diff --git a/src/cjson.c b/src/cjson.c
index f75407d..7a3a4f4 100644
--- a/src/cjson.c
+++ b/src/cjson.c
@@ -132,7 +132,7 @@ static double ipow( double n, int exp )
 /* Parse the input text to generate a number, and populate the result into item. */
 static const char *parse_number( cJSON *item, const char *num )
 {
-	long long i = 0;
+	int64_t i = 0;
 	double f = 0;
 	int isint = 1;
 	int sign = 1, scale = 0, subscale = 0, signsubscale = 1;
@@ -930,7 +930,7 @@ cJSON *cJSON_CreateBool( int b )
 	return item;
 }
 
-cJSON *cJSON_CreateInt( long long num )
+cJSON *cJSON_CreateInt( int64_t num )
 {
 	cJSON *item = cJSON_New_Item();
 	if ( item ) {
@@ -981,7 +981,7 @@ cJSON *cJSON_CreateObject( void )
 
 /* Create Arrays. */
 
-cJSON *cJSON_CreateIntArray( long long *numbers, int count )
+cJSON *cJSON_CreateIntArray( int64_t *numbers, int count )
 {
 	int i;
 	cJSON *n = 0, *p = 0, *a = cJSON_CreateArray();
diff --git a/src/cjson.h b/src/cjson.h
index e86629f..d4449e6 100644
--- a/src/cjson.h
+++ b/src/cjson.h
@@ -47,7 +47,7 @@ typedef struct cJSON {
 	int type;			/* The type of the item, as above. */
 
 	char *valuestring;		/* The item's string, if type==cJSON_String */
-	long long valueint;		/* The item's number, if type==cJSON_Number */
+	int64_t valueint;		/* The item's number, if type==cJSON_Number */
 	double valuefloat;		/* The item's number, if type==cJSON_Number */
 
 	char *string;			/* The item's name string, if this item is the child of, or is in the list of subitems of an object. */
@@ -86,14 +86,14 @@ extern cJSON *cJSON_CreateNull( void );
 extern cJSON *cJSON_CreateTrue( void );
 extern cJSON *cJSON_CreateFalse( void );
 extern cJSON *cJSON_CreateBool( int b );
-extern cJSON *cJSON_CreateInt( long long num );
+extern cJSON *cJSON_CreateInt( int64_t num );
 extern cJSON *cJSON_CreateFloat( double num );
 extern cJSON *cJSON_CreateString( const char *string );
 extern cJSON *cJSON_CreateArray( void );
 extern cJSON *cJSON_CreateObject( void );
 
 /* These utilities create an Array of count items. */
-extern cJSON *cJSON_CreateIntArray( long long *numbers, int count );
+extern cJSON *cJSON_CreateIntArray( int64_t *numbers, int count );
 extern cJSON *cJSON_CreateFloatArray( double *numbers, int count );
 extern cJSON *cJSON_CreateStringArray( const char **strings, int count );
 
diff --git a/src/iperf.h b/src/iperf.h
index 74e41dc..f6a17f5 100644
--- a/src/iperf.h
+++ b/src/iperf.h
@@ -15,6 +15,7 @@
 #include <stdint.h>
 #include <sys/socket.h>
 #include <netinet/tcp.h>
+#include "timer.h"
 #include "queue.h"
 
 typedef uint64_t iperf_size_t;
@@ -76,7 +77,8 @@ struct iperf_stream
 
     /* non configurable members */
     struct iperf_stream_result *result;	/* structure pointer to result */
-    struct timer *send_timer;
+    Timer     *send_timer;
+    int       udp_green_light;
     char      *buffer;		/* data to send */
 
     /*
@@ -149,9 +151,10 @@ struct iperf_test
     double    reporter_interval;
     void      (*stats_callback) (struct iperf_test *);
     void      (*reporter_callback) (struct iperf_test *);
-    struct timer *timer;
-    struct timer *stats_timer;
-    struct timer *reporter_timer;
+    Timer     *timer;
+    int        done;
+    Timer     *stats_timer;
+    Timer     *reporter_timer;
 
     double cpu_util;                            /* cpu utilization of the test */
     double remote_cpu_util;                     /* cpu utilization for the remote host/client */
diff --git a/src/iperf_api.c b/src/iperf_api.c
index 4ceb1d7..a82f49f 100644
--- a/src/iperf_api.c
+++ b/src/iperf_api.c
@@ -228,7 +228,7 @@ get_protocol(struct iperf_test *test, int prot_id)
     if (prot == NULL)
         i_errno = IEPROTOCOL;
 
-    return (prot);
+    return prot;
 }
 
 int
@@ -239,13 +239,13 @@ set_protocol(struct iperf_test *test, int prot_id)
     SLIST_FOREACH(prot, &test->protocols, protocols) {
         if (prot->id == prot_id) {
             test->protocol = prot;
-            return (0);
+            return 0;
         }
     }
 
     i_errno = IEPROTOCOL;
 
-    return (-1);
+    return -1;
 }
 
 
@@ -312,9 +312,6 @@ iperf_on_connect(struct iperf_test *test)
 void
 iperf_on_test_finish(struct iperf_test *test)
 {
-    if (test->verbose) {
-        printf("Test Complete. Summary Results:\n");
-    }
 }
 
 
@@ -364,7 +361,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
             case 'c':
                 if (test->role == 's') {
                     i_errno = IESERVCLIENT;
-                    return (-1);
+                    return -1;
                 } else {
                     test->role = 'c';
                     test->server_hostname = (char *) malloc(strlen(optarg)+1);
@@ -377,7 +374,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
             case 's':
                 if (test->role == 'c') {
                     i_errno = IESERVCLIENT;
-                    return (-1);
+                    return -1;
                 } else {
                     test->role = 's';
                 }
@@ -385,12 +382,12 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
             case 't':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->duration = atoi(optarg);
                 if (test->duration > MAX_TIME) {
                     i_errno = IEDURATION;
-                    return (-1);
+                    return -1;
                 }
                 break;
             case 'u':
@@ -398,7 +395,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
                     warning("ignoring client only argument --udp (-u)");
                 /* XXX: made a warning
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 */
                 }
                 set_protocol(test, Pudp);
@@ -407,12 +404,12 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
             case 'P':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->num_streams = atoi(optarg);
                 if (test->num_streams > MAX_STREAMS) {
                     i_errno = IENUMSTREAMS;
-                    return (-1);
+                    return -1;
                 }
                 break;
             case 'B':
@@ -422,31 +419,31 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
             case 'b':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->settings->rate = unit_atof(optarg);
                 break;
             case 'l':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->settings->blksize = unit_atoi(optarg);
                 if (test->settings->blksize > MAX_BLOCKSIZE) {
                     i_errno = IEBLOCKSIZE;
-                    return (-1);
+                    return -1;
                 }
                 break;
             case 'w':
                 // XXX: This is a socket buffer, not specific to TCP
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->settings->socket_bufsize = unit_atof(optarg);
                 if (test->settings->socket_bufsize > MAX_TCP_BUFFER) {
                     i_errno = IEBUFSIZE;
-                    return (-1);
+                    return -1;
                 }
                 break;
             case 'i':
@@ -456,32 +453,32 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
                 test->reporter_interval = atof(optarg);
                 if (test->stats_interval > MAX_INTERVAL) {
                     i_errno = IEINTERVAL;
-                    return (-1);
+                    return -1;
                 }
                 break;
             case 'n':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->settings->bytes = unit_atoi(optarg);
                 break;
             case 'N':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->no_delay = 1;
                 break;
             case 'M':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->settings->mss = atoi(optarg);
                 if (test->settings->mss > MAX_MSS) {
                     i_errno = IEMSS;
-                    return (-1);
+                    return -1;
                 }
                 break;
             case 'f':
@@ -499,14 +496,14 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
             case 'R':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 test->reverse = 1;
                 break;
             case 'S':
                 if (test->role == 's') {
                     i_errno = IECLIENTONLY;
-                    return (-1);
+                    return -1;
                 }
                 // XXX: Checking for errors in strtol is not portable. Leave as is?
                 test->settings->tos = strtol(optarg, NULL, 0);
@@ -529,14 +526,14 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
 
     if ((test->role != 'c') && (test->role != 's')) {
         i_errno = IENOROLE;
-        return (-1);
+        return -1;
     }
     if (test->verbose) {
 	fputs(version, stdout);
 	system("uname -a");
     }
 
-    return (0);
+    return 0;
 }
 
 int
@@ -544,11 +541,11 @@ all_data_sent(struct iperf_test * test)
 {
     if (test->settings->bytes > 0) {
         if (test->bytes_sent >= (test->num_streams * test->settings->bytes)) {
-            return (1);
+            return 1;
         }
     }
 
