X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=ustd%2Fustd.c;h=1144705fec00d0eaaf29bdc13d4471ada0bb4f6f;hb=5308038079d1b14a3fbaef282c39cced8444f5b3;hp=b38593b36b0d65cc9f89b2eea565aed612d97c58;hpb=c970a26f3e184f41495602b8028f6e163d7b5b9f;p=ust.git

diff --git a/ustd/ustd.c b/ustd/ustd.c
index b38593b..1144705 100644
--- a/ustd/ustd.c
+++ b/ustd/ustd.c
@@ -59,7 +59,7 @@ char *pidfile = NULL;
 int active_buffers = 0;
 pthread_mutex_t active_buffers_mutex = PTHREAD_MUTEX_INITIALIZER;
 /* Whether a request to end the program was received. */
-sig_atomic_t terminate_req = 0;
+volatile sig_atomic_t terminate_req = 0;
 
 int get_subbuffer(struct buffer_info *buf)
 {
@@ -71,7 +71,7 @@ int get_subbuffer(struct buffer_info *buf)
 
 	asprintf(&send_msg, "get_subbuffer %s", buf->name);
 	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
-	if((result == -1 && errno == EPIPE) || result == 0) {
+	if((result == -1 && (errno == ECONNRESET || errno == EPIPE)) || result == 0) {
 		DBG("app died while being traced");
 		retval = GET_SUBBUF_DIED;
 		goto end;
@@ -86,11 +86,10 @@ int get_subbuffer(struct buffer_info *buf)
 	if(result != 2 && result != 1) {
 		ERR("unable to parse response to get_subbuffer");
 		retval = -1;
+		free(received_msg);
 		goto end_rep;
 	}
 
-	DBG("received msg is %s", received_msg);
-
 	if(!strcmp(rep_code, "OK")) {
 		DBG("got subbuffer %s", buf->name);
 		retval = GET_SUBBUF_OK;
@@ -132,7 +131,7 @@ int put_subbuffer(struct buffer_info *buf)
 
 	asprintf(&send_msg, "put_subbuffer %s %ld", buf->name, buf->consumed_old);
 	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
-	if(result < 0 && errno == ECONNRESET) {
+	if(result < 0 && (errno == ECONNRESET || errno == EPIPE)) {
 		retval = PUT_SUBBUF_DIED;
 		goto end;
 	}
@@ -160,6 +159,14 @@ int put_subbuffer(struct buffer_info *buf)
 		DBG("subbuffer put %s", buf->name);
 		retval = PUT_SUBBUF_OK;
 	}
+	else if(!strcmp(received_msg, "NOTFOUND")) {
+		WARN("For buffer %s, the trace was not found. This likely means it was destroyed by the user.", buf->name);
+		/* However, maybe this was not the last subbuffer. So
+		 * we return the program died.
+		 */
+		retval = PUT_SUBBUF_DIED;
+		goto end_rep;
+	}
 	else {
 		DBG("put_subbuffer: received error, we were pushed");
 		retval = PUT_SUBBUF_PUSHED;
@@ -252,6 +259,9 @@ struct buffer_info *connect_buffer(pid_t pid, const char *bufname)
 		ERR("problem in ustcomm_send_request(get_pidunique)");
 		return NULL;
 	}
+	if(result == 0) {
+		goto error;
+	}
 
 	result = sscanf(received_msg, "%lld", &buf->pidunique);
 	if(result != 1) {
@@ -269,6 +279,9 @@ struct buffer_info *connect_buffer(pid_t pid, const char *bufname)
 		ERR("problem in ustcomm_send_request(get_shmid)");
 		return NULL;
 	}
+	if(result == 0) {
+		goto error;
+	}
 
 	result = sscanf(received_msg, "%d %d", &buf->shmid, &buf->bufstruct_shmid);
 	if(result != 2) {
@@ -286,6 +299,9 @@ struct buffer_info *connect_buffer(pid_t pid, const char *bufname)
 		ERR("problem in ustcomm_send_request(g_n_subbufs)");
 		return NULL;
 	}
+	if(result == 0) {
+		goto error;
+	}
 
 	result = sscanf(received_msg, "%d", &buf->n_subbufs);
 	if(result != 1) {
@@ -297,8 +313,15 @@ struct buffer_info *connect_buffer(pid_t pid, const char *bufname)
 
 	/* get subbuf size */
 	asprintf(&send_msg, "get_subbuf_size %s", buf->name);
-	ustcomm_send_request(&buf->conn, send_msg, &received_msg);
+	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 	free(send_msg);
+	if(result == -1) {
+		ERR("problem in ustcomm_send_request(get_subbuf_size)");
+		return NULL;
+	}
+	if(result == 0) {
+		goto error;
+	}
 
 	result = sscanf(received_msg, "%d", &buf->subbuf_size);
 	if(result != 1) {
@@ -370,6 +393,56 @@ struct buffer_info *connect_buffer(pid_t pid, const char *bufname)
 	pthread_mutex_unlock(&active_buffers_mutex);
 
