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Diffstat (limited to 'libparc/parc/concurrent/parc_Timeout.h')
-rw-r--r-- | libparc/parc/concurrent/parc_Timeout.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/libparc/parc/concurrent/parc_Timeout.h b/libparc/parc/concurrent/parc_Timeout.h new file mode 100644 index 00000000..9edc24a0 --- /dev/null +++ b/libparc/parc/concurrent/parc_Timeout.h @@ -0,0 +1,141 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/** + * @ingroup threading + * + */ +#ifndef parc_Timeout_h +#define parc_Timeout_h +#include <stdio.h> +#include <stdint.h> +#include <stdbool.h> + +typedef uint64_t PARCTimeout; + +/** + * @def PARCTimeout_Never + * This represents a timeout that will never happen. + */ +#define PARCTimeout_Never NULL + +/* + * @def PARCTimeout_Immediate + * This represents a timeout that immediately happens. + * Equivalent to parcTimeout_NanoSeconds(0) + */ +#define PARCTimeout_Immediate (&(PARCTimeout) { 0 }) + +/* + * @def PARCTimeout_NanoSeconds + * This represents a timeout that will occur in the specified number of nanoseconds. + */ +#define parcTimeout_NanoSeconds(_nsec_) (&(PARCTimeout) { _nsec_ }) + +/* + * @def PARCTimeout_MicroSeconds + * This represents a timeout that will occur in the specified number of microseconds. + */ +#define parcTimeout_MicroSeconds(_usec_) parcTimeout_NanoSeconds(_usec_ * 1000) + +/* + * @def PARCTimeout_MilliSeconds + * This represents a timeout that will occur in the specified number of microseconds. + */ +#define parcTimeout_MilliSeconds(_msec_) parcTimeout_MicroSeconds(_msec_ * 1000) + +/** + * Determine if two `PARCTimeout` instances are equal. + * + * The following equivalence relations on non-null `PARCTimeout` instances are maintained: * + * * It is reflexive: for any non-null reference value x, `parcTimeout_Equals(x, x)` must return true. + * + * * It is symmetric: for any non-null reference values x and y, `parcTimeout_Equals(x, y)` must return true if and only if + * `parcTimeout_Equals(y x)` returns true. + * + * * It is transitive: for any non-null reference values x, y, and z, if + * `parcTimeout_Equals(x, y)` returns true and + * `parcTimeout_Equals(y, z)` returns true, + * then `parcTimeout_Equals(x, z)` must return true. + * + * * It is consistent: for any non-null reference values x and y, multiple invocations of `parcTimeout_Equals(x, y)` + * consistently return true or consistently return false. + * + * * For any non-null reference value x, `parcTimeout_Equals(x, NULL)` must return false. + * + * @param [in] x A valid PARCTimeout instance. + * @param [in] y A valid PARCTimeout instance. + * + * @return true The instances x and y are equal. + * + * Example: + * @code + * { + * PARCTimeout *a = parcTimeout_Create(); + * PARCTimeout *b = parcTimeout_Create(); + * + * if (parcTimeout_Equals(a, b)) { + * printf("Instances are equal.\n"); + * } + * + * parcTimeout_Release(&a); + * parcTimeout_Release(&b); + * } + * @endcode + * @see parcTimeout_HashCode + */ +bool parcTimeout_Equals(PARCTimeout x, PARCTimeout y); + +/** + * Predicate function returning true if the given timeout represents an infinite delay. + * + * @param [in] timeout A pointer to a valid PARCTimeout value. + * + * @return true The given timeout represents an infinite delay. + */ +static inline bool +parcTimeout_IsNever(const PARCTimeout *timeout) +{ + return (timeout == PARCTimeout_Never); +} + +/** + * Predicate function returning true if the given timeout represents an immediate, no-delay timeout. + * + * @param [in] timeout A pointer to a valid PARCTimeout value. + * + * @return true The given timeout represents an immediate, no-delay timeout. + */ +static inline bool +parcTimeout_IsImmediate(const PARCTimeout *timeout) +{ + return parcTimeout_IsNever(timeout) ? false : (*timeout == 0); +} + +/** + * Return the number of nano-seconds in the given PARCTimeout instance. + * + * If the PARCTimeout is never (`parcTimeout_IsNever` returns `true`), the returned value is UINT64_MAX. + * + * @param [in] timeout A pointer to a valid PARCTimeout value. + * + * @return The number of nano-seconds in the given PARCTimeout instance, UINT64_MAX. + */ +static inline uint64_t +parcTimeout_InNanoSeconds(const PARCTimeout *timeout) +{ + return parcTimeout_IsNever(timeout) ? UINT64_MAX : *timeout; +} +#endif /* parc_Timeout_h */ |