[lttng-dev] [MI RFC 2/3] Mi: support for command list

Jonathan R.Julien jonathan.r.julien at gmail.com
Mon Apr 7 11:47:59 EDT 2014


On Mon, Apr 07, 2014 at 11:36:20AM -0400, Simon Marchi wrote:
> A small thing I just noticed. In the MI version of list, the attribute
> used to show if a session is started is <enabled>. In the CLI, the
> terms active/inactive are used. It might be a good idea to be
> consistent.

Actually we used the <enabled> element based on the
lttng_session struct.

struct lttng_session
    char name[NAME_MAX];
    /* The path where traces are written */
    char path[PATH_MAX];
    uint32_t enabled;   /* enabled/started: 1, disabled/stopped: 0 */
    uint32_t snapshot_mode;
    unsigned int live_timer_interval;   /* usec */
    char padding[LTTNG_SESSION_PADDING1];

Not sure which one is the most appropriate enabled or active.
Enabled is consistent with lttng_session struct but user are used to
active/inactive.

David ?

> 
> Other small stuff below.

Fixed

Thanks!

> 
> On 6 April 2014 15:30, Jonathan Rajotte <jonathan.r.julien at gmail.com> wrote:
> > Signed-off-by: Jonathan Rajotte <jonathan.r.julien at gmail.com>
> > ---
> >  src/bin/lttng/commands/list.c | 888 ++++++++++++++++++++++++++++++++++++------
> >  src/common/mi-lttng.c         | 685 +++++++++++++++++++++++++++++++-
> >  src/common/mi-lttng.h         | 299 +++++++++++++-
> >  3 files changed, 1735 insertions(+), 137 deletions(-)
> >
> > diff --git a/src/bin/lttng/commands/list.c b/src/bin/lttng/commands/list.c
> > index bbd674c..a0d0e4c 100644
> > --- a/src/bin/lttng/commands/list.c
> > +++ b/src/bin/lttng/commands/list.c
> > @@ -23,6 +23,8 @@
> >  #include <string.h>
> >  #include <assert.h>
> >
> > +#include <common/mi-lttng.h>
> > +
> >  #include "../command.h"
> >
> >  static int opt_userspace;
> > @@ -48,6 +50,7 @@ enum {
> >  };
> >
> >  static struct lttng_handle *handle;
> > +static struct mi_writer *writer;
> >
> >  static struct poptOption long_options[] = {
> >         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
> > @@ -148,89 +151,6 @@ static const char *snapshot_string(int value)
> >         }
> >  }
> >
> > -static
> > -const char *enabled_string(int value)
> > -{
> > -       switch (value) {
> > -       case 0: return " [disabled]";
> > -       case 1: return " [enabled]";
> > -       case -1: return "";
> > -       default: return NULL;
> > -       }
> > -}
> > -
> > -static
> > -const char *filter_string(int value)
> > -{
> > -       switch (value) {
> > -       case 1: return " [with filter]";
> > -       default: return "";
> > -       }
> > -}
> > -
> > -static
> > -const char *exclusion_string(int value)
> > -{
> > -       switch (value) {
> > -       case 1: return " [has exclusions]";
> > -       default: return "";
> > -       }
> > -}
> > -
> > -static const char *loglevel_string(int value)
> > -{
> > -       switch (value) {
> > -       case -1:
> > -               return "";
> > -       case LTTNG_LOGLEVEL_EMERG:
> > -               return "TRACE_EMERG";
> > -       case LTTNG_LOGLEVEL_ALERT:
> > -               return "TRACE_ALERT";
> > -       case LTTNG_LOGLEVEL_CRIT:
> > -               return "TRACE_CRIT";
> > -       case LTTNG_LOGLEVEL_ERR:
> > -               return "TRACE_ERR";
> > -       case LTTNG_LOGLEVEL_WARNING:
> > -               return "TRACE_WARNING";
> > -       case LTTNG_LOGLEVEL_NOTICE:
> > -               return "TRACE_NOTICE";
> > -       case LTTNG_LOGLEVEL_INFO:
> > -               return "TRACE_INFO";
> > -       case LTTNG_LOGLEVEL_DEBUG_SYSTEM:
> > -               return "TRACE_DEBUG_SYSTEM";
> > -       case LTTNG_LOGLEVEL_DEBUG_PROGRAM:
> > -               return "TRACE_DEBUG_PROGRAM";
> > -       case LTTNG_LOGLEVEL_DEBUG_PROCESS:
> > -               return "TRACE_DEBUG_PROCESS";
> > -       case LTTNG_LOGLEVEL_DEBUG_MODULE:
> > -               return "TRACE_DEBUG_MODULE";
> > -       case LTTNG_LOGLEVEL_DEBUG_UNIT:
> > -               return "TRACE_DEBUG_UNIT";
> > -       case LTTNG_LOGLEVEL_DEBUG_FUNCTION:
> > -               return "TRACE_DEBUG_FUNCTION";
> > -       case LTTNG_LOGLEVEL_DEBUG_LINE:
> > -               return "TRACE_DEBUG_LINE";
> > -       case LTTNG_LOGLEVEL_DEBUG:
> > -               return "TRACE_DEBUG";
> > -       default:
> > -               return "<<UNKNOWN>>";
> > -       }
> > -}
> > -
> > -static const char *logleveltype_string(enum lttng_loglevel_type value)
> > -{
> > -       switch (value) {
> > -       case LTTNG_EVENT_LOGLEVEL_ALL:
> > -               return ":";
> > -       case LTTNG_EVENT_LOGLEVEL_RANGE:
> > -               return " <=";
> > -       case LTTNG_EVENT_LOGLEVEL_SINGLE:
> > -               return " ==";
> > -       default:
> > -               return " <<TYPE UNKN>>";
> > -       }
> > -}
> > -
> >  /*
> >   * Pretty print single event.
> >   */
> > @@ -446,6 +366,118 @@ error:
> >  }
> >
> >  /*
> > + * Machine interface
> > + * Ask session daemon for all user space tracepoints available and print them
> > + *
> > + * print_domain 0-> do not print domains and domain element
> > + *                  (used when mi_list_jul_ust_events is nested under a domain)
> > + *              else print the domains and domain element
> > + */
> > +static int mi_list_jul_ust_events(enum lttng_domain_type type, int print_domain)
> > +{
> > +       int ret, i, size;
> > +       struct lttng_domain domain;
> > +       struct lttng_handle *handle;
> > +       struct lttng_event *event_list;
> > +       pid_t cur_pid = 0;
> > +       char *cmdline = NULL;
> > +       int pid_element_open = 0;
> > +
> > +       memset(&domain, 0, sizeof(domain));
> > +
> > +       domain.type = type;
> > +
> > +       handle = lttng_create_handle(NULL, &domain);
> > +       if (handle == NULL) {
> > +               ret = -LTTNG_ERR_NOMEM;
> > +               goto end;
> > +       }
> > +
> > +       size = lttng_list_tracepoints(handle, &event_list);
> > +       if (size < 0) {
> > +               if (LTTNG_DOMAIN_UST) {
> > +                       ERR("Unable to list UST events: %s", lttng_strerror(size));
> > +               } else if (LTTNG_DOMAIN_JUL) {
> > +                       ERR("Unable to list JUL events: %s", lttng_strerror(size));
> > +               }
> > +               lttng_destroy_handle(handle);
> > +               return size;
> > +       }
> > +
> > +       if (print_domain) {
> > +               /* Open domains element */
> > +               ret = mi_lttng_domains_open(writer);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +
> > +               /* Write domain */
> > +               ret = mi_lttng_domain(writer, &domain, 1);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +
> > +       /* Open pids element */
> > +       ret = mi_lttng_pids_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       for (i = 0; i < size; i++) {
> > +               if (cur_pid != event_list[i].pid) {
> > +                       if (pid_element_open) {
> > +                               /* Close the previous envents and  pid element */
> > +                               ret = mi_lttng_close_multi_element(writer, 2);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +                               pid_element_open = !pid_element_open;
> > +                       }
> > +
> > +                       cur_pid = event_list[i].pid;
> > +                       cmdline = get_cmdline_by_pid(cur_pid);
> > +
> > +                       if (!pid_element_open) {
> > +                               /* Open and write a pid elemen */
> > +                               ret = mi_lttng_pid(writer, cur_pid, cmdline, 1);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +
> > +                               /* Open events element */
> > +                               ret = mi_lttng_events_open(writer);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +
> > +                               pid_element_open = !pid_element_open;
> > +                       }
> > +                       free(cmdline);
> > +               }
> > +
> > +               /* Write an event */
> > +               ret = mi_lttng_event(writer, &event_list[i], 0);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +
> > +
> > +       /* Close pids */
> > +       ret = mi_lttng_writer_close_element(writer);
> > +
> > +       if (print_domain) {
> > +               /* Close domain, domains */
> > +               ret = mi_lttng_close_multi_element(writer, 2);
> > +       }
> > +end:
> > +       free(event_list);
> > +       lttng_destroy_handle(handle);
> > +       return ret;
> > +}
> > +
> > +/*
> >   * Ask session daemon for all user space tracepoint fields available.