 	return buf;
+
+error:
+	free(buf);
+	return NULL;
+}
+
+static void destroy_buffer(struct buffer_info *buf)
+{
+	int result;
+
+	result = ustcomm_close_app(&buf->conn);
+	if(result == -1) {
+		WARN("problem calling ustcomm_close_app");
+	}
+
+	result = shmdt(buf->mem);
+	if(result == -1) {
+		PERROR("shmdt");
+	}
+
+	result = shmdt(buf->bufstruct_mem);
+	if(result == -1) {
+		PERROR("shmdt");
+	}
+
+	result = close(buf->file_fd);
+	if(result == -1) {
+		PERROR("close");
+	}
+
+	free(buf);
+}
+
+int unwrite_last_subbuffer(struct buffer_info *buf)
+{
+	int result;
+
+	result = ftruncate(buf->file_fd, buf->previous_offset);
+	if(result == -1) {
+		PERROR("ftruncate");
+		return -1;
+	}
+
+	result = lseek(buf->file_fd, buf->previous_offset, SEEK_SET);
+	if(result == (int)(off_t)-1) {
+		PERROR("lseek");
+		return -1;
+	}
+
+	return 0;
 }
 
 int write_current_subbuffer(struct buffer_info *buf)
@@ -380,11 +453,20 @@ int write_current_subbuffer(struct buffer_info *buf)
 
 	size_t cur_sb_size = subbuffer_data_size(subbuf_mem);
 
+	off_t cur_offset = lseek(buf->file_fd, 0, SEEK_CUR);
+	if(cur_offset == (off_t)-1) {
+		PERROR("lseek");
+		return -1;
+	}
+
+	buf->previous_offset = cur_offset;
+	DBG("previous_offset: %ld", cur_offset);
+
 	result = patient_write(buf->file_fd, subbuf_mem, cur_sb_size);
 	if(result == -1) {
 		PERROR("write");
 		/* FIXME: maybe drop this trace */
-		return 0;
+		return -1;
 	}
 
 	return 0;
@@ -417,7 +499,6 @@ int consumer_loop(struct buffer_info *buf)
 		/* FIXME: handle return value? */
 
 		/* put the subbuffer */
-		/* FIXME: we actually should unput the buffer before consuming... */
 		result = put_subbuffer(buf);
 		if(result == -1) {
 			ERR("unknown error putting subbuffer (channel=%s)", buf->name);
@@ -429,7 +510,10 @@ int consumer_loop(struct buffer_info *buf)
 		}
 		else if(result == PUT_SUBBUF_DIED) {
 			WARN("application died while putting subbuffer");
-			/* FIXME: probably need to skip the first subbuffer in finish_consuming_dead_subbuffer */
+			/* Skip the first subbuffer. We are not sure it is trustable
+			 * because the put_subbuffer() did not complete.
+			 */
+			unwrite_last_subbuffer(buf);
 			finish_consuming_dead_subbuffer(buf);
 			break;
 		}
@@ -455,10 +539,6 @@ int consumer_loop(struct buffer_info *buf)
 	return 0;
 }
 
-void free_buffer(struct buffer_info *buf)
-{
-}
-
 struct consumer_thread_args {
 	pid_t pid;
 	const char *bufname;
@@ -479,7 +559,8 @@ void *consumer_thread(void *arg)
 
 	consumer_loop(buf);
 
-	free_buffer(buf);
+	free(args->bufname);
+	destroy_buffer(buf);
 
 	end:
 	/* bufname is free'd in free_buffer() */
@@ -491,6 +572,7 @@ int start_consuming_buffer(pid_t pid, const char *bufname)
 {
 	pthread_t thr;
 	struct consumer_thread_args *args;
+	int result;
 
 	DBG("beginning of start_consuming_buffer: args: pid %d bufname %s", pid, bufname);
 
@@ -500,7 +582,16 @@ int start_consuming_buffer(pid_t pid, const char *bufname)
 	args->bufname = strdup(bufname);
 	DBG("beginning2 of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);
 
-	pthread_create(&thr, NULL, consumer_thread, args);
+	result = pthread_create(&thr, NULL, consumer_thread, args);
+	if(result == -1) {
+		ERR("pthread_create failed");
+		return -1;
+	}
+	result = pthread_detach(thr);
+	if(result == -1) {
+		ERR("pthread_detach failed");
+		return -1;
+	}
 	DBG("end of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);
 
 	return 0;
@@ -616,6 +707,11 @@ int start_ustd(int fd)
 		PERROR("sigaction");
 		return 1;
 	}
+	result = sigaction(SIGINT, &sa, NULL);
+	if(result == -1) {
+		PERROR("sigaction");
+		return 1;
+	}
 
 	result = ustcomm_init_ustd(&ustd, sock_path);
 	if(result == -1) {
@@ -698,6 +794,9 @@ int start_ustd(int fd)
 				free_bufname:
 				free(bufname);
 			}
+			else {
+				WARN("unknown command: %s", recvbuf);
+			}
 
 			free(recvbuf);
 		}
@@ -714,6 +813,8 @@ int start_ustd(int fd)
 		}
 	}
 
+	ustcomm_fini_ustd(&ustd);
+
 	return 0;
 }