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