> >   */
> >  static int list_ust_event_fields(void)
> > @@ -514,6 +546,144 @@ error:
> >  }
> >
> >  /*
> > + * Machine interface
> > + * List all ust event with their fields
> > + */
> > +static int mi_list_ust_event_fields(void)
> > +{
> > +       int ret, i, size;
> > +       struct lttng_domain domain;
> > +       struct lttng_handle *handle;
> > +       struct lttng_event_field *event_field_list;
> > +       pid_t cur_pid = 0;
> > +       char *cmdline = NULL;
> > +       int pid_element_open = 0;
> > +       int event_element_open = 0;
> > +
> > +       struct lttng_event cur_event;
> > +
> > +       memset(&domain, 0, sizeof(domain));
> > +       memset(&cur_event, 0, sizeof(cur_event));
> > +
> > +       domain.type = LTTNG_DOMAIN_UST;
> > +
> > +       handle = lttng_create_handle(NULL, &domain);
> > +       if (handle == NULL) {
> > +               ret = -LTTNG_ERR_NOMEM;
> > +               goto end;
> > +       }
> > +
> > +       size = lttng_list_tracepoint_fields(handle, &event_field_list);
> > +       if (size < 0) {
> > +               ERR("Unable to list UST event fields: %s", lttng_strerror(size));
> > +               lttng_destroy_handle(handle);
> > +               return size;
> > +       }
> > +
> > +       /* Open domains element */
> > +       ret = mi_lttng_domains_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Write domain */
> > +       ret = mi_lttng_domain(writer, &domain, 1);
> > +
> > +       /* Open pids element */
> > +       ret = mi_lttng_pids_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +
> > +       for (i = 0; i < size; i++) {
> > +               if (cur_pid != event_field_list[i].event.pid) {
> > +                       if (pid_element_open) {
> > +                               if (event_element_open) {
> > +                                       /* Close the previous fields element
> > +                                        * and the previous event
> > +                                        */
> > +                                       ret = mi_lttng_close_multi_element(writer, 2);
> > +                                       if (ret) {
> > +                                               goto end;
> > +                                       }
> > +                                       event_element_open = !event_element_open ;
> > +                               }
> > +                               /* Close the previous events, pid element */
> > +                               ret = mi_lttng_close_multi_element(writer, 2);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +                               pid_element_open = !pid_element_open;
> > +                       }
> > +
> > +                       cur_pid = event_field_list[i].event.pid;
> > +                       cmdline = get_cmdline_by_pid(cur_pid);
> > +                       if (!pid_element_open) {
> > +                               /* Open and write a pid elemen */
> > +                               ret = mi_lttng_pid(writer, cur_pid, cmdline, 1);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +
> > +                               /* Open events element */
> > +                               ret = mi_lttng_events_open(writer);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +                               pid_element_open = !pid_element_open;
> > +                       }
> > +                       free(cmdline);
> > +                       /* Wipe current event since we are about to print a new PID. */
> > +                       memset(&cur_event, 0, sizeof(cur_event));
> > +               }
> > +
> > +               if (strcmp(cur_event.name, event_field_list[i].event.name) != 0) {
> > +                       if (event_element_open) {
> > +                               /* Close the previous fields element and the previous event */
> > +                               ret = mi_lttng_close_multi_element(writer, 2);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +                               event_element_open = !event_element_open ;
> > +                       }
> > +
> > +                       memcpy(&cur_event, &event_field_list[i].event,
> > +                                       sizeof(cur_event));
> > +
> > +                       if (!event_element_open) {
> > +                               /* Open and write the event */
> > +                               ret = mi_lttng_event(writer, &cur_event, 1);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +
> > +                               /* Open a fields element */
> > +                               ret = mi_lttng_event_fields_open(writer);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +                               event_element_open = !event_element_open ;
> > +                       }
> > +               }
> > +
> > +               /* Print the event_field */
> > +               ret = mi_lttng_event_field(writer, &event_field_list[i]);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +
> > +       /* Close pids, domain, domains */
> > +       ret = mi_lttng_close_multi_element(writer, 3);
> > +
> > +end:
> > +       free(event_field_list);
> > +       lttng_destroy_handle(handle);
> > +       return ret;
> > +}
> > +
> > +/*
> >   * Ask for all trace events in the kernel and pretty print them.
> >   */
> >  static int list_kernel_events(void)
> > @@ -560,6 +730,71 @@ error:
> >  }
> >
> >  /*
> > + * Machine interface
> > + * Ask for all trace events in the kernel
> > + */
> > +static int mi_list_kernel_events(void)
> > +{
> > +       int ret, i, size;
> > +       struct lttng_domain domain;
> > +       struct lttng_handle *handle;
> > +       struct lttng_event *event_list;
> > +
> > +       memset(&domain, 0, sizeof(domain));
> > +
> > +       domain.type = LTTNG_DOMAIN_KERNEL;
> > +
> > +       handle = lttng_create_handle(NULL, &domain);
> > +       if (handle == NULL) {
> > +               ret = -LTTNG_ERR_NOMEM;
> > +               goto end;
> > +       }
> > +
> > +       size = lttng_list_tracepoints(handle, &event_list);
> > +       if (size < 0) {
> > +               ERR("Unable to list kernel events: %s", lttng_strerror(size));
> > +               lttng_destroy_handle(handle);
> > +               return size;
> > +       }
> > +
> > +       /* Open domains element */
> > +       ret = mi_lttng_domains_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Write domain */
> > +       ret = mi_lttng_domain(writer, &domain, 1);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Open events */
> > +       ret = mi_lttng_events_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       for (i = 0; i < size; i++) {
> > +               mi_lttng_event(writer, &event_list[i], 0);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +
> > +       /* close events, domain and domains */
> > +       ret = mi_lttng_close_multi_element(writer, 3);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +end:
> > +       free(event_list);
> > +       lttng_destroy_handle(handle);
> > +       return ret;
> > +}
> > +
> > +/*
> >   * List JUL events for a specific session using the handle.
> >   *
> >   * Return CMD_SUCCESS on success else a negative value.
> > @@ -598,6 +833,43 @@ error:
> >  }
> >
> >  /*
> > + * Machine Interface
> > + * List JUL events for a specific session using the handle.
> > + */
> > +static int mi_list_session_jul_events(void)
> > +{
> > +       int ret, count, i;
> > +       struct lttng_event *events = NULL;
> > +
> > +       count = lttng_list_events(handle, "", &events);
> > +       if (count < 0) {
> > +               ret = count;
> > +               ERR("%s", lttng_strerror(ret));
> > +               goto end;
> > +       }
> > +
> > +       /* Open events element */
> > +       ret = mi_lttng_events_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       for (i = 0; i < count; i++) {
> > +               ret = mi_lttng_event(writer, &events[i], 0);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +
> > +       /* Close events element */
> > +       ret = mi_lttng_writer_close_element(writer);
> > +
> > +end:
> > +       free(events);
> > +       return ret;
> > +}
> > +
> > +/*
> >   * List events of channel of session and domain.
