/*
 * Manipulation routines for Job Control Records and
 *  handling of last_jobs_list.
 *
 *  Kern E. Sibbald, December 2000
 *
 *  Version $Id: jcr.c,v 1.75.2.8 2006/03/28 16:56:33 kerns Exp $
 *
 *  These routines are thread safe.
 *
 *  The job list routines were re-written in May 2005 to
 *  eliminate the global lock while traversing the list, and
 *  to use the dlist subroutines.  The locking is now done
 *  on the list each time the list is modified or traversed.
 *  That is it is "micro-locked" rather than globally locked.
 *  The result is that there is one lock/unlock for each entry
 *  in the list while traversing it rather than a single lock
 *  at the beginning of a traversal and one at the end.  This
 *  incurs slightly more overhead, but effectively eliminates 
 *  the possibilty of race conditions.  In addition, with the
 *  exception of the global locking of the list during the
 *  re-reading of the config file, no recursion is needed.
 *
 */
/*
   Copyright (C) 2000-2006 Kern Sibbald

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   version 2 as amended with additional clauses defined in the
   file LICENSE in the main source directory.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
   the file LICENSE for additional details.

 */

#include "bacula.h"
#include "jcr.h"

/* External variables we reference */
extern time_t watchdog_time;

/* Forward referenced functions */
extern "C" void timeout_handler(int sig);
static void jcr_timeout_check(watchdog_t *self);
#ifdef TRACE_JCR_CHAIN
static void b_lock_jcr_chain(const char *filen, int line);
static void b_unlock_jcr_chain(const char *filen, int line);
#define lock_jcr_chain() b_lock_jcr_chain(__FILE__, __LINE__);
#define unlock_jcr_chain() b_unlock_jcr_chain(__FILE__, __LINE__);
#else
static void lock_jcr_chain();
static void unlock_jcr_chain();
#endif


int num_jobs_run;
dlist *last_jobs = NULL;
const int max_last_jobs = 10;
 
static dlist *jcrs = NULL;            /* JCR chain */
static pthread_mutex_t jcr_lock = PTHREAD_MUTEX_INITIALIZER;

static pthread_mutex_t job_start_mutex = PTHREAD_MUTEX_INITIALIZER;

static pthread_mutex_t last_jobs_mutex = PTHREAD_MUTEX_INITIALIZER;


void lock_jobs()
{
   P(job_start_mutex);
}

void unlock_jobs()
{
   V(job_start_mutex);
}

void init_last_jobs_list()
{
   JCR *jcr = NULL;
   struct s_last_job *job_entry = NULL;
   if (!last_jobs) {
      last_jobs = New(dlist(job_entry, &job_entry->link));
   }
   if (!jcrs) {
      jcrs = New(dlist(jcr, &jcr->link));
   }
}

void term_last_jobs_list()
{
   if (last_jobs) {
      while (!last_jobs->empty()) {
         void *je = last_jobs->first();
         last_jobs->remove(je);
         free(je);
      }
      delete last_jobs;
      last_jobs = NULL;
   }
   if (jcrs) {
      delete jcrs;
      jcrs = NULL;
   }
}

bool read_last_jobs_list(int fd, uint64_t addr)
{
   struct s_last_job *je, job;
   uint32_t num;

   Dmsg1(100, "read_last_jobs seek to %d\n", (int)addr);
   if (addr == 0 || lseek(fd, (off_t)addr, SEEK_SET) < 0) {
      return false;
   }
   if (read(fd, &num, sizeof(num)) != sizeof(num)) {
      return false;
   }
   Dmsg1(100, "Read num_items=%d\n", num);
   if (num > 4 * max_last_jobs) {  /* sanity check */
      return false;
   }
   for ( ; num; num--) {
      if (read(fd, &job, sizeof(job)) != sizeof(job)) {
         Dmsg1(000, "Read job entry. ERR=%s\n", strerror(errno));
         return false;
      }
      if (job.JobId > 0) {
         je = (struct s_last_job *)malloc(sizeof(struct s_last_job));
         memcpy((char *)je, (char *)&job, sizeof(job));
         if (!last_jobs) {
            init_last_jobs_list();
         }
         last_jobs->append(je);
         if (last_jobs->size() > max_last_jobs) {
            je = (struct s_last_job *)last_jobs->first();
            last_jobs->remove(je);
            free(je);
         }
      }
   }
   return true;
}

uint64_t write_last_jobs_list(int fd, uint64_t addr)
{
   struct s_last_job *je;
   uint32_t num;

