Mercurial > jwe > octave
view liboctave/util/oct-locbuf.h @ 20955:77f5591878bf
maint: Use '! expr' rather than '!expr' to conform to coding guidelines.
* dialog.h, documentation-dock-widget.cc, files-dock-widget.cc,
find-files-dialog.cc, file-editor-tab.cc, file-editor.cc, find-dialog.cc,
octave-qscintilla.cc, main-window.cc, parser.cc, resource-manager.cc,
workspace-view.cc, data.cc, dlmread.cc, gl-render.cc, gl2ps-renderer.cc,
graphics.cc, graphics.in.h, ls-hdf5.cc, ls-mat5.cc, ls-oct-binary.cc, lsode.cc,
mappers.cc, pt-jit.cc, regexp.cc, spparms.cc, symtab.h, utils.cc, zfstream.cc,
__eigs__.cc, __glpk__.cc, __init_fltk__.cc, ccolamd.cc, colamd.cc,
ov-base-diag.cc, ov-base-int.cc, ov-base-sparse.cc, ov-bool-mat.cc,
ov-bool-sparse.cc, ov-bool.cc, ov-class.cc, ov-cx-sparse.cc, ov-fcn-handle.cc,
ov-fcn-inline.cc, ov-java.cc, ov-perm.cc, ov-re-sparse.cc, ov-str-mat.cc,
ov-struct.cc, ov.cc, pt-mat.cc, Array.cc, Array.h, CMatrix.cc, CSparse.cc,
MatrixType.cc, PermMatrix.cc, Sparse.h, dMatrix.cc, dSparse.cc, fCMatrix.cc,
fMatrix.cc, idx-vector.cc, CollocWt.h, SparseCmplxLU.cc, SparseCmplxQR.cc,
SparseQR.cc, SparsedbleLU.cc, base-qr.cc, eigs-base.cc, oct-fftw.cc,
randmtzig.c, sparse-dmsolve.cc, kpse.cc, lo-regexp.cc, oct-locbuf.h,
url-transfer.cc, url-transfer.h, bitset.m, interp2.m, __isequal__.m,
inpolygon.m, questdlg.m, help.m, compare_versions.m, substruct.m,
configure_make.m, whitebg.m, __marching_cube__.m, struct2hdl.m, polyfit.m,
spline.m, unique.m, svds.m, ellipke.m, binoinv.m, hygepdf.m, nbininv.m,
poissinv.m, tcdf.m, unidcdf.m, unidpdf.m, dec2base.m, assert.m, weekday.m,
mkoctfile.in.cc:
maint: Use '! expr' rather than '!expr' to conform to coding guidelines.
author | Rik <rik@octave.org> |
---|---|
date | Sun, 20 Dec 2015 10:15:02 -0800 |
parents | f7084eae3318 |
children | 538b57866b90 |
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/* Copyright (C) 2008-2015 Jaroslav Hajek This file is part of Octave. Octave is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. Octave is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Octave; see the file COPYING. If not, see <http://www.gnu.org/licenses/>. */ #if ! defined (octave_oct_locbuf_h) #define octave_oct_locbuf_h 1 #include <cstddef> #include "oct-cmplx.h" // The default local buffer simply encapsulates an *array* pointer // that gets deleted automatically. For common POD types, we provide // specializations. template <class T> class octave_local_buffer { public: octave_local_buffer (size_t size) : data (0) { if (size) data = new T [size]; } ~octave_local_buffer (void) { delete [] data; } operator T *() const { return data; } private: T *data; // No copying! octave_local_buffer (const octave_local_buffer&); octave_local_buffer& operator = (const octave_local_buffer&); }; // For buffers of POD types, we'll be smarter. There is one thing // that differentiates a local buffer from a dynamic array - the local // buffers, if not manipulated improperly, have a FIFO semantics, // meaning that if buffer B is allocated after buffer A, B *must* be // deallocated before A. This is *guaranteed* if you use local buffer // exclusively through the OCTAVE_LOCAL_BUFFER macro, because the C++ // standard requires that explicit local objects be destroyed in // reverse order of declaration. Therefore, we can avoid memory // fragmentation by allocating fairly large chunks of memory and // serving local buffers from them in a stack-like manner. The first // returning buffer in previous chunk will be responsible for // deallocating the chunk. class octave_chunk_buffer { public: OCTAVE_API octave_chunk_buffer (size_t size); OCTAVE_API virtual ~octave_chunk_buffer (void); char *data (void) const { return dat; } static OCTAVE_API void