-    return (0);
+    return 0;
 }
 
 int
@@ -567,14 +564,14 @@ iperf_send(struct iperf_test *test)
     result = select(test->max_fd + 1, NULL, &temp_write_set, NULL, &tv);
     if (result < 0 && errno != EINTR) {
         i_errno = IESELECT;
-        return (-1);
+        return -1;
     }
     if (result > 0) {
         SLIST_FOREACH(sp, &test->streams, streams) {
             if (FD_ISSET(sp->socket, &temp_write_set)) {
                 if ((bytes_sent = sp->snd(sp)) < 0) {
                     i_errno = IESTREAMWRITE;
-                    return (-1);
+                    return -1;
                 }
                 test->bytes_sent += bytes_sent;
                 FD_CLR(sp->socket, &temp_write_set);
@@ -582,7 +579,7 @@ iperf_send(struct iperf_test *test)
         }
     }
 
-    return (0);
+    return 0;
 }
 
 int
@@ -601,14 +598,14 @@ iperf_recv(struct iperf_test *test)
     result = select(test->max_fd + 1, &temp_read_set, NULL, NULL, &tv);
     if (result < 0) {
         i_errno = IESELECT;
-        return (-1);
+        return -1;
     }
     if (result > 0) {
         SLIST_FOREACH(sp, &test->streams, streams) {
             if (FD_ISSET(sp->socket, &temp_read_set)) {
                 if ((bytes_sent = sp->rcv(sp)) < 0) {
                     i_errno = IESTREAMREAD;
-                    return (-1);
+                    return -1;
                 }
                 test->bytes_sent += bytes_sent;
                 FD_CLR(sp->socket, &temp_read_set);
@@ -616,55 +613,84 @@ iperf_recv(struct iperf_test *test)
         }
     }
 
-    return (0);
+    return 0;
+}
+
+static void
+test_timer_proc(TimerClientData client_data, struct timeval* nowP)
+{
+    struct iperf_test *test = client_data.p;
+
+    test->done = 1;
+    test->timer = NULL;
+}
+
+static void
+stats_timer_proc(TimerClientData client_data, struct timeval* nowP)
+{
+    struct iperf_test *test = client_data.p;
+
+    if (test->done)
+        return;
+    test->stats_callback(test);
+}
+
+static void
+reporter_timer_proc(TimerClientData client_data, struct timeval* nowP)
+{
+    struct iperf_test *test = client_data.p;
+
+    if (test->done)
+        return;
+    test->reporter_callback(test);
 }
 
 int
 iperf_init_test(struct iperf_test *test)
 {
     struct iperf_stream *sp;
-    time_t sec;
-    time_t usec;
+    struct timeval now;
+    TimerClientData cd;
 
     if (test->protocol->init) {
         if (test->protocol->init(test) < 0)
-            return (-1);
+            return -1;
     }
 
-    /* Set timers */
+    /* Create timers. */
+    if (gettimeofday(&now, NULL) < 0) {
+            i_errno = IEINITTEST;
+            return -1;
+    }
     if (test->settings->bytes == 0) {
-        test->timer = new_timer(test->duration, 0);
+	test->done = 0;
+	cd.p = test;
+        test->timer = tmr_create(&now, test_timer_proc, cd, test->duration * SEC_TO_US, 0);
         if (test->timer == NULL)
-            return (-1);
+            return -1;
     } 
 
     if (test->stats_interval != 0) {
-        sec = (time_t) test->stats_interval;
-        usec = (test->stats_interval - sec) * SEC_TO_US;
-        test->stats_timer = new_timer(sec, usec);
+	cd.p = test;
+        test->stats_timer = tmr_create(&now, stats_timer_proc, cd, test->stats_interval * SEC_TO_US, 1);
         if (test->stats_timer == NULL)
-            return (-1);
+            return -1;
     }
     if (test->reporter_interval != 0) {
-        sec = (time_t) test->reporter_interval;
-        usec = (test->reporter_interval - sec) * SEC_TO_US;
-        test->reporter_timer = new_timer(sec, usec);
+	cd.p = test;
+        test->reporter_timer = tmr_create(&now, reporter_timer_proc, cd, test->reporter_interval * SEC_TO_US, 1);
         if (test->reporter_timer == NULL)
-            return (-1);
+            return -1;
     }
 
     /* Set start time */
-    SLIST_FOREACH(sp, &test->streams, streams) {
-        if (gettimeofday(&sp->result->start_time, NULL) < 0) {
-            i_errno = IEINITTEST;
-            return (-1);
-        }
-    }
+    SLIST_FOREACH(sp, &test->streams, streams)
+	sp->result->start_time = now;
 
     if (test->on_test_start)
         test->on_test_start(test);
 
-    return (0);
+    return 0;
 }
 
 /**
@@ -681,30 +707,30 @@ iperf_exchange_parameters(struct iperf_test * test)
     if (test->role == 'c') {
 
         if (send_parameters(test) < 0)
-            return (-1);
+            return -1;
 
     } else {
 
         if (get_parameters(test) < 0)
-            return (-1);
+            return -1;
 
         if ((s = test->protocol->listen(test)) < 0) {
             state = SERVER_ERROR;
             if (Nwrite(test->ctrl_sck, &state, sizeof(state), Ptcp) < 0) {
                 i_errno = IESENDMESSAGE;
-                return (-1);
+                return -1;
             }
             msg = htonl(i_errno);
             if (Nwrite(test->ctrl_sck, &msg, sizeof(msg), Ptcp) < 0) {
                 i_errno = IECTRLWRITE;
-                return (-1);
+                return -1;
             }
             msg = htonl(errno);
             if (Nwrite(test->ctrl_sck, &msg, sizeof(msg), Ptcp) < 0) {
                 i_errno = IECTRLWRITE;
-                return (-1);
+                return -1;
             }
-            return (-1);
+            return -1;
         }
         FD_SET(s, &test->read_set);
         test->max_fd = (s > test->max_fd) ? s : test->max_fd;
@@ -714,12 +740,12 @@ iperf_exchange_parameters(struct iperf_test * test)
         test->state = CREATE_STREAMS;
         if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
             i_errno = IESENDMESSAGE;
-            return (-1);
+            return -1;
         }
 
     }
 
-    return (0);
+    return 0;
 }
 
 /*************************************************************/
@@ -1073,7 +1099,7 @@ iperf_new_test()
     test = (struct iperf_test *) malloc(sizeof(struct iperf_test));
     if (!test) {
         i_errno = IENEWTEST;
-        return (NULL);
+        return NULL;
     }
     /* initialize everything to zero */
     memset(test, 0, sizeof(struct iperf_test));
@@ -1081,7 +1107,7 @@ iperf_new_test()
     test->settings = (struct iperf_settings *) malloc(sizeof(struct iperf_settings));
     memset(test->settings, 0, sizeof(struct iperf_settings));
 
-    return (test);
+    return test;
 }
 
 /**************************************************************************/
@@ -1116,11 +1142,11 @@ iperf_defaults(struct iperf_test * testp)
     struct protocol *tcp, *udp;
     tcp = (struct protocol *) malloc(sizeof(struct protocol));
     if (!tcp)
-        return (-1);
+        return -1;
     memset(tcp, 0, sizeof(struct protocol));
     udp = (struct protocol *) malloc(sizeof(struct protocol));
     if (!udp)
-        return (-1);
+        return -1;
     memset(udp, 0, sizeof(struct protocol));
 
     tcp->id = Ptcp;
@@ -1150,7 +1176,7 @@ iperf_defaults(struct iperf_test * testp)
     testp->on_connect = iperf_on_connect;
     testp->on_test_finish = iperf_on_test_finish;
 
-    return (0);
+    return 0;
 }
 
 
@@ -1171,9 +1197,12 @@ iperf_free_test(struct iperf_test * test)
     free(test->server_hostname);
     free(test->bind_address);
     free(test->settings);
-    free_timer(test->timer);
-    free_timer(test->stats_timer);
-    free_timer(test->reporter_timer);
+    if (test->timer != NULL)
+	tmr_cancel(test->timer);
+    if (test->stats_timer != NULL)
+	tmr_cancel(test->stats_timer);
+    if (test->reporter_timer != NULL)
+	tmr_cancel(test->reporter_timer);
 
     /* Free protocol list */
     while (!SLIST_EMPTY(&test->protocols)) {
@@ -1201,12 +1230,18 @@ iperf_reset_test(struct iperf_test *test)
         SLIST_REMOVE_HEAD(&test->streams, streams);
         iperf_free_stream(sp);
     }
-    free_timer(test->timer);
-    free_timer(test->stats_timer);
-    free_timer(test->reporter_timer);
-    test->timer = NULL;
-    test->stats_timer = NULL;
-    test->reporter_timer = NULL;
+    if (test->timer != NULL) {
+	tmr_cancel(test->timer);
+	test->timer = NULL;
+    }
+    if (test->stats_timer != NULL) {
+	tmr_cancel(test->stats_timer);
+	test->stats_timer = NULL;
+    }
+    if (test->reporter_timer != NULL) {
+	tmr_cancel(test->reporter_timer);
+	test->reporter_timer = NULL;
+    }
 
