| // Copyright (c) 2005, 2007, 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. |
| |
| // --- |
| // 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__ */ |
