From 061881255450e798abf887b4e8843a497ce33793 Mon Sep 17 00:00:00 2001
From: Cedric Roux <cedric.roux@eurecom.fr>
Date: Tue, 16 Aug 2022 12:01:52 +0200
Subject: [PATCH] T tracer: simplify
- don't call exit() if get_message() fails, simply terminate the thread and
disable the T tracer
- T_dont_fork disappears, monitor_and_kill() as well, so now it's only 2
processes: the main (enb/gnb/ue) and the local tracer
---
common/utils/T/T.c | 119 ++++++++++++++++++++-------------------------
common/utils/T/T.h | 14 ++----
2 files changed, 59 insertions(+), 74 deletions(-)
diff --git a/common/utils/T/T.c b/common/utils/T/T.c
index 2d724ffd00..6ba1962d1f 100644
--- a/common/utils/T/T.c
+++ b/common/utils/T/T.c
@@ -8,22 +8,19 @@
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/socket.h>
+#include <sys/types.h>
+#include <signal.h>
#include "common/config/config_userapi.h"
-#define QUIT(x) do { \
- printf("T tracer: QUIT: %s\n", x); \
- exit(1); \
- } while (0)
-
/* array used to activate/disactivate a log */
static int T_IDs[T_NUMBER_OF_IDS];
int *T_active = T_IDs;
int T_stdout = 1;
-
static int T_socket;
+static int local_tracer_pid;
/* T_cache
* - the T macro picks up the head of freelist and marks it busy
@@ -33,63 +30,78 @@ volatile int _T_freelist_head;
volatile int *T_freelist_head = &_T_freelist_head;
T_cache_t *T_cache;
-static void get_message(int s) {
+#define GET_MESSAGE_FAIL do { \
+ printf("T tracer: get_message failed\n"); \
+ return -1; \
+ } while (0)
+
+/* return -1 if error, 0 if no error */
+static int get_message(int s)
+{
char t;
int l;
int id;
int is_on;
- if (read(s, &t, 1) != 1) QUIT("get_message fails");
+ if (read(s, &t, 1) != 1) GET_MESSAGE_FAIL;
printf("T tracer: got mess %d\n", t);
switch (t) {
case 0:
-
/* toggle all those IDs */
/* optimze? (too much syscalls) */
- if (read(s, &l, sizeof(int)) != sizeof(int)) QUIT("get_message fails");
+ if (read(s, &l, sizeof(int)) != sizeof(int)) GET_MESSAGE_FAIL;
while (l) {
- if (read(s, &id, sizeof(int)) != sizeof(int)) QUIT("get_message fails");
+ if (read(s, &id, sizeof(int)) != sizeof(int)) GET_MESSAGE_FAIL;
T_IDs[id] = 1 - T_IDs[id];
l--;
}
-
break;
-
case 1:
-
/* set IDs as given */
/* optimize? */
- if (read(s, &l, sizeof(int)) != sizeof(int)) QUIT("get_message fails");
+ if (read(s, &l, sizeof(int)) != sizeof(int)) GET_MESSAGE_FAIL;
id = 0;
while (l) {
if (read(s, &is_on, sizeof(int)) != sizeof(int))
- QUIT("get_message fails");
+ GET_MESSAGE_FAIL;
T_IDs[id] = is_on;
id++;
l--;
}
-
break;
-
case 2:
break; /* do nothing, this message is to wait for local tracer */
}
+
+ return 0;
}
-static void *T_receive_thread(void *_) {
- while (1) get_message(T_socket);
+static void *T_receive_thread(void *_)
+{
+ int err = 0;
+ while (!err) err = get_message(T_socket);
+
+ printf("T tracer: fatal: T tracer disabled\n");
+
+ shutdown(T_socket, SHUT_RDWR);
+ close(T_socket);
+ kill(local_tracer_pid, SIGKILL);
+
+ /* disable all traces */
+ memset(T_IDs, 0, sizeof(T_IDs));
return NULL;
}
-static void new_thread(void *(*f)(void *), void *data) {
+static void new_thread(void *(*f)(void *), void *data)
+{
pthread_t t;
pthread_attr_t att;
@@ -118,27 +130,11 @@ static void new_thread(void *(*f)(void *), void *data) {
void T_local_tracer_main(int remote_port, int wait_for_tracer,
int local_socket, void *shm_array);
-/* We monitor the tracee and the local tracer processes.
- * When one dies we forcefully kill the other.
