mirror of
https://github.com/RGBCube/serenity
synced 2025-07-25 20:27:45 +00:00
Move Lock from AK to Kernel, since it only works inside the kernel.
This commit is contained in:
parent
15657f0916
commit
313ee8dd19
12 changed files with 14 additions and 25 deletions
113
Kernel/Lock.h
Normal file
113
Kernel/Lock.h
Normal file
|
@ -0,0 +1,113 @@
|
|||
#pragma once
|
||||
|
||||
#include <AK/Assertions.h>
|
||||
#include <AK/Types.h>
|
||||
#include <Kernel/i386.h>
|
||||
#include <Kernel/Scheduler.h>
|
||||
|
||||
class Process;
|
||||
extern Process* current;
|
||||
|
||||
static inline dword CAS(volatile dword* mem, dword newval, dword oldval)
|
||||
{
|
||||
dword ret;
|
||||
asm volatile(
|
||||
"cmpxchgl %2, %1"
|
||||
:"=a"(ret), "+m"(*mem)
|
||||
:"r"(newval), "0"(oldval)
|
||||
:"cc", "memory");
|
||||
return ret;
|
||||
}
|
||||
|
||||
class Lock {
|
||||
public:
|
||||
Lock(const char* name = nullptr) : m_name(name) { }
|
||||
~Lock() { }
|
||||
|
||||
void lock();
|
||||
void unlock();
|
||||
|
||||
const char* name() const { return m_name; }
|
||||
|
||||
private:
|
||||
volatile dword m_lock { 0 };
|
||||
dword m_level { 0 };
|
||||
Process* m_holder { nullptr };
|
||||
const char* m_name { nullptr };
|
||||
};
|
||||
|
||||
class Locker {
|
||||
public:
|
||||
[[gnu::always_inline]] inline explicit Locker(Lock& l) : m_lock(l) { lock(); }
|
||||
[[gnu::always_inline]] inline ~Locker() { unlock(); }
|
||||
[[gnu::always_inline]] inline void unlock() { m_lock.unlock(); }
|
||||
[[gnu::always_inline]] inline void lock() { m_lock.lock(); }
|
||||
|
||||
private:
|
||||
Lock& m_lock;
|
||||
};
|
||||
|
||||
[[gnu::always_inline]] inline void Lock::lock()
|
||||
{
|
||||
if (!are_interrupts_enabled()) {
|
||||
kprintf("Interrupts disabled when trying to take Lock{%s}\n", m_name);
|
||||
hang();
|
||||
}
|
||||
ASSERT(!Scheduler::is_active());
|
||||
for (;;) {
|
||||
if (CAS(&m_lock, 1, 0) == 0) {
|
||||
if (!m_holder || m_holder == current) {
|
||||
m_holder = current;
|
||||
++m_level;
|
||||
memory_barrier();
|
||||
m_lock = 0;
|
||||
return;
|
||||
}
|
||||
m_lock = 0;
|
||||
}
|
||||
Scheduler::donate_to(m_holder, m_name);
|
||||
}
|
||||
}
|
||||
|
||||
inline void Lock::unlock()
|
||||
{
|
||||
for (;;) {
|
||||
if (CAS(&m_lock, 1, 0) == 0) {
|
||||
ASSERT(m_holder == current);
|
||||
ASSERT(m_level);
|
||||
--m_level;
|
||||
if (m_level) {
|
||||
memory_barrier();
|
||||
m_lock = 0;
|
||||
return;
|
||||
}
|
||||
m_holder = nullptr;
|
||||
memory_barrier();
|
||||
m_lock = 0;
|
||||
return;
|
||||
}
|
||||
Scheduler::donate_to(m_holder, m_name);
|
||||
}
|
||||
}
|
||||
|
||||
#define LOCKER(lock) Locker locker(lock)
|
||||
|
||||
template<typename T>
|
||||
class Lockable {
|
||||
public:
|
||||
Lockable() { }
|
||||
Lockable(T&& resource) : m_resource(move(resource)) { }
|
||||
Lock& lock() { return m_lock; }
|
||||
T& resource() { return m_resource; }
|
||||
|
||||
T lock_and_copy()
|
||||
{
|
||||
LOCKER(m_lock);
|
||||
return m_resource;
|
||||
}
|
||||
|
||||
private:
|
||||
T m_resource;
|
||||
Lock m_lock;
|
||||
};
|
||||
|
Loading…
Add table
Add a link
Reference in a new issue