X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=ustd%2Fustd.c;h=fef0eae1680336dfe83eb05b8ca16b37d1d6fa39;hb=6af64c431c0a521fc927fa72b9f4015397ce11d4;hp=7d1eb49cec6de8d51157ca3c377a0d0be8d2318c;hpb=68ab7a5d576faa16e0da19d0f824785eac215ae9;p=ust.git

diff --git a/ustd/ustd.c b/ustd/ustd.c
index 7d1eb49..fef0eae 100644
--- a/ustd/ustd.c
+++ b/ustd/ustd.c
@@ -33,8 +33,9 @@
 #include <getopt.h>
 
 #include "ustd.h"
-#include "localerr.h"
+#include "usterr.h"
 #include "ustcomm.h"
+#include "share.h"
 
 /* return value: 0 = subbuffer is finished, it won't produce data anymore
  *               1 = got subbuffer successfully
@@ -51,6 +52,8 @@
 
 char *sock_path=NULL;
 char *trace_path=NULL;
+int daemon_mode = 0;
+char *pidfile = NULL;
 
 /* Number of active buffers and the mutex to protect it. */
 int active_buffers = 0;
@@ -58,40 +61,6 @@ pthread_mutex_t active_buffers_mutex = PTHREAD_MUTEX_INITIALIZER;
 /* Whether a request to end the program was received. */
 sig_atomic_t terminate_req = 0;
 
-int test_sigpipe(void)
-{
-	sigset_t sigset;
-	int result;
-
-	result = sigemptyset(&sigset);
-	if(result == -1) {
-		PERROR("sigemptyset");
-		return -1;
-	}
-	result = sigaddset(&sigset, SIGPIPE);
-	if(result == -1) {
-		PERROR("sigaddset");
-		return -1;
-	}
-
-	result = sigtimedwait(&sigset, NULL, &(struct timespec){0,0});
-	if(result == -1 && errno == EAGAIN) {
-		/* no signal received */
-		return 0;
-	}
-	else if(result == -1) {
-		PERROR("sigtimedwait");
-		return -1;
-	}
-	else if(result == SIGPIPE) {
-		/* received sigpipe */
-		return 1;
-	}
-	else {
-		assert(0);
-	}
-}
-
 int get_subbuffer(struct buffer_info *buf)
 {
 	char *send_msg=NULL;
@@ -102,9 +71,9 @@ 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(test_sigpipe()) {
-		WARN("process %d destroyed before we could connect to it", buf->pid);
-		retval = GET_SUBBUF_DONE;
+	if((result == -1 && errno == EPIPE) || result == 0) {
+		DBG("app died while being traced");
+		retval = GET_SUBBUF_DIED;
 		goto end;
 	}
 	else if(result < 0) {
@@ -198,30 +167,6 @@ end:
 	return retval;
 }
 
-/* This write is patient because it restarts if it was incomplete.
- */
-
-ssize_t patient_write(int fd, const void *buf, size_t count)
-{
-	const char *bufc = (const char *) buf;
-	int result;
-
-	for(;;) {
-		result = write(fd, bufc, count);
-		if(result <= 0) {
-			return result;
-		}
-		count -= result;
-		bufc += result;
-
-		if(count == 0) {
-			break;
-		}
-	}
-
-	return bufc-(const char *)buf;
-}
-
 void decrement_active_buffers(void *arg)
 {
 	pthread_mutex_lock(&active_buffers_mutex);
@@ -229,65 +174,6 @@ void decrement_active_buffers(void *arg)
 	pthread_mutex_unlock(&active_buffers_mutex);
 }
 
-void *consumer_thread(void *arg)
-{
-	struct buffer_info *buf = (struct buffer_info *) arg;
-	int result;
-
-	pthread_cleanup_push(decrement_active_buffers, NULL);
-
-	for(;;) {
-		/* get the subbuffer */
-		result = get_subbuffer(buf);
-		if(result == -1) {
-			ERR("error getting subbuffer");
-			continue;
-		}
-		else if(result == GET_SUBBUF_DONE) {
-			/* this is done */
-			break;
-		}
-		else if(result == GET_SUBBUF_DIED) {
-			finish_consuming_dead_subbuffer(buf);
-			break;
-		}
-
-		/* write data to file */
-		result = patient_write(buf->file_fd, buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1)), buf->subbuf_size);
-		if(result == -1) {
-			PERROR("write");
-			/* FIXME: maybe drop this trace */
-		}
-
-		/* put the subbuffer */
-		result = put_subbuffer(buf);
-		if(result == -1) {
-			ERR("unknown error putting subbuffer (channel=%s)", buf->name);
-			break;
-		}
-		else if(result == PUT_SUBBUF_PUSHED) {
-			ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
-			break;
-		}
-		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 */
-			finish_consuming_dead_subbuffer(buf);
-			break;
-		}
-		else if(result == PUT_SUBBUF_OK) {
-		}
-	}
-
-	DBG("thread for buffer %s is stopping", buf->name);
-
-	/* FIXME: destroy, unalloc... */
-
-	pthread_cleanup_pop(1);
-
-	return NULL;
-}
-
 int create_dir_if_needed(char *dir)
 {
 	int result;
@@ -320,7 +206,7 @@ int is_directory(const char *dir)
 	return 1;
 }
 
