[PATCH] test_tools: make tcp_conn tools more robust and reliable - LNST-developers - Fedora mailing-lists

6 Dec 2013

Major and minor fixes for tcp_conn suite,
* removed unused variables and code cleanup
* server/client processes are terminated in graceful way using shared
  flag instead of sending SIGKILL that left connections in unfinished state
* connection counters are now placed in shared memory instead of
  a variable available to controller only and incremented upon the
  signal delivery
Signed-off-by: Jan Tluka jtluka@redhat.com
---
 test_tools/tcp_conn/Makefile      |  4 +-
 test_tools/tcp_conn/tcp_connect.c | 73 ++++++++++++++++++++++++++-------
 test_tools/tcp_conn/tcp_listen.c  | 85 ++++++++++++++++++++++++++++-----------
 3 files changed, 123 insertions(+), 39 deletions(-)

diff --git a/test_tools/tcp_conn/Makefile b/test_tools/tcp_conn/Makefile
index 2e8f5e6..a570641 100644
--- a/test_tools/tcp_conn/Makefile
+++ b/test_tools/tcp_conn/Makefile
@@ -3,10 +3,10 @@ CC=gcc
 all: tcp_listen tcp_connect
tcp_listen: tcp_listen.c
-		$(CC) -o tcp_listen tcp_listen.c
+		$(CC) -o tcp_listen tcp_listen.c -pthread -lrt
tcp_connect: tcp_connect.c
-		$(CC) -o tcp_connect tcp_connect.c
+		$(CC) -o tcp_connect tcp_connect.c -pthread -lrt
clean:
    	rm -f tcp_connect tcp_listen
diff --git a/test_tools/tcp_conn/tcp_connect.c b/test_tools/tcp_conn/tcp_connect.c
index cb6b8c4..36a017f 100644
--- a/test_tools/tcp_conn/tcp_connect.c
+++ b/test_tools/tcp_conn/tcp_connect.c
@@ -1,21 +1,33 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
+#include <stdlib.h>
+#include <sys/wait.h>
#include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netinet/ip.h>
+#include <arpa/inet.h>
#include <errno.h>
 #include <signal.h>
+#include <semaphore.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#define IPCKEY 5678
int connection_handlers[1024];
 int handlers_count;
+int *connection_count;
int debug_on = 0;
 int cont = 0;
+int *term_flag;
+
+sem_t *mutex;
int usage()
 {
@@ -26,7 +38,7 @@ int usage()
 #define MSG_MAX 256
 char msg[MSG_MAX];
-int debug(char* msg)
+void debug(char* msg)
 {
     if (debug_on)
     {
@@ -36,24 +48,14 @@ int debug(char* msg)
void terminate_connections(int p)
 {
-    int cc;
-
     debug("signalled");
-    for (cc=0; cc < handlers_count; cc++)
-    {
-        snprintf(msg, MSG_MAX, "killing process %i", connection_handlers[cc]);
-        debug(msg);
-        kill(connection_handlers[cc], SIGKILL);
-    }
+    *term_flag = 1;
 }
int handle_connections(char* host, int port)
 {
     int conn_sock;
-    int remote_sock;
     struct sockaddr_in my_addr;
-    struct sockaddr remote;
-    int end_loop = 0;
     char data[] = "abcdefghijklmnopqrstuvwxyz0123456789";
     char buf[21*10*strlen(data)+1];
@@ -83,6 +85,10 @@ int handle_connections(char* host, int port)
             return 1;
         }
+        sem_wait(mutex);
+        *connection_count += 1;
+        sem_post(mutex);
+
         int bursts = 5*(random() % 10) + 1;
         int b;
         int sum = 0;
@@ -98,7 +104,11 @@ int handle_connections(char* host, int port)
                 strncpy(buf + (j*strlen(data)), data, strlen(data));
             }
-            int wr_rc = write(conn_sock, buf, parts * strlen(data));
+            if (write(conn_sock, buf, parts * strlen(data)) == -1)
+            {
+                perror("failed to send data");
+                return 1;
+            }
             usleep(100*(random()%100));
         }
@@ -108,7 +118,7 @@ int handle_connections(char* host, int port)
         debug(msg);
close(conn_sock);
-    } while (cont);
+    } while (cont && (*term_flag) == 0);
return 0;
 }
@@ -126,7 +136,40 @@ int main(int argc, char **argv)
     int opt;
     char *delimiter;
     struct sigaction sa;
+    int shm;
+
+    term_flag = mmap(NULL, sizeof *term_flag, PROT_READ | PROT_WRITE, 
+                    MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+    *term_flag = 0;
+
+    connection_count = mmap(NULL, sizeof *connection_count, PROT_READ | PROT_WRITE, 
+                    MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+    *connection_count = 0;
+    /* counter synchronization stuff - semaphore and shared memory */
+    if ((shm = shm_open("myshm", O_RDWR | O_CREAT, S_IRWXU))  < 0) {
+        perror("shm_open");
+        exit(1);
+    }
+
+    if ( ftruncate(shm, sizeof(sem_t)) < 0 ) {
+        perror("ftruncate");
+        exit(1);
+    }
+
+    /* place shared mutex into shared memory */
+    if ((mutex = (sem_t*) mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_SHARED, shm, 0)) == MAP_FAILED) {
+        perror("mmap");
+        exit(1);
+    }
+
+    if( sem_init(mutex,1,1) < 0)
+    {
