diff --git a/runtime/Makefile b/runtime/Makefile
index af244da..f36e951 100644
--- a/runtime/Makefile
+++ b/runtime/Makefile
@@ -13,7 +13,7 @@ CC=clang
 CC_OPTIONS = -O3 -flto -g -pthread -D_GNU_SOURCE
 
 # CC_OPTIONS for Debugging
-#CC_OPTIONS = -O0 -g -pthread -D_GNU_SOURCE
+# CC_OPTIONS = -O0 -g -pthread -D_GNU_SOURCE
 
 # CFI Sanitizer
 # CC_OPTIONS = -O0 -g -pthread -D_GNU_SOURCE -flto -fvisibility=default -fsanitize=cfi 
@@ -91,7 +91,6 @@ CFLAGS += -DUSE_MEM_VM
 LDFLAGS += -Wl,--export-dynamic -ldl -lm
 LDFLAGS += -Lthirdparty/dist/lib/
 INCLUDES += -Iinclude/ -Ithirdparty/dist/include/
-INCLUDES += -Iinclude/ -Ithirdparty/ck/include/
 
 # CFILES
 CFILES += src/*.c
@@ -100,7 +99,6 @@ CFILES += src/libc/*.c
 CFILES += src/memory/common.c
 CFILES += src/memory/64bit_nix.c
 CFILES += thirdparty/dist/lib/http_parser.o
-CFILES += thirdparty/dist/lib/libck.a
 
 # Configuring Jasmine
 JSMNCFLAGS += -DJSMN_STATIC
diff --git a/runtime/include/arch/aarch64/context.h b/runtime/include/arch/aarch64/context.h
index 02397fd..8c85b4a 100644
--- a/runtime/include/arch/aarch64/context.h
+++ b/runtime/include/arch/aarch64/context.h
@@ -41,7 +41,7 @@ arch_context_init(struct arch_context *actx, reg_t ip, reg_t sp)
  * which defaults to resuming execution of main
  */
 static inline int
-arch_context_switch(struct arch_context *a, struct arch_context *b) //save context to a and switch to context b
+arch_context_switch(struct arch_context *a, struct arch_context *b)
 {
 #ifndef NDEBUG
 	/*
@@ -61,7 +61,7 @@ arch_context_switch(struct arch_context *a, struct arch_context *b) //save conte
 	assert(a != b);
 
 	/* Set any NULLs to worker_thread_base_context to resume execution of main */
-	if (a == NULL) a = &worker_thread_base_context; //NULL indicates the main context of the worker thread before running any sandboxs
+	if (a == NULL) a = &worker_thread_base_context;
 	if (b == NULL) b = &worker_thread_base_context;
 
 	/* A Transition {Unused, Running} -> Fast */
diff --git a/runtime/include/sandbox_functions.h b/runtime/include/sandbox_functions.h
index 2d39d8a..0e7962c 100644
--- a/runtime/include/sandbox_functions.h
+++ b/runtime/include/sandbox_functions.h
@@ -143,7 +143,7 @@ sandbox_open_http(struct sandbox *sandbox)
 	http_parser_init(&sandbox->http_parser, HTTP_REQUEST);
 
 	/* Set the sandbox as the data the http-parser has access to */
-	sandbox->http_parser.data = sandbox; //assign data to sandbox in case to operator it when a callback happended
+	sandbox->http_parser.data = sandbox;
 
 	/* Freshly allocated sandbox going runnable for first time, so register client socket with epoll */
 	struct epoll_event accept_evt;
diff --git a/runtime/include/sandbox_receive_request.h b/runtime/include/sandbox_receive_request.h
index 79535b1..28686be 100644
--- a/runtime/include/sandbox_receive_request.h
+++ b/runtime/include/sandbox_receive_request.h
@@ -88,7 +88,6 @@ sandbox_receive_request(struct sandbox *sandbox)
 		sandbox->request_response_data_length += nparsed;
 	}
 
-	//http_request_print(&sandbox->http_request);
 	sandbox->request_length = sandbox->request_response_data_length;
 
 	rc = 0;
diff --git a/runtime/include/sandbox_request.h b/runtime/include/sandbox_request.h
index 0005dfa..5287ffd 100644
--- a/runtime/include/sandbox_request.h
+++ b/runtime/include/sandbox_request.h
@@ -25,7 +25,7 @@ struct sandbox_request {
 	uint64_t        absolute_deadline;         /* cycles */
 	char * previous_function_output;
 	ssize_t output_length;
-	ssize_t pre_request_length;                    /* previous request length */
+	ssize_t previous_request_length;                    /* previous request length */
 	/*
 	 * Unitless estimate of the instantaneous fraction of system capacity required to run the request
 	 * Calculated by estimated execution time (cycles) * runtime_admissions_granularity / relative deadline (cycles)
@@ -90,7 +90,7 @@ sandbox_request_allocate(struct module *module, bool request_from_outside, ssize
 	sandbox_request->absolute_deadline         = request_arrival_timestamp + module->relative_deadline;
 	sandbox_request->previous_function_output = previous_function_output;
 	sandbox_request->output_length = output_length;
-	sandbox_request->pre_request_length = request_length;
+	sandbox_request->previous_request_length = request_length;
 
