How to capture the time duration inside an enclave?

[li0926]

I'm new to intel sgx. I need an accurate timekeeper in enclave, preferably down to the millisecond.

1. I trying to use std::chrono.
   I write #include <chrono> in enclave.cpp and test it inside an enclave function, but the error is reported as below:

Enclave/Enclave.cpp:476:24: error: ‘std::chrono’ has not been declared
  476 |     auto begin1 = std::chrono::high_resolution_clock::now();
      |                        ^~~~~~

2. I trying to use time.h.
   I write #include <time.h> in enclave.cpp, but it still gives me the following error：

Enclave/Enclave.cpp:482:5: error: ‘time’ was not declared in this scope
  482 |     time(&t1);
      |     ^~~~

The Enclave_Link_Flags in makefile：

Enclave_Link_Flags :=  $(SGX_COMMON_CFLAGS) -Wl,--no-undefined -nostdlib -nodefaultlibs -nostartfiles -L$(SGX_LIBRARY_PATH) \
	$(SgxSSL_Link_Libraries) \
	-L/opt/intel/sgxsdk/lib64 \
	-L/opt/gmp/6.1.2/lib \
	$(Enclave_Security_Link_Flags) \
	-L$(SGX_LIBRARY_PATH) \
    -Wl,--no-undefined -nostdlib -nodefaultlibs -nostartfiles -L$(SGX_LIBRARY_PATH) \
	-Wl,--whole-archive  -l$(Trts_Library_Name) -Wl,--no-whole-archive \
	-Wl,--start-group -lsgx_tstdc -lsgx_tgmp -lsgx_pthread -lsgx_tcxx -l$(Crypto_Library_Name) -l$(Service_Library_Name) \
	-l$(SGX_TVL_Library_Name) -lsgx_ttls -Wl,--end-group \
	-Wl,-Bstatic -Wl,-Bsymbolic -Wl,--no-undefined \
	-Wl,-pie,-eenclave_entry -Wl,--export-dynamic  \
	-Wl,--defsym,__ImageBase=0 -Wl,--gc-sections   \
	-Wl,--version-script=Enclave/Enclave.lds

[lzha101]

There is no trust time support inside SGX enclaves. If you want to use time, an ocall is required. And you should be aware that the time cannot be trusted.

[li0926]

There is no trust time support inside SGX enclaves. If you want to use time, an ocall is required. And you should be aware that the time cannot be trusted.

I'm not looking for a trust time, I just want to log the time to test the efficiency of running some functions within the enclave.

[lzha101]

OK. Perhaps you can try to use the rdtsc instruction to monitor the performance for your case. This instruction is accessible inside enclaves if your platform supports SGX2.

[jinghe-INTC]

You can also try Intel® VTune™ Profiler, and the stand-alone version is recommended. It is able to collect the CPU time in clockticks of each functions even inside a SGX enclave, in GUI or CLI.
To do the measurement, your application don't need any change but should be built in debug configuration.
And you need to register an account to have a 31-day free trial first.