cpu_limit.hpp

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#pragma once
 
/// @file userver/hostinfo/cpu_limit.hpp
/// @brief Information about CPU limits in container.
/// @ingroup userver_universal
 
#include <optional>
 
USERVER_NAMESPACE_BEGIN
 
/// @brief Information about current host.
namespace hostinfo {
 
/// @brief Returns the CPU limit.
///
/// Unlike `nproc` and
/// `std::thread::hardware_concurrency` this method considers container limits
/// and may return fractional values.
///
/// Uses:
///   * CPU_LIMIT environment variable (example: `CPU_LIMIT=1.95c`).
///   * DEPLOY_VCPU_LIMIT environment variable (example: `DEPLOY_VCPU_LIMIT=2000`).
///   * cpu limit from cgroup v2 (CFS scheduler)
std::optional<double> CpuLimit();
 
/// @brief Returns true if the current process is run in container (CPU_LIMIT
/// environment variable is set).
bool IsInRtc();
 
}  // namespace hostinfo
 
USERVER_NAMESPACE_END