> >   */
> >  static int list_events(const char *channel_name)
> > @@ -633,6 +905,43 @@ error:
> >  }
> >
> >  /*
> > + * Machine interface
> > + * List events of channel of session and domain.
> > + */
> > +static int mi_list_events(const char *channel_name)
> > +{
> > +       int ret, count, i;
> > +       struct lttng_event *events = NULL;
> > +
> > +       count = lttng_list_events(handle, channel_name, &events);
> > +       if (count < 0) {
> > +               ret = count;
> > +               ERR("%s", lttng_strerror(ret));
> > +               goto end;
> > +       }
> > +
> > +       /* Open events element */
> > +       ret = mi_lttng_events_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       for (i = 0; i < count; i++) {
> > +               ret = mi_lttng_event(writer, &events[i], 0);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +
> > +       /* Close events element */
> > +       ret = mi_lttng_writer_close_element(writer);
> > +
> > +end:
> > +       free(events);
> > +       return ret;
> > +}
> > +
> > +/*
> >   * Pretty print channel
> >   */
> >  static void print_channel(struct lttng_channel *channel)
> > @@ -724,13 +1033,92 @@ error_channels:
> >  }
> >
> >  /*
> > + * Machine interface
> > + * List channel(s) of session and domain.
> > + *
> > + * If channel_name is NULL, all channels are listed.
> > + */
> > +static int mi_list_channels(const char *channel_name)
> > +{
> > +       int count, i, ret;
> > +       unsigned int chan_found = 0;
> > +       struct lttng_channel *channels = NULL;
> > +
> > +       count = lttng_list_channels(handle, &channels);
> > +       if (count < 0) {
> > +               switch (-count) {
> > +               case LTTNG_ERR_KERN_CHAN_NOT_FOUND:
> > +                       /* When printing mi this is not an error
> > +                        * but an empty channels element */
> > +                       count = 0;
> > +                       break;
> > +               default:
> > +                       /* We had a real error */
> > +                       ret = count;
> > +                       ERR("%s", lttng_strerror(ret));
> > +                       goto error_channels;
> > +                       break;
> > +               }
> > +       }
> > +
> > +       /* Open channels element */
> > +       ret = mi_lttng_channels_open(writer);
> > +       if (ret) {
> > +               goto error;
> > +       }
> > +
> > +       for (i = 0; i < count; i++) {
> > +               if (channel_name != NULL) {
> > +                       if (strncmp(channels[i].name, channel_name, NAME_MAX) == 0) {
> > +                               chan_found = 1;
> > +                       } else {
> > +                               continue;
> > +                       }
> > +               }
> > +
> > +               /* Write channel element  and leave it open */
> > +               ret = mi_lttng_channel(writer, &channels[i], 1);
> > +
> > +               /* Listing events per channel */
> > +               ret = mi_list_events(channels[i].name);
> > +               if (ret) {
> > +                       goto error;
> > +               }
> > +
> > +               /* Closing the channel element we opened earlier */
> > +               ret = mi_lttng_writer_close_element(writer);
> > +               if (ret) {
> > +                       goto error;
> > +               }
> > +
> > +               if (chan_found) {
> > +                       break;
> > +               }
> > +       }
> > +
> > +       /* Close channels element */
> > +       ret = mi_lttng_writer_close_element(writer);
> > +       if (ret) {
> > +               goto error;
> > +       }
> > +
> > +
> > +error:
> > +       free(channels);
> > +
> > +error_channels:
> > +       return ret;
> > +}
> > +
> > +/*
> >   * List available tracing session. List only basic information.
> >   *
> >   * If session_name is NULL, all sessions are listed.
> >   */
> >  static int list_sessions(const char *session_name)
> >  {
> > -       int ret, count, i;
> > +       int ret = CMD_SUCCESS;
> > +       int count, i;
> >         unsigned int session_found = 0;
> >         struct lttng_session *sessions;
> >
> > @@ -749,25 +1137,25 @@ static int list_sessions(const char *session_name)
> >                 MSG("Available tracing sessions:");
> >         }
> >
> > +
> >         for (i = 0; i < count; i++) {
> >                 if (session_name != NULL) {
> >                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
> >                                 session_found = 1;
> > -                               MSG("Tracing session %s: [%s%s]", session_name,
> > -                                               active_string(sessions[i].enabled),
> > -                                               snapshot_string(sessions[i].snapshot_mode));
> > -                               MSG("%sTrace path: %s\n", indent4, sessions[i].path);
> > +                                       MSG("Tracing session %s: [%s%s]", session_name,
> > +                                                       active_string(sessions[i].enabled),
> > +                                                       snapshot_string(sessions[i].snapshot_mode));
> > +                                       MSG("%sTrace path: %s\n", indent4, sessions[i].path);
> >                                 break;
> >                         }
> >                 } else {
> > -                       MSG("  %d) %s (%s) [%s%s]", i + 1, sessions[i].name, sessions[i].path,
> > -                                       active_string(sessions[i].enabled),
> > -                                       snapshot_string(sessions[i].snapshot_mode));
> > +                               MSG("  %d) %s (%s) [%s%s]", i + 1,
> > +                                               sessions[i].name, sessions[i].path,
> > +                                               active_string(sessions[i].enabled),
> > +                                               snapshot_string(sessions[i].snapshot_mode));
> >                 }
> >         }
> >
> > -       free(sessions);
> > -
> >         if (!session_found && session_name != NULL) {
> >                 ERR("Session '%s' not found", session_name);
> >                 ret = CMD_ERROR;
> > @@ -778,10 +1166,97 @@ static int list_sessions(const char *session_name)
> >                 MSG("\nUse lttng list <session_name> for more details");
> >         }
> >
> > +error:
> > +       free(sessions);
> >  end:
> > -       return CMD_SUCCESS;
> > +       return ret;
> > +}
> >
> > -error:
> > +/*
> > + * Machine interface
> > + * Find the session with session_name as name
> > + * and print his informations.
> > + */
> > +static int mi_list_session(const char *session_name)
> > +{
> > +       int ret, count, i;
> > +       struct lttng_session *sessions;
> > +       unsigned int session_found = 0;
> > +
> > +       count = lttng_list_sessions(&sessions);
> > +       if (count < 0) {
> > +               ret = count;
> > +               ERR("%s", lttng_strerror(ret));
> > +               goto end;
> > +       }
> > +
> > +       if (session_name == NULL) {
> > +               ret = -LTTNG_ERR_SESS_NOT_FOUND;
> > +               goto end;
> > +       }
> > +
> > +       for (i = 0; i < count; i++) {
> > +                       if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
> > +                               /* We need to left it unclosed to append other informations
> 
> left it -> leave it
> 
> I would also say unclosed -> open.
> 
> > +                                * like domain, channel, events etc.*/
> > +                               session_found = 1;
> > +                               ret = mi_lttng_session(writer, &sessions[i], 1);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +                               break;
> > +                       }
> > +       }
> > +
> > +       if (!session_found) {
> > +               ERR("Session not found");
> > +               ret = -LTTNG_ERR_SESS_NOT_FOUND;
> > +               goto end;
> > +       }
> > +
> > +end:
> > +       free(sessions);
> > +       return ret;
> > +}
> > +
> > +/*
> > + * Machine interface
> > + * List all availables session
> > + */
> > +static int mi_list_sessions()
> > +{
> > +       int ret, count, i;
> > +       struct lttng_session *sessions;
> > +
> > +       count = lttng_list_sessions(&sessions);
> > +       if (count < 0) {
> > +               ret = count;
> > +               ERR("%s", lttng_strerror(ret));
> > +               goto end;
> > +       }
> > +
> > +       /* Opening sessions element */
> > +       ret = mi_lttng_sessions_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Listing sessions */
> > +       for (i = 0; i < count; i++) {
> > +               ret = mi_lttng_session(writer, &sessions[i], 0);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +
> > +       /* Closing sessions element */
> > +       ret = mi_lttng_writer_close_element(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +end:
> > +       free(sessions);
> >         return ret;
> >  }
> >
> > @@ -829,6 +1304,39 @@ error:
> >  }
> >
> >  /*
> > + * Machine Interface
> > + * list available domain(s) for a session.