     SLIST_INIT(&test->streams);
 
@@ -1303,6 +1338,10 @@ iperf_print_intermediate(struct iperf_test *test)
         print_interval_results(test, sp);
 	/* sum up all streams */
 	irp = TAILQ_LAST(&sp->result->interval_results, irlisthead);
+	if (irp == NULL) {
+	    printf("iperf_print_intermediate Error: interval_results is NULL \n");
+	    return;
+	}
         bytes += irp->bytes_transferred;
 	if (test->protocol->id == Ptcp && has_tcpinfo_retransmits())
 	    retransmits += irp->this_retrans;
@@ -1330,7 +1369,7 @@ iperf_print_intermediate(struct iperf_test *test)
 }
 
 static void
-iperf_print_results (struct iperf_test *test)
+iperf_print_results(struct iperf_test *test)
 {
 
     long retransmits = 0, total_retransmits = 0;
@@ -1344,6 +1383,8 @@ iperf_print_results (struct iperf_test *test)
 
     /* print final summary for all intervals */
 
+    if (test->verbose)
+        printf("Test Complete. Summary Results:\n");
     if (test->protocol->id == Ptcp)
 	if (has_tcpinfo_retransmits())
 	    fputs(report_bw_retrans_header, stdout);
@@ -1464,7 +1505,7 @@ print_interval_results(struct iperf_test * test, struct iperf_stream * sp)
 
     irp = TAILQ_LAST(&sp->result->interval_results, irlisthead); /* get last entry in linked list */
     if (irp == NULL) {
-        printf("print_interval_results Error: interval_results = NULL \n");
+        printf("print_interval_results Error: interval_results is NULL \n");
         return;
     }
     /* First stream? */
@@ -1508,7 +1549,8 @@ iperf_free_stream(struct iperf_stream * sp)
         free(irp);
     }
     free(sp->result);
-    free(sp->send_timer);
+    if (sp->send_timer != NULL)
+	tmr_cancel(sp->send_timer);
     free(sp);
 }
 
@@ -1522,7 +1564,7 @@ iperf_new_stream(struct iperf_test *test, int s)
     sp = (struct iperf_stream *) malloc(sizeof(struct iperf_stream));
     if (!sp) {
         i_errno = IECREATESTREAM;
-        return (NULL);
+        return NULL;
     }
 
     memset(sp, 0, sizeof(struct iperf_stream));
@@ -1533,11 +1575,11 @@ iperf_new_stream(struct iperf_test *test, int s)
 
     if (!sp->buffer) {
         i_errno = IECREATESTREAM;
-        return (NULL);
+        return NULL;
     }
     if (!sp->result) {
         i_errno = IECREATESTREAM;
-        return (NULL);
+        return NULL;
     }
 
     memset(sp->result, 0, sizeof(struct iperf_stream_result));
@@ -1556,10 +1598,10 @@ iperf_new_stream(struct iperf_test *test, int s)
 
     /* Initialize stream */
     if (iperf_init_stream(sp, test) < 0)
-        return (NULL);
+        return NULL;
     iperf_add_stream(test, sp);
 
-    return (sp);
+    return sp;
 }
 
 /**************************************************************************/
@@ -1572,12 +1614,12 @@ iperf_init_stream(struct iperf_stream *sp, struct iperf_test *test)
     len = sizeof(struct sockaddr_storage);
     if (getsockname(sp->socket, (struct sockaddr *) &sp->local_addr, &len) < 0) {
         i_errno = IEINITSTREAM;
-        return (-1);
+        return -1;
     }
     len = sizeof(struct sockaddr_storage);
     if (getpeername(sp->socket, (struct sockaddr *) &sp->remote_addr, &len) < 0) {
         i_errno = IEINITSTREAM;
-        return (-1);
+        return -1;
     }
     /* Set IP TOS */
     if ((opt = test->settings->tos)) {
@@ -1585,21 +1627,21 @@ iperf_init_stream(struct iperf_stream *sp, struct iperf_test *test)
 #ifdef IPV6_TCLASS
             if (setsockopt(sp->socket, IPPROTO_IPV6, IPV6_TCLASS, &opt, sizeof(opt)) < 0) {
                 i_errno = IESETCOS;
-                return (-1);
+                return -1;
             }
 #else
             i_errno = IESETCOS;
-            return (-1);
+            return -1;
 #endif
         } else {
             if (setsockopt(sp->socket, IPPROTO_IP, IP_TOS, &opt, sizeof(opt)) < 0) {
                 i_errno = IESETTOS;
-                return (-1);
+                return -1;
             }
         }
     }
 
-    return (0);
+    return 0;
 }
 
 /**************************************************************************/
diff --git a/src/iperf_client_api.c b/src/iperf_client_api.c
index c065b1d..b90480f 100644
--- a/src/iperf_client_api.c
+++ b/src/iperf_client_api.c
@@ -33,7 +33,7 @@ iperf_create_streams(struct iperf_test *test)
     for (i = 0; i < test->num_streams; ++i) {
 
         if ((s = test->protocol->connect(test)) < 0)
-            return (-1);
+            return -1;
 
         FD_SET(s, &test->read_set);
         FD_SET(s, &test->write_set);
@@ -41,14 +41,14 @@ iperf_create_streams(struct iperf_test *test)
 
         sp = iperf_new_stream(test, s);
         if (!sp)
-            return (-1);
+            return -1;
 
         /* Perform the new stream callback */
         if (test->on_new_stream)
             test->on_new_stream(sp);
     }
 
-    return (0);
+    return 0;
 }
 
 int
@@ -59,36 +59,36 @@ iperf_handle_message_client(struct iperf_test *test)
     if ((rval = read(test->ctrl_sck, &test->state, sizeof(char))) <= 0) {
         if (rval == 0) {
             i_errno = IECTRLCLOSE;
-            return (-1);
+            return -1;
         } else {
             i_errno = IERECVMESSAGE;
-            return (-1);
+            return -1;
         }
     }
 
     switch (test->state) {
         case PARAM_EXCHANGE:
             if (iperf_exchange_parameters(test) < 0) {
-                return (-1);
+                return -1;
 	    }
             if (test->on_connect)
                 test->on_connect(test);
             break;
         case CREATE_STREAMS:
             if (iperf_create_streams(test) < 0) {
-                return (-1);
+                return -1;
 	    }
             break;
         case TEST_START:
             if (iperf_init_test(test) < 0) {
-                return (-1);
+                return -1;
 	    }
             break;
         case TEST_RUNNING:
             break;
         case EXCHANGE_RESULTS:
             if (iperf_exchange_results(test) < 0) {
-                return (-1);
+                return -1;
 	    }
             break;
         case DISPLAY_RESULTS:
@@ -100,28 +100,28 @@ iperf_handle_message_client(struct iperf_test *test)
             break;
         case SERVER_TERMINATE:
             i_errno = IESERVERTERM;
-            return (-1);
+            return -1;
         case ACCESS_DENIED:
             i_errno = IEACCESSDENIED;
-            return (-1);
+            return -1;
         case SERVER_ERROR:
             if (Nread(test->ctrl_sck, &i_errno, sizeof(i_errno), Ptcp) < 0) {
                 i_errno = IECTRLREAD;
-                return (-1);
+                return -1;
             }
             i_errno = ntohl(i_errno);
             if (Nread(test->ctrl_sck, &perr, sizeof(perr), Ptcp) < 0) {
                 i_errno = IECTRLREAD;
-                return (-1);
+                return -1;
             }
             errno = ntohl(perr);
-            return (-1);
+            return -1;
         default:
             i_errno = IEMESSAGE;
-            return (-1);
+            return -1;
     }
 
-    return (0);
+    return 0;
 }
 
 
@@ -139,19 +139,19 @@ iperf_connect(struct iperf_test *test)
     test->ctrl_sck = netdial(test->settings->domain, Ptcp, test->bind_address, test->server_hostname, test->server_port);
     if (test->ctrl_sck < 0) {
         i_errno = IECONNECT;
-        return (-1);
+        return -1;
     }
 
     if (Nwrite(test->ctrl_sck, test->cookie, COOKIE_SIZE, Ptcp) < 0) {
         i_errno = IESENDCOOKIE;
-        return (-1);
+        return -1;
     }
 
     FD_SET(test->ctrl_sck, &test->read_set);
     FD_SET(test->ctrl_sck, &test->write_set);
     test->max_fd = (test->ctrl_sck > test->max_fd) ? test->ctrl_sck : test->max_fd;
 
-    return (0);
+    return 0;
 }
 
 
@@ -171,10 +171,10 @@ iperf_client_end(struct iperf_test *test)
     test->state = IPERF_DONE;
     if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
         i_errno = IESENDMESSAGE;
-        return (-1);
+        return -1;
     }
 
