SharedMemoryBasic_android.cpp
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=8 et :
*/
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <android/log.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "base/process_util.h"
#include "SharedMemoryBasic.h"
//
// Temporarily go directly to the kernel interface until we can
// interact better with libcutils.
//
#include <linux/ashmem.h>
namespace mozilla {
namespace ipc {
static void
LogError(const char* what)
{
__android_log_print(ANDROID_LOG_ERROR, "Gecko",
"%s: %s (%d)", what, strerror(errno), errno);
}
SharedMemoryBasic::SharedMemoryBasic()
: mShmFd(-1)
, mMemory(nullptr)
{ }
SharedMemoryBasic::SharedMemoryBasic(const Handle& aHandle)
: mShmFd(aHandle.fd)
, mMemory(nullptr)
{ }
SharedMemoryBasic::~SharedMemoryBasic()
{
Unmap();
Destroy();
}
bool
SharedMemoryBasic::Create(size_t aNbytes)
{
NS_ABORT_IF_FALSE(-1 == mShmFd, "Already Create()d");
// Carve a new instance off of /dev/ashmem
int shmfd = open("/" ASHMEM_NAME_DEF, O_RDWR, 0600);
if (-1 == shmfd) {
LogError("ShmemAndroid::Create():open");
return false;
}
if (ioctl(shmfd, ASHMEM_SET_SIZE, aNbytes)) {
LogError("ShmemAndroid::Unmap():ioctl(SET_SIZE)");
close(shmfd);
return false;
}
mShmFd = shmfd;
Created(aNbytes);
return true;
}
bool
SharedMemoryBasic::Map(size_t nBytes)
{
NS_ABORT_IF_FALSE(nullptr == mMemory, "Already Map()d");
mMemory = mmap(nullptr, nBytes,
PROT_READ | PROT_WRITE,
MAP_SHARED,
mShmFd,
0);
if (MAP_FAILED == mMemory) {
LogError("ShmemAndroid::Map()");
mMemory = nullptr;
return false;
}
Mapped(nBytes);
return true;
}
bool
SharedMemoryBasic::ShareToProcess(base::ProcessHandle/*unused*/,
Handle* aNewHandle)
{
NS_ABORT_IF_FALSE(mShmFd >= 0, "Should have been Create()d by now");
int shmfdDup = dup(mShmFd);
if (-1 == shmfdDup) {
LogError("ShmemAndroid::ShareToProcess()");
return false;
}
aNewHandle->fd = shmfdDup;
aNewHandle->auto_close = true;
return true;
}
void
SharedMemoryBasic::Unmap()
{
if (!mMemory) {
return;
}
if (munmap(mMemory, Size())) {
LogError("ShmemAndroid::Unmap()");
}
mMemory = nullptr;
}
void
SharedMemoryBasic::Destroy()
{
if (mShmFd > 0) {
close(mShmFd);
}
}
} // namespace ipc
} // namespace mozilla