From: Michael Sills Lavoie Date: Fri, 26 Mar 2010 18:54:03 +0000 (-0400) Subject: Adds the multiple instances feature X-Git-Tag: 0.81~4 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=d6d516b717dfb30a882178494203bf4ceb4810fe;p=ltt-control.git Adds the multiple instances feature Signed-off-by: Mathieu Desnoyers --- diff --git a/liblttd/liblttd.c b/liblttd/liblttd.c index 0f0e5b5..0f703f5 100644 --- a/liblttd/liblttd.c +++ b/liblttd/liblttd.c @@ -75,8 +75,6 @@ static inline int inotify_rm_watch (int fd, __u32 wd) #undef HAS_INOTIFY #endif -struct liblttd_callbacks *callbacks; - struct channel_trace_fd { struct fd_pair *pair; int num_pairs; @@ -93,41 +91,50 @@ struct inotify_watch_array { int num; }; -struct channel_trace_fd fd_pairs = { NULL, 0 }; -int inotify_fd = -1; -struct inotify_watch_array inotify_watch_array = { NULL, 0 }; +struct liblttd_instance { + struct liblttd_callbacks *callbacks; + + int inotify_fd; + struct channel_trace_fd fd_pairs; + struct inotify_watch_array inotify_watch_array; -/* protects fd_pairs and inotify_watch_array */ -pthread_rwlock_t fd_pairs_lock = PTHREAD_RWLOCK_INITIALIZER; + /* protects fd_pairs and inotify_watch_array */ + pthread_rwlock_t fd_pairs_lock; -static char *channel_name = NULL; -static unsigned long num_threads = 1; -volatile static int quit_program = 0; /* For signal handler */ -static int dump_flight_only = 0; -static int dump_normal_only = 0; -static int verbose_mode = 0; + char channel_name[PATH_MAX]; + unsigned long num_threads; + int quit_program; /* For signal handler */ + int dump_flight_only; + int dump_normal_only; + int verbose_mode; +}; + +struct liblttd_thread_data { + int thread_num; + struct liblttd_instance *instance; +}; #define printf_verbose(fmt, args...) \ do { \ - if (verbose_mode) \ + if (instance->verbose_mode) \ printf(fmt, ##args); \ } while (0) -int open_buffer_file(char *filename, char *path_channel, - char *base_path_channel, struct channel_trace_fd *fd_pairs) +int open_buffer_file(struct liblttd_instance *instance, char *filename, + char *path_channel, char *base_path_channel) { int open_ret = 0; int ret = 0; if(strncmp(filename, "flight-", sizeof("flight-")-1) != 0) { - if(dump_flight_only) { + if(instance->dump_flight_only) { printf_verbose("Skipping normal channel %s\n", path_channel); return 0; } } else { - if(dump_normal_only) { + if(instance->dump_normal_only) { printf_verbose("Skipping flight channel %s\n", path_channel); return 0; @@ -135,26 +142,26 @@ int open_buffer_file(char *filename, char *path_channel, } printf_verbose("Opening file.\n"); - fd_pairs->pair = realloc(fd_pairs->pair, - ++fd_pairs->num_pairs * sizeof(struct fd_pair)); + instance->fd_pairs.pair = realloc(instance->fd_pairs.pair, + ++instance->fd_pairs.num_pairs * sizeof(struct fd_pair)); /* Open the channel in read mode */ - fd_pairs->pair[fd_pairs->num_pairs-1].channel = + instance->fd_pairs.pair[instance->fd_pairs.num_pairs-1].channel = open(path_channel, O_RDONLY | O_NONBLOCK); - if(fd_pairs->pair[fd_pairs->num_pairs-1].channel == -1) { + if(instance->fd_pairs.pair[instance->fd_pairs.num_pairs-1].channel == -1) { perror(path_channel); - fd_pairs->num_pairs--; + instance->fd_pairs.num_pairs--; return 0; /* continue */ } - if(callbacks->on_open_channel) ret = callbacks->on_open_channel( - callbacks, &fd_pairs->pair[fd_pairs->num_pairs-1], + if(instance->callbacks->on_open_channel) ret = instance->callbacks->on_open_channel( + instance->callbacks, &instance->fd_pairs.pair[instance->fd_pairs.num_pairs-1], base_path_channel); if(ret != 0) { open_ret = -1; - close(fd_pairs->pair[fd_pairs->num_pairs-1].channel); - fd_pairs->num_pairs--; + close(instance->fd_pairs.pair[instance->fd_pairs.num_pairs-1].channel); + instance->fd_pairs.num_pairs--; goto end; } @@ -162,10 +169,8 @@ end: return open_ret; } -int open_channel_trace_pairs(char *subchannel_name, - char *base_subchannel_name, - struct channel_trace_fd *fd_pairs, int *inotify_fd, - struct inotify_watch_array *iwatch_array) +int open_channel_trace_pairs(struct liblttd_instance *instance, + char *subchannel_name, char *base_subchannel_name) { DIR *channel_dir = opendir(subchannel_name); struct dirent *entry; @@ -184,9 +189,9 @@ int open_channel_trace_pairs(char *subchannel_name, goto end; } - printf_verbose("Calling on new channels folder"); - if(callbacks->on_new_channels_folder) ret = callbacks-> - on_new_channels_folder(callbacks, + printf_verbose("Calling on new