-    return (0);
+    return 0;
 }
 
 
@@ -183,32 +183,31 @@ iperf_run_client(struct iperf_test * test)
 {
     int result;
     fd_set temp_read_set, temp_write_set;
-    struct timeval tv;
-    time_t sec, usec;
+    struct timeval now;
 
     /* Start the client and connect to the server */
     if (iperf_connect(test) < 0) {
-        return (-1);
+        return -1;
     }
 
     // Begin calculating CPU utilization
     cpu_util(NULL);
 
+    (void) gettimeofday(&now, NULL);
     while (test->state != IPERF_DONE) {
 
         memcpy(&temp_read_set, &test->read_set, sizeof(fd_set));
         memcpy(&temp_write_set, &test->write_set, sizeof(fd_set));
-        tv.tv_sec = 15;
-        tv.tv_usec = 0;
 
-        result = select(test->max_fd + 1, &temp_read_set, &temp_write_set, NULL, &tv);
+        result = select(test->max_fd + 1, &temp_read_set, &temp_write_set, NULL, tmr_timeout(&now));
         if (result < 0 && errno != EINTR) {
             i_errno = IESELECT;
-            return (-1);
-        } else if (result > 0) {
+            return -1;
+        }
+	if (result > 0) {
             if (FD_ISSET(test->ctrl_sck, &temp_read_set)) {
                 if (iperf_handle_message_client(test) < 0) {
-                    return (-1);
+                    return -1;
 		}
                 FD_CLR(test->ctrl_sck, &temp_read_set);
             }
@@ -217,46 +216,32 @@ iperf_run_client(struct iperf_test * test)
                 if (test->reverse) {
                     // Reverse mode. Client receives.
                     if (iperf_recv(test) < 0) {
-                        return (-1);
+                        return -1;
 		    }
                 } else {
                     // Regular mode. Client sends.
                     if (iperf_send(test) < 0) {
-                        return (-1);
+                        return -1;
 		    }
                 }
 
-                /* Perform callbacks */
-                if (timer_expired(test->stats_timer)) {
-                    test->stats_callback(test);
-                    sec = (time_t) test->stats_interval;
-                    usec = (test->stats_interval - sec) * SEC_TO_US;
-                    if (update_timer(test->stats_timer, sec, usec) < 0) {
-                        return (-1);
-		    }
-                }
-                if (timer_expired(test->reporter_timer)) {
-                    test->reporter_callback(test);
-                    sec = (time_t) test->reporter_interval;
-                    usec = (test->reporter_interval - sec) * SEC_TO_US;
-                    if (update_timer(test->reporter_timer, sec, usec) < 0) {
-                        return (-1);
-		    }
-                }
+                /* Run the timers. */
+		(void) gettimeofday(&now, NULL);
+		tmr_run(&now);
 
                 /* Send TEST_END if all data has been sent or timer expired */
-                if (all_data_sent(test) || timer_expired(test->timer)) {
+                if (all_data_sent(test) || test->done) {
                     cpu_util(&test->cpu_util);
                     test->stats_callback(test);
                     test->state = TEST_END;
                     if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
                         i_errno = IESENDMESSAGE;
-                        return (-1);
+                        return -1;
                     }
                 }
             }
         }
     }
 
-    return (0);
+    return 0;
 }
diff --git a/src/iperf_error.c b/src/iperf_error.c
index 1528c8b..fad4534 100644
--- a/src/iperf_error.c
+++ b/src/iperf_error.c
@@ -232,7 +232,7 @@ iperf_strerror(int i_errno)
         strncat(errstr, strerror(errno), len);
     }
 
-    return (errstr);
+    return errstr;
 }
 
 void
diff --git a/src/iperf_server_api.c b/src/iperf_server_api.c
index 0c73c9c..cd301d3 100644
--- a/src/iperf_server_api.c
+++ b/src/iperf_server_api.c
@@ -49,7 +49,7 @@ iperf_server_listen(struct iperf_test *test)
 {
     if((test->listener = netannounce(test->settings->domain, Ptcp, test->bind_address, test->server_port)) < 0) {
         i_errno = IELISTEN;
-        return (-1);
+        return -1;
     }
 
     printf("-----------------------------------------------------------\n");
@@ -101,14 +101,14 @@ iperf_accept(struct iperf_test *test)
     len = sizeof(addr);
     if ((s = accept(test->listener, (struct sockaddr *) &addr, &len)) < 0) {
         i_errno = IEACCEPT;
-        return (-1);
+        return -1;
     }
 
     if (test->ctrl_sck == -1) {
         /* Server free, accept new client */
         if (Nread(s, test->cookie, COOKIE_SIZE, Ptcp) < 0) {
             i_errno = IERECVCOOKIE;
-            return (-1);
+            return -1;
         }
 
         FD_SET(s, &test->read_set);
@@ -119,10 +119,10 @@ iperf_accept(struct iperf_test *test)
         test->state = PARAM_EXCHANGE;
         if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
             i_errno = IESENDMESSAGE;
-            return (-1);
+            return -1;
         }
         if (iperf_exchange_parameters(test) < 0) {
-            return (-1);
+            return -1;
         }
         if (test->on_connect) {
             test->on_connect(test);
@@ -131,16 +131,16 @@ iperf_accept(struct iperf_test *test)
         // XXX: Do we even need to receive cookie if we're just going to deny anyways?
         if (Nread(s, cookie, COOKIE_SIZE, Ptcp) < 0) {
             i_errno = IERECVCOOKIE;
-            return (-1);
+            return -1;
         }
         if (Nwrite(s, &rbuf, sizeof(int), Ptcp) < 0) {
             i_errno = IESENDMESSAGE;
-            return (-1);
+            return -1;
         }
         close(s);
     }
 
-    return (0);
+    return 0;
 }
 
 
@@ -157,10 +157,10 @@ iperf_handle_message_server(struct iperf_test *test)
             fprintf(stderr, "The client has unexpectedly closed the connection.\n");
             i_errno = IECTRLCLOSE;
             test->state = IPERF_DONE;
-            return (0);
+            return 0;
         } else {
             i_errno = IERECVMESSAGE;
-            return (-1);
+            return -1;
         }
     }
 
@@ -178,14 +178,14 @@ iperf_handle_message_server(struct iperf_test *test)
             test->state = EXCHANGE_RESULTS;
             if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
                 i_errno = IESENDMESSAGE;
-                return (-1);
+                return -1;
             }
             if (iperf_exchange_results(test) < 0)
-                return (-1);
+                return -1;
             test->state = DISPLAY_RESULTS;
             if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
                 i_errno = IESENDMESSAGE;
-                return (-1);
+                return -1;
             }
             if (test->on_test_finish)
                 test->on_test_finish(test);
@@ -207,10 +207,10 @@ iperf_handle_message_server(struct iperf_test *test)
             break;
         default:
             i_errno = IEMESSAGE;
-            return (-1);
+            return -1;
     }
 
-    return (0);
+    return 0;
 }
 
 /* XXX: This function is not used anymore */
@@ -227,12 +227,18 @@ iperf_test_reset(struct iperf_test *test)
         SLIST_REMOVE_HEAD(&test->streams, streams);
         iperf_free_stream(sp);
     }
-    free_timer(test->timer);
-    free_timer(test->stats_timer);
-    free_timer(test->reporter_timer);
-    test->timer = NULL;
-    test->stats_timer = NULL;
-    test->reporter_timer = NULL;
+    if (test->timer != NULL) {
+	tmr_cancel(test->timer);
+	test->timer = NULL;
+    }
+    if (test->stats_timer != NULL) {
+	tmr_cancel(test->stats_timer);
+	test->stats_timer = NULL;
+    }
+    if (test->reporter_timer != NULL) {
+	tmr_cancel(test->reporter_timer);
+	test->reporter_timer = NULL;
+    }
 
     SLIST_INIT(&test->streams);
 
@@ -269,12 +275,11 @@ iperf_run_server(struct iperf_test *test)
     int result, s, streams_accepted;
     fd_set temp_read_set, temp_write_set;
     struct iperf_stream *sp;
-    struct timeval tv;
-    time_t sec, usec;
+    struct timeval now;
 
     // Open socket and listen
     if (iperf_server_listen(test) < 0) {
-        return (-1);
+        return -1;
     }
 
     // Begin calculating CPU utilization
@@ -283,29 +288,29 @@ iperf_run_server(struct iperf_test *test)
     test->state = IPERF_START;
     streams_accepted = 0;
 
+    (void) gettimeofday(&now, NULL);
     while (test->state != IPERF_DONE) {
 
         memcpy(&temp_read_set, &test->read_set, sizeof(fd_set));
         memcpy(&temp_write_set, &test->write_set, sizeof(fd_set));
-        tv.tv_sec = 15;
-        tv.tv_usec = 0;
 
