| 1 | // Copyright (c) 2005, 2007, Google Inc. |
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| 2 | // All rights reserved. |
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| 3 | // |
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| 4 | // Redistribution and use in source and binary forms, with or without |
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| 5 | // modification, are permitted provided that the following conditions are |
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| 6 | // met: |
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| 7 | // |
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| 8 | // * Redistributions of source code must retain the above copyright |
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| 9 | // notice, this list of conditions and the following disclaimer. |
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| 10 | // * Redistributions in binary form must reproduce the above |
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| 11 | // copyright notice, this list of conditions and the following disclaimer |
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| 12 | // in the documentation and/or other materials provided with the |
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| 13 | // distribution. |
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| 14 | // * Neither the name of Google Inc. nor the names of its |
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| 15 | // contributors may be used to endorse or promote products derived from |
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| 16 | // this software without specific prior written permission. |
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| 17 | // |
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| 18 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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| 19 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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| 20 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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| 21 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| 22 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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| 23 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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| 24 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 25 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 26 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 27 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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| 28 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 29 | |
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| 30 | // --- |
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| 31 | // Author: Sanjay Ghemawat |
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| 32 | // |
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| 33 | // Routine that uses sbrk/mmap to allocate memory from the system. |
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| 34 | // Useful for implementing malloc. |
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| 35 | |
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| 36 | #ifndef TCMALLOC_SYSTEM_ALLOC_H__ |
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| 37 | #define TCMALLOC_SYSTEM_ALLOC_H__ |
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| 38 | |
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| 39 | // REQUIRES: "alignment" is a power of two or "0" to indicate default alignment |
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| 40 | // |
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| 41 | // Allocate and return "N" bytes of zeroed memory. |
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| 42 | // |
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| 43 | // If actual_bytes is NULL then the returned memory is exactly the |
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| 44 | // requested size. If actual bytes is non-NULL then the allocator |
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| 45 | // may optionally return more bytes than asked for (i.e. return an |
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| 46 | // entire "huge" page if a huge page allocator is in use). |
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| 47 | // |
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| 48 | // The returned pointer is a multiple of "alignment" if non-zero. |
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| 49 | // |
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| 50 | // Returns NULL when out of memory. |
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| 51 | extern void* TCMalloc_SystemAlloc(size_t bytes, size_t *actual_bytes, |
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| 52 | size_t alignment = 0); |
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| 53 | |
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| 54 | // This call is a hint to the operating system that the pages |
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| 55 | // contained in the specified range of memory will not be used for a |
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| 56 | // while, and can be released for use by other processes or the OS. |
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| 57 | // Pages which are released in this way may be destroyed (zeroed) by |
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| 58 | // the OS. The benefit of this function is that it frees memory for |
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| 59 | // use by the system, the cost is that the pages are faulted back into |
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| 60 | // the address space next time they are touched, which can impact |
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| 61 | // performance. (Only pages fully covered by the memory region will |
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| 62 | // be released, partial pages will not.) |
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| 63 | extern void TCMalloc_SystemRelease(void* start, size_t length); |
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| 64 | |
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| 65 | extern void TCMalloc_SystemCommit(void* start, size_t length); |
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| 66 | |
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| 67 | #if !HAVE(MADV_FREE_REUSE) && !HAVE(MADV_DONTNEED) && !HAVE(MMAP) && !HAVE(VIRTUALALLOC) |
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| 68 | inline void TCMalloc_SystemRelease(void*, size_t) { } |
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| 69 | #endif |
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| 70 | |
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| 71 | #if !HAVE(VIRTUALALLOC) && !HAVE(MADV_FREE_REUSE) |
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| 72 | inline void TCMalloc_SystemCommit(void*, size_t) { } |
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| 73 | #endif |
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| 74 | |
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| 75 | #endif /* TCMALLOC_SYSTEM_ALLOC_H__ */ |
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| 76 | |
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