X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=ltt%2Fbranches%2Fpoly%2Flttd%2Flttd.c;h=27240882189de464882d2f2ab1d64fa674fc8f29;hb=cdad978721add90e7f10411e68795099bf87946e;hp=fc4e4472e09806d4b698e2c613c6dec8022b1fa2;hpb=90ccaa9add7209dac24ed9b407a04fd9304f5762;p=ltt-control.git

diff --git a/ltt/branches/poly/lttd/lttd.c b/ltt/branches/poly/lttd/lttd.c
index fc4e447..2724088 100644
--- a/ltt/branches/poly/lttd/lttd.c
+++ b/ltt/branches/poly/lttd/lttd.c
@@ -10,16 +10,41 @@
  * 	Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
  */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _REENTRANT
+#define _GNU_SOURCE
+#include <features.h>
 #include <stdio.h>
+#include <unistd.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <unistd.h>
 #include <stdlib.h>
 #include <dirent.h>
 #include <string.h>
 #include <fcntl.h>
 #include <sys/poll.h>
+#include <sys/mman.h>
+#include <signal.h>
+#include <pthread.h>
+
+/* Relayfs IOCTL */
+#include <asm/ioctl.h>
+#include <asm/types.h>
+
+/* Get the next sub buffer that can be read. */
+#define RELAYFS_GET_SUBBUF        _IOR(0xF4, 0x00,__u32)
+/* Release the oldest reserved (by "get") sub buffer. */
+#define RELAYFS_PUT_SUBBUF        _IOW(0xF4, 0x01,__u32)
+/* returns the number of sub buffers in the per cpu channel. */
+#define RELAYFS_GET_N_SUBBUFS     _IOR(0xF4, 0x02,__u32)
+/* returns the size of the sub buffers. */
+#define RELAYFS_GET_SUBBUF_SIZE   _IOR(0xF4, 0x03,__u32)
+
+
 
 enum {
 	GET_SUBBUF,
@@ -31,6 +56,10 @@ enum {
 struct fd_pair {
 	int channel;
 	int trace;
+	unsigned int n_subbufs;
+	unsigned int subbuf_size;
+	void *mmap;
+	pthread_mutex_t	mutex;
 };
 
 struct channel_trace_fd {
@@ -42,6 +71,8 @@ static char *trace_name = NULL;
 static char *channel_name = NULL;
 static int	daemon_mode = 0;
 static int	append_mode = 0;
+static unsigned long num_threads = 1;
+volatile static int	quit_program = 0;	/* For signal handler */
 
 /* Args :
  *
@@ -49,6 +80,7 @@ static int	append_mode = 0;
  * -c directory		Root directory of the relayfs trace channels.
  * -d          		Run in background (daemon).
  * -a							Trace append mode.
+ * -s							Send SIGUSR1 to parent when ready for IO.
  */
 void show_arguments(void)
 {
@@ -59,6 +91,7 @@ void show_arguments(void)
 	printf("-c directory  Root directory of the relayfs trace channels.\n");
 	printf("-d            Run in background (daemon).\n");
 	printf("-a            Append to an possibly existing trace.\n");
+	printf("-N            Number of threads to start.\n");
 	printf("\n");
 }
 
@@ -104,6 +137,12 @@ int parse_arguments(int argc, char **argv)
 					case 'a':
 						append_mode = 1;
 						break;
+					case 'N':
+						if(argn+1 < argc) {
+							num_threads = strtoul(argv[argn+1], NULL, 0);
+							argn++;
+						}
+						break;
 					default:
 						printf("Invalid argument '%s'.\n", argv[argn]);
 						printf("\n");
@@ -143,6 +182,16 @@ void show_info(void)
 }
 
 
+/* signal handling */
+
+static void handler(int signo)
+{
+	printf("Signal %d received : exiting cleanly\n", signo);
+	quit_program = 1;
+}
+
+
+
 int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name,
 		struct channel_trace_fd *fd_pairs)
 {
@@ -156,22 +205,21 @@ int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name,
 	char path_trace[PATH_MAX];
 	int path_trace_len;
 	char *path_trace_ptr;
+  int open_ret = 0;
 
 	if(channel_dir == NULL) {
 		perror(subchannel_name);
-		return ENOENT;
+		open_ret = ENOENT;
+    goto end;
 	}
 