- */
-#include <sys/types.h>
-#include <sys/wait.h>
-static void monitor_and_kill(int child1, int child2) {
- int child;
- int status;
- child = wait(&status);
-
- if (child == -1) perror("wait");
-
- kill(child1, SIGKILL);
- kill(child2, SIGKILL);
- exit(0);
-}
-
-void T_init(int remote_port, int wait_for_tracer, int dont_fork) {
+void T_init(int remote_port, int wait_for_tracer)
+{
int socket_pair[2];
int s;
- int child1, child2;
+ int child;
int i;
if (socketpair(AF_UNIX, SOCK_STREAM, 0, socket_pair)) {
@@ -162,47 +158,40 @@ void T_init(int remote_port, int wait_for_tracer, int dont_fork) {
for (i = 0; i < T_CACHE_SIZE; i++) T_cache[i].busy = 0;
- /* child1 runs the local tracer and child2 (or main) runs the tracee */
- child1 = fork();
+ /* child runs the local tracer and main runs the tracee */
+ child = fork();
- if (child1 == -1) abort();
+ if (child == -1) abort();
- if (child1 == 0) {
+ if (child == 0) {
close(socket_pair[1]);
T_local_tracer_main(remote_port, wait_for_tracer, socket_pair[0],
T_cache);
exit(0);
}
- close(socket_pair[0]);
+ local_tracer_pid = child;
- if (dont_fork == 0) {
- child2 = fork();
+ close(socket_pair[0]);
- if (child2 == -1) abort();
+ s = socket_pair[1];
+ T_socket = s;
- if (child2 != 0) {
- close(socket_pair[1]);
- munmap(T_cache, T_CACHE_SIZE * sizeof(T_cache_t));
- monitor_and_kill(child1, child2);
- }
+ /* wait for first message - initial list of active T events */
+ if (get_message(s) == -1) {
+ kill(local_tracer_pid, SIGKILL);
+ return;
}
- s = socket_pair[1];
- /* wait for first message - initial list of active T events */
- get_message(s);
- T_socket = s;
new_thread(T_receive_thread, NULL);
}
-void T_Config_Init(void) {
- int T_port=TTRACER_DEFAULT_PORTNUM; /* by default we wait for the tracer */
- int T_nowait=0; /* default port to listen to to wait for the tracer */
- int T_dont_fork=0; /* default is to fork, see 'T_init' to understand */
+void T_Config_Init(void)
+{
+ int T_port = TTRACER_DEFAULT_PORTNUM;
+ int T_nowait = 0;
paramdef_t ttraceparams[] = CMDLINE_TTRACEPARAMS_DESC;
- /* for a cleaner config file, TTracer params should be defined in a
- * specific section...
- */
+
config_get(ttraceparams,
sizeof(ttraceparams) / sizeof(paramdef_t),
TTRACER_CONFIG_PREFIX);
@@ -217,5 +206,5 @@ void T_Config_Init(void) {
}
if (T_stdout == 0 || T_stdout == 2)
- T_init(T_port, 1-T_nowait, T_dont_fork);
+ T_init(T_port, 1-T_nowait);
}
diff --git a/common/utils/T/T.h b/common/utils/T/T.h
index df1e95d2df..dd698906c8 100644
--- a/common/utils/T/T.h
+++ b/common/utils/T/T.h
@@ -15,8 +15,8 @@
#include "T_IDs.h"
#define T_ACTIVE_STDOUT 2
-/* known type - this is where you add new types */
+/* known type - this is where you add new types */
#define T_INT(x) int, (x)
#define T_FLOAT(x) float, (x)
#define T_BUFFER(x, len) buffer, ((T_buffer){addr:(x), length:(len)})
@@ -111,6 +111,7 @@ typedef struct {
extern volatile int *T_freelist_head;
extern T_cache_t *T_cache;
extern int *T_active;
+
#define T_GET_SLOT \
T_LOCAL_busy = __sync_fetch_and_or(&T_cache[T_LOCAL_slot].busy, 0x01);
@@ -559,14 +560,12 @@ extern int *T_active;
} \
} while (0)
-
#define CONFIG_HLP_TPORT "tracer port\n"
#define CONFIG_HLP_NOTWAIT "don't wait for tracer, start immediately\n"
-#define CONFIG_HLP_TNOFORK "to ease debugging with gdb\n"
#define CONFIG_HLP_STDOUT "print log messges on console\n"
-
#define TTRACER_CONFIG_PREFIX "TTracer"
+
/*-------------------------------------------------------------------------------------------------------------------------------------------------*/
/* configuration parameters for TTRACE utility */
/* optname helpstr paramflags XXXptr defXXXval type numelt */
@@ -575,15 +574,12 @@ extern int *T_active;
#define CMDLINE_TTRACEPARAMS_DESC { \
{"T_port", CONFIG_HLP_TPORT, 0, iptr:&T_port, defintval:TTRACER_DEFAULT_PORTNUM, TYPE_INT, 0},\
{"T_nowait", CONFIG_HLP_NOTWAIT, PARAMFLAG_BOOL, iptr:&T_nowait, defintval:0, TYPE_INT, 0},\
- {"T_dont_fork", CONFIG_HLP_TNOFORK, PARAMFLAG_BOOL, iptr:&T_dont_fork, defintval:0, TYPE_INT, 0},\
{"T_stdout", CONFIG_HLP_STDOUT, 0, iptr:&T_stdout, defintval:1, TYPE_INT, 0},\
}
-
-
-/* log on stdout */
-void T_init(int remote_port, int wait_for_tracer, int dont_fork);
+void T_init(int remote_port, int wait_for_tracer);
void T_Config_Init(void);
+
#else /* T_TRACER */
/* if T_TRACER is not defined or is 0, the T is deactivated */
--
2.26.2