay Ghemawat

//

// Routine that uses sbrk/mmap to allocate memory from the system.

// Useful for implementing malloc.

#ifndef TCMALLOC_SYSTEM_ALLOC_H__

#define TCMALLOC_SYSTEM_ALLOC_H__

// REQUIRES: "alignment" is a power of two or "0" to indicate default alignment

//

// Allocate and return "N" bytes of zeroed memory.

//

// If actual_bytes is NULL then the returned memory is exactly the

// requested size.  If actual bytes is non-NULL then the allocator

// may optionally return more bytes than asked for (i.e. return an

// entire "huge" page if a huge page allocator is in use).

//

// The returned pointer is a multiple of "alignment" if non-zero.

//

// Returns NULL when out of memory.

extern void* TCMalloc_SystemAlloc(size_t bytes, size_t *actual_bytes,

                                  size_t alignment = 0);

// This call is a hint to the operating system that the pages

// contained in the specified range of memory will not be used for a

// while, and can be released for use by other processes or the OS.

// Pages which are released in this way may be destroyed (zeroed) by

// the OS.  The benefit of this function is that it frees memory for

// use by the system, the cost is that the pages are faulted back into

// the address space next time they are touched, which can impact

// performance.  (Only pages fully covered by the memory region will

// be released, partial pages will not.)

extern void TCMalloc_SystemRelease(void* start, size_t length);

extern void TCMalloc_SystemCommit(void* start, size_t length);

#if !HAVE(MADV_FREE_REUSE) && !HAVE(MADV_DONTNEED) && !HAVE(MMAP) && !HAVE(VIRTUALALLOC)

inline void TCMalloc_SystemRelease(void*, size_t) { }

#endif

#if !HAVE(VIRTUALALLOC) && !HAVE(MADV_FREE_REUSE)

inline void TCMalloc_SystemCommit(void*, size_t) { }

#endif

#endif /* TCMALLOC_SYSTEM_ALLOC_H__ */