> > + */
> > +static int mi_list_domains(const char *session_name)
> > +{
> > +       int i, count, ret;
> > +       struct lttng_domain *domains = NULL;
> > +
> > +       /* Open domains element */
> > +       ret = mi_lttng_domains_open(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       count = lttng_list_domains(session_name, &domains);
> > +       if (count < 0) {
> > +               ret = count;
> > +               ERR("%s", lttng_strerror(ret));
> > +               goto end;
> > +       }
> > +
> > +       for (i = 0; i < count; i++) {
> > +               ret = mi_lttng_domain(writer, &domains[i] , 0);
> > +       }
> > +
> > +       /* Closing domains element */
> > +       ret = mi_lttng_writer_close_element(writer);
> > +end:
> > +       free(domains);
> > +       return ret;
> > +}
> > +
> > +/*
> >   * The 'list <options>' first level command
> >   */
> >  int cmd_list(int argc, const char **argv)
> > @@ -850,13 +1358,6 @@ int cmd_list(int argc, const char **argv)
> >         pc = poptGetContext(NULL, argc, argv, long_options, 0);
> >         poptReadDefaultConfig(pc, 0);
> >
> > -       /* TODO: mi support */
> > -       if (lttng_opt_mi) {
> > -               ret = -LTTNG_ERR_MI_NOT_IMPLEMENTED;
> > -               ERR("mi option not supported");
> > -               goto end;
> > -       }
> > -
> >         while ((opt = poptGetNextOpt(pc)) != -1) {
> >                 switch (opt) {
> >                 case OPT_HELP:
> > @@ -875,6 +1376,29 @@ int cmd_list(int argc, const char **argv)
> >                 }
> >         }
> >
> > +       /* Mi check */
> > +       if (lttng_opt_mi) {
> > +               writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
> > +               if (!writer) {
> > +                       ret = -LTTNG_ERR_NOMEM;
> > +                       goto end;
> > +               }
> > +
> > +               /* Open command element */
> > +               ret = mi_lttng_writer_command_open(writer,
> > +                               mi_lttng_element_command_list);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +
> > +               /* Open output element */
> > +               ret = mi_lttng_writer_open_element(writer,
> > +                               mi_lttng_element_command_output);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +
> >         /* Get session name (trailing argument) */
> >         session_name = poptGetArg(pc);
> >         DBG2("Session name: %s", session_name);
> > @@ -899,53 +1423,111 @@ int cmd_list(int argc, const char **argv)
> >
> >         if (session_name == NULL) {
> >                 if (!opt_kernel && !opt_userspace && !opt_jul) {
> > -                       ret = list_sessions(NULL);
> > -                       if (ret != 0) {
> > +                       if (lttng_opt_mi) {
> > +                               ret = mi_list_sessions();
> > +                       } else {
> > +                               ret = list_sessions(NULL);
> > +                       }
> > +                       if (ret) {
> >                                 goto end;
> >                         }
> >                 }
> >                 if (opt_kernel) {
> > -                       ret = list_kernel_events();
> > -                       if (ret < 0) {
> > -                               ret = CMD_ERROR;
> > +                       if (lttng_opt_mi) {
> > +                               ret = mi_list_kernel_events();
> > +                       } else {
> > +                               ret = list_kernel_events();
> > +                       }
> > +                       if (ret) {
> >                                 goto end;
> >                         }
> >                 }
> >                 if (opt_userspace) {
> >                         if (opt_fields) {
> > -                               ret = list_ust_event_fields();
> > +                               if (lttng_opt_mi) {
> > +                                       ret = mi_list_ust_event_fields();
> > +                               } else {
> > +                                       ret = list_ust_event_fields();
> > +                               }
> >                         } else {
> > -                               ret = list_ust_events();
> > +                               if (lttng_opt_mi) {
> > +                                       ret = mi_list_jul_ust_events(LTTNG_DOMAIN_UST, 1);
> > +                               } else {
> > +                                       ret = list_ust_events();
> > +                               }
> >                         }
> > -                       if (ret < 0) {
> > -                               ret = CMD_ERROR;
> > +                       if (ret) {
> >                                 goto end;
> >                         }
> >                 }
> >                 if (opt_jul) {
> > -                       ret = list_jul_events();
> > -                       if (ret < 0) {
> > -                               ret = CMD_ERROR;
> > +                       if (lttng_opt_mi) {
> > +                               ret = mi_list_jul_ust_events(LTTNG_DOMAIN_JUL, 1);
> > +                       } else {
> > +                               ret = list_jul_events();
> > +                       }
> > +                       if (ret) {
> >                                 goto end;
> >                         }
> >                 }
> >         } else {
> >                 /* List session attributes */
> > -               ret = list_sessions(session_name);
> > -               if (ret != 0) {
> > +               if (lttng_opt_mi) {
> > +                       /* Open element sessions
> > +                        * Present for xml consistency */
> > +                       ret = mi_lttng_sessions_open(writer);
> > +                       if (ret) {
> > +                               goto end;
> > +                       }
> > +
> > +                       /* MI: the ouptut of list_sessions is an unclosed session element */
> > +                       ret = mi_list_session(session_name);
> > +               } else {
> > +                       ret = list_sessions(session_name);
> > +               }
> > +               if (ret) {
> >                         goto end;
> >                 }
> >
> >                 /* Domain listing */
> >                 if (opt_domain) {
> > -                       ret = list_domains(session_name);
> > +                       if (lttng_opt_mi) {
> > +                               ret = mi_list_domains(session_name);
> > +                       } else {
> > +                               ret = list_domains(session_name);
> > +                       }
> >                         goto end;
> >                 }
> >
> > +               /* Channel listing */
> >                 if (opt_kernel || opt_userspace) {
> > -                       /* Channel listing */
> > -                       ret = list_channels(opt_channel);
> > -                       if (ret < 0) {
> > +                       if (lttng_opt_mi) {
> > +                               /* Add of domains and domain element for xml
> > +                                * consistency and validation
> > +                                */
> > +                               ret = mi_lttng_domains_open(writer);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +
> > +                               /* Open domain and leave it open for
> > +                                * nested channels printing */
> > +                               ret = mi_lttng_domain(writer, &domain, 1);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +
> > +                               ret = mi_list_channels(opt_channel);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +
> > +                               /* Close domain and domain element */
> > +                               ret = mi_lttng_close_multi_element(writer, 2);
> > +                       } else {
> > +                               ret = list_channels(opt_channel);
> > +                       }
> > +                       if (ret) {
> >                                 goto end;
> >                         }
> >                 } else {
> > @@ -959,6 +1541,13 @@ int cmd_list(int argc, const char **argv)
> >                                 goto end;
> >                         }
> >
> > +                       if (lttng_opt_mi) {
> > +                               ret = mi_lttng_domains_open(writer);
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +                       }
> > +
> >                         for (i = 0; i < nb_domain; i++) {
> >                                 switch (domains[i].type) {
> >                                 case LTTNG_DOMAIN_KERNEL:
> > @@ -978,6 +1567,13 @@ int cmd_list(int argc, const char **argv)
> >                                         break;
> >                                 }
> >
> > +                               if (lttng_opt_mi) {
> > +                                       ret = mi_lttng_domain(writer, &domains[i], 1);
