| 1 | //===-- Timeout.h -----------------------------------------------*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #ifndef LLDB_UTILITY_TIMEOUT_H |
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| 10 | #define LLDB_UTILITY_TIMEOUT_H |
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| 11 | |
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| 12 | #include "llvm/Support/Chrono.h" |
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| 13 | #include "llvm/Support/FormatProviders.h" |
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| 14 | #include <optional> |
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| 15 | |
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| 16 | namespace lldb_private { |
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| 17 | |
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| 18 | // A general purpose class for representing timeouts for various APIs. It's |
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| 19 | // basically an std::optional<std::chrono::duration<int64_t, Ratio>>, but we |
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| 20 | // customize it a bit to enable the standard chrono implicit conversions (e.g. |
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| 21 | // from Timeout<std::milli> to Timeout<std::micro>. |
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| 22 | // |
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| 23 | // The intended meaning of the values is: |
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| 24 | // - std::nullopt - no timeout, the call should wait forever - 0 - poll, only |
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| 25 | // complete the call if it will not block - >0 - wait for a given number of |
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| 26 | // units for the result |
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| 27 | template <typename Ratio> |
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| 28 | class Timeout : public std::optional<std::chrono::duration<int64_t, Ratio>> { |
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| 29 | private: |
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| 30 | template <typename Ratio2> using Dur = std::chrono::duration<int64_t, Ratio2>; |
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| 31 | template <typename Rep2, typename Ratio2> |
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| 32 | using EnableIf = std::enable_if< |
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| 33 | std::is_convertible<std::chrono::duration<Rep2, Ratio2>, |
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| 34 | std::chrono::duration<int64_t, Ratio>>::value>; |
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| 35 | |
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| 36 | using Base = std::optional<Dur<Ratio>>; |
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| 37 | |
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| 38 | public: |
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| 39 | Timeout(std::nullopt_t none) : Base(none) {} |
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| 40 | |
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| 41 | template <typename Ratio2, |
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| 42 | typename = typename EnableIf<int64_t, Ratio2>::type> |
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| 43 | Timeout(const Timeout<Ratio2> &other) |
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| 44 | : Base(other ? Base(Dur<Ratio>(*other)) : std::nullopt) {} |
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| 45 | |
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| 46 | template <typename Rep2, typename Ratio2, |
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| 47 | typename = typename EnableIf<Rep2, Ratio2>::type> |
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| 48 | Timeout(const std::chrono::duration<Rep2, Ratio2> &other) |
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| 49 | : Base(Dur<Ratio>(other)) {} |
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| 50 | }; |
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| 51 | |
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| 52 | } // namespace lldb_private |
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| 53 | |
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| 54 | namespace llvm { |
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| 55 | template<typename Ratio> |
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| 56 | struct format_provider<lldb_private::Timeout<Ratio>, void> { |
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| 57 | static void format(const lldb_private::Timeout<Ratio> &timeout, |
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| 58 | raw_ostream &OS, StringRef Options) { |
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| 59 | typedef typename lldb_private::Timeout<Ratio>::value_type Dur; |
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| 60 | |
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| 61 | if (!timeout) |
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| 62 | OS << "<infinite>" ; |
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| 63 | else |
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| 64 | format_provider<Dur>::format(*timeout, OS, Options); |
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| 65 | } |
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| 66 | }; |
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| 67 | } |
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| 68 | |
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| 69 | #endif // LLDB_UTILITY_TIMEOUT_H |
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| 70 | |
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