* Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
*/
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE
#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>
+
+/* 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;
};
struct channel_trace_fd {
static char *channel_name = NULL;
static int daemon_mode = 0;
static int append_mode = 0;
+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)
{
}
+/* 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;
+
+
+ err = ioctl(pair->channel, RELAYFS_GET_SUBBUF,
+ &consumed_old);
+ printf("cookie : %u\n", consumed_old);
+ if(err != 0) {
+ perror("Error in reserving sub buffer");
+ ret = -EPERM;
+ goto get_error;
+ }
+
+ err = TEMP_FAILURE_RETRY(write(pair->trace,
+ pair->mmap + (consumed_old & (~(pair->subbuf_size-1))),
+ pair->subbuf_size));
+
+ if(err < 0) {
+ perror("Error in writing to file");
+ ret = err;
+ goto write_error;
+ }
+
+
+write_error:
+ err = ioctl(pair->channel, RELAYFS_PUT_SUBBUF, &consumed_old);
+ if(err != 0) {
+ if(errno == -EFAULT) {
+ perror("Error in unreserving sub buffer");
+ ret = -EFAULT;
+ } else if(errno == -EIO) {
+ perror("Reader has been pushed by the writer, last subbuffer corrupted.");
+ ret = -EIO;
+ }
+ goto get_error;
+ }
+
+get_error:
+ return ret;
+}
+
+
/* read_channels
*
* Read the realyfs channels and write them in the paired tracefiles.
int read_channels(struct channel_trace_fd *fd_pairs)
{
struct pollfd *pollfd;
- int i;
- int num_rdy;
+ int i,j;
+ int num_rdy, num_hup;
int high_prio;
+ int ret;
+
+ 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;
+ }
+ }
+
+ /* 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;
+ }
+ }
+
+
+ /* 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:
+ printf("Urgent read on fd %d\n", pollfd[i].fd);
/* Take care of high priority channels first. */
high_prio = 1;
+ ret |= read_subbuffer(&fd_pairs->pair[i]);
break;
}
}
+ /* 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:
/* Take care of low priority channels. */
+ printf("Normal read on fd %d\n", pollfd[i].fd);
+ ret |= read_subbuffer(&fd_pairs->pair[i]);
break;
}
}
}
+free_fd:
free(pollfd);
- return 0;
+ /* munmap only the successfully mmapped indexes */
+ i = fd_pairs->num_pairs;
+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 main(int argc, char ** argv)
{
int ret;
- pid_t pid;
struct channel_trace_fd fd_pairs = { NULL, 0 };
+ struct sigaction act;
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);
+
+ //return 0;
if(ret = open_channel_trace_pairs(channel_name, trace_name, &fd_pairs))
goto close_channel;
projects / ltt-control.git / blobdiff