> > +                                       if (ret) {
> > +                                               goto end;
> > +                                       }
> > +                               }
> > +
> >                                 /* Clean handle before creating a new one */
> >                                 if (handle) {
> >                                         lttng_destroy_handle(handle);
> > @@ -990,22 +1586,66 @@ int cmd_list(int argc, const char **argv)
> >                                 }
> >
> >                                 if (domains[i].type == LTTNG_DOMAIN_JUL) {
> > -                                       ret = list_session_jul_events();
> > -                                       if (ret < 0) {
> > +                                       if (lttng_opt_mi) {
> > +                                               ret = mi_list_session_jul_events();
> > +                                       } else {
> > +                                               ret = list_session_jul_events();
> > +                                       }
> > +                                       if (ret) {
> >                                                 goto end;
> >                                         }
> >                                         continue;
> >                                 }
> >
> > -                               ret = list_channels(opt_channel);
> > -                               if (ret < 0) {
> > +                               if (lttng_opt_mi) {
> > +                                       ret = mi_list_channels(opt_channel);
> > +                               } else {
> > +                                       ret = list_channels(opt_channel);
> > +                               }
> > +                               if (ret) {
> > +                                       goto end;
> > +                               }
> > +
> > +                               if (lttng_opt_mi) {
> > +                                       /* Close domain element */
> > +                                       ret = mi_lttng_writer_close_element(writer);
> > +                                       if (ret) {
> > +                                               goto end;
> > +                                       }
> > +                               }
> > +
> > +                       }
> > +                       if (lttng_opt_mi) {
> > +                               /* Close the domains, session and sessions element */
> > +                               ret = mi_lttng_close_multi_element(writer, 3);
> > +                               if (ret) {
> >                                         goto end;
> >                                 }
> >                         }
> >                 }
> >         }
> >
> > +       /* Mi closing */
> > +       if (lttng_opt_mi) {
> > +               /* Close  output element */
> > +               ret = mi_lttng_writer_close_element(writer);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +
> > +               /* Command element close */
> > +               ret = mi_lttng_writer_command_close(writer);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> >  end:
> > +       /* Mi clean-up */
> > +       if (writer && mi_lttng_writer_destroy(writer)) {
> > +               /* Preserve original error code */
> > +               ret = ret ? ret : LTTNG_ERR_MI_IO_FAIL;
> > +       }
> > +
> >         free(domains);
> >         if (handle) {
> >                 lttng_destroy_handle(handle);
> > diff --git a/src/common/mi-lttng.c b/src/common/mi-lttng.c
> > index bbec2c5..19af444 100644
> > --- a/src/common/mi-lttng.c
> > +++ b/src/common/mi-lttng.c
> > @@ -16,10 +16,13 @@
> >   * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> >   */
> >
> > +
> >  #include <include/config.h>
> >  #include <common/config/config.h>
> >  #include "mi-lttng.h"
> >
> > +#include <assert.h>
> > +
> >  /* Strings related to command */
> >  const char * const mi_lttng_element_command = "command";
> >  const char * const mi_lttng_element_command_version = "version";
> > @@ -37,6 +40,159 @@ const char * const mi_lttng_element_version_license = "license";
> >  const char * const mi_lttng_element_version_patch_level = "patchLevel";
> >  const char * const mi_lttng_element_version_description = "description";
> >
> > +/* Strings related to pid */
> > +const char * const mi_lttng_element_pids = "pids";
> > +const char * const mi_lttng_element_pid = "pid";
> > +const char * const mi_lttng_element_pid_id = "id";
> > +
> > +/* String related to a lttng_event_field */
> > +const char * const mi_lttng_element_event_field = "event_field";
> > +const char * const mi_lttng_element_event_fields = "event_fields";
> > +
> > +/* General elements of mi_lttng */
> > +const char * const mi_lttng_element_type_other = "OTHER";
> > +const char * const mi_lttng_element_type_integer = "INTEGER";
> > +const char * const mi_lttng_element_type_enum = "ENUM";
> > +const char * const mi_lttng_element_type_float = "FLOAT";
> > +const char * const mi_lttng_element_type_string = "STRING";
> > +const char * const mi_lttng_element_nowrite = "nowrite";
> > +
> > +const char * const mi_lttng_element_empty = "";
> > +
> > +const char *enabled_string(int value)
> > +{
> > +       switch (value) {
> > +       case 0: return " [disabled]";
> > +       case 1: return " [enabled]";
> > +       case -1: return "";
> > +       default: return NULL;
> > +       }
> > +}
> > +
> > +const char *filter_string(int value)
> > +{
> > +       switch (value) {
> > +       case 1: return " [with filter]";
> > +       default: return "";
> > +       }
> > +}
> > +
> > +const char *exclusion_string(int value)
> > +{
> > +       switch (value) {
> > +       case 1: return " [has exclusions]";
> > +       default: return "";
> > +       }
> > +}
> > +
> > +const char *loglevel_string(int value)
> > +{
> > +       switch (value) {
> > +       case -1:
> > +               return "";
> > +       case LTTNG_LOGLEVEL_EMERG:
> > +               return "TRACE_EMERG";
> > +       case LTTNG_LOGLEVEL_ALERT:
> > +               return "TRACE_ALERT";
> > +       case LTTNG_LOGLEVEL_CRIT:
> > +               return "TRACE_CRIT";
> > +       case LTTNG_LOGLEVEL_ERR:
> > +               return "TRACE_ERR";
> > +       case LTTNG_LOGLEVEL_WARNING:
> > +               return "TRACE_WARNING";
> > +       case LTTNG_LOGLEVEL_NOTICE:
> > +               return "TRACE_NOTICE";
> > +       case LTTNG_LOGLEVEL_INFO:
> > +               return "TRACE_INFO";
> > +       case LTTNG_LOGLEVEL_DEBUG_SYSTEM:
> > +               return "TRACE_DEBUG_SYSTEM";
> > +       case LTTNG_LOGLEVEL_DEBUG_PROGRAM:
> > +               return "TRACE_DEBUG_PROGRAM";
> > +       case LTTNG_LOGLEVEL_DEBUG_PROCESS:
> > +               return "TRACE_DEBUG_PROCESS";
> > +       case LTTNG_LOGLEVEL_DEBUG_MODULE:
> > +               return "TRACE_DEBUG_MODULE";
> > +       case LTTNG_LOGLEVEL_DEBUG_UNIT:
> > +               return "TRACE_DEBUG_UNIT";
> > +       case LTTNG_LOGLEVEL_DEBUG_FUNCTION:
> > +               return "TRACE_DEBUG_FUNCTION";
> > +       case LTTNG_LOGLEVEL_DEBUG_LINE:
> > +               return "TRACE_DEBUG_LINE";
> > +       case LTTNG_LOGLEVEL_DEBUG:
> > +               return "TRACE_DEBUG";
> > +       default:
> > +               return "UNKNOWN";
> > +       }
> > +}
> > +
> > +const char *logleveltype_string(enum lttng_loglevel_type value)
> > +{
> > +       switch (value) {
> > +       case LTTNG_EVENT_LOGLEVEL_ALL:
> > +               return ":";
> > +       case LTTNG_EVENT_LOGLEVEL_RANGE:
> > +               return " <=";
> > +       case LTTNG_EVENT_LOGLEVEL_SINGLE:
> > +               return " ==";
> > +       default:
> > +               return " TYPE UNKN";
> > +       }
> > +}
> > +
> > +const char *eventtype_string(enum lttng_event_type value)
> > +{
> > +       switch (value) {
> > +       case LTTNG_EVENT_ALL:
> > +               return config_event_type_all;
> > +               break;
> > +       case LTTNG_EVENT_TRACEPOINT:
> > +               return config_event_type_tracepoint;
> > +               break;
> > +       case LTTNG_EVENT_PROBE:
> > +               return config_event_type_probe;
> > +               break;
> > +       case LTTNG_EVENT_FUNCTION:
> > +               return config_event_type_function;
> > +               break;
> > +       case LTTNG_EVENT_FUNCTION_ENTRY:
> > +               return config_event_type_function_entry;
> > +               break;
> > +       case LTTNG_EVENT_SYSCALL:
> > +               return config_event_type_syscall;
> > +               break;
> > +       case LTTNG_EVENT_NOOP:
> > +               return config_event_type_noop;
> > +               break;
> > +       default:
> > +               return mi_lttng_element_empty;
> > +               break;
> > +       }
> > +}
> > +
> > +const char *eventfieldtype_string(enum lttng_event_field_type val)
> > +{
> > +       const char *ret;
> > +
> > +       switch (val) {