channels folder\n"); + if(instance->callbacks->on_new_channels_folder) ret = instance->callbacks-> + on_new_channels_folder(instance->callbacks, base_subchannel_name); if(ret == -1) { open_ret = -1; @@ -202,18 +207,18 @@ int open_channel_trace_pairs(char *subchannel_name, (base_subchannel_name - subchannel_name); #ifdef HAS_INOTIFY - iwatch_array->elem = realloc(iwatch_array->elem, - ++iwatch_array->num * sizeof(struct inotify_watch)); + instance->inotify_watch_array.elem = realloc(instance->inotify_watch_array.elem, + ++instance->inotify_watch_array.num * sizeof(struct inotify_watch)); printf_verbose("Adding inotify for channel %s\n", path_channel); - iwatch_array->elem[iwatch_array->num-1].wd = inotify_add_watch(*inotify_fd, path_channel, IN_CREATE); - strcpy(iwatch_array->elem[iwatch_array->num-1].path_channel, path_channel); - iwatch_array->elem[iwatch_array->num-1].base_path_channel = - iwatch_array->elem[iwatch_array->num-1].path_channel + + instance->inotify_watch_array.elem[instance->inotify_watch_array.num-1].wd = inotify_add_watch(instance->inotify_fd, path_channel, IN_CREATE); + strcpy(instance->inotify_watch_array.elem[instance->inotify_watch_array.num-1].path_channel, path_channel); + instance->inotify_watch_array.elem[instance->inotify_watch_array.num-1].base_path_channel = + instance->inotify_watch_array.elem[instance->inotify_watch_array.num-1].path_channel + (base_subchannel_name - subchannel_name); printf_verbose("Added inotify for channel %s, wd %u\n", - iwatch_array->elem[iwatch_array->num-1].path_channel, - iwatch_array->elem[iwatch_array->num-1].wd); + instance->inotify_watch_array.elem[instance->inotify_watch_array.num-1].path_channel, + instance->inotify_watch_array.elem[instance->inotify_watch_array.num-1].wd); #endif while((entry = readdir(channel_dir)) != NULL) { @@ -233,12 +238,11 @@ int open_channel_trace_pairs(char *subchannel_name, if(S_ISDIR(stat_buf.st_mode)) { printf_verbose("Entering channel subdirectory...\n"); - ret = open_channel_trace_pairs(path_channel, base_subchannel_ptr, fd_pairs, - inotify_fd, iwatch_array); + ret = open_channel_trace_pairs(instance, path_channel, base_subchannel_ptr); if(ret < 0) continue; } else if(S_ISREG(stat_buf.st_mode)) { - open_ret = open_buffer_file(entry->d_name, path_channel, base_subchannel_ptr, - fd_pairs); + open_ret = open_buffer_file(instance, entry->d_name, + path_channel, base_subchannel_ptr); if(open_ret) goto end; } @@ -251,7 +255,7 @@ end: } -int read_subbuffer(struct fd_pair *pair) +int read_subbuffer(struct liblttd_instance *instance, struct fd_pair *pair) { unsigned int consumed_old, len; int err; @@ -274,8 +278,8 @@ int read_subbuffer(struct fd_pair *pair) goto get_error; } - if(callbacks->on_read_subbuffer) ret = callbacks->on_read_subbuffer( - callbacks, pair, len); + if(instance->callbacks->on_read_subbuffer) ret = instance->callbacks->on_read_subbuffer( + instance->callbacks, pair, len); write_error: ret = 0; @@ -296,13 +300,12 @@ get_error: } -int map_channels(struct channel_trace_fd *fd_pairs, - int idx_begin, int idx_end) +int map_channels(struct liblttd_instance *instance, int idx_begin, int idx_end) { int i,j; int ret=0; - if(fd_pairs->num_pairs <= 0) { + if(instance->fd_pairs.num_pairs <= 0) { printf("No channel to read\n"); goto end; } @@ -310,7 +313,7 @@ int map_channels(struct channel_trace_fd *fd_pairs, /* Get the subbuf sizes and number */ for(i=idx_begin;ipair[i]; + struct fd_pair *pair = &instance->fd_pairs.pair[i]; ret = ioctl(pair->channel, RELAY_GET_N_SB, &pair->n_sb); if(ret != 0) { @@ -334,14 +337,14 @@ end: return ret; } -int unmap_channels(struct channel_trace_fd *fd_pairs) +int unmap_channels(struct liblttd_instance *instance) { int j; int ret=0; /* Munmap each FD */ - for(j=0;jnum_pairs;j++) { - struct fd_pair *pair = &fd_pairs->pair[j]; + for(j=0;jfd_pairs.num_pairs;j++) { + struct fd_pair *pair = &instance->fd_pairs.pair[j]; int err_ret; err_ret = pthread_mutex_destroy(&pair->mutex); @@ -359,10 +362,7 @@ int unmap_channels(struct channel_trace_fd *fd_pairs) * * Only support add file for now. */ - -int read_inotify(int inotify_fd, - struct channel_trace_fd *fd_pairs, - struct inotify_watch_array *iwatch_array) +int read_inotify(struct liblttd_instance *instance) { char buf[sizeof(struct inotify_event) + PATH_MAX]; char path_channel[PATH_MAX]; @@ -374,7 +374,7 @@ int read_inotify(int inotify_fd, int old_num; offset = 0; - len = read(inotify_fd, buf, sizeof(struct