-        result = select(test->max_fd + 1, &temp_read_set, &temp_write_set, NULL, &tv);
+        result = select(test->max_fd + 1, &temp_read_set, &temp_write_set, NULL, tmr_timeout(&now));
         if (result < 0 && errno != EINTR) {
             i_errno = IESELECT;
-            return (-1);
-        } else if (result > 0) {
+            return -1;
+        }
+	if (result > 0) {
             if (FD_ISSET(test->listener, &temp_read_set)) {
                 if (test->state != CREATE_STREAMS) {
                     if (iperf_accept(test) < 0) {
-                        return (-1);
+                        return -1;
                     }
                     FD_CLR(test->listener, &temp_read_set);
                 }
             }
             if (FD_ISSET(test->ctrl_sck, &temp_read_set)) {
                 if (iperf_handle_message_server(test) < 0)
-                    return (-1);
+                    return -1;
                 FD_CLR(test->ctrl_sck, &temp_read_set);                
             }
 
@@ -313,12 +318,12 @@ iperf_run_server(struct iperf_test *test)
                 if (FD_ISSET(test->prot_listener, &temp_read_set)) {
     
                     if ((s = test->protocol->accept(test)) < 0)
-                        return (-1);
+                        return -1;
 
                     if (!is_closed(s)) {
                         sp = iperf_new_stream(test, s);
                         if (!sp)
-                            return (-1);
+                            return -1;
 
                         FD_SET(s, &test->read_set);
                         FD_SET(s, &test->write_set);
@@ -341,7 +346,7 @@ iperf_run_server(struct iperf_test *test)
                             close(test->listener);
                             if ((s = netannounce(test->settings->domain, Ptcp, test->bind_address, test->server_port)) < 0) {
                                 i_errno = IELISTEN;
-                                return (-1);
+                                return -1;
                             }
                             test->listener = s;
                             test->max_fd = (s > test->max_fd ? s : test->max_fd);
@@ -352,14 +357,14 @@ iperf_run_server(struct iperf_test *test)
                     test->state = TEST_START;
                     if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
                         i_errno = IESENDMESSAGE;
-                        return (-1);
+                        return -1;
                     }
                     if (iperf_init_test(test) < 0)
-                        return (-1);
+                        return -1;
                     test->state = TEST_RUNNING;
                     if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
                         i_errno = IESENDMESSAGE;
-                        return (-1);
+                        return -1;
                     }
                 }
             }
@@ -368,28 +373,16 @@ iperf_run_server(struct iperf_test *test)
                 if (test->reverse) {
                     // Reverse mode. Server sends.
                     if (iperf_send(test) < 0)
-                        return (-1);
+                        return -1;
                 } else {
                     // Regular mode. Server receives.
                     if (iperf_recv(test) < 0)
-                        return (-1);
+                        return -1;
                 }
 
-                /* Perform callbacks */
-                if (timer_expired(test->stats_timer)) {
-                    test->stats_callback(test);
-                    sec = (time_t) test->stats_interval;
-                    usec = (test->stats_interval - sec) * SEC_TO_US;
-                    if (update_timer(test->stats_timer, sec, usec) < 0)
-                        return (-1);
-                }
-                if (timer_expired(test->reporter_timer)) {
-                    test->reporter_callback(test);
-                    sec = (time_t) test->reporter_interval;
-                    usec = (test->reporter_interval - sec) * SEC_TO_US;
-                    if (update_timer(test->reporter_timer, sec, usec) < 0)
-                        return (-1);
-                }
+		/* Run the timers. */
+		(void) gettimeofday(&now, NULL);
+		tmr_run(&now);
             }
         }
     }
@@ -398,5 +391,5 @@ iperf_run_server(struct iperf_test *test)
     close(test->ctrl_sck);
     close(test->listener);
 
-    return (0);
+    return 0;
 }
diff --git a/src/iperf_tcp.c b/src/iperf_tcp.c
index 891c989..7f65642 100644
--- a/src/iperf_tcp.c
+++ b/src/iperf_tcp.c
@@ -39,13 +39,13 @@ iperf_tcp_recv(struct iperf_stream *sp)
     result = Nread(sp->socket, sp->buffer, size, Ptcp);
 
     if (result < 0) {
-        return (-1);
+        return -1;
     }
 
     sp->result->bytes_received += result;
     sp->result->bytes_received_this_interval += result;
 
-    return (result);
+    return result;
 }
 
 
@@ -62,13 +62,13 @@ iperf_tcp_send(struct iperf_stream *sp)
     result = Nwrite(sp->socket, sp->buffer, size, Ptcp);
 
     if (result < 0) {
-        return (-1);
+        return -1;
     }
 
     sp->result->bytes_sent += result;
     sp->result->bytes_sent_this_interval += result;
 
-    return (result);
+    return result;
 }
 
 
@@ -88,23 +88,23 @@ iperf_tcp_accept(struct iperf_test * test)
     len = sizeof(addr);
     if ((s = accept(test->listener, (struct sockaddr *) &addr, &len)) < 0) {
         i_errno = IESTREAMCONNECT;
-        return (-1);
+        return -1;
     }
 
     if (Nread(s, cookie, COOKIE_SIZE, Ptcp) < 0) {
         i_errno = IERECVCOOKIE;
-        return (-1);
+        return -1;
     }
 
     if (strcmp(test->cookie, cookie) != 0) {
         if (Nwrite(s, &rbuf, sizeof(char), Ptcp) < 0) {
             i_errno = IESENDMESSAGE;
-            return (-1);
+            return -1;
         }
         close(s);
     }
 
-    return (s);
+    return s;
 }
 
 
@@ -125,36 +125,36 @@ iperf_tcp_listen(struct iperf_test *test)
         close(s);
         if ((s = socket(test->settings->domain, SOCK_STREAM, 0)) < 0) {
             i_errno = IESTREAMLISTEN;
-            return (-1);
+            return -1;
         }
         if (test->no_delay) {
             opt = 1;
             if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)) < 0) {
                 i_errno = IESETNODELAY;
-                return (-1);
+                return -1;
             }
         }
         // XXX: Setting MSS is very buggy!
         if ((opt = test->settings->mss)) {
             if (setsockopt(s, IPPROTO_TCP, TCP_MAXSEG, &opt, sizeof(opt)) < 0) {
                 i_errno = IESETMSS;
-                return (-1);
+                return -1;
             }
         }
         if ((opt = test->settings->socket_bufsize)) {
             if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)) < 0) {
                 i_errno = IESETBUF;
-                return (-1);
+                return -1;
             }
             if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) < 0) {
                 i_errno = IESETBUF;
-                return (-1);
+                return -1;
             }
         }
         opt = 1;
         if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
             i_errno = IEREUSEADDR;
-            return (-1);
+            return -1;
         }
 
         snprintf(portstr, 6, "%d", test->server_port);
@@ -165,26 +165,26 @@ iperf_tcp_listen(struct iperf_test *test)
         // XXX: Check getaddrinfo for errors!
         if (getaddrinfo(test->bind_address, portstr, &hints, &res) != 0) {
             i_errno = IESTREAMLISTEN;
-            return (-1);
+            return -1;
         }
 
         if (bind(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0) {
             close(s);
             i_errno = IESTREAMLISTEN;
-            return (-1);
+            return -1;
         }
 
         freeaddrinfo(res);
 
         if (listen(s, 5) < 0) {
             i_errno = IESTREAMLISTEN;
-            return (-1);
+            return -1;
         }
 
         test->listener = s;
     }
     
-    return (s);
+    return s;
 }
 
 
@@ -201,7 +201,7 @@ iperf_tcp_connect(struct iperf_test *test)
 
     if ((s = socket(test->settings->domain, SOCK_STREAM, 0)) < 0) {
         i_errno = IESTREAMCONNECT;
-        return (-1);
+        return -1;
     }
 
     if (test->bind_address) {
@@ -211,12 +211,12 @@ iperf_tcp_connect(struct iperf_test *test)
         // XXX: Check getaddrinfo for errors!
         if (getaddrinfo(test->bind_address, NULL, &hints, &res) != 0) {
             i_errno = IESTREAMCONNECT;
-            return (-1);
+            return -1;
         }
 
         if (bind(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0) {
             i_errno = IESTREAMCONNECT;
-            return (-1);
+            return -1;
         }
 
         freeaddrinfo(res);
@@ -227,23 +227,23 @@ iperf_tcp_connect(struct iperf_test *test)
         opt = 1;
         if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)) < 0) {
             i_errno = IESETNODELAY;
-            return (-1);
+            return -1;
         }
     }
     if ((opt = test->settings->mss)) {
         if (setsockopt(s, IPPROTO_TCP, TCP_MAXSEG, &opt, sizeof(opt)) < 0) {
             i_errno = IESETMSS;
-            return (-1);
+            return -1;
         }
     }
     if ((opt = test->settings->socket_bufsize)) {
         if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)) < 0) {
             i_errno = IESETBUF;
-            return (-1);
+            return -1;
         }
         if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) < 0) {
             i_errno = IESETBUF;
-            return (-1);
+            return -1;
         }
     }
 
