ladybird/Kernel/SharedBuffer.h
Andreas Kling 0317ca5ccc Kernel+LibC: Make all SharedBuffers purgeable (default: non-volatile)
This patch makes SharedBuffer use a PurgeableVMObject as its underlying
memory object.

A new syscall is added to control the volatile flag of a SharedBuffer.
2019-12-09 20:06:47 +01:00

59 lines
1.6 KiB
C++

#pragma once
#include <AK/OwnPtr.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/VM/PurgeableVMObject.h>
struct SharedBuffer {
private:
struct Reference {
Reference(pid_t pid)
: pid(pid)
{
}
pid_t pid;
unsigned count { 0 };
Region* region { nullptr };
};
public:
SharedBuffer(int id, int size)
: m_shared_buffer_id(id)
, m_vmobject(PurgeableVMObject::create_with_size(size))
{
#ifdef SHARED_BUFFER_DEBUG
dbgprintf("Created shared buffer %d of size %d\n", m_shared_buffer_id, size);
#endif
}
~SharedBuffer()
{
#ifdef SHARED_BUFFER_DEBUG
dbgprintf("Destroyed shared buffer %d of size %d\n", m_shared_buffer_id, size());
#endif
}
void sanity_check(const char* what);
bool is_shared_with(pid_t peer_pid);
void* ref_for_process_and_get_address(Process& process);
void share_with(pid_t peer_pid);
void share_globally() { m_global = true; }
void deref_for_process(Process& process);
void disown(pid_t pid);
size_t size() const { return m_vmobject->size(); }
void destroy_if_unused();
void seal();
PurgeableVMObject& vmobject() { return m_vmobject; }
const PurgeableVMObject& vmobject() const { return m_vmobject; }
int id() const { return m_shared_buffer_id; }
int m_shared_buffer_id { -1 };
bool m_writable { true };
bool m_global { false };
NonnullRefPtr<PurgeableVMObject> m_vmobject;
Vector<Reference, 2> m_refs;
unsigned m_total_refs { 0 };
};
Lockable<HashMap<int, NonnullOwnPtr<SharedBuffer>>>& shared_buffers();