inotify_event) + PATH_MAX); + len = read(instance->inotify_fd, buf, sizeof(struct inotify_event) + PATH_MAX); if(len < 0) { if(errno == EAGAIN) @@ -385,24 +385,24 @@ int read_inotify(int inotify_fd, } while(offset < len) { ievent = (struct inotify_event *)&(buf[offset]); - for(i=0; inum; i++) { - if(iwatch_array->elem[i].wd == ievent->wd && + for(i=0; iinotify_watch_array.num; i++) { + if(instance->inotify_watch_array.elem[i].wd == ievent->wd && ievent->mask == IN_CREATE) { printf_verbose( "inotify wd %u event mask : %u for %s%s\n", ievent->wd, ievent->mask, - iwatch_array->elem[i].path_channel, + instance->inotify_watch_array.elem[i].path_channel, ievent->name); - old_num = fd_pairs->num_pairs; - strcpy(path_channel, iwatch_array->elem[i].path_channel); + old_num = instance->fd_pairs.num_pairs; + strcpy(path_channel, instance->inotify_watch_array.elem[i].path_channel); strcat(path_channel, ievent->name); - if(ret = open_buffer_file(ievent->name, path_channel, - path_channel + (iwatch_array->elem[i].base_path_channel - - iwatch_array->elem[i].path_channel), fd_pairs)) { + if(ret = open_buffer_file(instance, ievent->name, path_channel, + path_channel + (instance->inotify_watch_array.elem[i].base_path_channel - + instance->inotify_watch_array.elem[i].path_channel))) { printf("Error opening buffer file\n"); return -1; } - if(ret = map_channels(fd_pairs, old_num, fd_pairs->num_pairs)) { + if(ret = map_channels(instance, old_num, instance->fd_pairs.num_pairs)) { printf("Error mapping channel\n"); return -1; } @@ -432,8 +432,7 @@ int read_inotify(int inotify_fd, * full. */ -int read_channels(unsigned long thread_num, struct channel_trace_fd *fd_pairs, - int inotify_fd, struct inotify_watch_array *iwatch_array) +int read_channels(struct liblttd_instance *instance, unsigned long thread_num) { struct pollfd *pollfd = NULL; int num_pollfd; @@ -450,24 +449,24 @@ int read_channels(unsigned long thread_num, struct channel_trace_fd *fd_pairs, inotify_fds = 0; #endif - pthread_rwlock_rdlock(&fd_pairs_lock); + pthread_rwlock_rdlock(&instance->fd_pairs_lock); /* Start polling the FD. Keep one fd for inotify */ - pollfd = malloc((inotify_fds + fd_pairs->num_pairs) * sizeof(struct pollfd)); + pollfd = malloc((inotify_fds + instance->fd_pairs.num_pairs) * sizeof(struct pollfd)); #ifdef HAS_INOTIFY - pollfd[0].fd = inotify_fd; + pollfd[0].fd = instance->inotify_fd; pollfd[0].events = POLLIN|POLLPRI; #endif - for(i=0;inum_pairs;i++) { - pollfd[inotify_fds+i].fd = fd_pairs->pair[i].channel; + for(i=0;ifd_pairs.num_pairs;i++) { + pollfd[inotify_fds+i].fd = instance->fd_pairs.pair[i].channel; pollfd[inotify_fds+i].events = POLLIN|POLLPRI; } - num_pollfd = inotify_fds + fd_pairs->num_pairs; + num_pollfd = inotify_fds + instance->fd_pairs.num_pairs; - pthread_rwlock_unlock(&fd_pairs_lock); + pthread_rwlock_unlock(&instance->fd_pairs_lock); while(1) { high_prio = 0; @@ -480,7 +479,7 @@ int read_channels(unsigned long thread_num, struct channel_trace_fd *fd_pairs, #endif //DEBUG /* Have we received a signal ? */ - if(quit_program) break; + if(instance->quit_program) break; num_rdy = poll(pollfd, num_pollfd, -1); @@ -513,9 +512,9 @@ int read_channels(unsigned long thread_num, struct channel_trace_fd *fd_pairs, "Polling inotify fd %d : data ready.\n", pollfd[0].fd); - pthread_rwlock_wrlock(&fd_pairs_lock); - read_inotify(inotify_fd, fd_pairs, iwatch_array); - pthread_rwlock_unlock(&fd_pairs_lock); + pthread_rwlock_wrlock(&instance->fd_pairs_lock); + read_inotify(instance); + pthread_rwlock_unlock(&instance->fd_pairs_lock); break; } @@ -542,22 +541,22 @@ int read_channels(unsigned long thread_num, struct channel_trace_fd *fd_pairs, num_hup++; break; case POLLPRI: - pthread_rwlock_rdlock(&fd_pairs_lock); - if(pthread_mutex_trylock(&fd_pairs->pair[i-inotify_fds].mutex) == 0) { + pthread_rwlock_rdlock(&instance->fd_pairs_lock); + if(pthread_mutex_trylock(&instance->fd_pairs.pair[i-inotify_fds].mutex) == 0) { printf_verbose( "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 sub-buffer */ - ret = read_subbuffer(&fd_pairs->pair[i-inotify_fds]); + ret = read_subbuffer(instance, &instance->fd_pairs.pair[i-inotify_fds]); if(ret == EAGAIN) ret = 0; - ret = pthread_mutex_unlock(&fd_pairs->pair[i-inotify_fds].mutex); + ret = pthread_mutex_unlock(&instance->fd_pairs.pair[i-inotify_fds].mutex); if(ret) printf("Error in mutex unlock : %s\n", strerror(ret)); } - pthread_rwlock_unlock(&fd_pairs_lock); + pthread_rwlock_unlock(&instance->fd_pairs_lock); break; } } @@ -568,38 +567,38 @@ int read_channels(unsigned long thread_num, struct channel_trace_fd *fd_pairs, for(i=inotify_fds;ipair[i-inotify_fds].mutex) == 0) { + pthread_rwlock_rdlock(&instance->fd_pairs_lock); + if(pthread_mutex_trylock(&instance->fd_pairs.pair[i-inotify_fds].mutex) == 0) { /* Take care of low priority channels. */ printf_verbose( "Normal read on fd %d\n", pollfd[i].fd); /* it's ok to have an unavailable subbuffer */ - ret = read_subbuffer(&fd_pairs->pair[i-inotify_fds]); + ret = read_subbuffer(instance, &instance->fd_pairs.pair[i-inotify_fds]); if(ret == EAGAIN) ret = 0; - ret = pthread_mutex_unlock(&fd_pairs->pair[i-inotify_fds].mutex); + ret = pthread_mutex_unlock(&instance->fd_pairs.pair[i-inotify_fds].mutex); if(ret) printf("Error in mutex unlock : %s\n", strerror(ret)); } - pthread_rwlock_unlock(&fd_pairs_lock); + pthread_rwlock_unlock(&instance->fd_pairs_lock); break; } } } /* Update pollfd array if an entry was added to fd_pairs */ - pthread_rwlock_rdlock(&fd_pairs_lock); - if((inotify_fds + fd_pairs->num_pairs) != num_pollfd) { + pthread_rwlock_rdlock(&instance->fd_pairs_lock); + if((inotify_fds + instance->fd_pairs.num_pairs) != num_pollfd) { pollfd = realloc(pollfd, - (inotify_fds + fd_pairs->num_pairs) * sizeof(struct pollfd)); - for(i=num_pollfd-inotify_fds;inum_pairs;i++) { - pollfd[inotify_fds+i].fd = fd_pairs->pair[i].channel; + (inotify_fds + instance->fd_pairs.num_pairs) * sizeof(struct pollfd)); + for(i=num_pollfd-inotify_fds;ifd_pairs.num_pairs;i++) { + pollfd[inotify_fds+i].fd = instance->fd_pairs.pair[i].channel; pollfd[inotify_fds+i].events = POLLIN|POLLPRI; } - num_pollfd = fd_pairs->num_pairs + inotify_fds; + num_pollfd = instance->fd_pairs.num_pairs + inotify_fds; } - pthread_rwlock_unlock(&fd_pairs_lock); + pthread_rwlock_unlock(&instance->fd_pairs_lock); /* NB: If the fd_pairs structure is updated by another thread from this * point forward, the current thread will wait in the poll without @@ -620,104 +619,111 @@ end: } -void close_channel_trace_pairs(struct channel_trace_fd *fd_pairs, int inotify_fd, - struct inotify_watch_array *iwatch_array) +void close_channel_trace_pairs(struct liblttd_instance *instance) { int i; int ret; - for(i=0;inum_pairs;i++) { - ret = close(fd_pairs->pair[i].channel); + for(i=0;ifd_pairs.num_pairs;i++) { + ret = close(instance->fd_pairs.pair[i].channel); if(ret == -1) perror("Close error on channel"); - if(callbacks->on_close_channel) { - ret = callbacks->on_close_channel( - callbacks, &fd_pairs->pair[i]); + if(instance->callbacks->on_close_channel) { + ret = instance->callbacks->on_close_channel( + instance->callbacks, &instance->fd_pairs.pair[i]); if(ret != 0) perror("Error on close channel callback"); } } - free(fd_pairs->pair); - free(iwatch_array->elem); + free(instance->fd_pairs.pair); + free(instance->inotify_watch_array.elem); } /* Thread worker */ void * thread_main(void *arg) { long ret = 0; - unsigned long thread_num = (unsigned long)arg; + struct liblttd_thread_data *thread_data = (struct liblttd_thread_data*) arg; - if(callbacks->on_new_thread) - ret = callbacks->on_new_thread(callbacks, thread_num); + if(thread_data->instance->callbacks->on_new_thread) + ret = thread_data->instance->callbacks->on_new_thread( + thread_data->instance->callbacks, thread_data->thread_num); if (ret < 0) { return (void*)ret; } - ret = read_channels(thread_num, &fd_pairs, inotify_fd, &inotify_watch_array); + ret = read_channels(thread_data->instance, thread_data->thread_num); + + if(thread_data->instance->callbacks->on_close_thread) + thread_data->instance->callbacks->on_close_thread( + thread_data->instance->callbacks, thread_data->thread_num); - if(callbacks->on_close_thread) - callbacks->on_close_thread(callbacks, thread_num); + free(thread_data); return (void*)ret; } -/*on_close_thread has to be reentrant, it'll be called by many threads*/ -int(*on_close_thread)(struct liblttd_callbacks *data, unsigned long thread_num); - -int channels_init() +int channels_init(struct liblttd_instance *instance) { int ret = 0; - inotify_fd = inotify_init(); - fcntl(inotify_fd, F_SETFL, O_NONBLOCK); + instance->inotify_fd = inotify_init(); + fcntl(instance->inotify_fd, F_SETFL, O_NONBLOCK); - if(ret = open_channel_trace_pairs(channel_name, - channel_name + strlen(channel_name), &fd_pairs, - &inotify_fd, &inotify_watch_array)) + if(ret = open_channel_trace_pairs(instance, instance->channel_name, + instance->channel_name + + strlen(instance->channel_name))) goto close_channel; - if (fd_pairs.num_pairs == 0) { + if (instance->fd_pairs.num_pairs == 0) { printf("No channel available for reading, exiting\n"); ret = -ENOENT; goto close_channel; } - if(ret = map_channels(&fd_pairs, 0, fd_pairs.num_pairs)) + + if(ret = map_channels(instance, 0, instance->fd_pairs.num_pairs)) goto close_channel; return 0; close_channel: - close_channel_trace_pairs(&fd_pairs, inotify_fd, &inotify_watch_array); - if(inotify_fd >= 0) - close(inotify_fd); + close_channel_trace_pairs(instance); + if(instance->inotify_fd >= 0) + close(instance->inotify_fd); return ret; } -int liblttd_start(char *channel_path, unsigned long n_threads, - int flight_only, int normal_only, int verbose, - struct liblttd_callbacks *user_data){ +int delete_instance(struct liblttd_instance *instance) +{ + pthread_rwlock_destroy(&instance->fd_pairs_lock); + free(instance); + return 0; +} + +int liblttd_start_instance(struct liblttd_instance *instance) +{ int ret = 0; pthread_t *tids; unsigned long i; void *tret; - channel_name = channel_path; - num_threads = n_threads; - dump_flight_only = flight_only; - dump_normal_only = normal_only; - verbose_mode = verbose; - callbacks = user_data; + if(!instance) + return -EINVAL; - if(ret = channels_init()) + if(ret = channels_init(instance)) return ret; - tids = malloc(sizeof(pthread_t) * num_threads); - for(i=0; inum_threads); + for(i=0; inum_threads; i++) { + struct liblttd_thread_data *thread_data = + malloc(sizeof(struct liblttd_thread_data)); + thread_data->thread_num = i; + thread_data->instance = instance; - ret = pthread_create(&tids[i], NULL, thread_main, (void*)i); + ret = pthread_create(&tids[i], NULL, thread_main, thread_data); if(ret) { perror("Error creating thread"); break; } } - for(i=0; inum_threads; i++) { ret = pthread_join(tids[i], &tret); if(ret) { perror("Error joining thread"); @@ -730,18 +736,55 @@ int liblttd_start(char *channel_path, unsigned long n_threads, } free(tids); - ret = unmap_channels(&fd_pairs); - close_channel_trace_pairs(&fd_pairs, inotify_fd, &inotify_watch_array); - if(inotify_fd >= 0) - close(inotify_fd); + ret = unmap_channels(instance); + close_channel_trace_pairs(instance); + if(instance->inotify_fd >= 0) + close(instance->inotify_fd); - if(callbacks->on_trace_end) callbacks->on_trace_end(callbacks); + if(instance->callbacks->on_trace_end) + instance->callbacks->on_trace_end(instance->callbacks); + + delete_instance(instance); return ret; } -int liblttd_stop() { - quit_program = 1; +struct liblttd_instance * liblttd_new_instance( + struct liblttd_callbacks *callbacks, char *channel_path, + unsigned long n_threads, int flight_only, int normal_only, int verbose) +{ + struct liblttd_instance * instance; + if(!channel_path || !callbacks) return NULL; + if(n_threads == 0) n_threads = 1; + if(flight_only && normal_only) return NULL; + + instance = malloc(sizeof(struct liblttd_instance)); + if(!instance) return NULL; + + instance->callbacks = callbacks; + + instance->inotify_fd = -1; + + instance->fd_pairs.pair = NULL; + instance->fd_pairs.num_pairs = 0; + + instance->inotify_watch_array.elem = NULL; + instance->inotify_watch_array.num = 0; + + pthread_rwlock_init(&instance->fd_pairs_lock, NULL); + + strncpy(instance->channel_name, channel_path, PATH_MAX -1); + instance->num_threads = n_threads; + instance->dump_flight_only = flight_only; + instance->dump_normal_only = normal_only; + instance->verbose_mode = verbose; + + return instance; +} + +int liblttd_stop_instance(struct liblttd_instance *instance) +{ + instance->quit_program = 1; return 0; } diff --git a/liblttd/liblttd.h b/liblttd/liblttd.h index bd76eeb..02e7e9c 100644 --- a/liblttd/liblttd.h +++ b/liblttd/liblttd.h @@ -23,196 +23,192 @@ #include /** -* This structure contains the data associated with the channel file descriptor. -* The lib user can use user_data to store the data associated to the specified -* channel. The lib user can read but MUST NOT change the other attributes. -*/ + * struct fd_pair - Contains the data associated with the channel file + * descriptor. The lib user can use user_data to store the data associated to + * the specified channel. The lib user can read but MUST NOT change the other + * attributes. + * @channel: channel file descriptor + * @n_sb: the number of subbuffer for this channel + * @max_sb_size: the subbuffer