library/cpp/lwtrace/example5/lwtrace_example5.cpp


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#include <library/cpp/lwtrace/all.h>
#include <library/cpp/lwtrace/lwprobe.h>
 
template <ui64 N> 
ui64 Fact() { 
    ui64 result = N * Fact<N - 1>();
 
#ifndef LWTRACE_DISABLE
    // Note that probe is create on the first pass 
    // LWTRACE_DECLARE_PROVIDER and LWTRACE_DEFINE_PROVIDER are not needed 
    // (Provider is created implicitly) 
    static NLWTrace::TLWProbe<ui64> factProbe( 
        "LWTRACE_EXAMPLE_PROVIDER", "FactProbe_" + ToString(N), {}, {"result"}); 
 
    LWPROBE_OBJ(factProbe, result); 
#endif // LWTRACE_DISABLE
    return result; 
} 
 
template <> 
ui64 Fact<0>() { 
    return 1; 
} 
 
int main() { 
    Fact<6>();                       // First run is required to create probes we can use later in trace query
    NLWTrace::StartLwtraceFromEnv(); // parse trace query and create trace session 
    Cout << Fact<6>() << Endl;       // actually trigger probes
    return 0; 
}