ladybird/Kernel/PTYMultiplexer.cpp
Andreas Kling b4e478aa50 Deallocate PTY's when they close.
This required a fair bit of plumbing. The CharacterDevice::close() virtual
will now be closed by ~FileDescriptor(), allowing device implementations to
do custom cleanup at that point.

One big problem remains: if the master PTY is closed before the slave PTY,
we go into crashy land.
2019-01-30 18:47:18 +01:00

50 lines
1.2 KiB
C++

#include "PTYMultiplexer.h"
#include "MasterPTY.h"
#include <LibC/errno_numbers.h>
static const unsigned s_max_pty_pairs = 8;
static PTYMultiplexer* s_the;
PTYMultiplexer& PTYMultiplexer::the()
{
ASSERT(s_the);
return *s_the;
}
void PTYMultiplexer::initialize_statics()
{
s_the = nullptr;
}
PTYMultiplexer::PTYMultiplexer()
: CharacterDevice(5, 2)
{
s_the = this;
m_freelist.ensure_capacity(s_max_pty_pairs);
for (int i = s_max_pty_pairs; i > 0; --i)
m_freelist.unchecked_append(i - 1);
}
PTYMultiplexer::~PTYMultiplexer()
{
}
RetainPtr<FileDescriptor> PTYMultiplexer::open(int& error, int options)
{
LOCKER(m_lock);
if (m_freelist.is_empty()) {
error = -EBUSY;
return nullptr;
}
auto master_index = m_freelist.take_last();
auto master = adopt(*new MasterPTY(master_index));
dbgprintf("PTYMultiplexer::open: Vending master %u\n", master->index());
return VFS::the().open(move(master), error, options);
}
void PTYMultiplexer::notify_master_destroyed(Badge<MasterPTY>, unsigned index)
{
LOCKER(m_lock);
m_freelist.append(index);
dbgprintf("PTYMultiplexer: %u added to freelist\n", index);
}