> > +       case(LTTNG_EVENT_FIELD_INTEGER):
> > +               ret = mi_lttng_element_type_integer;
> > +               break;
> > +       case(LTTNG_EVENT_FIELD_ENUM):
> > +               ret = mi_lttng_element_type_enum;
> > +               break;
> > +       case(LTTNG_EVENT_FIELD_FLOAT):
> > +               ret = mi_lttng_element_type_float;
> > +               break;
> > +       case(LTTNG_EVENT_FIELD_STRING):
> > +               ret = mi_lttng_element_type_string;
> > +               break;
> > +       default:
> > +               ret = mi_lttng_element_type_other;
> > +               break;
> > +       }
> > +       return ret;
> > +}
> > +
> >  LTTNG_HIDDEN
> >  struct mi_writer *mi_lttng_writer_create(int fd_output, int mi_output_type)
> >  {
> > @@ -119,6 +275,25 @@ int mi_lttng_writer_close_element(struct mi_writer *writer)
> >  }
> >
> >  LTTNG_HIDDEN
> > +int mi_lttng_close_multi_element(struct mi_writer *writer,
> > +               unsigned int nb_element)
> > +{
> > +       int ret, i;
> > +       if (nb_element < 1) {
> > +               ret = 0;
> > +               goto end;
> > +       }
> > +       for (i = 0; i < nb_element; i++) {
> > +               ret = mi_lttng_writer_close_element(writer);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +end:
> > +       return ret;
> > +}
> > +
> > +LTTNG_HIDDEN
> >  int mi_lttng_writer_write_element_unsigned_int(struct mi_writer *writer,
> >                 const char *element_name, uint64_t value)
> >  {
> > @@ -226,12 +401,20 @@ end:
> >  }
> >
> >  LTTNG_HIDDEN
> > +int mi_lttng_sessions_open(struct mi_writer *writer)
> > +{
> > +       return mi_lttng_writer_open_element(writer, config_element_sessions);
> > +}
> > +
> > +LTTNG_HIDDEN
> >  int mi_lttng_session(struct mi_writer *writer,
> >                 struct lttng_session *session, int is_open)
> >  {
> >         int ret;
> >
> > -       /* open sessions element */
> > +       assert(session);
> > +
> > +       /* Open sessions element */
> >         ret = mi_lttng_writer_open_element(writer,
> >                         config_element_session);
> >         if (ret) {
> > @@ -245,28 +428,28 @@ int mi_lttng_session(struct mi_writer *writer,
> >                 goto end;
> >         }
> >
> > -       /* path */
> > +       /* Path */
> >         ret = mi_lttng_writer_write_element_string(writer,
> >                         config_element_path, session->path);
> >         if (ret) {
> >                 goto end;
> >         }
> >
> > -       /* enabled ? */
> > -       ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +       /* Enabled ? */
> > +       ret = mi_lttng_writer_write_element_bool(writer,
> >                         config_element_enabled, session->enabled);
> >         if (ret) {
> >                 goto end;
> >         }
> >
> > -       /* snapshot mode */
> > +       /* Snapshot mode */
> >         ret = mi_lttng_writer_write_element_unsigned_int(writer,
> >                         config_element_snapshot_mode, session->snapshot_mode);
> >         if (ret) {
> >                 goto end;
> >         }
> >
> > -       /* live timer interval in usec */
> > +       /* Live timer interval in usec */
> >         ret = mi_lttng_writer_write_element_unsigned_int(writer,
> >                         config_element_live_timer_interval,
> >                         session->live_timer_interval);
> > @@ -282,3 +465,493 @@ end:
> >         return ret;
> >
> >  }
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_domains_open(struct mi_writer *writer)
> > +{
> > +       return mi_lttng_writer_open_element(writer, config_element_domains);
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_domain(struct mi_writer *writer,
> > +               struct lttng_domain *domain, int is_open)
> > +{
> > +       int ret = 0;
> > +       const char *str_domain;
> > +       const char *str_buffer;
> > +
> > +       assert(domain);
> > +
> > +       /* Open domain element */
> > +       ret = mi_lttng_writer_open_element(writer, config_element_domain);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Type
> > +        * Note: This is a *duplicate* of get_domain_str from bin/lttng/utils.c
> > +        */
> > +       switch (domain->type) {
> > +       case LTTNG_DOMAIN_KERNEL:
> > +               str_domain = config_domain_type_kernel;
> > +               break;
> > +       case LTTNG_DOMAIN_UST:
> > +               str_domain = config_domain_type_ust;
> > +               break;
> > +       case LTTNG_DOMAIN_JUL:
> > +               str_domain = config_domain_type_jul;
> > +               break;
> > +       default:
> > +               /* Should not have an unknown domain */
> > +               assert(0);
> > +       }
> > +
> > +       ret = mi_lttng_writer_write_element_string(writer, config_element_type,
> > +                       str_domain);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Buffer Type */
> > +       switch (domain->buf_type) {
> > +       case LTTNG_BUFFER_PER_PID:
> > +               str_buffer = config_buffer_type_per_pid;
> > +               break;
> > +       case LTTNG_BUFFER_PER_UID:
> > +               str_buffer = config_buffer_type_per_uid;
> > +               break;
> > +       case LTTNG_BUFFER_GLOBAL:
> > +               str_buffer = config_buffer_type_global;
> > +               break;
> > +       default:
> > +               /* Shoul not have an unknow buffer type */
> > +               assert(0);
> > +       }
> > +
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +                       config_element_buffer_type, str_buffer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* TODO: attr... not sure how to use the union.... */
> > +
> > +       if (!is_open) {
> > +               /* Closing domain element */
> > +               ret = mi_lttng_writer_close_element(writer);
> > +       }
> > +
> > +end:
> > +       return ret;
> > +
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_channels_open(struct mi_writer *writer)
> > +{
> > +       return mi_lttng_writer_open_element(writer, config_element_channels);
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_channel(struct mi_writer *writer,
> > +               struct lttng_channel *channel, int is_open)
> > +{
> > +       int ret = 0;
> > +
> > +       assert(channel);
> > +
> > +       /* Opening channel element */
> > +       ret = mi_lttng_writer_open_element(writer, config_element_channel);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +       /* Name */
> > +       ret = mi_lttng_writer_write_element_string(writer, config_element_name,
> > +                       channel->name);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Enabled ? */
> > +       ret = mi_lttng_writer_write_element_bool(writer,
> > +                       config_element_enabled, channel->enabled);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Attribute */
> > +       ret = mi_lttng_channel_attr(writer, &channel->attr);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       if (!is_open) {
> > +               /* Closing channel element */
> > +               ret = mi_lttng_writer_close_element(writer);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +end:
> > +       return ret;
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_channel_attr(struct mi_writer *writer,
> > +               struct lttng_channel_attr *attr)
> > +{
> > +       int ret = 0;
> > +
> > +       assert(attr);
> > +
> > +       /* Opening Attributes */
> > +       ret = mi_lttng_writer_open_element(writer, config_element_attributes);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Overwrite */
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +               config_element_overwrite_mode,
> > +               attr->overwrite ? config_overwrite_mode_overwrite :
> > +                       config_overwrite_mode_discard);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Sub buffer size in byte */
> > +       ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +               config_element_subbuf_size, attr->subbuf_size);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Number of sub buffer (power of two) */
> > +       ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +               config_element_num_subbuf,
> > +               attr->num_subbuf);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Switch timer interval in usec */
> > +       ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +               config_element_switch_timer_interval,
> > +               attr->switch_timer_interval);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Read timer interval in usec */
> > +       ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +               config_element_read_timer_interval,
> > +               attr->read_timer_interval);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Event output */
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +               config_element_output_type,
> > +               attr->output == LTTNG_EVENT_SPLICE ?
