ladybird/Libraries/LibC/SharedBuffer.cpp
Robin Burchell b907608e46 SharedBuffer: Split the creation and share steps
This allows us to seal a buffer *before* anyone else has access to it
(well, ok, the creating process still does, but you can't win them all).

It also means that a SharedBuffer can be shared with multiple clients:
all you need is to have access to it to share it on again.
2019-07-18 10:06:20 +02:00

67 lines
1.6 KiB
C++

#include <AK/kmalloc.h>
#include <SharedBuffer.h>
#include <stdio.h>
#include <unistd.h>
RefPtr<SharedBuffer> SharedBuffer::create_with_size(int size)
{
void* data;
int shared_buffer_id = create_shared_buffer(size, &data);
if (shared_buffer_id < 0) {
perror("create_shared_buffer");
return nullptr;
}
return adopt(*new SharedBuffer(shared_buffer_id, size, data));
}
bool SharedBuffer::share_with(pid_t peer)
{
int ret = share_buffer_with(shared_buffer_id(), peer);
if (ret < 0) {
perror("share_buffer_with");
return false;
}
return true;
}
RefPtr<SharedBuffer> SharedBuffer::create_from_shared_buffer_id(int shared_buffer_id)
{
void* data = get_shared_buffer(shared_buffer_id);
if (data == (void*)-1) {
perror("get_shared_buffer");
return nullptr;
}
int size = get_shared_buffer_size(shared_buffer_id);
if (size < 0) {
perror("get_shared_buffer_size");
return nullptr;
}
return adopt(*new SharedBuffer(shared_buffer_id, size, data));
}
SharedBuffer::SharedBuffer(int shared_buffer_id, int size, void* data)
: m_shared_buffer_id(shared_buffer_id)
, m_size(size)
, m_data(data)
{
}
SharedBuffer::~SharedBuffer()
{
if (m_shared_buffer_id >= 0) {
int rc = release_shared_buffer(m_shared_buffer_id);
if (rc < 0) {
perror("release_shared_buffer");
}
}
}
void SharedBuffer::seal()
{
int rc = seal_shared_buffer(m_shared_buffer_id);
if (rc < 0) {
perror("seal_shared_buffer");
ASSERT_NOT_REACHED();
}
}