size for this channel + * @mmap: Not used anymore. + * @mutex: a mutex for internal library usage + * @user_data: library user data + */ struct fd_pair { - /** - * This is the channel file descriptor. - */ int channel; - - /** - * This is the number of subbuffer for this channel. - */ unsigned int n_sb; - - /** - * This is the subbuffer size for this channel. - */ unsigned int max_sb_size; - - /** - * Not used anymore. - */ void *mmap; - - /** - * This is a mutex for internal library usage. - */ pthread_mutex_t mutex; - - /** - * Library user data. - */ void *user_data; }; +struct liblttd_instance; + /** -* This structure contains the necessary callbacks for a tracing session. The -* user can set the unnecessary functions to NULL if he does not need them. +* struct liblttd_callbacks - Contains the necessary callbacks for a tracing +* session. The user can set the unnecessary functions to NULL if he does not +* need them. */ struct liblttd_callbacks { /** - * This callback is called after a channel file is open. - * - * @args data This argument is a pointeur to the callbacks struct that - * has been passed to the lib. - * @args pair This structure contains the data associated with the - * channel file descriptor. The lib user can use user_data to - * store the data associated to the specified channel. - * @args relative_channel_path This argument represents a relative path - * to the channel file. This path is relative to the root - * folder of the trace channels. - * - * @return Should return 0 if the callback succeeds else not 0. - */ + * on_open_channel - Is called after a channel file is open. + * @data: pointeur to the callbacks struct that has been passed to the + * lib. + * @pair: structure that contains the data associated with the + * channel file descriptor. The lib user can use user_data to + * store the data associated to the specified channel. + * @relative_channel_path: represents a relative path to the channel + * file. This path is relative to the root folder of the trace channels. + * + * Returns 0 if the callback succeeds else not 0. + */ int(*on_open_channel)(struct liblttd_callbacks *data, struct fd_pair *pair, char *relative_channel_path); /** - * This callback is called after a channel file is closed. - * - * @remarks After a channel file has been closed, it will never be read - * again. - * - * @args data This argument is a pointeur to the callbacks struct that - * has been passed to the lib. - * @args pair This structure contains the data associated with the - * channel file descriptor. The lib user should clean - * user_data at this time. - * - * @return Should return 0 if the callback succeeds else not 0. - */ + * on_close_channel - Is called after a channel file is closed. + * @data: pointeur to the callbacks struct that has been passed to the + * lib. + * @pair: structure that contains the data associated with the channel + * file descriptor. The lib user should clean user_data at this time. + * + * Returns 0 if the callback succeeds else not 0. + * + * After a channel file has been closed, it will never be read again. + */ int(*on_close_channel)(struct liblttd_callbacks *data, struct fd_pair *pair); - /** - * This callback is called when the library enter in a new subfolder - * while it is scanning the trace channel tree. It can be used to create - * the output file structure of the trace. - * - * @args data This argument is a pointeur to the callbacks struct that - * has been passed to the lib. - * @args relative_folder_path This argument represents a relative path - * to the channel folder. This path is relative to the root - * folder of the trace channels. - * - * @return Should return 0 if the callback succeeds else not 0. - */ + * on_new_channels_folder - Is called when the library enter in a new + * subfolder while it is scanning the trace channel tree. It can be used + * to create the output file structure of the trace. + * @data: pointeur to the callbacks struct that has been passed to the + * lib. + * @relative_folder_path: represents a relative path + * to the channel folder. This path is relative to the root + * folder of the trace channels. + * + * Returns 0 if the callback succeeds else not 0. + */ int(*on_new_channels_folder)(struct liblttd_callbacks *data, char *relative_folder_path); /** - * This callback is called after a subbuffer is a reserved. - * - * @attention It has to be thread safe, it'll be called by many