-int add_buffer(pid_t pid, char *bufname)
+struct buffer_info *connect_buffer(pid_t pid, const char *bufname)
 {
 	struct buffer_info *buf;
 	char *send_msg;
@@ -328,13 +214,12 @@ int add_buffer(pid_t pid, char *bufname)
 	int result;
 	char *tmp;
 	int fd;
-	pthread_t thr;
 	struct shmid_ds shmds;
 
 	buf = (struct buffer_info *) malloc(sizeof(struct buffer_info));
 	if(buf == NULL) {
 		ERR("add_buffer: insufficient memory");
-		return -1;
+		return NULL;
 	}
 
 	buf->name = bufname;
@@ -344,7 +229,7 @@ int add_buffer(pid_t pid, char *bufname)
 	result = ustcomm_connect_app(buf->pid, &buf->conn);
 	if(result) {
 		WARN("unable to connect to process, it probably died before we were able to connect");
-		return -1;
+		return NULL;
 	}
 
 	/* get pidunique */
@@ -353,13 +238,13 @@ int add_buffer(pid_t pid, char *bufname)
 	free(send_msg);
 	if(result == -1) {
 		ERR("problem in ustcomm_send_request(get_pidunique)");
-		return -1;
+		return NULL;
 	}
 
 	result = sscanf(received_msg, "%lld", &buf->pidunique);
 	if(result != 1) {
 		ERR("unable to parse response to get_pidunique");
-		return -1;
+		return NULL;
 	}
 	free(received_msg);
 	DBG("got pidunique %lld", buf->pidunique);
@@ -370,13 +255,13 @@ int add_buffer(pid_t pid, char *bufname)
 	free(send_msg);
 	if(result == -1) {
 		ERR("problem in ustcomm_send_request(get_shmid)");
-		return -1;
+		return NULL;
 	}
 
 	result = sscanf(received_msg, "%d %d", &buf->shmid, &buf->bufstruct_shmid);
 	if(result != 2) {
 		ERR("unable to parse response to get_shmid");
-		return -1;
+		return NULL;
 	}
 	free(received_msg);
 	DBG("got shmids %d %d", buf->shmid, buf->bufstruct_shmid);
@@ -387,13 +272,13 @@ int add_buffer(pid_t pid, char *bufname)
 	free(send_msg);
 	if(result == -1) {
 		ERR("problem in ustcomm_send_request(g_n_subbufs)");
-		return -1;
+		return NULL;
 	}
 
 	result = sscanf(received_msg, "%d", &buf->n_subbufs);
 	if(result != 1) {
 		ERR("unable to parse response to get_n_subbufs");
-		return -1;
+		return NULL;
 	}
 	free(received_msg);
 	DBG("got n_subbufs %d", buf->n_subbufs);
@@ -406,7 +291,7 @@ int add_buffer(pid_t pid, char *bufname)
 	result = sscanf(received_msg, "%d", &buf->subbuf_size);
 	if(result != 1) {
 		ERR("unable to parse response to get_subbuf_size");
-		return -1;
+		return NULL;
 	}
 	free(received_msg);
 	DBG("got subbuf_size %d", buf->subbuf_size);
@@ -415,14 +300,14 @@ int add_buffer(pid_t pid, char *bufname)
 	buf->mem = shmat(buf->shmid, NULL, 0);
 	if(buf->mem == (void *) 0) {
 		PERROR("shmat");
-		return -1;
+		return NULL;
 	}
 	DBG("successfully attached buffer memory");
 
 	buf->bufstruct_mem = shmat(buf->bufstruct_shmid, NULL, 0);
 	if(buf->bufstruct_mem == (void *) 0) {
 		PERROR("shmat");
-		return -1;
+		return NULL;
 	}
 	DBG("successfully attached buffer bufstruct memory");
 
@@ -430,7 +315,7 @@ int add_buffer(pid_t pid, char *bufname)
 	result = shmctl(buf->shmid, IPC_STAT, &shmds);
 	if(result == -1) {
 		PERROR("shmctl");
-		return -1;
+		return NULL;
 	}
 	buf->memlen = shmds.shm_segsz;
 