clear (void); private: // The number of bytes we allocate for each large chunk of memory we // manage. static const size_t chunk_size; // Pointer to the end end of the last allocation. static char *top; // Pointer to the current active chunk. static char *chunk; // The number of bytes remaining in the active chunk. static size_t left; // The number of active allocations. static size_t active; // Pointer to the current chunk. char *cnk; // Pointer to the beginning of the most recent allocation. char *dat; // No copying! octave_chunk_buffer (const octave_chunk_buffer&); octave_chunk_buffer& operator = (const octave_chunk_buffer&); }; // This specializes octave_local_buffer to use the chunked buffer // mechanism for POD types. #define SPECIALIZE_POD_BUFFER(TYPE) \ template <> \ class octave_local_buffer<TYPE> : private octave_chunk_buffer \ { \ public: \ octave_local_buffer (size_t size) \ : octave_chunk_buffer (size * sizeof (TYPE)) { } \ \ operator TYPE *() const \ { \ return reinterpret_cast<TYPE *> (this->data ()); \ } \ } SPECIALIZE_POD_BUFFER (bool); SPECIALIZE_POD_BUFFER (char); SPECIALIZE_POD_BUFFER (unsigned short); SPECIALIZE_POD_BUFFER (short); SPECIALIZE_POD_BUFFER (int); SPECIALIZE_POD_BUFFER (unsigned int); SPECIALIZE_POD_BUFFER (long); SPECIALIZE_POD_BUFFER (unsigned long); SPECIALIZE_POD_BUFFER (float); SPECIALIZE_POD_BUFFER (double); // FIXME: Are these guaranteed to be POD and satisfy alignment? SPECIALIZE_POD_BUFFER (Complex); SPECIALIZE_POD_BUFFER (FloatComplex); // MORE ? // All pointers and const pointers are also POD types. template <class T> class octave_local_buffer<T *> : private octave_chunk_buffer { public: octave_local_buffer (size_t size) : octave_chunk_buffer (size * sizeof (T *)) { } operator T **() const { return reinterpret_cast<T **> (this->data ()); } }; template <class T> class octave_local_buffer<const T *> : private octave_chunk_buffer { public: octave_local_buffer (size_t size) : octave_chunk_buffer (size * sizeof (const T *)) { } operator const T **() const { return reinterpret_cast<const T **> (this->data ()); } }; // If the compiler supports dynamic stack arrays, we can use the // attached hack to place small buffer arrays on the stack. It may be // even faster than our obstack-like optimization, but is dangerous // because stack is a very limited resource, so we disable it. #if 0 // defined (HAVE_DYNAMIC_AUTO_ARRAYS) // Maximum buffer size (in bytes) to be placed on the stack. #define OCTAVE_LOCAL_BUFFER_MAX_STACK_SIZE 8192 // If we have automatic arrays, we use an automatic array if the size // is small enough. To avoid possibly evaluating 'size' multiple // times, we first cache it. Note that we always construct both the // stack array and the octave_local_buffer object, but only one of // them will be nonempty. #define OCTAVE_LOCAL_BUFFER(T, buf, size) \ const size_t _bufsize_ ## buf = size; \ const bool _lbufaut_ ## buf = _bufsize_ ## buf * sizeof (T) \ <= OCTAVE_LOCAL_BUFFER_MAX_STACK_SIZE; \ T _bufaut_ ## buf [_lbufaut_ ## buf ? _bufsize_ ## buf : 0]; \ octave_local_buffer<T> _bufheap_ ## buf \ (! _lbufaut_ ## buf ? _bufsize_ ## buf : 0); \ T *buf = _lbufaut_ ## buf \ ? _bufaut_ ## buf : static_cast<T *> (_bufheap_ ## buf) #else // If we don't have automatic arrays, we simply always use // octave_local_buffer. #define OCTAVE_LOCAL_BUFFER(T, buf, size) \ octave_local_buffer<T> _buffer_ ## buf (size); \ T *buf = _buffer_ ## buf #endif // Note: we use weird variables in the for loop to avoid warnings // about shadowed parameters. #define OCTAVE_LOCAL_BUFFER_INIT(T, buf, size, value) \ OCTAVE_LOCAL_BUFFER (T, buf, size); \ for (size_t _buf_iter = 0, _buf_size = size; \ _buf_iter < _buf_size; _buf_iter++) \ buf[_buf_iter] = value #endif