X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=ustd%2Fustd.c;h=b6b362f4fcc3a44eb5c0cba3e84e6eeb49efaa60;hb=ab805ccdcd0269b28d7288be5e69e9042afbb61c;hp=8205ed2b2b5e3c77cc6fa9ecae56e2c2ef7ed0ae;hpb=3a7b90de71f2a82f73f06fb14a7b77805aea1064;p=ust.git

diff --git a/ustd/ustd.c b/ustd/ustd.c
index 8205ed2..b6b362f 100644
--- a/ustd/ustd.c
+++ b/ustd/ustd.c
@@ -1,73 +1,139 @@
+/* Copyright (C) 2009  Pierre-Marc Fournier
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
 #define _GNU_SOURCE
 
 #include <sys/types.h>
+#include <sys/stat.h>
 #include <sys/shm.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <signal.h>
 
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <getopt.h>
 
+#include "ustd.h"
 #include "localerr.h"
 #include "ustcomm.h"
 
-struct list_head buffers = LIST_HEAD_INIT(buffers);
+/* return value: 0 = subbuffer is finished, it won't produce data anymore
+ *               1 = got subbuffer successfully
+ *               <0 = error
+ */
 
-struct buffer_info {
-	char *name;
-	pid_t pid;
+#define GET_SUBBUF_OK 1
+#define GET_SUBBUF_DONE 0
+#define GET_SUBBUF_DIED 2
 
-	int shmid;
-	void *mem;
-	int memlen;
+#define PUT_SUBBUF_OK 1
+#define PUT_SUBBUF_DIED 0
+#define PUT_SUBBUF_PUSHED 2
 
-	int n_subbufs;
-	int subbuf_size;
+char *sock_path=NULL;
+char *trace_path=NULL;
 
-	int file_fd; /* output file */
+/* Number of active buffers and the mutex to protect it. */
+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;
 
-	struct list_head list;
+int test_sigpipe(void)
+{
+	sigset_t sigset;
+	int result;
 
-	long consumed_old;
-};
+	result = sigemptyset(&sigset);
+	if(result == -1) {
+		PERROR("sigemptyset");
+		return -1;
+	}
+	result = sigaddset(&sigset, SIGPIPE);
+	if(result == -1) {
+		PERROR("sigaddset");
+		return -1;
+	}
 
-/* return value: 0 = subbuffer is finished, it won't produce data anymore
- *               1 = got subbuffer successfully
- *               <0 = error
- */
+	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;
-	char *received_msg;
-	char *rep_code;
+	char *send_msg=NULL;
+	char *received_msg=NULL;
+	char *rep_code=NULL;
 	int retval;
 	int result;
 
 	asprintf(&send_msg, "get_subbuffer %s", buf->name);
-	result = send_message(buf->pid, send_msg, &received_msg);
-	if(result < 0) {
-		ERR("get_subbuffer: send_message failed");
-		return -1;
+	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;
+		goto end;
+	}
+	else if(result < 0) {
+		ERR("get_subbuffer: ustcomm_send_request failed");
+		retval = -1;
+		goto end;
+	}
+	else if(result == 0) {
+		DBG("app died while being traced");
+		retval = GET_SUBBUF_DIED;
+		goto end;
 	}
-	free(send_msg);
 
 	result = sscanf(received_msg, "%as %ld", &rep_code, &buf->consumed_old);
 	if(result != 2 && result != 1) {
 		ERR("unable to parse response to get_subbuffer");
-		return -1;
+		retval = -1;
+		goto end_rep;
 	}
 
 	DBG("received msg is %s", received_msg);
 
 	if(!strcmp(rep_code, "OK")) {
 		DBG("got subbuffer %s", buf->name);
-		retval = 1;
+		retval = GET_SUBBUF_OK;
 	}
 	else if(nth_token_is(received_msg, "END", 0) == 1) {
-		return 0;
+		retval = GET_SUBBUF_DONE;
+		goto end_rep;
 	}
 	else {
 		DBG("error getting subbuffer %s", buf->name);
@@ -75,46 +141,71 @@ int get_subbuffer(struct buffer_info *buf)
 	}
 
 	/* FIMXE: free correctly the stuff */
-	free(received_msg);
-	free(rep_code);
+end_rep:
+	if(rep_code)
+		free(rep_code);
+end:
+	if(send_msg)
+		free(send_msg);
+	if(received_msg)
+		free(received_msg);
+
 	return retval;
 }
 
 int put_subbuffer(struct buffer_info *buf)
 {
-	char *send_msg;
-	char *received_msg;
-	char *rep_code;
+	char *send_msg=NULL;
+	char *received_msg=NULL;
+	char *rep_code=NULL;
 	int retval;
 	int result;
 
 	asprintf(&send_msg, "put_subbuffer %s %ld", buf->name, buf->consumed_old);
-	result = send_message(buf->pid, send_msg, &received_msg);
+	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
+	if(result < 0 && errno == ECONNRESET) {
+		retval = PUT_SUBBUF_DIED;
+		goto end;
+	}
 	if(result < 0) {
 		ERR("put_subbuffer: send_message failed");
-		return -1;
+		retval = -1;
+		goto end;
 	}
-	free(send_msg);
 