@@ -254,12 +254,12 @@ iperf_tcp_connect(struct iperf_test *test)
     // XXX: Check getaddrinfo for errors!
     if (getaddrinfo(test->server_hostname, portstr, &hints, &res) != 0) {
         i_errno = IESTREAMCONNECT;
-        return (-1);
+        return -1;
     }
 
     if (connect(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0 && errno != EINPROGRESS) {
         i_errno = IESTREAMCONNECT;
-        return (-1);
+        return -1;
     }
 
     freeaddrinfo(res);
@@ -267,9 +267,9 @@ iperf_tcp_connect(struct iperf_test *test)
     /* Send cookie for verification */
     if (Nwrite(s, test->cookie, COOKIE_SIZE, Ptcp) < 0) {
         i_errno = IESENDCOOKIE;
-        return (-1);
+        return -1;
     }
 
-    return (s);
+    return s;
 }
 
diff --git a/src/iperf_udp.c b/src/iperf_udp.c
index 733cc1d..f744907 100644
--- a/src/iperf_udp.c
+++ b/src/iperf_udp.c
@@ -44,7 +44,7 @@ iperf_udp_recv(struct iperf_stream *sp)
     result = Nread(sp->socket, sp->buffer, size, Pudp);
 
     if (result < 0) {
-        return (-1);
+        return -1;
     }
 
     sp->result->bytes_received += result;
@@ -82,7 +82,21 @@ iperf_udp_recv(struct iperf_stream *sp)
     //      J = |(R1 - S1) - (R0 - S0)| [/ number of packets, for average]
     sp->jitter += (d - sp->jitter) / 16.0;
 
-    return (result);
+    return result;
+}
+
+
+static void
+send_timer_proc(TimerClientData client_data, struct timeval* nowP)
+{
+    struct iperf_stream *sp = client_data.p;
+
+    /* All we do here is set a flag saying that this UDP stream may be sent
+    ** to.  The actual sending gets done in iperf_udp_send(), which then
+    ** resets the flag and makes a new adjusted timer.
+    */
+    sp->send_timer = NULL;
+    sp->udp_green_light = 1;
 }
 
 
@@ -95,18 +109,13 @@ iperf_udp_send(struct iperf_stream *sp)
 {
     ssize_t   result = 0;
     int64_t   dtargus;
-    int64_t   adjustus = 0;
+    int64_t   adjustus;
     uint64_t  sec, usec, pcount;
     int       size = sp->settings->blksize;
     struct timeval before, after;
+    TimerClientData cd;
 
-    if (timer_expired(sp->send_timer)) {
-
-        dtargus = (int64_t) (sp->settings->blksize) * SEC_TO_US * 8;
-        dtargus /= sp->settings->rate;
-
-        assert(dtargus != 0);
-
+    if (sp->udp_green_light) {
         gettimeofday(&before, 0);
 
         ++sp->packet_count;
@@ -121,26 +130,31 @@ iperf_udp_send(struct iperf_stream *sp)
         result = Nwrite(sp->socket, sp->buffer, size, Pudp);
 
         if (result < 0)
-            return (-1);
+            return -1;
 
         sp->result->bytes_sent += result;
         sp->result->bytes_sent_this_interval += result;
 
-        gettimeofday(&after, 0);
-
-        adjustus = dtargus;
-        adjustus += (before.tv_sec - after.tv_sec) * SEC_TO_US;
-        adjustus += (before.tv_usec - after.tv_usec);
-
-        if (adjustus > 0) {
-            dtargus = adjustus;
-        }
-
-        if (update_timer(sp->send_timer, 0, dtargus) < 0)
-            return (-1);
+	if (sp->settings->rate != 0) {
+	    gettimeofday(&after, 0);
+	    dtargus = (int64_t) (sp->settings->blksize) * SEC_TO_US * 8;
+	    dtargus /= sp->settings->rate;
+	    assert(dtargus != 0);
+	    adjustus = dtargus;
+	    adjustus += (before.tv_sec - after.tv_sec) * SEC_TO_US;
+	    adjustus += (before.tv_usec - after.tv_usec);
+	    if (adjustus > 0) {
+		dtargus = adjustus;
+	    }
+	    cd.p = sp;
+	    sp->udp_green_light = 0;
+	    sp->send_timer = tmr_create((struct timeval*) 0, send_timer_proc, cd, dtargus, 0);
+	    if (sp->send_timer == NULL)
+		return -1;
+	}
     }
 
-    return (result);
+    return result;
 }
 
 
@@ -163,18 +177,18 @@ iperf_udp_accept(struct iperf_test *test)
     len = sizeof sa_peer;
     if ((sz = recvfrom(test->prot_listener, &buf, sizeof(buf), 0, (struct sockaddr *) &sa_peer, &len)) < 0) {
         i_errno = IESTREAMACCEPT;
-        return (-1);
+        return -1;
     }
 
     if (connect(s, (struct sockaddr *) &sa_peer, len) < 0) {
         i_errno = IESTREAMACCEPT;
-        return (-1);
+        return -1;
     }
 
     test->prot_listener = netannounce(test->settings->domain, Pudp, test->bind_address, test->server_port);
     if (test->prot_listener < 0) {
         i_errno = IESTREAMLISTEN;
-        return (-1);
+        return -1;
     }
 
     FD_SET(test->prot_listener, &test->read_set);
@@ -183,10 +197,10 @@ iperf_udp_accept(struct iperf_test *test)
     /* Let the client know we're ready "accept" another UDP "stream" */
     if (write(s, &buf, sizeof(buf)) < 0) {
         i_errno = IESTREAMWRITE;
-        return (-1);
+        return -1;
     }
 
-    return (s);
+    return s;
 }
 
 
@@ -201,10 +215,10 @@ iperf_udp_listen(struct iperf_test *test)
 
     if ((s = netannounce(test->settings->domain, Pudp, test->bind_address, test->server_port)) < 0) {
         i_errno = IESTREAMLISTEN;
-        return (-1);
+        return -1;
     }
 
-    return (s);
+    return s;
 }
 
 
@@ -219,23 +233,23 @@ iperf_udp_connect(struct iperf_test *test)
 
     if ((s = netdial(test->settings->domain, Pudp, test->bind_address, test->server_hostname, test->server_port)) < 0) {
         i_errno = IESTREAMCONNECT;
-        return (-1);
+        return -1;
     }
 
     /* Write to the UDP stream to give the server this stream's credentials */
     if (write(s, &buf, sizeof(buf)) < 0) {
         // XXX: Should this be changed to IESTREAMCONNECT? 
         i_errno = IESTREAMWRITE;
-        return (-1);
+        return -1;
     }
     /* Wait until the server confirms the client UDP write */
     // XXX: Should this read be TCP instead?
     if (read(s, &buf, sizeof(buf)) < 0) {
         i_errno = IESTREAMREAD;
-        return (-1);
+        return -1;
     }
 
-    return (s);
+    return s;
 }
 
 
@@ -248,19 +262,27 @@ iperf_udp_init(struct iperf_test *test)
 {
     int64_t dtargus;
     struct iperf_stream *sp;
+    TimerClientData cd;
 
-    /* Calculate the send delay needed to hit target bandwidth (-b) */
-    dtargus = (int64_t) test->settings->blksize * SEC_TO_US * 8;
-    dtargus /= test->settings->rate;
+    if (test->settings->rate == 0) {
+	SLIST_FOREACH(sp, &test->streams, streams) {
+	    sp->udp_green_light = 1;
+	}
+    } else {
+	/* Calculate the send delay needed to hit target bandwidth (-b) */
+	dtargus = (int64_t) test->settings->blksize * SEC_TO_US * 8;
+	dtargus /= test->settings->rate;
 
-    assert(dtargus != 0);
+	assert(dtargus != 0);
 
-//    for (sp = test->streams; sp; sp = sp->next) {
-    SLIST_FOREACH(sp, &test->streams, streams) {
-        sp->send_timer = new_timer(dtargus / SEC_TO_US, dtargus % SEC_TO_US);
-        if (sp->send_timer == NULL)
-            return (-1);
+	SLIST_FOREACH(sp, &test->streams, streams) {
+	    cd.p = sp;
+	    sp->udp_green_light = 0;
+	    sp->send_timer = tmr_create((struct timeval*) 0, send_timer_proc, cd, dtargus, 0);
+	    if (sp->send_timer == NULL)
+		return -1;
+	}
     }
 
-    return (0);
+    return 0;
 }
diff --git a/src/iperf_util.c b/src/iperf_util.c
index bfbc939..1795d03 100644
--- a/src/iperf_util.c
+++ b/src/iperf_util.c
@@ -78,9 +78,9 @@ is_closed(int fd)
 
     if (select(fd+1, &readset, NULL, NULL, &tv) < 0) {
         if (errno == EBADF)
-            return (1);
+            return 1;
     }
-    return (0);
+    return 0;
 }
 
