rss_limit_checker.h revision 1.1.1.1 
1//===-- common.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 SCUDO_RSS_LIMIT_CHECKER_H_
10#define SCUDO_RSS_LIMIT_CHECKER_H_
11
12#include "atomic_helpers.h"
13#include "common.h"
14#include "internal_defs.h"
15
16namespace scudo {
17
18class RssLimitChecker {
19public:
20  enum RssLimitExceeded {
21    Neither,
22    Soft,
23    Hard,
24  };
25
26  void init(int SoftRssLimitMb, int HardRssLimitMb) {
27    CHECK_GE(SoftRssLimitMb, 0);
28    CHECK_GE(HardRssLimitMb, 0);
29    this->SoftRssLimitMb = static_cast<uptr>(SoftRssLimitMb);
30    this->HardRssLimitMb = static_cast<uptr>(HardRssLimitMb);
31  }
32
33  // Opportunistic RSS limit check. This will update the RSS limit status, if
34  // it can, every 250ms, otherwise it will just return the current one.
35  RssLimitExceeded getRssLimitExceeded() {
36    if (!HardRssLimitMb && !SoftRssLimitMb)
37      return RssLimitExceeded::Neither;
38
39    u64 NextCheck = atomic_load_relaxed(&RssNextCheckAtNS);
40    u64 Now = getMonotonicTime();
41
42    if (UNLIKELY(Now >= NextCheck))
43      check(NextCheck);
44
45    return static_cast<RssLimitExceeded>(atomic_load_relaxed(&RssLimitStatus));
46  }
47
48  uptr getSoftRssLimit() const { return SoftRssLimitMb; }
49  uptr getHardRssLimit() const { return HardRssLimitMb; }
50
51private:
52  void check(u64 NextCheck);
53
54  uptr SoftRssLimitMb = 0;
55  uptr HardRssLimitMb = 0;
56
57  atomic_u64 RssNextCheckAtNS = {};
58  atomic_u8 RssLimitStatus = {};
59};
60
61} // namespace scudo
62
63#endif // SCUDO_RSS_LIMIT_CHECKER_H_
64