-	//FIXME : check if the directory already exist, and ask the user if he wants
-	//to append to the traces.
 	printf("Creating trace subdirectory %s\n", subtrace_name);
 	ret = mkdir(subtrace_name, S_IRWXU|S_IRWXG|S_IRWXO);
 	if(ret == -1) {
-		if(errno == EEXIST && append_mode) {
-			printf("Appending to directory %s as resquested\n", subtrace_name);
-		} else {
+		if(errno != EEXIST) {
 			perror(subtrace_name);
-			return -1;
+      open_ret = -1;
+			goto end;
 		}
 	}
 
@@ -218,12 +266,14 @@ int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name,
 				open(path_channel, O_RDONLY | O_NONBLOCK);
 			if(fd_pairs->pair[fd_pairs->num_pairs-1].channel == -1) {
 				perror(path_channel);
+				fd_pairs->num_pairs--;
+				continue;
 			}
 			/* Open the trace in write mode, only append if append_mode */
 			ret = stat(path_trace, &stat_buf);
 			if(ret == 0) {
 				if(append_mode) {
-					printf("Appending to file %s as resquested\n", path_trace);
+					printf("Appending to file %s as requested\n", path_trace);
 
 					fd_pairs->pair[fd_pairs->num_pairs-1].trace = 
 						open(path_trace, O_WRONLY|O_APPEND,
@@ -234,7 +284,8 @@ int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name,
 					}
 				} else {
 					printf("File %s exists, cannot open. Try append mode.\n", path_trace);
-					return -1;
+					open_ret = -1;
+          goto end;
 				}
 			} else {
 				if(errno == ENOENT) {
@@ -249,18 +300,164 @@ int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name,
 		}
 	}
 	
+end:
 	closedir(channel_dir);
 
-	return 0;
+	return open_ret;
+}
+
+
+int read_subbuffer(struct fd_pair *pair)
+{
+	unsigned int	consumed_old;
+	int err, ret=0;
+
+
+	err = ioctl(pair->channel, RELAYFS_GET_SUBBUF, 
+								&consumed_old);
+	printf("cookie : %u\n", consumed_old);
+	if(err != 0) {
+		ret = errno;
+		perror("Reserving sub buffer failed (everything is normal)");
+		goto get_error;
+	}
+	
+	err = TEMP_FAILURE_RETRY(write(pair->trace,
+				pair->mmap 
+					+ (consumed_old & ((pair->n_subbufs * pair->subbuf_size)-1)),
+				pair->subbuf_size));
+
+	if(err < 0) {
+		ret = errno;
+		perror("Error in writing to file");
+		goto write_error;
+	}
+
+
+write_error:
+	err = ioctl(pair->channel, RELAYFS_PUT_SUBBUF, &consumed_old);
+	if(err != 0) {
+		ret = errno;
+		if(errno == -EFAULT) {
+			perror("Error in unreserving sub buffer\n");
+		} else if(errno == -EIO) {
+			perror("Reader has been pushed by the writer, last subbuffer corrupted.");
+			/* FIXME : we may delete the last written buffer if we wish. */
+		}
+		goto get_error;
+	}
+
+get_error:
+	return ret;
+}
+
+
+
+int map_channels(struct channel_trace_fd *fd_pairs)
+{
+	int i,j;
+	int ret=0;
+
+	if(fd_pairs->num_pairs <= 0) {
+		printf("No channel to read\n");
+		goto end;
+	}
+	
+	/* Get the subbuf sizes and number */
+
+	for(i=0;i<fd_pairs->num_pairs;i++) {
+		struct fd_pair *pair = &fd_pairs->pair[i];
+
+		ret = ioctl(pair->channel, RELAYFS_GET_N_SUBBUFS, 
+							&pair->n_subbufs);
+		if(ret != 0) {
+			perror("Error in getting the number of subbuffers");
+			goto end;
+		}
+		ret = ioctl(pair->channel, RELAYFS_GET_SUBBUF_SIZE, 
+							&pair->subbuf_size);
+		if(ret != 0) {
+			perror("Error in getting the size of the subbuffers");
+			goto end;
+		}
+		ret = pthread_mutex_init(&pair->mutex, NULL);	/* Fast mutex */
+		if(ret != 0) {
+			perror("Error in mutex init");
+			goto end;
+		}
+	}
+
+	/* Mmap each FD */
+	for(i=0;i<fd_pairs->num_pairs;i++) {
+		struct fd_pair *pair = &fd_pairs->pair[i];
+
+		pair->mmap = mmap(0, pair->subbuf_size * pair->n_subbufs, PROT_READ,
+				MAP_SHARED, pair->channel, 0);
+		if(pair->mmap == MAP_FAILED) {
+			perror("Mmap error");
+			goto munmap;
+		}
+	}
+
+	goto end; /* success */
+
+	/* Error handling */
+	/* munmap only the successfully mmapped indexes */
+munmap:
+		/* Munmap each FD */
+	for(j=0;j<i;j++) {
+		struct fd_pair *pair = &fd_pairs->pair[j];
+		int err_ret;
+
+		err_ret = munmap(pair->mmap, pair->subbuf_size * pair->n_subbufs);
+		if(err_ret != 0) {
+			perror("Error in munmap");
+		}
+		ret |= err_ret;
+	}
+
+end:
+	return ret;
+
+
+}
+
+
+int unmap_channels(struct channel_trace_fd *fd_pairs)
+{
+	int j;
+	int ret=0;
+
+	/* Munmap each FD */
+	for(j=0;j<fd_pairs->num_pairs;j++) {
+		struct fd_pair *pair = &fd_pairs->pair[j];
+		int err_ret;
+
+		err_ret = munmap(pair->mmap, pair->subbuf_size * pair->n_subbufs);
+		if(err_ret != 0) {
+			perror("Error in munmap");
+		}
+		ret |= err_ret;
+		err_ret = pthread_mutex_destroy(&pair->mutex);
+		if(err_ret != 0) {
+			perror("Error in mutex destroy");
+		}
+		ret |= err_ret;
+	}
+
+	return ret;
 }
 
