1 //===-- LockFileBase.h ------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLDB_HOST_LOCKFILEBASE_H
10 #define LLDB_HOST_LOCKFILEBASE_H
11 
12 #include "lldb/Utility/Status.h"
13 
14 #include <functional>
15 
16 namespace lldb_private {
17 
18 class LockFileBase {
19 public:
20   virtual ~LockFileBase() = default;
21 
22   bool IsLocked() const;
23 
24   Status WriteLock(const uint64_t start, const uint64_t len);
25   Status TryWriteLock(const uint64_t start, const uint64_t len);
26 
27   Status ReadLock(const uint64_t start, const uint64_t len);
28   Status TryReadLock(const uint64_t start, const uint64_t len);
29 
30   Status Unlock();
31 
32 protected:
33   using Locker = std::function<Status(const uint64_t, const uint64_t)>;
34 
35   LockFileBase(int fd);
36 
37   virtual bool IsValidFile() const;
38 
39   virtual Status DoWriteLock(const uint64_t start, const uint64_t len) = 0;
40   virtual Status DoTryWriteLock(const uint64_t start, const uint64_t len) = 0;
41 
42   virtual Status DoReadLock(const uint64_t start, const uint64_t len) = 0;
43   virtual Status DoTryReadLock(const uint64_t start, const uint64_t len) = 0;
44 
45   virtual Status DoUnlock() = 0;
46 
47   Status DoLock(const Locker &locker, const uint64_t start, const uint64_t len);
48 
49   int m_fd; // not owned.
50   bool m_locked;
51   uint64_t m_start;
52   uint64_t m_len;
53 };
54 }
55 
56 #endif
57