threads. - * - * @args data This argument is a pointeur to the callbacks struct that - * has been passed to the lib. - * @args pair This structure contains the data associated with the - * channel file descriptor. The lib user should clean - * user_data at this time. - * @args len This argument represents the length the data that has to be - * read. - * - * @return Should return 0 if the callback succeeds else not 0. - */ + * on_read_subbuffer - Is called after a subbuffer is a reserved. + * + * @data: pointeur to the callbacks struct that has been passed to the + * lib. + * @pair: structure that contains the data associated with the + * channel file descriptor. + * @len: represents the length the data that has to be read. + * + * Returns 0 if the callback succeeds else not 0. + * + * It has to be thread safe, it'll be called by many threads. + */ int(*on_read_subbuffer)(struct liblttd_callbacks *data, struct fd_pair *pair, unsigned int len); /** - * This callback is called at the very end of the tracing session. At - * this time, all the channels have been closed and the threads have been - * destroyed. - * - * @remarks After this callback is called, no other callback will be - * called again. - * - * @attention It has to be thread safe, it'll be called by many threads. - * - * @args data This argument is a pointeur to the callbacks struct that - * has been passed to the lib. - * - * @return Should return 0 if the callback succeeds else not 0. - */ + * on_trace_en - Is called at the very end of the tracing session. At + * this time, all the channels have been closed and the threads have + * been destroyed. + * + * @data: pointeur to the callbacks struct that has been passed to the + * lib. + * + * Returns 0 if the callback succeeds else not 0. + * + * It has to be thread safe, it'll be called by many threads. + * After this callback is called, no other callback will be called + * again and the tracing instance will be deleted automatically by + * liblttd. After this call, the user must not use the liblttd instance. + */ int(*on_trace_end)(struct liblttd_callbacks *data); /** - * This callback is called after a new thread has been created. - * - * @attention It has to be thread safe, it'll be called by many threads. - * - * @args data This argument is a pointeur to the callbacks struct that - * has been passed to the lib. - * @args thread_num This argument represents the id of the thread. - * - * @return Should return 0 if the callback succeeds else not 0. - */ + * on_new_thread - Is called after a new thread has been created. + * + * @data: pointeur to the callbacks struct that has been passed to the + * lib. + * @thread_num: represents the id of the thread. + * + * Returns 0 if the callback succeeds else not 0. + * + * It has to be thread safe, it'll be called by many threads. + */ int(*on_new_thread)(struct liblttd_callbacks *data, unsigned long thread_num); /** - * This callback is called just before a thread is destroyed. - * - * @attention It has to be thread safe, it'll be called by many threads. - * - * @args data This argument is a pointeur to the callbacks struct that - * has been passed to the lib. - * @args thread_num This argument represents the number of the thread. - * - * @return Should return 0 if the callback succeeds else not 0. - */ + * on_close_thread - Is Called just before a thread is destroyed. + * + * @data: pointeur to the callbacks struct that has been passed to the + * lib. + * @thread_num: represents the number of the thread. + * + * Returns 0 if the callback succeeds else not 0. + * + * It has to be thread safe, it'll be called by many threads. + */ int(*on_close_thread)(struct liblttd_callbacks *data, unsigned long thread_num); /** - * This is where the user can put the library's data. - */ + * The library's data. + */ void *user_data; }; /** -* This function is called to start a new tracing session. -* -* @attention It has to be thread safe, it'll be called by many threads. -* -* @args channel_path This argument is a path to the root folder of the trace's -* channels. -* @args n_threads This argument represents the number of threads that will be -* used by the library. -* @args flight_only If this argument to set to 1, only the channel that are in -* flight recorder mode will be recorded. -* @args normal_only If this argument to set to 1, only the channel that are in -* normal mode will be recorded. -* @args verbose If this argument to set to 