+
 /* read_channels
  *
- * Read the realyfs channels and write them in the paired tracefiles.
+ * Thread worker.
+ *
+ * Read the relayfs channels and write them in the paired tracefiles.
  *
  * @fd_pairs : paired channels and trace files.
  *
- * returns 0 on success, -1 on error.
+ * returns (void*)0 on success, (void*)-1 on error.
  *
  * Note that the high priority polled channels are consumed first. We then poll
  * again to see if these channels are still in priority. Only when no
@@ -270,25 +467,42 @@ int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name,
  * full.
  */
 
-int read_channels(struct channel_trace_fd *fd_pairs)
+void * read_channels(void *arg)
 {
 	struct pollfd *pollfd;
-	int i;
-	int num_rdy;
+	int i,j;
+	int num_rdy, num_hup;
+	int high_prio;
+	int ret = 0;
+	struct channel_trace_fd *fd_pairs = (struct channel_trace_fd *)arg;
 
+	/* Start polling the FD */
+	
 	pollfd = malloc(fd_pairs->num_pairs * sizeof(struct pollfd));
 
+	/* Note : index in pollfd is the same index as fd_pair->pair */
 	for(i=0;i<fd_pairs->num_pairs;i++) {
 		pollfd[i].fd = fd_pairs->pair[i].channel;
 		pollfd[i].events = POLLIN|POLLPRI;
 	}
 
 	while(1) {
+		high_prio = 0;
+		num_hup = 0; 
+#ifdef DEBUG
+		printf("Press a key for next poll...\n");
+		char buf[1];
+		read(STDIN_FILENO, &buf, 1);
+		printf("Next poll (polling %d fd) :\n", fd_pairs->num_pairs);
+#endif //DEBUG
+		
+		/* Have we received a signal ? */
+		if(quit_program) break;
 		
 		num_rdy = poll(pollfd, fd_pairs->num_pairs, -1);
 		if(num_rdy == -1) {
 			perror("Poll error");
-			return -1;
+			goto free_fd;
 		}
 
