SharedMemoryUnix.cpp [plain text]
#include "config.h"
#if USE(UNIX_DOMAIN_SOCKETS)
#include "SharedMemory.h"
#include "ArgumentDecoder.h"
#include "ArgumentEncoder.h"
#include "WebCoreArgumentCoders.h"
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <wtf/Assertions.h>
#include <wtf/CurrentTime.h>
#if PLATFORM(QT)
#include <QDir>
#elif PLATFORM(GTK)
#include <wtf/gobject/GOwnPtr.h>
#endif
namespace WebKit {
SharedMemory::Handle::Handle()
: m_fileDescriptor(-1)
, m_size(0)
{
}
SharedMemory::Handle::~Handle()
{
if (!isNull())
while (close(m_fileDescriptor) == -1 && errno == EINTR) { }
}
bool SharedMemory::Handle::isNull() const
{
return m_fileDescriptor == -1;
}
void SharedMemory::Handle::encode(CoreIPC::ArgumentEncoder* encoder) const
{
ASSERT(!isNull());
encoder->encode(releaseToAttachment());
}
bool SharedMemory::Handle::decode(CoreIPC::ArgumentDecoder* decoder, Handle& handle)
{
ASSERT_ARG(handle, !handle.m_size);
ASSERT_ARG(handle, handle.isNull());
CoreIPC::Attachment attachment;
if (!decoder->decode(attachment))
return false;
handle.adoptFromAttachment(attachment.releaseFileDescriptor(), attachment.size());
return true;
}
CoreIPC::Attachment SharedMemory::Handle::releaseToAttachment() const
{
ASSERT(!isNull());
int temp = m_fileDescriptor;
m_fileDescriptor = -1;
return CoreIPC::Attachment(temp, m_size);
}
void SharedMemory::Handle::adoptFromAttachment(int fileDescriptor, size_t size)
{
ASSERT(!m_size);
ASSERT(isNull());
m_fileDescriptor = fileDescriptor;
m_size = size;
}
PassRefPtr<SharedMemory> SharedMemory::create(size_t size)
{
#if PLATFORM(QT)
QString tempName = QDir::temp().filePath(QLatin1String("qwkshm.XXXXXX"));
QByteArray tempNameCSTR = tempName.toLocal8Bit();
char* tempNameC = tempNameCSTR.data();
#elif PLATFORM(GTK)
GOwnPtr<gchar> tempName(g_build_filename(g_get_tmp_dir(), "WK2SharedMemoryXXXXXX", NULL));
gchar* tempNameC = tempName.get();
#endif
int fileDescriptor;
while ((fileDescriptor = mkstemp(tempNameC)) == -1) {
if (errno != EINTR)
return 0;
}
while (fcntl(fileDescriptor, F_SETFD, FD_CLOEXEC) == -1) {
if (errno != EINTR) {
while (close(fileDescriptor) == -1 && errno == EINTR) { }
unlink(tempNameC);
return 0;
}
}
while (ftruncate(fileDescriptor, size) == -1) {
if (errno != EINTR) {
while (close(fileDescriptor) == -1 && errno == EINTR) { }
unlink(tempNameC);
return 0;
}
}
void* data = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileDescriptor, 0);
if (data == MAP_FAILED) {
while (close(fileDescriptor) == -1 && errno == EINTR) { }
unlink(tempNameC);
return 0;
}
unlink(tempNameC);
RefPtr<SharedMemory> instance = adoptRef(new SharedMemory());
instance->m_data = data;
instance->m_fileDescriptor = fileDescriptor;
instance->m_size = size;
return instance.release();
}
static inline int accessModeMMap(SharedMemory::Protection protection)
{
switch (protection) {
case SharedMemory::ReadOnly:
return PROT_READ;
case SharedMemory::ReadWrite:
return PROT_READ | PROT_WRITE;
}
ASSERT_NOT_REACHED();
return PROT_READ | PROT_WRITE;
}
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;
}
SharedMemory::~SharedMemory()
{
munmap(m_data, m_size);
while (close(m_fileDescriptor) == -1 && errno == EINTR) { }
}
static inline int accessModeFile(SharedMemory::Protection protection)
{
switch (protection) {
case SharedMemory::ReadOnly:
return O_RDONLY;
case SharedMemory::ReadWrite:
return O_RDWR;
}
ASSERT_NOT_REACHED();
return O_RDWR;
}
bool SharedMemory::createHandle(Handle& handle, Protection protection)
{
ASSERT_ARG(handle, !handle.m_size);
ASSERT_ARG(handle, handle.isNull());
int duplicatedHandle;
while ((duplicatedHandle = dup(m_fileDescriptor)) == -1) {
if (errno != EINTR) {
ASSERT_NOT_REACHED();
return false;
}
}
while ((fcntl(duplicatedHandle, F_SETFD, FD_CLOEXEC | accessModeFile(protection)) == -1)) {
if (errno != EINTR) {
ASSERT_NOT_REACHED();
while (close(duplicatedHandle) == -1 && errno == EINTR) { }
return false;
}
}
handle.m_fileDescriptor = duplicatedHandle;
handle.m_size = m_size;
return true;
}
unsigned SharedMemory::systemPageSize()
{
static unsigned pageSize = 0;
if (!pageSize)
pageSize = getpagesize();
return pageSize;
}
}
#endif