+        perror("semaphore initilization");
+        exit(0);
+    }
+
+    /* signal handling */
     memset(&sa, 0, sizeof(sa));
sa.sa_handler = &terminate_connections;
@@ -200,5 +243,7 @@ int main(int argc, char **argv)
debug("tcp_connect finished");
+    printf("made %i connections\n", *connection_count);
+
     return 0;
 }
diff --git a/test_tools/tcp_conn/tcp_listen.c b/test_tools/tcp_conn/tcp_listen.c
index ef5eeb2..7911cfe 100644
--- a/test_tools/tcp_conn/tcp_listen.c
+++ b/test_tools/tcp_conn/tcp_listen.c
@@ -1,21 +1,33 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
+#include <stdlib.h>
+#include <sys/wait.h>
#include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netinet/ip.h>
+#include <arpa/inet.h>
#include <errno.h>
 #include <signal.h>
+#include <semaphore.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#define IPCKEY 5678
int listener_count;
 int listeners[1024];
+int *connection_count;
-int connection_count;
 int debug_on = 0;
 int cont = 0;
+int *term_flag;
+
+sem_t *mutex;
int usage()
 {
@@ -23,7 +35,7 @@ int usage()
     return 0;
 }
-int debug(char* msg)
+void debug(char* msg)
 {
     if (debug_on)
     {
@@ -36,21 +48,8 @@ char msg[MSG_MAX];
void terminate_connections(int p)
 {
-    int l;
-
     debug("signal received, killing servers");
-    for (l=0; l < listener_count; l++)
-    {
-        snprintf(msg, MSG_MAX, "killing process %i", listeners[l]);
-        debug(msg);
-        kill(listeners[l], SIGKILL);
-    }
-}
-
-void connection_counter(int p)
-{
-    debug("increase counter");
-    connection_count += 1;
+    *term_flag = 1;
 }
int handle_connections(char* host, int port)
@@ -81,6 +80,13 @@ int handle_connections(char* host, int port)
         return 1;
     }
+    int on = 1;
+    if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, (const char*) &on, sizeof(on)) == -1)
+    {
+        perror("fail on setsockopt");
+        return 1;
+    }
+
     if (bind(listen_sock, (struct sockaddr*) &my_addr, sizeof(struct sockaddr_in)))
     {
         perror("fail on bind");
@@ -109,6 +115,11 @@ int handle_connections(char* host, int port)
             return 1;
         }
+        sem_wait(mutex);
+        *connection_count += 1;
+        sem_post(mutex);
+
+
         inet_ntop(AF_INET, &ra, host_address_str, 255);
         snprintf(msg, MSG_MAX, "accepted connection from host %s port %i", host_address_str, port);
         debug(msg);
@@ -122,8 +133,7 @@ int handle_connections(char* host, int port)
         snprintf(msg, MSG_MAX, "connection closed, read %d bytes (%i)", sum, port);
         debug(msg);
         close(remote_sock);
-        kill(getppid(), SIGUSR1);
-    } while (cont);
+    } while (cont && (*term_flag) == 0);
close(listen_sock);
@@ -144,7 +154,40 @@ int main(int argc, char **argv)
     char *delimiter;
     struct sigaction sa;
     struct sigaction sa2;
+    int shm;
+
+    term_flag = mmap(NULL, sizeof *term_flag, PROT_READ | PROT_WRITE, 
+                    MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+    *term_flag = 0;
+
+    connection_count = mmap(NULL, sizeof *connection_count, PROT_READ | PROT_WRITE, 
+                    MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+    *connection_count = 0;
+
+    /* counter synchronization stuff - semaphore and shared memory */
+    if ((shm = shm_open("myshm", O_RDWR | O_CREAT, S_IRWXU))  < 0) {
+        perror("shm_open");
+        exit(1);
+    }
+
+    if ( ftruncate(shm, sizeof(sem_t)) < 0 ) {
+        perror("ftruncate");
+        exit(1);
+    }
+    /* place shared mutex into shared memory */
+    if ((mutex = (sem_t*) mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_SHARED, shm, 0)) == MAP_FAILED) {
+        perror("mmap");
+        exit(1);
+    }
+
+    if( sem_init(mutex,1,1) < 0)
+    {
+        perror("semaphore initilization");
+        exit(0);
+    }
+
+    /* signal handling */
     memset(&sa, 0, sizeof(sa));
     memset(&sa2, 0, sizeof(sa2));
@@ -152,9 +195,6 @@ int main(int argc, char **argv)
     sigaction(SIGTERM, &sa, NULL);
     sigaction(SIGINT, &sa, NULL);
-    sa2.sa_handler = &connection_counter;
-    sigaction(SIGUSR1, &sa2, NULL);
-
     /* collect program args */
     while ((opt = getopt(argc, argv, "p:a:dc")) != -1) {
         switch (opt) {
@@ -216,7 +256,6 @@ int main(int argc, char **argv)
     int i;
     for (i=0; i < listener_count; i++)
     {
-        int rc = -1;
         while (wait(&child_status) == -1  && errno == EINTR)
         {
             ;
@@ -226,7 +265,7 @@ int main(int argc, char **argv)
debug("tcp_listener finished");
-    printf("handled %i connections\n", connection_count);
+    printf("handled %i connections\n", *connection_count);
return 0;
 }
-- 
1.8.1.4


    