> > +               config_output_type_splice : config_output_type_mmap);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Tracefile size in bytes */
> > +       ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +               config_element_tracefile_size, attr->tracefile_size);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Count of tracefiles */
> > +       ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +               config_element_tracefile_count,
> > +               attr->tracefile_count);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Live timer interval in usec*/
> > +       ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +               config_element_live_timer_interval,
> > +               attr->live_timer_interval);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Closing attributes */
> > +       ret = mi_lttng_writer_close_element(writer);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +end:
> > +       return ret;
> > +
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_event_common_attributes(struct mi_writer *writer,
> > +               struct lttng_event *event)
> > +{
> > +       int ret;
> > +
> > +       /* Open event element */
> > +       ret = mi_lttng_writer_open_element(writer, config_element_event);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* event name */
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +                       config_element_name, event->name);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* event type */
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +                       config_element_type, eventtype_string(event->type));
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* is event enabled */
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +                       config_element_enabled, enabled_string(event->enabled));
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* event filter */
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +                       config_element_filter, filter_string(event->filter));
> > +
> > +end:
> > +       return ret;
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_event_tracepoint_loglevel(struct mi_writer *writer,
> > +               struct lttng_event *event)
> > +{
> > +       int ret;
> > +
> > +       /* event loglevel */
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +                       config_element_loglevel, loglevel_string(event->loglevel));
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* event exclusion filter */
> > +       ret = mi_lttng_writer_write_element_string(writer,
> > +                       config_element_exclusion, exclusion_string(event->exclusion));
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +end:
> > +       return ret;
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_event_tracepoint_no_loglevel(struct mi_writer *writer,
> > +               struct lttng_event *event)
> > +{
> > +       /* event exclusion filter */
> > +       return mi_lttng_writer_write_element_string(writer,
> > +                       config_element_exclusion, exclusion_string(event->exclusion));
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_event_function_probe(struct mi_writer *writer,
> > +               struct lttng_event *event)
> > +{
> > +       int ret;
> > +
> > +       if (event->attr.probe.addr != 0) {
> > +               /* event probe address */
> > +               ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +                               config_element_address, event->attr.probe.addr);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       } else {
> > +               /* event probe offset */
> > +               ret = mi_lttng_writer_write_element_unsigned_int(writer,
> > +                               config_element_offset, event->attr.probe.offset);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +
> > +               /* event probe symbol_name */
> > +               ret = mi_lttng_writer_write_element_string(writer,
> > +                               config_element_symbol_name, event->attr.probe.symbol_name);
> > +               if (ret) {
> > +                       goto end;
> > +               }
> > +       }
> > +end:
> > +       return ret;
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_event_function_entry(struct mi_writer *writer,
> > +               struct lttng_event *event)
> > +{
> > +       /* event probe symbol_name */
> > +       return mi_lttng_writer_write_element_string(writer,
> > +                       config_element_symbol_name, event->attr.ftrace.symbol_name);
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_events_open(struct mi_writer *writer)
> > +{
> > +       return mi_lttng_writer_open_element(writer, config_element_events);
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_event(struct mi_writer *writer,
> > +               struct lttng_event *event, int is_open)
> > +{
> > +       int ret;
> > +
> > +       ret = mi_lttng_event_common_attributes(writer, event);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       switch (event->type) {
> > +       case LTTNG_EVENT_ALL:
> > +               /* We should never have "all" events in list. */
> > +               assert(0);
> > +               break;
> > +       case LTTNG_EVENT_TRACEPOINT:
> > +       {
> > +               if (event->loglevel != -1) {
> > +                       ret = mi_lttng_event_tracepoint_loglevel(writer, event);
> > +               } else {
> > +                       ret = mi_lttng_event_tracepoint_no_loglevel(writer, event);
> > +               }
> > +               break;
> > +       }
> > +       case LTTNG_EVENT_PROBE:
> > +               ret = mi_lttng_event_function_probe(writer, event);
> > +               break;
> > +       case LTTNG_EVENT_FUNCTION_ENTRY:
> > +               ret = mi_lttng_event_function_entry(writer, event);
> > +               break;
> > +       default:
> > +               break;
> > +       }
> > +
> > +       if (!is_open) {
> > +               ret = mi_lttng_writer_close_element(writer);
> > +       }
> > +
> > +end:
> > +       return ret;
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_pids_open(struct mi_writer *writer)
> > +{
> > +       return mi_lttng_writer_open_element(writer, mi_lttng_element_pids);
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_pid(struct mi_writer *writer, pid_t pid , const char *cmdline,
> > +               int is_open)
> > +{
> > +       int ret;
> > +
> > +       /* Open element pid */
> > +       ret = mi_lttng_writer_open_element(writer, mi_lttng_element_pid);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Writing pid number */
> > +       ret = mi_lttng_writer_write_element_signed_int(writer,
> > +                       mi_lttng_element_pid_id, (int)pid);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Writing name of the process */
> > +       ret = mi_lttng_writer_write_element_string(writer, config_element_name,
> > +                       cmdline);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       if (!is_open) {
> > +               /* Closing Pid */
> > +               ret = mi_lttng_writer_close_element(writer);
> > +       }
> > +
> > +end:
> > +       return ret;
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_event_fields_open(struct mi_writer *writer)
> > +{
> > +       return mi_lttng_writer_open_element(writer, mi_lttng_element_event_fields);
> > +}
> > +
> > +LTTNG_HIDDEN
> > +int mi_lttng_event_field(struct mi_writer *writer,
> > +               struct lttng_event_field *field)
> > +{
> > +       int ret;
> > +
> > +       if (!field->field_name[0]) {
> > +               /* To Review: not sure if legal david ?
> > +                * how should this be handle ?
> > +                */
> > +               ret = 0;
> > +               goto end;
> > +       }
> > +
> > +       /* Open field */
> > +       ret = mi_lttng_writer_open_element(writer, mi_lttng_element_event_field);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       if (!field->field_name[0]) {
> > +               goto close;
> > +       }
> > +
> > +       /* Name */
> > +       ret = mi_lttng_writer_write_element_string(writer, config_element_name,
> > +                       field->field_name);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* Type */
> > +       ret = mi_lttng_writer_write_element_string(writer, config_element_type,
> > +                       eventfieldtype_string(field->type));
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +       /* nowrite  */
> > +       ret = mi_lttng_writer_write_element_signed_int(writer,
> > +                       mi_lttng_element_nowrite, field->nowrite);
> > +       if (ret) {
> > +               goto end;
> > +       }
> > +
> > +close:
> > +       /* Close field element */
> > +       ret = mi_lttng_writer_close_element(writer);
> > +
> > +end:
> > +       return ret;
> > +}
> > diff --git a/src/common/mi-lttng.h b/src/common/mi-lttng.h
> > index 69ec0f5..33b5547 100644
> > --- a/src/common/mi-lttng.h
> > +++ b/src/common/mi-lttng.h
> > @@ -63,6 +63,31 @@ const char * const mi_lttng_element_version_license;
> >  const char * const mi_lttng_element_version_patch_level;
> >  const char * const mi_lttng_element_version_description;
> >
> > +/* String related to a lttng_event_field */
> > +const char * const mi_lttng_element_event_field;
> > +const char * const mi_lttng_element_event_fields;
> > +
> > +/* Strings related to pid */
> > +const char * const mi_lttng_element_pids;
> > +const char * const mi_lttng_element_pid;
> > +const char * const mi_lttng_element_pid_id;
> > +
> > +/* General element of mi_lttng */
> > +const char * const mi_lttng_element_type_other;
> > +const char * const mi_lttng_element_type_integer;
> > +const char * const mi_lttng_element_type_enum;
> > +const char * const mi_lttng_element_type_float;
> > +const char * const mi_lttng_element_type_string;
> > +const char * const mi_lttng_element_nowrite;
> > +
> > +/* Utility string function  */
> > +const char *enabled_string(int value);
> > +const char *filter_string(int value);
> > +const char *exclusion_string(int value);
> > +const char *loglevel_string(int value);
> > +const char *logleveltype_string(enum lttng_loglevel_type value);
> > +const char *eventfieldtype_string(enum lttng_event_field_type value);
> > +
> >  /*
> >   * Create an instance of a machine interface writer.