 	/*
 	 * Admissions Control State
diff --git a/runtime/include/sandbox_set_as_initialized.h b/runtime/include/sandbox_set_as_initialized.h
index 6e66c9a..28ccb19 100644
--- a/runtime/include/sandbox_set_as_initialized.h
+++ b/runtime/include/sandbox_set_as_initialized.h
@@ -37,7 +37,7 @@ sandbox_set_as_initialized(struct sandbox *sandbox, struct sandbox_request *sand
 	sandbox->request_from_outside = sandbox_request->request_from_outside;
 	sandbox->previous_function_output = sandbox_request->previous_function_output;
 	sandbox->output_length = sandbox_request->output_length;
-	sandbox->pre_request_length = sandbox_request->pre_request_length;
+	sandbox->previous_request_length = sandbox_request->previous_request_length;
 	/* Initialize the sandbox's context, stack, and instruction pointer */
 	/* stack_start points to the bottom of the usable stack, so add stack_size to get to top */
 	arch_context_init(&sandbox->ctxt, (reg_t)current_sandbox_start,
diff --git a/runtime/include/sandbox_types.h b/runtime/include/sandbox_types.h
index 9cf510a..9b3f455 100644
--- a/runtime/include/sandbox_types.h
+++ b/runtime/include/sandbox_types.h
@@ -35,7 +35,7 @@ struct sandbox {
 	int current_func_index; /* indicate the index of next function in the chain */
 	char * previous_function_output; /* the output of the previous function */
 	ssize_t output_length; /* the length of previous_function_output */
-	ssize_t pre_request_length; /* the length of previous_function_output */
+	ssize_t previosu_request_length; /* the length of previous request */
 	sandbox_state_t state;
 
 	uint32_t sandbox_size; /* The struct plus enough buffer to hold the request or response (sized off largest) */
@@ -68,7 +68,6 @@ struct sandbox {
 
 	uint64_t absolute_deadline;
 	uint64_t total_time; /* From Request to Response */
-	uint64_t execution_time; /* From running to response */
 
 	/*
 	 * Unitless estimate of the instantaneous fraction of system capacity required to run the request
diff --git a/runtime/src/current_sandbox.c b/runtime/src/current_sandbox.c
index bc2acb2..7dcd5d5 100644
--- a/runtime/src/current_sandbox.c
+++ b/runtime/src/current_sandbox.c
@@ -69,24 +69,21 @@ current_sandbox_start(void)
 
 	sandbox_initialize_stdio(sandbox);
 
-	sandbox_open_http(sandbox);//add IN/OUT event to epoll
+	sandbox_open_http(sandbox);
 
 	if (sandbox->request_from_outside) {
-		if (sandbox_receive_request(sandbox) < 0) {//read data from client socket to get http request, 
-						           //the result populates http_request structure
-						   	   // if read blocked, then remove the sandbox from the 
-						   	   // local runqueue and pause the sandbox
+		if (sandbox_receive_request(sandbox) < 0) { 
 			error_message = "Unable to receive or parse client request\n";
 			goto err;
 		};
 	} else {
-		/* copy previous output to sandbox->request_response_data, as the input for the sandbox.*/
+		/* copy previous output to sandbox->request_response_data, as the input for the current sandbox.*/
 		/* let sandbox->http_request->body points to sandbox->request_response_data*/
 		assert(sandbox->previous_function_output != NULL);
 		memcpy(sandbox->request_response_data, sandbox->previous_function_output, sandbox->output_length);
 		sandbox->http_request.body = sandbox->request_response_data;
 		sandbox->http_request.body_length = sandbox->output_length;
-		sandbox->request_length = sandbox->pre_request_length;
+		sandbox->request_length = sandbox->previous_request_length;
 		sandbox->request_response_data_length = sandbox->request_length;
 	}
 
@@ -94,7 +91,9 @@ current_sandbox_start(void)
 	struct module *current_module = sandbox_get_module(sandbox);
 	module_initialize_globals(current_module);
 	module_initialize_memory(current_module);
-	sandbox_setup_arguments(sandbox); //this arguments is not the http body content
+	sandbox_setup_arguments(sandbox);
+
+ 
 	/* Executing the function */
 	int32_t argument_count = module_get_argument_count(current_module);
 	current_sandbox_enable_preemption(sandbox);
@@ -116,16 +115,16 @@ current_sandbox_start(void)
                                                            (const struct sockaddr *)&sandbox->client_address,
                                                            sandbox->request_arrival_timestamp, enqueue_timestamp, 
 							   true, pre_func_output, output_length);
-                /* reset the request id to the same as the current request id */
+		/* TODO: all sandboxs in the chain share the same request id, but sandbox_request_allocate() will busy-wait to generate an unique
+		   id, should we optimize it here?*/
 		sandbox_request->id = sandbox->id;  
 		/* Add to the Global Sandbox Request Scheduler */
-                global_request_scheduler_add(sandbox_request);
+		global_request_scheduler_add(sandbox_request);
 		sandbox_remove_from_epoll(sandbox);
 		sandbox_set_as_returned(sandbox, SANDBOX_RUNNING);
 	} else {
 		/* Retrieve the result, construct the HTTP response, and send to client */
-		if (sandbox_send_response(sandbox) < 0) { // if send blocked, remove the sandbox from the local runqueue
-						  	  // and pause the sandbox
+		if (sandbox_send_response(sandbox) < 0) {
 			error_message = "Unable to build and send client response\n";
 			goto err;
 		};
@@ -136,12 +135,12 @@ current_sandbox_start(void)
 