1, more informations will be printed. -* @args user_data This argument is a pointeur to the callbacks struct that -* contains the user's functions. -* -* @return Return 0 if the function succeeds else not 0. -*/ -int liblttd_start(char *channel_path, unsigned long n_threads, - int flight_only, int normal_only, int verbose, - struct liblttd_callbacks *user_data); + * liblttd_new_instance - Is called to create a new tracing session. + * + * @callbacks: Pointer to a callbacks struct that contain the user callbacks and + * data. + * @channel_path: This argument is a path to the root folder of the trace's + * channels. + * @n_threads: This argument represents the number of threads that will be + * used by the library. + * @flight_only: If this argument to set to 1, only the channel that are in + * flight recorder mode will be recorded. + * @normal_only: If this argument to set to 1, only the channel that are in + * normal mode will be recorded. + * @verbose: If this argument to set to 1, more informations will be printed. + * + * Returns the instance if the function succeeds else NULL. + */ +struct liblttd_instance * liblttd_new_instance( + struct liblttd_callbacks *callbacks, char *channel_path, + unsigned long n_threads, int flight_only, int normal_only, int verbose); /** -* This function is called to stop a tracing session. -* -* @return Return 0 if the function succeeds. -*/ -int liblttd_stop(); + * liblttd_start - Is called to start a new tracing session. + * + * @instance: The tracing session instance that needs to be starded. + * + * Returns 0 if the function succeeds. + * + * This is a blocking function. The caller will be bloked on it until the + * tracing session is stoped by the user usign liblttd_stop_instance or until + * the trace is stoped by LTTng directly. + */ +int liblttd_start_instance(struct liblttd_instance *instance); + +/** + * liblttd_stop - Is called to stop a tracing session. + * + * @instance: The tracing session instance that needs to be stoped. + * + * Returns 0 if the function succeeds. + * + * This function return immediately, it only tells liblttd to stop the instance. + * The on_trace_end callback will be called when the tracing session will really + * be stoped (after every thread will be done). The instance is deleted + * automatically by liblttd after on_trace_end is called. + */ +int liblttd_stop_instance(struct liblttd_instance *instance); #endif /*_LIBLTTD_H */ diff --git a/lttd/lttd.c b/lttd/lttd.c index ec757ae..d3c12d5 100644 --- a/lttd/lttd.c +++ b/lttd/lttd.c @@ -46,6 +46,7 @@ struct lttd_channel_data { int trace; }; +struct liblttd_instance *instance; static char path_trace[PATH_MAX]; static char *end_path_trace; static int path_trace_len = 0; @@ -191,7 +192,7 @@ void show_info(void) static void handler(int signo) { printf("Signal %d received : exiting cleanly\n", signo); - liblttd_stop(); + liblttd_stop_instance(instance); } int lttd_on_open_channel(struct liblttd_callbacks *data, struct fd_pair *pair, char *relative_channel_path) @@ -306,7 +307,8 @@ write_error: return ret; } -int on_new_thread(struct liblttd_callbacks *data, unsigned long thread_num) { +int lttd_on_new_thread(struct liblttd_callbacks *data, unsigned long thread_num) +{ int ret; ret = pipe(thread_pipe); if (ret < 0) { @@ -316,7 +318,8 @@ int on_new_thread(struct liblttd_callbacks *data, unsigned long thread_num) { return 0; } -int on_close_thread(struct liblttd_callbacks *data, unsigned long thread_num) { +int lttd_on_close_thread(struct liblttd_callbacks *data, unsigned long thread_num) +{ close(thread_pipe[0]); /* close read end */ close(thread_pipe[1]); /* close write end */ return 0; @@ -333,8 +336,8 @@ int main(int argc, char ** argv) lttd_on_new_channels_folder, lttd_on_read_subbuffer, NULL, - on_new_thread, - on_close_thread, + lttd_on_new_thread, + lttd_on_close_thread, NULL }; @@ -365,13 +368,18 @@ int main(int argc, char ** argv) exit(-1); } } - strncpy(path_trace, trace_name, PATH_MAX-1); path_trace_len = strlen(path_trace); end_path_trace = path_trace + path_trace_len; - liblttd_start(channel_name, num_threads, dump_flight_only, dump_normal_only, - verbose_mode, &callbacks); + instance = liblttd_new_instance(&callbacks, channel_name, num_threads, + dump_flight_only, dump_normal_only, verbose_mode); + if(!instance) { + perror("An error occured while creating the liblttd instance"); + return ret; + } + + liblttd_start_instance(instance); return ret; }