@@ -443,7 +328,7 @@ int add_buffer(pid_t pid, char *bufname)
 		result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
 		if(result == -1) {
 			ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
-			return -1;
+			return NULL;
 		}
 
 		trace_path = USTD_DEFAULT_TRACE_PATH;
@@ -454,7 +339,7 @@ int add_buffer(pid_t pid, char *bufname)
 	if(result == -1) {
 		ERR("could not create directory %s", tmp);
 		free(tmp);
-		return -1;
+		return NULL;
 	}
 	free(tmp);
 
@@ -463,7 +348,7 @@ int add_buffer(pid_t pid, char *bufname)
 	if(result == -1) {
 		PERROR("open");
 		ERR("failed opening trace file %s", tmp);
-		return -1;
+		return NULL;
 	}
 	buf->file_fd = fd;
 	free(tmp);
@@ -472,7 +357,115 @@ int add_buffer(pid_t pid, char *bufname)
 	active_buffers++;
 	pthread_mutex_unlock(&active_buffers_mutex);
 
-	pthread_create(&thr, NULL, consumer_thread, buf);
+	return buf;
+}
+
+int consumer_loop(struct buffer_info *buf)
+{
+	int result;
+
+	pthread_cleanup_push(decrement_active_buffers, NULL);
+
+	for(;;) {
+		/* get the subbuffer */
+		result = get_subbuffer(buf);
+		if(result == -1) {
+			ERR("error getting subbuffer");
+			continue;
+		}
+		else if(result == GET_SUBBUF_DONE) {
+			/* this is done */
+			break;
+		}
+		else if(result == GET_SUBBUF_DIED) {
+			finish_consuming_dead_subbuffer(buf);
+			break;
+		}
+
+		/* write data to file */
+		result = patient_write(buf->file_fd, buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1)), buf->subbuf_size);
+		if(result == -1) {
+			PERROR("write");
+			/* FIXME: maybe drop this trace */
+		}
+
+		/* 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);
+			break;
+		}
+		else if(result == PUT_SUBBUF_PUSHED) {
+			ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
+			break;
+		}
+		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 */
+			finish_consuming_dead_subbuffer(buf);
+			break;
+		}
+		else if(result == PUT_SUBBUF_OK) {
+		}
+	}
+
+	DBG("thread for buffer %s is stopping", buf->name);
+
+	/* FIXME: destroy, unalloc... */
+
+	pthread_cleanup_pop(1);
+
+	return 0;
+}
+
+void free_buffer(struct buffer_info *buf)
+{
+}
+
+struct consumer_thread_args {
+	pid_t pid;
+	const char *bufname;
+};
+
+void *consumer_thread(void *arg)
+{
+	struct buffer_info *buf = (struct buffer_info *) arg;
+	struct consumer_thread_args *args = (struct consumer_thread_args *) arg;
+
+	DBG("GOT ARGS: pid %d bufname %s", args->pid, args->bufname);
+
+	buf = connect_buffer(args->pid, args->bufname);
+	if(buf == NULL) {
+		ERR("failed to connect to buffer");
+		goto end;
+	}
+
+	consumer_loop(buf);
+
+	free_buffer(buf);
+
+	end:
+	/* bufname is free'd in free_buffer() */
+	free(args);
+	return NULL;
+}
+
+int start_consuming_buffer(pid_t pid, const char *bufname)
+{
+	pthread_t thr;
+	struct consumer_thread_args *args;
+
+	DBG("beginning of start_consuming_buffer: args: pid %d bufname %s", pid, bufname);
+
+	args = (struct consumer_thread_args *) malloc(sizeof(struct consumer_thread_args));
+
+	args->pid = pid;
+	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);
+	DBG("end of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);
 
 	return 0;
 }
@@ -482,7 +475,9 @@ void usage(void)
 	fprintf(stderr, "Usage:\nustd OPTIONS\n\nOptions:\n"
 			"\t-h\t\tDisplay this usage.\n"
 			"\t-o DIR\t\tSpecify the directory where to output the traces.\n"
-			"\t-s PATH\t\tSpecify the path to use for the daemon socket.\n");
+			"\t-s PATH\t\tSpecify the path to use for the daemon socket.\n"
+			"\t-d\t\tStart as a daemon.\n"
+			"\t--pidfile FILE\tWrite the PID in this file (when using -d).\n");
 }
 
 int parse_args(int argc, char **argv)
@@ -492,12 +487,13 @@ int parse_args(int argc, char **argv)
 	while (1) {
 		int option_index = 0;
 		static struct option long_options[] = {
+			{"pidfile", 1, 0, 'p'},
 			{"help", 0, 0, 'h'},
 			{"version", 0, 0, 'V'},
 			{0, 0, 0, 0}
 		};
 
