| // Copyright 2017 The Abseil Authors. | |
| // | |
| // 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 | |
| // | |
| // https://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. | |
| // | |
| // ----------------------------------------------------------------------------- | |
| // File: clock.h | |
| // ----------------------------------------------------------------------------- | |
| // | |
| // This header file contains utility functions for working with the system-wide | |
| // realtime clock. For descriptions of the main time abstractions used within | |
| // this header file, consult the time.h header file. | |
| namespace absl { | |
| ABSL_NAMESPACE_BEGIN | |
| // Now() | |
| // | |
| // Returns the current time, expressed as an `absl::Time` absolute time value. | |
| absl::Time Now(); | |
| // GetCurrentTimeNanos() | |
| // | |
| // Returns the current time, expressed as a count of nanoseconds since the Unix | |
| // Epoch (https://en.wikipedia.org/wiki/Unix_time). Prefer `absl::Now()` instead | |
| // for all but the most performance-sensitive cases (i.e. when you are calling | |
| // this function hundreds of thousands of times per second). | |
| int64_t GetCurrentTimeNanos(); | |
| // SleepFor() | |
| // | |
| // Sleeps for the specified duration, expressed as an `absl::Duration`. | |
| // | |
| // Notes: | |
| // * Signal interruptions will not reduce the sleep duration. | |
| // * Returns immediately when passed a nonpositive duration. | |
| void SleepFor(absl::Duration duration); | |
| ABSL_NAMESPACE_END | |
| } // namespace absl | |
| // ----------------------------------------------------------------------------- | |
| // Implementation Details | |
| // ----------------------------------------------------------------------------- | |
| // In some build configurations we pass --detect-odr-violations to the | |
| // gold linker. This causes it to flag weak symbol overrides as ODR | |
| // violations. Because ODR only applies to C++ and not C, | |
| // --detect-odr-violations ignores symbols not mangled with C++ names. | |
| // By changing our extension points to be extern "C", we dodge this | |
| // check. | |
| extern "C" { | |
| ABSL_DLL void ABSL_INTERNAL_C_SYMBOL(AbslInternalSleepFor)( | |
| absl::Duration duration); | |
| } // extern "C" | |
| inline void absl::SleepFor(absl::Duration duration) { | |
| ABSL_INTERNAL_C_SYMBOL(AbslInternalSleepFor)(duration); | |
| } | |