* 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,
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 {
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 :
*
* -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)
{
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");
}
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");
}
+/* 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)
{
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;
}
}
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,
}
} else {
printf("File %s exists, cannot open. Try append mode.\n", path_trace);
- return -1;
+ open_ret = -1;
+ goto end;
}
} else {
if(errno == ENOENT) {
}
}
+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;
+ }
+#if 0
+ err = fsync(pair->trace);
+ if(err < 0) {
+ ret = errno;
+ perror("Error in writing to file");
+ goto write_error;
+ }
+#endif //0
+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
* 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");
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;
}
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);
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);
projects / ltt-control.git / blobdiff