Merge "Make PIC native code architecture independent" into main

    return kMaxNonce;

}

size_t NonceStore::getMaxByte() const {

int32_t NonceStore::getMaxByte() const {

    return kMaxByte;

}

}

// Copy the byte block to the target and return the current hash.

int32_t NonceStore::getByteBlock(block_t* block, size_t len) const {

int32_t NonceStore::getByteBlock(block_t* block, int32_t len) const {

    memcpy(block, (void*) byteBlock(), std::min(kMaxByte, len));

    return mByteHash;

}

// Set the byte block and the hash.

void NonceStore::setByteBlock(int hash, const block_t* block, size_t len) {

void NonceStore::setByteBlock(int hash, const block_t* block, int32_t len) {

    memcpy((void*) byteBlock(), block, len = std::min(kMaxByte, len));

    mByteHash = hash;

}

 * location.  Fields with a variable location are found via offsets.  The offsets make this

 * object position-independent, which is required because it is in shared memory and would be

 * mapped into different virtual addresses for different processes.

 *

 * This structure is shared between 64-bit and 32-bit processes.  Therefore it is imperative

 * that the structure not use any datatypes that are architecture-dependent (like size_t).

 * Additionally, care must be taken to avoid unexpected padding in the structure.

 */

class NonceStore {

class alignas(8) NonceStore {

  protected:

    // A convenient typedef.  The jbyteArray element type is jbyte, which the compiler treats as

    // signed char.

    // The value of an unset field.

    static constexpr int UNSET = 0;

    // The size of the nonce array.

    // The size of the nonce array.  This and the following sizes are int32_t to

    // be ABI independent.

    const int32_t kMaxNonce;

    // The size of the byte array.

    const size_t kMaxByte;

    const int32_t kMaxByte;

    // The offset to the nonce array.

    const size_t mNonceOffset;

    const int32_t mNonceOffset;

    // The offset to the byte array.

    const size_t mByteOffset;

    const int32_t mByteOffset;

    // The byte block hash.  This is fixed and at a known offset, so leave it in the base class.

    volatile std::atomic<int32_t> mByteHash;

    // A 4-byte padd that makes the size of this structure a multiple of 8 bytes.

    const int32_t _pad = 0;

    // The constructor is protected!  It only makes sense when called from a subclass.

    NonceStore(int kMaxNonce, size_t kMaxByte, volatile nonce_t* nonce, volatile block_t* block) :

    NonceStore(int kMaxNonce, int kMaxByte, volatile nonce_t* nonce, volatile block_t* block) :

            kMaxNonce(kMaxNonce),

            kMaxByte(kMaxByte),

            mNonceOffset(offset(this, const_cast<nonce_t*>(nonce))),

    // These provide run-time access to the sizing parameters.

    int getMaxNonce() const;

    size_t getMaxByte() const;

    int getMaxByte() const;

    // Fetch a nonce, returning UNSET if the index is out of range.  This method specifically

    // does not throw or generate an error if the index is out of range; this allows the method

    int32_t getHash() const;

    // Copy the byte block to the target and return the current hash.

    int32_t getByteBlock(block_t* block, size_t len) const;

    int32_t getByteBlock(block_t* block, int32_t len) const;

    // Set the byte block and the hash.

    void setByteBlock(int hash, const block_t* block, size_t len);

    void setByteBlock(int hash, const block_t* block, int32_t len);

  private:

    }

};

// Assert that the size of the object is fixed, independent of the CPU architecture.  There are

// four int32_t fields and one atomic<int32_t>, which sums to 20 bytes total.  This assertion

// uses a constant instead of computing the size of the objects in the compiler, to avoid

// different answers on different architectures.

static_assert(sizeof(NonceStore) == 24);

/**

 * A cache nonce block contains an array of std::atomic<int64_t> and an array of bytes.  The

 * byte array has an associated hash.  This class provides methods to read and write the fields

 * The template is parameterized by the number of nonces it supports and the number of bytes in

 * the string block.

 */

template<int maxNonce, size_t maxByte> class CacheNonce : public NonceStore {

template<int MAX_NONCE, int MAX_BYTE> class CacheNonce : public NonceStore {

    // The array of nonces

    volatile nonce_t mNonce[maxNonce];

    volatile nonce_t mNonce[MAX_NONCE];

    // The byte array.  This is not atomic but it is guarded by the mByteHash.

    volatile block_t mByteBlock[maxByte];

    volatile block_t mByteBlock[MAX_BYTE];

  public:

    // Export the parameters for use in compiler assertions.

    static constexpr int kMaxNonceCount = MAX_NONCE;

    static constexpr int kMaxByteCount = MAX_BYTE;

    // Construct and initialize the memory.

    CacheNonce() :

            NonceStore(maxNonce, maxByte, &mNonce[0], &mByteBlock[0])

    {

        for (int i = 0; i < maxNonce; i++) {

    CacheNonce() : NonceStore(MAX_NONCE, MAX_BYTE, &mNonce[0], &mByteBlock[0]) {

        for (int i = 0; i < MAX_NONCE; i++) {

            mNonce[i] = UNSET;

        }

        mByteHash = UNSET;

typedef CacheNonce</* max nonce */ 128, /* byte block size */ 8192> SystemCacheNonce;

// LINT.ThenChange(/core/tests/coretests/src/android/app/PropertyInvalidatedCacheTests.java:system_nonce_config)

// Verify that there is no padding in the final class.

static_assert(sizeof(SystemCacheNonce) ==

              sizeof(NonceStore)

              + SystemCacheNonce::kMaxNonceCount*8

              + SystemCacheNonce::kMaxByteCount);

} // namespace android.app.PropertyInvalidatedCache