Get rid of the additional throughput management thread

1) Additional thread brings extra overhead to system;
2) Current main thread can run the throughput management.

src/main.c

@@ -81,19 +81,6 @@ int run_ntttcp_sender(struct ntttcp_test_endpoint *tep)
 	/* prepare to create threads */
 	pthread_attr_init(&pth_attrs);
 	pthread_attr_setstacksize(&pth_attrs, THREAD_STACK_SIZE);
-
-	/* create throughput management thread */
-	rc = pthread_create(tep->throughput_mgmt_thread,
-			    &pth_attrs,
-			    run_ntttcp_throughput_management,
-			    (void*)tep);
-	if (rc) {
-		ASPRINTF(&log, "pthread_create(): failed to create throughput management thread. errno = %d", errno);
-		PRINT_ERR_FREE(log);
-		pthread_attr_destroy(&pth_attrs);
-		return ERROR_PTHREAD_CREATE;
-	}
-
 	/* create test threads */
 	for (t = 0; t < test->server_ports; t++) {
 		for (n = 0; n < test->threads_per_server_port; n++ ) {
@@ -146,16 +133,18 @@ int run_ntttcp_sender(struct ntttcp_test_endpoint *tep)
 		return err_code;
 	}
 
-	/* wait for test done (after the timer fired, or CTRL+C) */
-	wait_light_off();
+	/* manage the test cycle
+	 * will return after light is turned off
+	 * (calling wait_light_off() inside of below
+	 */
+	run_ntttcp_throughput_management(tep);
 
 	for (n = 0; n < threads_created; n++) {
 		if (pthread_join(tep->threads[n], &p_retval) !=0 ) {
 			PRINT_ERR("sender: error when pthread_join");
 			continue;
 		}
 	}
-	pthread_join(*(tep->throughput_mgmt_thread), &p_retval);
 
 	return err_code;
 }
@@ -170,17 +159,6 @@ int run_ntttcp_receiver(struct ntttcp_test_endpoint *tep)
 	struct ntttcp_stream_server *ss;
 	int rc;
 
-	/* create throughput management thread */
-	rc = pthread_create(tep->throughput_mgmt_thread,
-			    NULL,
-			    run_ntttcp_throughput_management,
-			    (void*)tep);
-	if (rc) {
-		ASPRINTF(&log, "pthread_create(): failed to create throughput management thread. errno = %d", errno);
-		PRINT_ERR_FREE(log);
-		return ERROR_PTHREAD_CREATE;
-	}
-
 	/* create test threads */
 	for (t = 0; t < test->server_ports; t++) {
 		ss = tep->server_streams[t];
@@ -270,8 +248,11 @@ int run_ntttcp_receiver(struct ntttcp_test_endpoint *tep)
 			return err_code;
 		}
 
-		/* wait test done */
-		wait_light_off();
+		/* manage the test cycle
+		 * will return after light is turned off
+		 * (calling wait_light_off() inside of below function)
+		 */
+		run_ntttcp_throughput_management(tep);
 
 		/* reset thiss variable, in case receiver is running as '-H' (receiver is running in loop) */
 		tep->num_remote_endpoints = 0;
@@ -288,7 +269,6 @@ int run_ntttcp_receiver(struct ntttcp_test_endpoint *tep)
 			continue;
 		}
 	}
-	pthread_join(*(tep->throughput_mgmt_thread), NULL);
 
 	return err_code;
 }

src/main.h

@@ -7,6 +7,5 @@
 #define _GNU_SOURCE
 #include <stdio.h>
 #include <limits.h>
-#include "endpointsync.h"
 #include "throughputmanagement.h"
 #include "udpstream.h"

src/ntttcp.c

@@ -127,8 +127,6 @@ struct ntttcp_test_endpoint *new_ntttcp_test_endpoint(struct ntttcp_test *test,
 			return NULL;
 		}
 	}
-	/* for throughput management thread */
-	e->throughput_mgmt_thread = malloc( sizeof(pthread_t) );
 
 	/* for test results */
 	e->results = (struct ntttcp_test_endpoint_results *) malloc(sizeof(struct ntttcp_test_endpoint_results));
@@ -215,7 +213,6 @@ void free_ntttcp_test_endpoint_and_test(struct ntttcp_test_endpoint* e)
 	free( e->results->final_tcp_retrans);
 	free( e->results );
 	free( e->threads );
-	free( e->throughput_mgmt_thread );
 	free( e->test );
 	free( e );
 }

src/ntttcp.h

@@ -66,7 +66,6 @@ struct ntttcp_test_endpoint{
 	struct	ntttcp_stream_client **client_streams;	/* alloc memory for this if client/sender role */
 	struct	ntttcp_stream_server **server_streams;	/* alloc memory for this if server/receiver role */
 	pthread_t	*threads;			/* linux threads created to transfer test data */
-	pthread_t       *throughput_mgmt_thread;        /* linux thread created to manage the throughput on endpoint */
 
 	struct	ntttcp_test_endpoint_results	*results;	/* test results */
 

src/throughputmanagement.c

@@ -42,9 +42,8 @@ struct report_segment report_real_time_throughput(struct ntttcp_test_endpoint *t
 	return this_checkpoint;
 }
 
-void *run_ntttcp_throughput_management(void *ptr)
+void run_ntttcp_throughput_management(struct ntttcp_test_endpoint *tep)
 {
-	struct ntttcp_test_endpoint *tep = (struct ntttcp_test_endpoint *) ptr;
 	uint n = 0;
 	uint i = 0;
 	double elapsed_sec = 0.0;
@@ -59,7 +58,7 @@ void *run_ntttcp_throughput_management(void *ptr)
 	uint64_t nbytes;
 	uint total_test_threads = tep->total_threads;
 
-	wait_light_on();
+	/* light is already turned on before entering this function */
 
 	/* Now the ntttcp test traffic is running now */
 	tep->state = TEST_RUNNING;
@@ -210,5 +209,5 @@ void *run_ntttcp_throughput_management(void *ptr)
 	}
 
 	tep->state = TEST_FINISHED;
-	return NULL;
+	return;
 }

src/throughputmanagement.h

@@ -21,4 +21,4 @@ struct report_segment
 	uint64_t	bytes;
 };
 
-void *run_ntttcp_throughput_management(void *ptr);
+void run_ntttcp_throughput_management(struct ntttcp_test_endpoint *tep);