The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/gfx/skia/trunk/src/ports/SkDiscardableMemory_ashmem.cpp	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,113 @@
     1.4 +/*
     1.5 + * Copyright 2013 Google Inc.
     1.6 + *
     1.7 + * Use of this source code is governed by a BSD-style license that can be
     1.8 + * found in the LICENSE file.
     1.9 + */
    1.10 +
    1.11 +#include <unistd.h>
    1.12 +#include <sys/mman.h>
    1.13 +#include "SkDiscardableMemory.h"
    1.14 +#include "SkTypes.h"
    1.15 +#include "android/ashmem.h"
    1.16 +
    1.17 +////////////////////////////////////////////////////////////////////////////////
    1.18 +namespace {
    1.19 +/**
    1.20 + *  DiscardableMemory implementation that uses the Android kernel's
    1.21 + *  ashmem (Android shared memory).
    1.22 + */
    1.23 +class SkAshmemDiscardableMemory : public SkDiscardableMemory {
    1.24 +public:
    1.25 +    SkAshmemDiscardableMemory(int fd, void* address, size_t size);
    1.26 +    virtual ~SkAshmemDiscardableMemory();
    1.27 +    virtual bool lock() SK_OVERRIDE;
    1.28 +    virtual void* data() SK_OVERRIDE;
    1.29 +    virtual void unlock() SK_OVERRIDE;
    1.30 +private:
    1.31 +    bool         fLocked;
    1.32 +    int          fFd;
    1.33 +    void*        fMemory;
    1.34 +    const size_t fSize;
    1.35 +};
    1.36 +
    1.37 +SkAshmemDiscardableMemory::SkAshmemDiscardableMemory(int fd,
    1.38 +                                                     void* address,
    1.39 +                                                     size_t size)
    1.40 +    : fLocked(true)  // Ashmem pages are pinned by default.
    1.41 +    , fFd(fd)
    1.42 +    , fMemory(address)
    1.43 +    , fSize(size) {
    1.44 +    SkASSERT(fFd >= 0);
    1.45 +    SkASSERT(fMemory != NULL);
    1.46 +    SkASSERT(fSize > 0);
    1.47 +}
    1.48 +
    1.49 +SkAshmemDiscardableMemory::~SkAshmemDiscardableMemory() {
    1.50 +    SkASSERT(!fLocked);
    1.51 +    if (NULL != fMemory) {
    1.52 +        munmap(fMemory, fSize);
    1.53 +    }
    1.54 +    if (fFd != -1) {
    1.55 +        close(fFd);
    1.56 +    }
    1.57 +}
    1.58 +
    1.59 +bool SkAshmemDiscardableMemory::lock() {
    1.60 +    SkASSERT(!fLocked);
    1.61 +    if (-1 == fFd) {
    1.62 +        fLocked = false;
    1.63 +        return false;
    1.64 +    }
    1.65 +    SkASSERT(fMemory != NULL);
    1.66 +    if (fLocked || (ASHMEM_NOT_PURGED == ashmem_pin_region(fFd, 0, 0))) {
    1.67 +        fLocked = true;
    1.68 +        return true;
    1.69 +    } else {
    1.70 +        munmap(fMemory, fSize);
    1.71 +        fMemory = NULL;
    1.72 +
    1.73 +        close(fFd);
    1.74 +        fFd = -1;
    1.75 +        fLocked = false;
    1.76 +        return false;
    1.77 +    }
    1.78 +}
    1.79 +
    1.80 +void* SkAshmemDiscardableMemory::data() {
    1.81 +    SkASSERT(fLocked);
    1.82 +    return fLocked ? fMemory : NULL;
    1.83 +}
    1.84 +
    1.85 +void SkAshmemDiscardableMemory::unlock() {
    1.86 +    SkASSERT(fLocked);
    1.87 +    if (fLocked && (fFd != -1)) {
    1.88 +        ashmem_unpin_region(fFd, 0, 0);
    1.89 +    }
    1.90 +    fLocked = false;
    1.91 +}
    1.92 +}  // namespace
    1.93 +////////////////////////////////////////////////////////////////////////////////
    1.94 +
    1.95 +SkDiscardableMemory* SkDiscardableMemory::Create(size_t bytes) {
    1.96 +    // ashmem likes lengths on page boundaries.
    1.97 +    const size_t mask = getpagesize() - 1;
    1.98 +    size_t size = (bytes + mask) & ~mask;
    1.99 +
   1.100 +    static const char name[] = "Skia_Ashmem_Discardable_Memory";
   1.101 +    int fd = ashmem_create_region(name, size);
   1.102 +    if (fd < 0) {
   1.103 +        return NULL;
   1.104 +    }
   1.105 +    if (0 != ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE)) {
   1.106 +        close(fd);
   1.107 +        return NULL;
   1.108 +    }
   1.109 +    void* addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
   1.110 +    if ((MAP_FAILED == addr) || (NULL == addr)) {
   1.111 +        close(fd);
   1.112 +        return NULL;
   1.113 +    }
   1.114 +
   1.115 +    return SkNEW_ARGS(SkAshmemDiscardableMemory, (fd, addr, size));
   1.116 +}