-		c = getopt_long(argc, argv, "hs:o:", long_options, &option_index);
+		c = getopt_long(argc, argv, "hs:o:d", long_options, &option_index);
 		if (c == -1)
 			break;
 
@@ -518,6 +514,12 @@ int parse_args(int argc, char **argv)
 				return -1;
 			}
 			break;
+		case 'd':
+			daemon_mode = 1;
+			break;
+		case 'p':
+			pidfile = strdup(optarg);
+			break;
 		case 'h':
 			usage();
 			exit(0);
@@ -540,7 +542,7 @@ void sigterm_handler(int sig)
 	terminate_req = 1;
 }
 
-int main(int argc, char **argv)
+int start_ustd(int fd)
 {
 	struct ustcomm_ustd ustd;
 	int result;
@@ -561,11 +563,6 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	result = parse_args(argc, argv);
-	if(result == -1) {
-		exit(1);
-	}
-
 	result = ustcomm_init_ustd(&ustd, sock_path);
 	if(result == -1) {
 		ERR("failed to initialize socket");
@@ -589,6 +586,24 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	/* Notify parent that we are successfully started. */
+	if(fd != -1) {
+		/* write any one character */
+		result = write(fd, "!", 1);
+		if(result == -1) {
+			PERROR("write");
+			return -1;
+		}
+		if(result != 1) {
+			ERR("Problem sending confirmation of daemon start to parent");
+			return -1;
+		}
+		result = close(fd);
+		if(result == -1) {
+			PERROR("close");
+		}
+	}
+
 	/* app loop */
 	for(;;) {
 		char *recvbuf;
@@ -597,7 +612,7 @@ int main(int argc, char **argv)
 		result = ustcomm_ustd_recv_message(&ustd, &recvbuf, NULL, 100);
 		if(result == -1) {
 			ERR("error in ustcomm_ustd_recv_message");
-			continue;
+			goto loop_end;
 		}
 		if(result > 0) {
 			if(!strncmp(recvbuf, "collect", 7)) {
@@ -607,19 +622,25 @@ int main(int argc, char **argv)
 
 				result = sscanf(recvbuf, "%*s %d %50as", &pid, &bufname);
 				if(result != 2) {
-					fprintf(stderr, "parsing error: %s\n", recvbuf);
+					ERR("parsing error: %s", recvbuf);
+					goto free_bufname;
 				}
 
-				result = add_buffer(pid, bufname);
+				result = start_consuming_buffer(pid, bufname);
 				if(result < 0) {
 					ERR("error in add_buffer");
-					continue;
+					goto free_bufname;
 				}
+
+				free_bufname:
+				free(bufname);
 			}
 
 			free(recvbuf);
 		}
 
+		loop_end:
+
 		if(terminate_req) {
 			pthread_mutex_lock(&active_buffers_mutex);
 			if(active_buffers == 0) {
@@ -632,3 +653,86 @@ int main(int argc, char **argv)
 
 	return 0;
 }
+
+int start_ustd_daemon()
+{
+	int result;
+	int fd[2];
+	pid_t child_pid;
+
+	result = pipe(fd);
+
+	result = child_pid = fork();
+	if(result == -1) {
+		PERROR("fork");
+		return -1;
+	}
+	else if(result == 0) {
+		return start_ustd(fd[1]);
+	}
+	else {
+		char buf;
+		FILE *pidfp;
+
+		/* It's important to write the file *before*
+		 * the parent ends, because the file may be
+		 * read as soon as the parent ends.
+		 */
+		if(pidfile) {
+			pidfp = fopen(pidfile, "w+");
+			if(!pidfp) {
+				PERROR("fopen (%s)", pidfile);
+				WARN("killing child process");
+				result = kill(child_pid, SIGTERM);
+				if(result == -1) {
+					PERROR("kill");
+				}
+				return -1;
+			}
+
+			fprintf(pidfp, "%d\n", child_pid);
+			fclose(pidfp);
+		}
+
+		result = read(fd[0], &buf, 1);
+		if(result == -1) {
+			PERROR("read");
+			return -1;
+		}
+		if(result != 1) {
+			ERR("did not receive valid confirmation that the daemon is started");
+			return -1;
+		}
+
+		result = close(fd[0]);
+		if(result == -1) {
+			PERROR("close");
+		}
+
+		DBG("The daemon is now successfully started");
+	}
+
+	/* Wait for confirmation that the server is ready. */
+
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int result;
+
+	result = parse_args(argc, argv);
+	if(result == -1) {
+		exit(1);
+	}
+
+	if(daemon_mode) {
+		result = start_ustd_daemon();
+	}
+	else {
+		result = start_ustd(-1);
+	}
+
+	return result;
+}