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Diffstat (limited to 'Source/JavaScriptCore/wtf/TCSystemAlloc.h')
| -rw-r--r-- | Source/JavaScriptCore/wtf/TCSystemAlloc.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/wtf/TCSystemAlloc.h b/Source/JavaScriptCore/wtf/TCSystemAlloc.h new file mode 100644 index 0000000..1c67788 --- /dev/null +++ b/Source/JavaScriptCore/wtf/TCSystemAlloc.h @@ -0,0 +1,75 @@ +// 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__ */ |