1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/Platform-Posix.cpp	Tue Jul 24 23:53:34 2012 -0700
     1.3 @@ -0,0 +1,101 @@
     1.4 +/* vim: set ts=4 sw=4 tw=99 et:
     1.5 + *
     1.6 + * Copyright (C) 2012 David Anderson
     1.7 + *
     1.8 + * This file is part of JITCraft.
     1.9 + *
    1.10 + * JITCraft is free software: you can redistribute it and/or modify it under
    1.11 + * the terms of the GNU General Public License as published by the Free
    1.12 + * Software Foundation, either version 3 of the License, or (at your option)
    1.13 + * any later version.
    1.14 + * 
    1.15 + * Foobar is distributed in the hope that it will be useful, but WITHOUT ANY
    1.16 + * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    1.17 + * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
    1.18 + *
    1.19 + * You should have received a copy of the GNU General Public License along with
    1.20 + * JITCraft. If not, see http://www.gnu.org/licenses/.
    1.21 + */
    1.22 +#include <sys/mman.h>
    1.23 +#include "Platform.h"
    1.24 +
    1.25 +using namespace jc;
    1.26 +
    1.27 +static inline int
    1.28 +ToProtBits(OS::Protection prot)
    1.29 +{
    1.30 +    switch (prot) {
    1.31 +      case OS::Prot_ReadWrite:
    1.32 +        return PROT_READ | PROT_WRITE;
    1.33 +      case OS::Prot_ReadWriteExecute:
    1.34 +        return PROT_READ | PROT_WRITE | PROT_EXEC;
    1.35 +      default:
    1.36 +        assert(prot == OS::Prot_ReadExecute);
    1.37 +        return PROT_READ | PROT_EXEC;
    1.38 +    }
    1.39 +}
    1.40 +
    1.41 +Address
    1.42 +OS::MapMemory(size_t amount, MapMode mode, Protection prot_)
    1.43 +{
    1.44 +    int prot = ToProtBits(prot_);
    1.45 +    void *addr = mmap(NULL, amount, prot, MAP_ANON | MAP_PRIVATE, -1, 0);
    1.46 +    if (addr == MAP_FAILED)
    1.47 +        return NULL;
    1.48 +
    1.49 +    return Address(addr);
    1.50 +}
    1.51 +
    1.52 +bool
    1.53 +OS::CommitMemory(Address address, size_t amount, Protection prot_)
    1.54 +{
    1.55 +    return true;
    1.56 +}
    1.57 +
    1.58 +void
    1.59 +OS::UnmapMemory(Address address, size_t size)
    1.60 +{
    1.61 +    munmap(address, size);
    1.62 +}
    1.63 +
    1.64 +OS::AlignableMapping
    1.65 +OS::MapAlignedMemory(size_t amount, size_t alignment, MapMode mode)
    1.66 +{
    1.67 +    assert(amount >= alignment);
    1.68 +    assert(IsPowerOfTwo(alignment));
    1.69 +
    1.70 +    if (alignment == kPageAlignment) {
    1.71 +        Address address = MapMemory(amount, mode, Prot_ReadWrite);
    1.72 +        if (!address)
    1.73 +            return AlignableMapping();
    1.74 +        return AlignableMapping(address, alignment, amount);
    1.75 +    }
    1.76 +
    1.77 +    size_t requested = Min(amount * 2, amount + 2 * alignment);
    1.78 +    Address address = MapMemory(amount, mode, Prot_ReadWrite);
    1.79 +    if (!address)
    1.80 +        return AlignableMapping();
    1.81 +
    1.82 +    size_t begin = 0;
    1.83 +    Address aligned = AlignedBase(address, alignment);
    1.84 +    if (!IsAligned(address, alignment)) {
    1.85 +        // Shave off the first part of the unaligned region.
    1.86 +        aligned += alignment;
    1.87 +        begin = size_t(aligned - address);
    1.88 +        UnmapAlignedMemory(address, begin);
    1.89 +    }
    1.90 +
    1.91 +    if (requested - begin > amount) {
    1.92 +        // Shave off the last part of the unaligned region.
    1.93 +        UnmapAlignedMemory(address + amount, requested - amount - begin);
    1.94 +    }
    1.95 +
    1.96 +    return AlignableMapping(aligned, alignment, amount);
    1.97 +}
    1.98 +
    1.99 +void
   1.100 +OS::UnmapAlignedMemory(Address address, size_t size)
   1.101 +{
   1.102 +    OS::UnmapMemory(address, size);
   1.103 +}
   1.104 +