ladybird/Kernel/SharedBuffer.h
Andreas Kling 94ca55cefd Meta: Add license header to source files
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.

For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.

Going forward, all new source files should include a license header.
2020-01-18 09:45:54 +01:00

86 lines
3.0 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#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();