 		assert(sandbox->state == SANDBOX_RUNNING);
 		sandbox_close_http(sandbox);
-		sandbox_set_as_returned(sandbox, SANDBOX_RUNNING); //request is completed, remove the sandbox from the local runqueue
+		sandbox_set_as_returned(sandbox, SANDBOX_RUNNING);
 	}
 done:
 	/* Cleanup connection and exit sandbox */
 	generic_thread_dump_lock_overhead();
-	scheduler_yield(); //put the sandbox to the complete queue
+	scheduler_yield();
 
 	/* This assert prevents a segfault discussed in
 	 * https://github.com/phanikishoreg/awsm-Serverless-Framework/issues/66
diff --git a/runtime/src/global_request_scheduler_minheap.c b/runtime/src/global_request_scheduler_minheap.c
index d799936..c312405 100644
--- a/runtime/src/global_request_scheduler_minheap.c
+++ b/runtime/src/global_request_scheduler_minheap.c
@@ -19,6 +19,7 @@ global_request_scheduler_minheap_add(void *sandbox_request)
 {
 	assert(sandbox_request);
 	assert(global_request_scheduler_minheap);
+	/* panic is not applicable here because all worker_threads can add a request to the global queue if it's a chain function */
 	//if (unlikely(!listener_thread_is_running())) panic("%s is only callable by the listener thread\n", __func__);
 
 	int return_code = priority_queue_enqueue(global_request_scheduler_minheap, sandbox_request);
diff --git a/runtime/src/main.c b/runtime/src/main.c
index 0729edf..e2101ce 100644
--- a/runtime/src/main.c
+++ b/runtime/src/main.c
@@ -226,7 +226,6 @@ runtime_configure()
 		if (runtime_sandbox_perf_log == NULL) { perror("sandbox perf log"); }
 		fprintf(runtime_sandbox_perf_log, "id,function,state,deadline,actual,queued,initializing,runnable,"
 		                                  "running,blocked,returned,memory\n");
-		fflush(runtime_sandbox_perf_log);
 	} else {
 		printf("\tSandbox Performance Log: Disabled\n");
 	}
diff --git a/runtime/src/runtime.c b/runtime/src/runtime.c
index bc24bd8..7b061fc 100644
--- a/runtime/src/runtime.c
+++ b/runtime/src/runtime.c
@@ -65,12 +65,12 @@ runtime_set_resource_limits_to_max()
 		int resource = resources[i];
 		if (getrlimit(resource, &limit) < 0) panic_err();
 
-		if (limit.rlim_cur == RLIM_INFINITY) { // rlim_cur is soft limit
+		if (limit.rlim_cur == RLIM_INFINITY) {
 			strncpy(lim, "Infinite", uint64_t_max_digits);
 		} else {
 			snprintf(lim, uint64_t_max_digits, "%lu", limit.rlim_cur);
 		}
-		if (limit.rlim_max == RLIM_INFINITY) { // rlim_max is hard limit
+		if (limit.rlim_max == RLIM_INFINITY) {
 			strncpy(max, "Infinite", uint64_t_max_digits);
 		} else {
 			snprintf(max, uint64_t_max_digits, "%lu", limit.rlim_max);
@@ -91,19 +91,18 @@ runtime_set_resource_limits_to_max()
 void
 runtime_initialize(void)
 {
-	http_total_init(); //initilize http requests/error response counter
-	sandbox_request_count_initialize(); //initilize sandbox requests counter
-	sandbox_count_initialize(); //initilize sandbox state counter
+	http_total_init();
+	sandbox_request_count_initialize();
+	sandbox_count_initialize();
 
 	/* Setup Scheduler */
-	scheduler_initialize(); //set function pointers to global_request_scheduler, both EDF and FIFO have a set of functions
+	scheduler_initialize();
 
 	/* Configure Signals */
-	signal(SIGPIPE, SIG_IGN); // ignore SIGPIPE
-	signal(SIGTERM, runtime_cleanup); // call runtime_cleanup when get SIGTERM signal
+	signal(SIGPIPE, SIG_IGN);
+	signal(SIGTERM, runtime_cleanup);
 
-	http_parser_settings_initialize(); // set function pointers for http parser lib, when get a http message, some callback
-					   // functions will be called
+	http_parser_settings_initialize();
 	admissions_control_initialize();
 }