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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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"
#include "mozilla/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), mOpenRights(RightsReadWrite) {}
SharedMemoryBasic::~SharedMemoryBasic() {
Unmap();
CloseHandle();
}
bool SharedMemoryBasic::SetHandle(Handle aHandle, OpenRights aRights) {
MOZ_ASSERT(-1 == mShmFd, "Already Create()d");
mShmFd = aHandle.release();
mOpenRights = aRights;
return true;
}
bool SharedMemoryBasic::Create(size_t aNbytes) {
MOZ_ASSERT(-1 == mShmFd, "Already Create()d");
// Carve a new instance off of /dev/ashmem
int shmfd = mozilla::android::ashmem_create(nullptr, aNbytes);
if (-1 == shmfd) {
LogError("ShmemAndroid::Create():open");
return false;
}
mShmFd = shmfd;
Created(aNbytes);
return true;
}
bool SharedMemoryBasic::Map(size_t nBytes, void* fixed_address) {
MOZ_ASSERT(nullptr == mMemory, "Already Map()d");
int prot = PROT_READ;
if (mOpenRights == RightsReadWrite) {
prot |= PROT_WRITE;
}
// Don't use MAP_FIXED when a fixed_address was specified, since that can
// replace pages that are alread mapped at that address.
mMemory = mmap(fixed_address, nBytes, prot, MAP_SHARED, mShmFd, 0);
if (MAP_FAILED == mMemory) {
if (!fixed_address) {
LogError("ShmemAndroid::Map()");
}
mMemory = nullptr;
return false;
}
if (fixed_address && mMemory != fixed_address) {
if (munmap(mMemory, nBytes)) {
LogError("ShmemAndroid::Map():unmap");
mMemory = nullptr;
return false;
}
}
Mapped(nBytes);
return true;
}
void* SharedMemoryBasic::FindFreeAddressSpace(size_t size) {
void* memory =
mmap(NULL, size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
munmap(memory, size);
return memory != (void*)-1 ? memory : NULL;
}
auto SharedMemoryBasic::CloneHandle() -> Handle {
MOZ_ASSERT(mShmFd >= 0, "Should have been Create()d by now");
int shmfdDup = dup(mShmFd);
if (-1 == shmfdDup) {
LogError("ShmemAndroid::CloneHandle()");
return nullptr;
}
return mozilla::UniqueFileHandle(shmfdDup);
}
void SharedMemoryBasic::Unmap() {
if (!mMemory) {
return;
}
if (munmap(mMemory, Size())) {
LogError("ShmemAndroid::Unmap()");
}
mMemory = nullptr;
}
void SharedMemoryBasic::CloseHandle() {
if (mShmFd != -1) {
close(mShmFd);
mShmFd = -1;
mOpenRights = RightsReadWrite;
}
}
} // namespace ipc
} // namespace mozilla