 
@@ -114,7 +114,7 @@ timeval_diff(struct timeval * tv0, struct timeval * tv1)
     time1 = time1 - time2;
     if (time1 < 0)
         time1 = -time1;
-    return (time1);
+    return time1;
 }
 
 
@@ -149,7 +149,7 @@ delay(int us)
     tv.tv_sec = 0;
     tv.tv_usec = us;
     (void) select(1, (fd_set *) 0, (fd_set *) 0, (fd_set *) 0, &tv);
-    return (1);
+    return 1;
 }
 #endif
 
diff --git a/src/main.c b/src/main.c
index 808b1c9..a8bb24d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -87,7 +87,7 @@ main(int argc, char **argv)
             test->state = (test->role == 'c') ? CLIENT_TERMINATE : SERVER_TERMINATE;
             if (Nwrite(test->ctrl_sck, &test->state, sizeof(char), Ptcp) < 0) {
                 i_errno = IESENDMESSAGE;
-                return (-1);
+                return -1;
             }
         }
         exit(1);
@@ -109,7 +109,7 @@ main(int argc, char **argv)
 
     printf("\niperf Done.\n");
 
-    return (0);
+    return 0;
 }
 
 /**************************************************************************/
@@ -137,6 +137,6 @@ iperf_run(struct iperf_test * test)
             break;
     }
 
-    return (0);
+    return 0;
 }
 
diff --git a/src/net.c b/src/net.c
index bf98daf..4b7f695 100644
--- a/src/net.c
+++ b/src/net.c
@@ -37,7 +37,7 @@ netdial(int domain, int proto, char *local, char *server, int port)
 
     s = socket(domain, proto, 0);
     if (s < 0) {
-        return (-1);
+        return -1;
     }
 
     if (local) {
@@ -47,10 +47,10 @@ netdial(int domain, int proto, char *local, char *server, int port)
 
         // XXX: Check getaddrinfo for errors!
         if (getaddrinfo(local, NULL, &hints, &res) != 0)
-            return (-1);
+            return -1;
 
         if (bind(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0)
-            return (-1);
+            return -1;
 
         freeaddrinfo(res);
     }
@@ -61,17 +61,17 @@ netdial(int domain, int proto, char *local, char *server, int port)
 
     // XXX: Check getaddrinfo for errors!
     if (getaddrinfo(server, NULL, &hints, &res) != 0)
-        return (-1);
+        return -1;
 
     ((struct sockaddr_in *) res->ai_addr)->sin_port = htons(port);
 
     if (connect(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0 && errno != EINPROGRESS) {
-        return (-1);
+        return -1;
     }
 
     freeaddrinfo(res);
 
-    return (s);
+    return s;
 }
 
 /***************************************************************/
@@ -85,7 +85,7 @@ netannounce(int domain, int proto, char *local, int port)
 
     s = socket(domain, proto, 0);
     if (s < 0) {
-        return (-1);
+        return -1;
     }
     opt = 1;
     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *) &opt, sizeof(opt));
@@ -97,22 +97,22 @@ netannounce(int domain, int proto, char *local, int port)
     hints.ai_flags = AI_PASSIVE;
     // XXX: Check getaddrinfo for errors!
     if (getaddrinfo(local, portstr, &hints, &res) != 0)
-        return (-1); 
+        return -1; 
 
     if (bind(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0) {
         close(s);
-        return (-1);
+        return -1;
     }
 
     freeaddrinfo(res);
     
     if (proto == SOCK_STREAM) {
         if (listen(s, 5) < 0) {
-            return (-1);
+            return -1;
         }
     }
 
-    return (s);
+    return s;
 }
 
 
@@ -131,14 +131,14 @@ Nread(int fd, void *buf, int count, int prot)
             if (errno == EINTR)
                 n = 0;
             else
-                return (-1);
+                return -1;
         } else if (n == 0)
             break;
 
         nleft -= n;
         buf += n;
     }
-    return (count - nleft);
+    return count - nleft;
 }
 
 
@@ -166,7 +166,7 @@ Nwrite(int fd, void *buf, int count, int prot)
                     delay(18000);   // XXX: Fixme!
                     n = 0;
                 } else {
-                    return (-1);
+                    return -1;
                 }
             }
             nleft -= n;
@@ -178,13 +178,13 @@ Nwrite(int fd, void *buf, int count, int prot)
                 if (errno == EINTR)
                     n = 0;
                 else
-                    return (-1);
+                    return -1;
             }
             nleft -= n;
             buf += n;
         }
     }
-    return (count);
+    return count;
 }
 
 /*************************************************************************/
diff --git a/src/t_timer.c b/src/t_timer.c
index 47ca18b..936fec0 100644
--- a/src/t_timer.c
+++ b/src/t_timer.c
@@ -14,25 +14,42 @@
 
 #include "timer.h"
 
+
+static int flag;
+
+
+static void
+timer_proc( TimerClientData client_data, struct timeval* nowP )
+{
+    flag = 1;
+}
+
+
 int 
 main(int argc, char **argv)
 {
-    struct timer *tp;
-    tp = new_timer(3, 0);
+    struct Timer *tp;
+
+    flag = 0;
+    tp = tmr_create((struct timeval*) 0, timer_proc, JunkClientData, 3000000, 0);
 
     sleep(2);
 
-    if (tp->expired(tp))
+    tmr_run((struct timeval*) 0);
+    if (flag)
     {
 	printf("timer should not have expired\n");
 	exit(-1);
     }
     sleep(1);
 
-    if (!tp->expired(tp))
+    tmr_run((struct timeval*) 0);
+    if (!flag)
     {
 	printf("timer should have expired\n");
 	exit(-2);
     }
+
+    tmr_destroy();
     exit(0);
 }
diff --git a/src/timer.c b/src/timer.c
index bc78485..eb1e7ed 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -5,104 +5,239 @@
  *
  * This code is distributed under a BSD style license, see the LICENSE file
  * for complete information.
+ *
+ * Based on timers.c by Jef Poskanzer. Used with permission.
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <sys/time.h>
-#include <sys/errno.h>
 #include <sys/types.h>
-#include <stdint.h>
-#include <time.h>
+#include <stdlib.h>
 
 #include "timer.h"
-#include "iperf_api.h"
 
 
-int
-timer_expired(struct timer * tp)
+static Timer* timers = NULL;
+static Timer* free_timers = NULL;
+
+TimerClientData JunkClientData;
+
+
+
+/* This is an efficiency tweak.  All the routines that need to know the
+** current time get passed a pointer to a struct timeval.  If it's non-NULL
+** it gets used, otherwise we do our own gettimeofday() to fill it in.
+** This lets the caller avoid extraneous gettimeofday()s when efficiency
+** is needed, and not bother with the extra code when efficiency doesn't
+** matter too much.
+*/
+static void
+getnow( struct timeval* nowP, struct timeval* nowP2 )
 {
-    if (tp == NULL)
-        return 0;
+    if ( nowP != NULL )
+	*nowP2 = *nowP;
+    else
+	(void) gettimeofday( nowP2, NULL );
+}
 
+
+static void
+list_add( Timer* t )
+{
+    Timer* t2;
+    Timer* t2prev;
+
+    if ( timers == NULL ) {
+	/* The list is empty. */
+	timers = t;
+	t->prev = t->next = NULL;
+    } else {
+	if ( t->time.tv_sec < timers->time.tv_sec ||
+	     ( t->time.tv_sec == timers->time.tv_sec &&
+	       t->time.tv_usec < timers->time.tv_usec ) ) {
+	    /* The new timer goes at the head of the list. */
+	    t->prev = NULL;
+	    t->next = timers;
+	    timers->prev = t;
+	    timers = t;
+	} else {
+	    /* Walk the list to find the insertion point. */
+	    for ( t2prev = timers, t2 = timers->next; t2 != NULL;
+		  t2prev = t2, t2 = t2->next ) {
+		if ( t->time.tv_sec < t2->time.tv_sec ||
+		     ( t->time.tv_sec == t2->time.tv_sec &&
+		       t->time.tv_usec < t2->time.tv_usec ) ) {
+		    /* Found it. */
+		    t2prev->next = t;
+		    t->prev = t2prev;
+		    t->next = t2;
+		    t2->prev = t;
+		    return;
+		}
+	    }
+	    /* Oops, got to the end of the list.  Add to tail. */
+	    t2prev->next = t;
+	    t->prev = t2prev;
+	    t->next = NULL;
+	}
+    }
+}
+
+
+static void
+list_remove( Timer* t )
+{
+    if ( t->prev == NULL )
+	timers = t->next;
+    else
+	t->prev->next = t->next;
+    if ( t->next != NULL )
+	t->next->prev = t->prev;
+}
+
+
+static void
+list_resort( Timer* t )
+{
+    /* Remove the timer from the list. */
+    list_remove( t );
+    /* And add it back in, sorted correctly. */
+    list_add( t );
+}
+
+
+static void
+add_usecs( struct timeval* t, int64_t usecs )
+{
+    t->tv_sec += usecs / 1000000L;
+    t->tv_usec += usecs % 1000000L;
+    if ( t->tv_usec >= 1000000L ) {
+	t->tv_sec += t->tv_usec / 1000000L;
+	t->tv_usec %= 1000000L;
+    }
+}
+
+
+Timer*
+tmr_create(
+    struct timeval* nowP, TimerProc* timer_proc, TimerClientData client_data,
+    int64_t usecs, int periodic )
+{
     struct timeval now;
-    int64_t end = 0, current = 0;
+    Timer* t;
 