 	result = sscanf(received_msg, "%as", &rep_code);
 	if(result != 1) {
 		ERR("unable to parse response to put_subbuffer");
-		return -1;
+		retval = -1;
+		goto end_rep;
 	}
-	free(received_msg);
 
 	if(!strcmp(rep_code, "OK")) {
 		DBG("subbuffer put %s", buf->name);
-		retval = 1;
+		retval = PUT_SUBBUF_OK;
 	}
 	else {
-		ERR("invalid response to put_subbuffer");
+		DBG("put_subbuffer: received error, we were pushed");
+		retval = PUT_SUBBUF_PUSHED;
+		goto end_rep;
 	}
 
-	free(rep_code);
+end_rep:
+	if(rep_code)
+		free(rep_code);
+
+end:
+	if(send_msg)
+		free(send_msg);
+	if(received_msg)
+		free(received_msg);
+
 	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;
@@ -136,21 +227,35 @@ ssize_t patient_write(int fd, const void *buf, size_t count)
 	return bufc-(const char *)buf;
 }
 
+void decrement_active_buffers(void *arg)
+{
+	pthread_mutex_lock(&active_buffers_mutex);
+	active_buffers--;
+	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;
 		}
-		if(result == 0) {
+		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);
@@ -159,18 +264,66 @@ void *consumer_thread(void *arg)
 			/* FIXME: maybe drop this trace */
 		}
 
+		/* put the subbuffer */
 		result = put_subbuffer(buf);
 		if(result == -1) {
-			ERR("error putting subbuffer");
+			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);
+		}
+		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;
+	result = mkdir(dir, 0777);
+	if(result == -1) {
+		if(errno != EEXIST) {
+			PERROR("mkdir");
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int is_directory(const char *dir)
+{
+	int result;
+	struct stat st;
+
+	result = stat(dir, &st);
+	if(result == -1) {
+		PERROR("stat");
+		return 0;
+	}
+
+	if(!S_ISDIR(st.st_mode)) {
+		return 0;
+	}
+
+	return 1;
+}
+
 int add_buffer(pid_t pid, char *bufname)
 {
 	struct buffer_info *buf;
@@ -180,6 +333,7 @@ int add_buffer(pid_t pid, char *bufname)
 	char *tmp;
 	int fd;
 	pthread_t thr;
+	struct shmid_ds shmds;
 
 	buf = (struct buffer_info *) malloc(sizeof(struct buffer_info));
 	if(buf == NULL) {
@@ -190,24 +344,55 @@ int add_buffer(pid_t pid, char *bufname)
 	buf->name = bufname;
 	buf->pid = pid;
 
+	/* connect to app */
+	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;
+	}
+
+	/* get pidunique */
+	asprintf(&send_msg, "get_pidunique");
+	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
+	free(send_msg);
+	if(result == -1) {
+		ERR("problem in ustcomm_send_request(get_pidunique)");
+		return -1;
+	}
+
+	result = sscanf(received_msg, "%lld", &buf->pidunique);
+	if(result != 1) {
+		ERR("unable to parse response to get_pidunique");
+		return -1;
+	}
+	free(received_msg);
+	DBG("got pidunique %lld", buf->pidunique);
+
 	/* get shmid */
 	asprintf(&send_msg, "get_shmid %s", buf->name);
-	send_message(pid, send_msg, &received_msg);
+	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 	free(send_msg);
-	DBG("got buffer name %s", buf->name);
+	if(result == -1) {
+		ERR("problem in ustcomm_send_request(get_shmid)");
+		return -1;
+	}
 
-	result = sscanf(received_msg, "%d", &buf->shmid);
-	if(result != 1) {
+	result = sscanf(received_msg, "%d %d", &buf->shmid, &buf->bufstruct_shmid);
+	if(result != 2) {
 		ERR("unable to parse response to get_shmid");
 		return -1;
 	}
 	free(received_msg);
-	DBG("got shmid %d", buf->shmid);
+	DBG("got shmids %d %d", buf->shmid, buf->bufstruct_shmid);
 
 	/* get n_subbufs */
 	asprintf(&send_msg, "get_n_subbufs %s", buf->name);
-	send_message(pid, 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(g_n_subbufs)");
+		return -1;
+	}
 
 	result = sscanf(received_msg, "%d", &buf->n_subbufs);
 	if(result != 1) {
@@ -219,7 +404,7 @@ int add_buffer(pid_t pid, char *bufname)
 
