What's the relationship among Enclave , thread and process?
Does SGX support multi-thread or multi-process?
What will happen if I call the "fork" to create a new process inside a enclave?
Creating a new process inside the Enclave is not allowed. For multiple threads running inside the Enclave, you need to follow the "Thread Binding Policy" which has two modes: non-binding and binding. Please refer to section of "Thread Binding Policy" in the SGX Developer Guide at https://software.intel.com/sites/default/files/managed/33/70/intel-sgx-developer-guide.pdf