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/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "ProcessGroup.h"
namespace Kernel {
RecursiveSpinLock g_process_groups_lock;
InlineLinkedList<ProcessGroup>* g_process_groups;
ProcessGroup::~ProcessGroup()
{
ScopedSpinLock lock(g_process_groups_lock);
if (m_next || m_prev) {
g_process_groups->remove(this);
}
}
RefPtr<ProcessGroup> ProcessGroup::create(ProcessGroupID pgid)
{
auto process_group = adopt_ref_if_nonnull(new ProcessGroup(pgid));
if (process_group) {
ScopedSpinLock lock(g_process_groups_lock);
g_process_groups->prepend(process_group);
}
return process_group;
}
RefPtr<ProcessGroup> ProcessGroup::find_or_create(ProcessGroupID pgid)
{
// Avoid allocating under spinlock, this compromises by wasting the
// allocation when we race with another process to see if they have
// already created a process group.
auto process_group = adopt_ref_if_nonnull(new ProcessGroup(pgid));
ScopedSpinLock lock(g_process_groups_lock);
if (auto existing = from_pgid_nolock(pgid))
return existing.release_nonnull();
if (!process_group)
return {};
g_process_groups->prepend(process_group);
return process_group;
}
RefPtr<ProcessGroup> ProcessGroup::from_pgid(ProcessGroupID pgid)
{
ScopedSpinLock lock(g_process_groups_lock);
return from_pgid_nolock(pgid);
}
RefPtr<ProcessGroup> ProcessGroup::from_pgid_nolock(ProcessGroupID pgid)
{
VERIFY(g_process_groups_lock.own_lock());
for (auto& group : *g_process_groups) {
if (group.pgid() == pgid)
return &group;
}
return nullptr;
}
}
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