From b196c6498d22e47bb9d0da0153068ec54eac7956 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 11:44:33 +0200 Subject: Adding upstream version 1.6.0. Signed-off-by: Daniel Baumann --- example/dynamic_load/dynamic_load-example.cpp | 69 +++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 example/dynamic_load/dynamic_load-example.cpp (limited to 'example/dynamic_load/dynamic_load-example.cpp') diff --git a/example/dynamic_load/dynamic_load-example.cpp b/example/dynamic_load/dynamic_load-example.cpp new file mode 100644 index 0000000..f49996f --- /dev/null +++ b/example/dynamic_load/dynamic_load-example.cpp @@ -0,0 +1,69 @@ +// Demonstrates how to load a tracer library in at runtime and how to use it +// to construct spans. To run it using the mocktracer, invoke with +// +// TRACER_CONFIG=`mktemp` +// echo '{ "output_file": "/dev/stdout" }' > $TRACER_CONFIG +// dynamic_load-example /path/to/libopentracing_mocktracer.so $TRACER_CONFIG + +#include +#include +#include +#include +#include +#include +#include + +#ifdef _MSC_VER +#pragma warning(push) +#pragma warning(disable : 4996) +#endif + +int main(int argc, char* argv[]) { + if (argc != 3) { + std::cerr << "Usage: \n"; + return -1; + } + + // Load the tracer library. + std::string error_message; + auto handle_maybe = + opentracing::DynamicallyLoadTracingLibrary(argv[1], error_message); + if (!handle_maybe) { + std::cerr << "Failed to load tracer library " << error_message << "\n"; + return -1; + } + + // Read in the tracer's configuration. + std::ifstream istream{argv[2]}; + if (!istream.good()) { + std::cerr << "Failed to open tracer config file " << argv[2] << ": " + << std::strerror(errno) << "\n"; + return -1; + } + std::string tracer_config{std::istreambuf_iterator{istream}, + std::istreambuf_iterator{}}; + + // Construct a tracer. + auto& tracer_factory = handle_maybe->tracer_factory(); + auto tracer_maybe = + tracer_factory.MakeTracer(tracer_config.c_str(), error_message); + if (!tracer_maybe) { + std::cerr << "Failed to create tracer " << error_message << "\n"; + return -1; + } + auto& tracer = *tracer_maybe; + + // Use the tracer to create some spans. + { + auto span_a = tracer->StartSpan("A"); + assert(span_a != nullptr); + span_a->SetTag("abc", 123); + auto span_b = + tracer->StartSpan("B", {opentracing::ChildOf(&span_a->context())}); + assert(span_b != nullptr); + span_b->SetTag("xyz", 987); + } + + tracer->Close(); + return 0; +} -- cgit v1.2.3