xref: /openbsd-src/gnu/llvm/compiler-rt/lib/scudo/standalone/rss_limit_checker.h (revision 810390e339a5425391477d5d41c78d7cab2424ac)
1*810390e3Srobert //===-- common.h ------------------------------------------------*- C++ -*-===//
2*810390e3Srobert //
3*810390e3Srobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*810390e3Srobert // See https://llvm.org/LICENSE.txt for license information.
5*810390e3Srobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*810390e3Srobert //
7*810390e3Srobert //===----------------------------------------------------------------------===//
8*810390e3Srobert 
9*810390e3Srobert #ifndef SCUDO_RSS_LIMIT_CHECKER_H_
10*810390e3Srobert #define SCUDO_RSS_LIMIT_CHECKER_H_
11*810390e3Srobert 
12*810390e3Srobert #include "atomic_helpers.h"
13*810390e3Srobert #include "common.h"
14*810390e3Srobert #include "internal_defs.h"
15*810390e3Srobert 
16*810390e3Srobert namespace scudo {
17*810390e3Srobert 
18*810390e3Srobert class RssLimitChecker {
19*810390e3Srobert public:
20*810390e3Srobert   enum RssLimitExceeded {
21*810390e3Srobert     Neither,
22*810390e3Srobert     Soft,
23*810390e3Srobert     Hard,
24*810390e3Srobert   };
25*810390e3Srobert 
init(int SoftRssLimitMb,int HardRssLimitMb)26*810390e3Srobert   void init(int SoftRssLimitMb, int HardRssLimitMb) {
27*810390e3Srobert     CHECK_GE(SoftRssLimitMb, 0);
28*810390e3Srobert     CHECK_GE(HardRssLimitMb, 0);
29*810390e3Srobert     this->SoftRssLimitMb = static_cast<uptr>(SoftRssLimitMb);
30*810390e3Srobert     this->HardRssLimitMb = static_cast<uptr>(HardRssLimitMb);
31*810390e3Srobert   }
32*810390e3Srobert 
33*810390e3Srobert   // Opportunistic RSS limit check. This will update the RSS limit status, if
34*810390e3Srobert   // it can, every 250ms, otherwise it will just return the current one.
getRssLimitExceeded()35*810390e3Srobert   RssLimitExceeded getRssLimitExceeded() {
36*810390e3Srobert     if (!HardRssLimitMb && !SoftRssLimitMb)
37*810390e3Srobert       return RssLimitExceeded::Neither;
38*810390e3Srobert 
39*810390e3Srobert     u64 NextCheck = atomic_load_relaxed(&RssNextCheckAtNS);
40*810390e3Srobert     u64 Now = getMonotonicTime();
41*810390e3Srobert 
42*810390e3Srobert     if (UNLIKELY(Now >= NextCheck))
43*810390e3Srobert       check(NextCheck);
44*810390e3Srobert 
45*810390e3Srobert     return static_cast<RssLimitExceeded>(atomic_load_relaxed(&RssLimitStatus));
46*810390e3Srobert   }
47*810390e3Srobert 
getSoftRssLimit()48*810390e3Srobert   uptr getSoftRssLimit() const { return SoftRssLimitMb; }
getHardRssLimit()49*810390e3Srobert   uptr getHardRssLimit() const { return HardRssLimitMb; }
50*810390e3Srobert 
51*810390e3Srobert private:
52*810390e3Srobert   void check(u64 NextCheck);
53*810390e3Srobert 
54*810390e3Srobert   uptr SoftRssLimitMb = 0;
55*810390e3Srobert   uptr HardRssLimitMb = 0;
56*810390e3Srobert 
57*810390e3Srobert   atomic_u64 RssNextCheckAtNS = {};
58*810390e3Srobert   atomic_u8 RssLimitStatus = {};
59*810390e3Srobert };
60*810390e3Srobert 
61*810390e3Srobert } // namespace scudo
62*810390e3Srobert 
63*810390e3Srobert #endif // SCUDO_RSS_LIMIT_CHECKER_H_
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