RefPtr<SharedMemory> SharedMemory::map(const Handle& handle, Protection protection)
{
ASSERT(!handle.isNull());
int fd = handle.m_attachment.releaseFileDescriptor();
void* data = mmap(0, handle.m_attachment.size(), accessModeMMap(protection), MAP_SHARED, fd, 0);
closeWithRetry(fd);
if (data == MAP_FAILED)
return nullptr;
RefPtr<SharedMemory> instance = wrapMap(data, handle.m_attachment.size(), -1);
instance->m_fileDescriptor = std::nullopt;
instance->m_isWrappingMap = false;
return instance;
}
PassRefPtr<SharedMemory> SharedMemory::create(const Handle& handle, Protection protection)
{
ASSERT(!handle.isNull());
void* data = mmap(0, handle.m_size, accessModeMMap(protection), MAP_SHARED, handle.m_fileDescriptor, 0);
if (data == MAP_FAILED)
return 0;
RefPtr<SharedMemory> instance = adoptRef(new SharedMemory());
instance->m_data = data;
instance->m_fileDescriptor = handle.m_fileDescriptor;
instance->m_size = handle.m_size;
handle.m_fileDescriptor = -1;
return instance;
}
RefPtr<SharedMemory> SharedMemory::create(void* address, size_t size, Protection protection)
{
CString tempName;
int fileDescriptor = -1;
for (int tries = 0; fileDescriptor == -1 && tries < 10; ++tries) {
String name = String("/WK2SharedMemory.") + String::number(static_cast<unsigned>(WTF::randomNumber() * (std::numeric_limits<unsigned>::max() + 1.0)));
tempName = name.utf8();
do {
fileDescriptor = shm_open(tempName.data(), O_CREAT | O_RDWR, S_IRUSR | S_IWUSR);
} while (fileDescriptor == -1 && errno == EINTR);
}
if (fileDescriptor == -1) {
WTFLogAlways("Failed to create shared memory file %s: %s", tempName.data(), strerror(errno));
return 0;
}
while (ftruncate(fileDescriptor, size) == -1) {
if (errno != EINTR) {
closeWithRetry(fileDescriptor);
shm_unlink(tempName.data());
return 0;
}
}
void* data = mmap(address, size, accessModeMMap(protection), MAP_SHARED, fileDescriptor, 0);
if (data == MAP_FAILED) {
closeWithRetry(fileDescriptor);
shm_unlink(tempName.data());
return 0;
}
shm_unlink(tempName.data());
RefPtr<SharedMemory> instance = adoptRef(new SharedMemory());
instance->m_data = data;
instance->m_fileDescriptor = fileDescriptor;
instance->m_size = size;
return instance.release();
}