-    gettimeofday(&now, NULL);
+    getnow( nowP, &now );
 
-    end += tp->end.tv_sec * 1000000;
-    end += tp->end.tv_usec;
+    if ( free_timers != NULL ) {
+	t = free_timers;
+	free_timers = t->next;
+    } else {
+	t = (Timer*) malloc( sizeof(Timer) );
+	if ( t == NULL )
+	    return NULL;
+    }
 
-    current += now.tv_sec * 1000000;
-    current += now.tv_usec;
+    t->timer_proc = timer_proc;
+    t->client_data = client_data;
+    t->usecs = usecs;
+    t->periodic = periodic;
+    t->time = now;
+    add_usecs( &t->time, usecs );
+    /* Add the new timer to the active list. */
+    list_add( t );
 
-    return current > end;
+    return t;
 }
 
-int
-update_timer(struct timer * tp, time_t sec, suseconds_t usec)
+
+struct timeval*
+tmr_timeout( struct timeval* nowP )
 {
-    if (gettimeofday(&tp->begin, NULL) < 0) {
-        i_errno = IEUPDATETIMER;
-        return (-1);
-    }
+    struct timeval now;
+    int64_t usecs;
+    static struct timeval timeout;
 
-    tp->end.tv_sec = tp->begin.tv_sec + (time_t) sec;
-    tp->end.tv_usec = tp->begin.tv_usec + (time_t) usec;
-
-    tp->expired = timer_expired;
-    return (0);
+    getnow( nowP, &now );
+    /* Since the list is sorted, we only need to look at the first timer. */
+    if ( timers == NULL )
+	return NULL;
+    usecs = ( timers->time.tv_sec - now.tv_sec ) * 1000000L +
+	    ( timers->time.tv_usec - now.tv_usec );
+    if ( usecs <= 0 )
+	usecs = 0;
+    timeout.tv_sec = usecs / 1000000L;
+    timeout.tv_usec = usecs % 1000000L;
+    return &timeout;
 }
 
-struct timer *
-new_timer(time_t sec, suseconds_t usec)
-{
-    struct timer *tp = NULL;
-    tp = (struct timer *) calloc(1, sizeof(struct timer));
-    if (tp == NULL) {
-        i_errno = IENEWTIMER;
-        return (NULL);
-    }
-
-    if (gettimeofday(&tp->begin, NULL) < 0) {
-        i_errno = IENEWTIMER;
-        return (NULL);
-    }
-
-    tp->end.tv_sec = tp->begin.tv_sec + (time_t) sec;
-    tp->end.tv_usec = tp->begin.tv_usec + (time_t) usec;
-
-    tp->expired = timer_expired;
-
-    return tp;
-}
 
 void
-free_timer(struct timer * tp)
-{
-    free(tp);
-}
-
-
-int64_t
-timer_remaining(struct timer * tp)
+tmr_run( struct timeval* nowP )
 {
     struct timeval now;
-    long int  end_time = 0, current_time = 0, diff = 0;
+    Timer* t;
+    Timer* next;
 
-    gettimeofday(&now, NULL);
-
-    end_time += tp->end.tv_sec * 1000000;
-    end_time += tp->end.tv_usec;
-
-    current_time += now.tv_sec * 1000000;
-    current_time += now.tv_usec;
-
-    diff = end_time - current_time;
-    if (diff > 0)
-        return diff;
-    else
-        return 0;
+    getnow( nowP, &now );
+    for ( t = timers; t != NULL; t = next ) {
+	next = t->next;
+	/* Since the list is sorted, as soon as we find a timer
+	** that isn't ready yet, we are done.
+	*/
+	if ( t->time.tv_sec > now.tv_sec ||
+	     ( t->time.tv_sec == now.tv_sec &&
+	       t->time.tv_usec > now.tv_usec ) )
+	    break;
+	(t->timer_proc)( t->client_data, &now );
+	if ( t->periodic ) {
+	    /* Reschedule. */
+	    add_usecs( &t->time, t->usecs );
+	    list_resort( t );
+	} else
+	    tmr_cancel( t );
+    }
+}
+
+
+void
+tmr_reset( struct timeval* nowP, Timer* t )
+{
+    struct timeval now;
+    
+    getnow( nowP, &now );
+    t->time = now;
+    add_usecs( &t->time, t->usecs );
+    list_resort( t );
+}
+
+
+void
+tmr_cancel( Timer* t )
+{
+    /* Remove it from the active list. */
+    list_remove( t );
+    /* And put it on the free list. */
+    t->next = free_timers;
+    free_timers = t;
+    t->prev = NULL;
+}
+
+
+void
+tmr_cleanup( void )
+{
+    Timer* t;
+
+    while ( free_timers != NULL ) {
+	t = free_timers;
+	free_timers = t->next;
+	free( (void*) t );
+    }
+}
+
+
+void
+tmr_destroy( void )
+{
+    while ( timers != NULL )
+	tmr_cancel( timers );
+    tmr_cleanup();
 }
diff --git a/src/timer.h b/src/timer.h
index f154261..0d50d60 100644
--- a/src/timer.h
+++ b/src/timer.h
@@ -5,28 +5,75 @@
  *
  * This code is distributed under a BSD style license, see the LICENSE file
  * for complete information.
+ *
+ * Based on timers.h by Jef Poskanzer. Used with permission.
  */
 
 #ifndef __TIMER_H
 #define __TIMER_H
 
-#include <time.h>
 #include <sys/time.h>
 
-struct timer {
-    struct timeval begin;
-    struct timeval end;
-    int (*expired)(struct timer *timer);
-};
+/* TimerClientData is an opaque value that tags along with a timer.  The
+** client can use it for whatever, and it gets passed to the callback when
+** the timer triggers.
+*/
+typedef union
+{
+    void* p;
+    int i;
+    long l;
+} TimerClientData;
 
-struct timer *new_timer(time_t sec, suseconds_t usec);
+extern TimerClientData JunkClientData;	/* for use when you don't care */
 
-int update_timer(struct timer *tp, time_t sec, suseconds_t usec);
+/* The TimerProc gets called when the timer expires.  It gets passed
+** the TimerClientData associated with the timer, and a timeval in case
+** it wants to schedule another timer.
+*/
+typedef void TimerProc( TimerClientData client_data, struct timeval* nowP );
 
-int64_t timer_remaining(struct timer *tp);
+/* The Timer struct. */
+typedef struct TimerStruct
+{
+    TimerProc* timer_proc;
+    TimerClientData client_data;
+    int64_t usecs;
+    int periodic;
+    struct timeval time;
+    struct TimerStruct* prev;
+    struct TimerStruct* next;
+    int hash;
+} Timer;
 
-void free_timer(struct timer *tp);
+/* Set up a timer, either periodic or one-shot. Returns (Timer*) 0 on errors. */
+extern Timer* tmr_create(
+    struct timeval* nowP, TimerProc* timer_proc, TimerClientData client_data,
+    int64_t usecs, int periodic );
 
-int timer_expired(struct timer *);
+/* Returns a timeout indicating how long until the next timer triggers.  You
+** can just put the call to this routine right in your select().  Returns
+** (struct timeval*) 0 if no timers are pending.
+*/
+extern struct timeval* tmr_timeout( struct timeval* nowP );
 
-#endif
+/* Run the list of timers. Your main program needs to call this every so often,
+** or as indicated by tmr_timeout().
+*/
+extern void tmr_run( struct timeval* nowP );
+
+/* Reset the clock on a timer, to current time plus the original timeout. */
+extern void tmr_reset( struct timeval* nowP, Timer* timer );
+
+/* Deschedule a timer.  Note that non-periodic timers are automatically
+** descheduled when they run, so you don't have to call this on them.
+*/
+extern void tmr_cancel( Timer* timer );
+
+/* Clean up the timers package, freeing any unused storage. */
+extern void tmr_cleanup( void );
+
+/* Cancel all timers and free storage, usually in preparation for exitting. */
+extern void tmr_destroy( void );
+
+#endif /* __TIMER_H */