 		printf("Data received\n");
@@ -297,32 +511,62 @@ int read_channels(struct channel_trace_fd *fd_pairs)
 			switch(pollfd[i].revents) {
 				case POLLERR:
 					printf("Error returned in polling fd %d.\n", pollfd[i].fd);
+					num_hup++;
 					break;
 				case POLLHUP:
 					printf("Polling fd %d tells it has hung up.\n", pollfd[i].fd);
+					num_hup++;
 					break;
 				case POLLNVAL:
 					printf("Polling fd %d tells fd is not open.\n", pollfd[i].fd);
+					num_hup++;
 					break;
 				case POLLPRI:
-					/* Take care of high priority channels first. */
+					if(pthread_mutex_trylock(&fd_pairs->pair[i].mutex) == 0) {
+						printf("Urgent read on fd %d\n", pollfd[i].fd);
+						/* Take care of high priority channels first. */
+						high_prio = 1;
+						/* it's ok to have an unavailable subbuffer */
+						ret = read_subbuffer(&fd_pairs->pair[i]);
+						if(ret == -EAGAIN) ret = 0;
+
+						ret = pthread_mutex_unlock(&fd_pairs->pair[i].mutex);
+						if(ret)
+							printf("Error in mutex unlock : %s\n", strerror(ret));
+					}
 					break;
-				default:
+			}
 		}
-
-		for(i=0;i<fd_pairs->num_pairs;i++) {
-			switch(pollfd[i].revents) {
-				case POLLIN:
-					/* Take care of low priority channels. */
-					break;
-				default:
+		/* If every FD has hung up, we end the read loop here */
+		if(num_hup == fd_pairs->num_pairs) break;
+
+		if(!high_prio) {
+			for(i=0;i<fd_pairs->num_pairs;i++) {
+				switch(pollfd[i].revents) {
+					case POLLIN:
+						if(pthread_mutex_trylock(&fd_pairs->pair[i].mutex) == 0) {
+							/* Take care of low priority channels. */
+							printf("Normal read on fd %d\n", pollfd[i].fd);
+							/* it's ok to have an unavailable subbuffer */
+							ret = read_subbuffer(&fd_pairs->pair[i]);
+							if(ret == -EAGAIN) ret = 0;
+
+							ret = pthread_mutex_unlock(&fd_pairs->pair[i].mutex);
+							if(ret)
+								printf("Error in mutex unlock : %s\n", strerror(ret));
+						}
+						break;
+				}
+			}
 		}
 
 	}
 
+free_fd:
 	free(pollfd);
 
-	return 0;
+end:
+	return (void*)ret;
 }
 
 
@@ -342,9 +586,12 @@ void close_channel_trace_pairs(struct channel_trace_fd *fd_pairs)
 
 int main(int argc, char ** argv)
 {
-	int ret;
-	pid_t pid;
+	int ret = 0;
 	struct channel_trace_fd fd_pairs = { NULL, 0 };
+	struct sigaction act;
+	pthread_t *tids;
+	unsigned int i;
+	void *tret;
 	
 	ret = parse_arguments(argc, argv);
 
@@ -355,23 +602,55 @@ int main(int argc, char ** argv)
 	show_info();
 
 	if(daemon_mode) {
-		pid = fork();
-		
-		if(pid > 0) {
-			/* parent */
-			return 0;
-		} else if(pid < 0) {
-			/* error */
-			printf("An error occured while forking.\n");
-			return -1;
-		}
-		/* else, we are the child, continue... */
-	}
+		ret = daemon(0, 0);
+    
+    if(ret == -1) {
+      perror("An error occured while daemonizing.");
+      exit(-1);
+    }
+  }
+
+	/* Connect the signal handlers */
+	act.sa_handler = handler;
+	act.sa_flags = 0;
+	sigemptyset(&(act.sa_mask));
+	sigaddset(&(act.sa_mask), SIGTERM);
+	sigaddset(&(act.sa_mask), SIGQUIT);
+	sigaddset(&(act.sa_mask), SIGINT);
+	sigaction(SIGTERM, &act, NULL);
+	sigaction(SIGQUIT, &act, NULL);
+	sigaction(SIGINT, &act, NULL);
+
 
 	if(ret = open_channel_trace_pairs(channel_name, trace_name, &fd_pairs))
 		goto close_channel;
 
-	ret = read_channels(&fd_pairs);
+	if(ret = map_channels(&fd_pairs))
+		goto close_channel;
+	
+	tids = malloc(sizeof(pthread_t) * num_threads);
+	for(i=0; i<num_threads; i++) {
+		ret = pthread_create(&tids[i], NULL, read_channels, &fd_pairs);
+		if(ret) {
+			perror("Error creating thread");
+			break;
+		}
+	}
+
+	for(i=0; i<num_threads; i++) {
+		ret = pthread_join(tids[i], &tret);
+		if(ret) {
+			perror("Error joining thread");
+			break;
+		}
+		if((int)tret != 0) {
+			printf("Error %s occured in thread %u\n", strerror(-(int)tret), i);
+		}
+	}
+
+	free(tids);
+			
+	ret |= unmap_channels(&fd_pairs);
 
 close_channel:
 	close_channel_trace_pairs(&fd_pairs);