GCC Code Coverage Report
Directory: . Exec Total Coverage
File: src/prop/minisat/mtl/Alloc.h Lines: 45 47 95.7 %
Date: 2021-03-22 Branches: 21 108 19.4 %

Line Exec Source
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/*****************************************************************************************[Alloc.h]
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Copyright (c) 2008-2010, Niklas Sorensson
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Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
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associated documentation files (the "Software"), to deal in the Software without restriction,
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including without limitation the rights to use, copy, modify, merge, publish, distribute,
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sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all copies or
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substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
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NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
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OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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**************************************************************************************************/
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#ifndef Minisat_Alloc_h
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#define Minisat_Alloc_h
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#include "base/check.h"
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#include "prop/minisat/mtl/Vec.h"
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#include "prop/minisat/mtl/XAlloc.h"
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namespace CVC4 {
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namespace Minisat {
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//=================================================================================================
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// Simple Region-based memory allocator:
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template<class T>
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class RegionAllocator
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{
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    T*        memory;
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    uint32_t  sz;
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    uint32_t  cap;
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    uint32_t  wasted_;
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    void capacity(uint32_t min_cap);
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 public:
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    // TODO: make this a class for better type-checking?
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    typedef uint32_t Ref;
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    enum { Ref_Undef = UINT32_MAX };
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    enum { Unit_Size = sizeof(uint32_t) };
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    explicit RegionAllocator(uint32_t start_cap = 1024*1024) : memory(NULL), sz(0), cap(0), wasted_(0){ capacity(start_cap); }
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    ~RegionAllocator()
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    {
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        if (memory != NULL)
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            ::free(memory);
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    }
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    uint32_t size      () const      { return sz; }
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    uint32_t wasted    () const      { return wasted_; }
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    Ref      alloc     (int size);
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    void     free      (int size)    { wasted_ += size; }
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    // Deref, Load Effective Address (LEA), Inverse of LEA (AEL):
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    T& operator[](Ref r)
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    {
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      Assert(r >= 0 && r < sz);
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      return memory[r];
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    }
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    const T& operator[](Ref r) const
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    {
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      Assert(r >= 0 && r < sz);
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      return memory[r];
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    }
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    T* lea(Ref r)
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    {
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      Assert(r >= 0 && r < sz);
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      return &memory[r];
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    }
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    const T* lea(Ref r) const
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    {
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      Assert(r >= 0 && r < sz);
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      return &memory[r];
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    }
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    Ref ael(const T* t)
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    {
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      Assert((void*)t >= (void*)&memory[0]
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             && (void*)t < (void*)&memory[sz - 1]);
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      return (Ref)(t - &memory[0]);
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    }
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    void     moveTo(RegionAllocator& to) {
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        if (to.memory != NULL) ::free(to.memory);
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        to.memory = memory;
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        to.sz = sz;
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        to.cap = cap;
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        to.wasted_ = wasted_;
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        memory = NULL;
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        sz = cap = wasted_ = 0;
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    }
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};
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template<class T>
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void RegionAllocator<T>::capacity(uint32_t min_cap)
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{
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    if (cap >= min_cap) return;
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    uint32_t prev_cap = cap;
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    while (cap < min_cap){
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        // NOTE: Multiply by a factor (13/8) without causing overflow, then add 2 and make the
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        // result even by clearing the least significant bit. The resulting sequence of capacities
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        // is carefully chosen to hit a maximum capacity that is close to the '2^32-1' limit when
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        // using 'uint32_t' as indices so that as much as possible of this space can be used.
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        uint32_t delta = ((cap >> 1) + (cap >> 3) + 2) & ~1;
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        cap += delta;
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        if (cap <= prev_cap)
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            throw OutOfMemoryException();
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    }
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    // printf(" .. (%p) cap = %u\n", this, cap);
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    Assert(cap > 0);
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    memory = (T*)xrealloc(memory, sizeof(T)*cap);
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}
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template<class T>
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typename RegionAllocator<T>::Ref
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RegionAllocator<T>::alloc(int size)
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{
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    // printf("ALLOC called (this = %p, size = %d)\n", this, size); fflush(stdout);
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    Assert(size > 0);
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    capacity(sz + size);
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    uint32_t prev_sz = sz;
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    sz += size;
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    // Handle overflow:
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    if (sz < prev_sz)
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        throw OutOfMemoryException();
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    return prev_sz;
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}
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//=================================================================================================
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}
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}
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#endif