> >   *
> > @@ -130,6 +155,19 @@ int mi_lttng_writer_open_element(struct mi_writer *writer,
> >  int mi_lttng_writer_close_element(struct mi_writer *writer);
> >
> >  /*
> > + * Close multiple element .
> > + *
> > + * writer An instance of a machine interface writer.
> > + *
> > + * nb_element
> > + *
> > + * Returns zero if the XML document could be closed cleanly.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_close_multi_element(struct mi_writer *writer,
> > +               unsigned int nb_element);
> > +
> > +/*
> >   * Write an element of type unsigned int.
> >   *
> >   * writer An instance of a machine interface writer.
> > @@ -207,24 +245,271 @@ int mi_lttng_version(struct mi_writer *writer, struct mi_lttng_version *version,
> >                 const char *lttng_description, const char *lttng_license);
> >
> >  /*
> > + * Machine interface: open a sessions element.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_sessions_open(struct mi_writer *writer);
> > +
> > +/*
> >   * Machine interface of struct session.
> >   *
> >   * writer An instance of a machine interface writer
> >   *
> >   * session An instance of a session
> >   *
> > - * isOpen Define if we close the session element
> > - *        This should be use carefully and the client
> > - *        need to close the session element.
> > - *        Use case: nested addition information on a session
> > + * is_open Define if we close the session element
> > + *         This should be used carefully and the client
> > + *         need to close the session element.
> > + *         Use case: nested addtionnal information on a session
> >   *                  ex: domain,channel event.
> > - *        0-> False
> > - *        1-> True
> > + *         0-> False
> > + *         1-> True
> >   *
> >   * Returns zero if the element's value could be written.
> >   * Negative values indicate an error.
> >   */
> >  int mi_lttng_session(struct mi_writer *writer,
> > -               struct lttng_session *session, int isOpen);
> > +               struct lttng_session *session, int is_open);
> > +
> > +/*
> > + * Machine interface: open a domains element.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_domains_open(struct mi_writer *writer);
> > +
> > +/*
> > + * Machine interface of struct domain.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * domain An instance of a domain
> > + *
> > + * is_open Define if we close the domain element
> > + *         This should be used carefully and the client
> > + *         need to close the domain element.
> > + *         Use case: nested addition information on a domain
> > + *                  ex: channel event.
> > + *         0-> False
> > + *         1-> True
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_domain(struct mi_writer *writer,
> > +               struct lttng_domain *domain, int is_open);
> > +
> > +/*
> > + * Machine interface: open a channels element.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_channels_open(struct mi_writer *writer);
> > +
> > +/*
> > + * Machine interface of struct channel.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * channel An instance of a channel
> > + *
> > + * is_open Define if we close the channel element
> > + *         This should be used carefully and the client
> > + *         need to close the channel element.
> > + *         Use case: nested addition information on a domain
> > + *                  ex: channel event.
> > + *         0-> False
> > + *         1-> True
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_channel(struct mi_writer *writer,
> > +               struct lttng_channel *channel, int is_open);
> > +
> > +/*
> > + * Machine interface of struct channel_attr.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * attr An instance of a channel_attr struct
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_channel_attr(struct mi_writer *writer,
> > +               struct lttng_channel_attr *attr);
> > +
> > +/*
> > +* Machine interface for event common attribute.
> > +*
> > +* writer An instance of a mi writer.
> > +*
> > +* event single trace event.
> > +*
> > +* The common attribute are:
> > +* - mi event element
> > +* - event name
> > +* - event type
> > +* - enabled tag
> > +* - event filter
> > +*
> > +* Returns zero if the element's value could be written.
> > +* Negative values indicate an error.
> > +*/
> > +int mi_lttng_event_common_attributes(struct mi_writer *writer,
> > +               struct lttng_event *event);
> > +
> > +/*
> > + * Machine interface for kernel tracepoint event with a loglevel.
> > + *
> > + * writer An instance of a mi writer.
> > + *
> > + * event single trace event.
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_event_tracepoint_loglevel(struct mi_writer *writer,
> > +               struct lttng_event *event);
> > +
> > +/*
> > + * Machine interface for kernel tracepoint event with no loglevel.
> > + *
> > + * writer An instance of a mi writer.
> > + *
> > + * event single trace event.
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_event_tracepoint_no_loglevel(struct mi_writer *writer,
> > +               struct lttng_event *event);
> > +
> > +/*
> > + * Machine interface for kernel function and probe event.
> > + *
> > + * writer An instance of a mi writer.
> > + *
> > + * event single trace event.
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_event_function_probe(struct mi_writer *writer,
> > +               struct lttng_event *event);
> > +
> > +/*
> > + * Machine interface for kernel function entry event.
> > + *
> > + * writer An instance of a mi writer.
> > + *
> > + * event single trace event.
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_event_function_entry(struct mi_writer *writer,
> > +               struct lttng_event *event);
> > +
> > +/*
> > + * Machine interface: open an events element.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_events_open(struct mi_writer *writer);
> > +
> > +/*
> > + * Machine interface for printing an event.
> > + * The trace event type currently supported are:
> > + *  TRACEPOINT,
> > + *  PROBE,
> > + *  FUNCTION,
> > + *  FUNCTION_ENTRY,
> > + *  SYSCALL
> > + *
> > + * writer An instance of a mi writer.
> > + *
> > + * event single trace event.
> > + *
> > + * is_open Define if we close the event element
> > + *         This should be used carefully and the client
> > + *         need to close the event element.
> > + *         Use case: nested additional information
> > + *         0-> False
> > + *         1-> True
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_event(struct mi_writer *writer, struct lttng_event *event,
> > +               int is_open);
> > +
> > +/*
> > + * Machine interface for struct lttng_event_field .
> > + *
> > + * writer An instance of a mi writer.
> > + *
> > + * field An event_field instance.
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_event_field(struct mi_writer *writer,
> > +               struct lttng_event_field *field);
> > +
> > +/*
> > + * Machine interface: open a event_fields element.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_event_fields_open(struct mi_writer *writer);
> > +
> > +/*
> > + * Machine interface: open a pids element.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_pids_open(struct mi_writer *writer);
> > +
> > +/*
> > + * Machine interface of a pid.
> > + *
> > + * writer An instance of a machine interface writer
> > + *
> > + * pid A pid
> > + *
> > + * is_open Define if we close the pid element
> > + *         This should be used carefully and the client
> > + *         need to close the pid element.
> > + *         Use case: nested addition information on a domain
> > + *                  ex: channel event.
> > + *         0-> False
> > + *         1-> True
> > + *
> > + * Returns zero if the element's value could be written.
> > + * Negative values indicate an error.
> > + */
> > +int mi_lttng_pid(struct mi_writer *writer, pid_t pid , const char *cmdline,
> > +               int is_open);
> >
> >  #endif /* _MI_LTTNG_H */
> > --
> > 1.8.3.2
> >
> >
> > _______________________________________________
> > lttng-dev mailing list
> > lttng-dev at lists.lttng.org
> > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev



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