From 228dbcc51e8a00cc8e7c002f66b4411aada3a3fa Mon Sep 17 00:00:00 2001 From: Alan Mishchenko Date: Tue, 21 Oct 2014 19:45:52 -0700 Subject: Adding code of MiniSAT 2.2. --- src/sat/bsat2/Alloc.h | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 src/sat/bsat2/Alloc.h (limited to 'src/sat/bsat2/Alloc.h') diff --git a/src/sat/bsat2/Alloc.h b/src/sat/bsat2/Alloc.h new file mode 100644 index 00000000..7f506cb5 --- /dev/null +++ b/src/sat/bsat2/Alloc.h @@ -0,0 +1,131 @@ +/*****************************************************************************************[Alloc.h] +Copyright (c) 2008-2010, Niklas Sorensson + +Permission is hereby granted, free of charge, to any person obtaining a copy of this software and +associated documentation files (the "Software"), to deal in the Software without restriction, +including without limitation the rights to use, copy, modify, merge, publish, distribute, +sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all copies or +substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT +NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, +DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT +OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +**************************************************************************************************/ + + +#ifndef Minisat_Alloc_h +#define Minisat_Alloc_h + +#include "XAlloc.h" +#include "Vec.h" + +namespace Minisat { + +//================================================================================================= +// Simple Region-based memory allocator: + +template +class RegionAllocator +{ + T* memory; + uint32_t sz; + uint32_t cap; + uint32_t wasted_; + + void capacity(uint32_t min_cap); + + public: + // TODO: make this a class for better type-checking? + typedef uint32_t Ref; + enum { Ref_Undef = UINT32_MAX }; + enum { Unit_Size = sizeof(uint32_t) }; + + explicit RegionAllocator(uint32_t start_cap = 1024*1024) : memory(NULL), sz(0), cap(0), wasted_(0){ capacity(start_cap); } + ~RegionAllocator() + { + if (memory != NULL) + ::free(memory); + } + + + uint32_t size () const { return sz; } + uint32_t wasted () const { return wasted_; } + + Ref alloc (int size); + void _free (int size) { wasted_ += size; } + + // Deref, Load Effective Address (LEA), Inverse of LEA (AEL): + T& operator[](Ref r) { assert(r >= 0 && r < sz); return memory[r]; } + const T& operator[](Ref r) const { assert(r >= 0 && r < sz); return memory[r]; } + + T* lea (Ref r) { assert(r >= 0 && r < sz); return &memory[r]; } + const T* lea (Ref r) const { assert(r >= 0 && r < sz); return &memory[r]; } + Ref ael (const T* t) { assert((void*)t >= (void*)&memory[0] && (void*)t < (void*)&memory[sz-1]); + return (Ref)(t - &memory[0]); } + + void moveTo(RegionAllocator& to) { + if (to.memory != NULL) ::free(to.memory); + to.memory = memory; + to.sz = sz; + to.cap = cap; + to.wasted_ = wasted_; + + memory = NULL; + sz = cap = wasted_ = 0; + } + + +}; + +template +void RegionAllocator::capacity(uint32_t min_cap) +{ + if (cap >= min_cap) return; + + uint32_t prev_cap = cap; + while (cap < min_cap){ + // NOTE: Multiply by a factor (13/8) without causing overflow, then add 2 and make the + // result even by clearing the least significant bit. The resulting sequence of capacities + // is carefully chosen to hit a maximum capacity that is close to the '2^32-1' limit when + // using 'uint32_t' as indices so that as much as possible of this space can be used. + uint32_t delta = ((cap >> 1) + (cap >> 3) + 2) & ~1; + cap += delta; + + if (cap <= prev_cap) + throw OutOfMemoryException(); + } + // printf(" .. (%p) cap = %u\n", this, cap); + + assert(cap > 0); + memory = (T*)xrealloc(memory, sizeof(T)*cap); +} + + +template +typename RegionAllocator::Ref +RegionAllocator::alloc(int size) +{ + // printf("ALLOC called (this = %p, size = %d)\n", this, size); fflush(stdout); + assert(size > 0); + capacity(sz + size); + + uint32_t prev_sz = sz; + sz += size; + + // Handle overflow: + if (sz < prev_sz) + throw OutOfMemoryException(); + + return prev_sz; +} + + +//================================================================================================= +} + +#endif -- cgit v1.2.3