 	/* get subbuf size */
 	asprintf(&send_msg, "get_subbuf_size %s", buf->name);
-	send_message(pid, send_msg, &received_msg);
+	ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 	free(send_msg);
 
 	result = sscanf(received_msg, "%d", &buf->subbuf_size);
@@ -233,39 +418,181 @@ int add_buffer(pid_t pid, char *bufname)
 	/* attach memory */
 	buf->mem = shmat(buf->shmid, NULL, 0);
 	if(buf->mem == (void *) 0) {
-		perror("shmat");
+		PERROR("shmat");
+		return -1;
+	}
+	DBG("successfully attached buffer memory");
+
+	buf->bufstruct_mem = shmat(buf->bufstruct_shmid, NULL, 0);
+	if(buf->bufstruct_mem == (void *) 0) {
+		PERROR("shmat");
 		return -1;
 	}
-	DBG("successfully attached memory");
+	DBG("successfully attached buffer bufstruct memory");
+
+	/* obtain info on the memory segment */
+	result = shmctl(buf->shmid, IPC_STAT, &shmds);
+	if(result == -1) {
+		PERROR("shmctl");
+		return -1;
+	}
+	buf->memlen = shmds.shm_segsz;
 
 	/* open file for output */
-	asprintf(&tmp, "/tmp/trace/%s_0", buf->name);
-	result = fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC, 00600);
+	if(!trace_path) {
+		/* Only create the directory if using the default path, because
+		 * of the risk of typo when using trace path override. We don't
+		 * want to risk creating plenty of useless directories in that case.
+		 */
+		result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
+		if(result == -1) {
+			ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
+			return -1;
+		}
+
+		trace_path = USTD_DEFAULT_TRACE_PATH;
+	}
+
+	asprintf(&tmp, "%s/%u_%lld", trace_path, buf->pid, buf->pidunique);
+	result = create_dir_if_needed(tmp);
+	if(result == -1) {
+		ERR("could not create directory %s", tmp);
+		free(tmp);
+		return -1;
+	}
+	free(tmp);
+
+	asprintf(&tmp, "%s/%u_%lld/%s_0", trace_path, buf->pid, buf->pidunique, buf->name);
+	result = fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 00600);
 	if(result == -1) {
 		PERROR("open");
+		ERR("failed opening trace file %s", tmp);
 		return -1;
 	}
 	buf->file_fd = fd;
 	free(tmp);
 
-	//list_add(&buf->list, &buffers);
+	pthread_mutex_lock(&active_buffers_mutex);
+	active_buffers++;
+	pthread_mutex_unlock(&active_buffers_mutex);
 
 	pthread_create(&thr, NULL, consumer_thread, buf);
 
 	return 0;
 }
 
+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");
+}
+
+int parse_args(int argc, char **argv)
+{
+	int c;
+
+	while (1) {
+		int option_index = 0;
+		static struct option long_options[] = {
+			{"help", 0, 0, 'h'},
+			{"version", 0, 0, 'V'},
+			{0, 0, 0, 0}
+		};
+
+		c = getopt_long(argc, argv, "hs:o:", long_options, &option_index);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 0:
+			printf("option %s", long_options[option_index].name);
+			if (optarg)
+				printf(" with arg %s", optarg);
+			printf("\n");
+			break;
+		case 's':
+			sock_path = optarg;
+			break;
+		case 'o':
+			trace_path = optarg;
+			if(!is_directory(trace_path)) {
+				ERR("Not a valid directory. (%s)", trace_path);
+				return -1;
+			}
+			break;
+		case 'h':
+			usage();
+			exit(0);
+		case 'V':
+			printf("Version 0.0\n");
+			break;
+
+		default:
+			/* unknown option or other error; error is
+			printed by getopt, just return */
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+void sigterm_handler(int sig)
+{
+	terminate_req = 1;
+}
+
 int main(int argc, char **argv)
 {
 	struct ustcomm_ustd ustd;
 	int result;
+	sigset_t sigset;
+	struct sigaction sa;
 
-	result = ustcomm_init_ustd(&ustd);
+	result = sigemptyset(&sigset);
+	if(result == -1) {
+		PERROR("sigemptyset");
+		return 1;
+	}
+	sa.sa_handler = sigterm_handler;
+	sa.sa_mask = sigset;
+	sa.sa_flags = SA_RESTART;
+	result = sigaction(SIGTERM, &sa, NULL);
+	if(result == -1) {
+		PERROR("sigaction");
+		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");
 		return 1;
 	}
 
+	/* setup handler for SIGPIPE */
+	result = sigemptyset(&sigset);
+	if(result == -1) {
+		PERROR("sigemptyset");
+		return 1;
+	}
+	result = sigaddset(&sigset, SIGPIPE);
+	if(result == -1) {
+		PERROR("sigaddset");
+		return 1;
+	}
+	result = sigprocmask(SIG_BLOCK, &sigset, NULL);
+	if(result == -1) {
+		PERROR("sigprocmask");
+		return 1;
+	}
+
 	/* app loop */
 	for(;;) {
 		char *recvbuf;
@@ -296,6 +623,15 @@ int main(int argc, char **argv)
 
 			free(recvbuf);
 		}
+
+		if(terminate_req) {
+			pthread_mutex_lock(&active_buffers_mutex);
+			if(active_buffers == 0) {
+				pthread_mutex_unlock(&active_buffers_mutex);
+				break;
+			}
+			pthread_mutex_unlock(&active_buffers_mutex);
+		}
 	}
 
 	return 0;