   Dmsg1(100, "write_last_jobs seek to %d\n", (int)addr);
   if (lseek(fd, (off_t)addr, SEEK_SET) < 0) {
      return 0;
   }
   if (last_jobs) {
      /* First record is number of entires */
      num = last_jobs->size();
      if (write(fd, &num, sizeof(num)) != sizeof(num)) {
         Dmsg1(000, "Error writing num_items: ERR=%s\n", strerror(errno));
         return 0;
      }
      foreach_dlist(je, last_jobs) {
         if (write(fd, je, sizeof(struct s_last_job)) != sizeof(struct s_last_job)) {
            Dmsg1(000, "Error writing job: ERR=%s\n", strerror(errno));
            return 0;
         }
      }
   }
   /* Return current address */
   ssize_t stat = lseek(fd, 0, SEEK_CUR);
   if (stat < 0) {
      stat = 0;
   }
   return stat;

}

void lock_last_jobs_list()
{
   P(last_jobs_mutex);
}

void unlock_last_jobs_list()
{
   V(last_jobs_mutex);
}

/*
 * Push a subroutine address into the job end callback stack
 */
void job_end_push(JCR *jcr, void job_end_cb(JCR *jcr,void *), void *ctx)
{
   jcr->job_end_push.append((void *)job_end_cb);
   jcr->job_end_push.append(ctx);
}

/* Pop each job_end subroutine and call it */
static void job_end_pop(JCR *jcr)
{
   void (*job_end_cb)(JCR *jcr, void *ctx);
   void *ctx;
   for (int i=jcr->job_end_push.size()-1; i > 0; ) {
      ctx = jcr->job_end_push.get(i--);
      job_end_cb = (void (*)(JCR *,void *))jcr->job_end_push.get(i--);
      job_end_cb(jcr, ctx);
   }
}

/*
 * Create a Job Control Record and link it into JCR chain
 * Returns newly allocated JCR
 * Note, since each daemon has a different JCR, he passes
 *  us the size.
 */
JCR *new_jcr(int size, JCR_free_HANDLER *daemon_free_jcr)
{
   JCR *jcr;
   MQUEUE_ITEM *item = NULL;
   struct sigaction sigtimer;

   Dmsg0(3400, "Enter new_jcr\n");
   jcr = (JCR *)malloc(size);
   memset(jcr, 0, size);
   jcr->my_thread_id = pthread_self();
   jcr->msg_queue = New(dlist(item, &item->link));
   jcr->job_end_push.init(1, false);
   jcr->sched_time = time(NULL);
   jcr->daemon_free_jcr = daemon_free_jcr;    /* plug daemon free routine */
   jcr->init_mutex();
   jcr->inc_use_count();   
   jcr->JobStatus = JS_Created;       /* ready to run */
   jcr->VolumeName = get_pool_memory(PM_FNAME);
   jcr->VolumeName[0] = 0;
   jcr->errmsg = get_pool_memory(PM_MESSAGE);
   jcr->errmsg[0] = 0;
   /* Setup some dummy values */
   bstrncpy(jcr->Job, "*System*", sizeof(jcr->Job));
   jcr->JobId = 0;
   jcr->JobType = JT_SYSTEM;          /* internal job until defined */
   jcr->JobLevel = L_NONE;
   jcr->JobStatus = JS_Created;

   sigtimer.sa_flags = 0;
   sigtimer.sa_handler = timeout_handler;
   sigfillset(&sigtimer.sa_mask);
   sigaction(TIMEOUT_SIGNAL, &sigtimer, NULL);

   /*
    * Locking jobs is a global lock that is needed
    * so that the Director can stop new jobs from being
    * added to the jcr chain while it processes a new
    * conf file and does the job_end_push().
    */
   lock_jobs();
   lock_jcr_chain();
   if (!jcrs) {
      jcrs = New(dlist(jcr, &jcr->link));
   }
   jcrs->append(jcr);
   unlock_jcr_chain();
   unlock_jobs();

   return jcr;
}


/*
 * Remove a JCR from the chain
 * NOTE! The chain must be locked prior to calling
 *       this routine.
 */
static void remove_jcr(JCR *jcr)
{
   Dmsg0(3400, "Enter remove_jcr\n");
   if (!jcr) {
      Emsg0(M_ABORT, 0, _("NULL jcr.\n"));
   }
   jcrs->remove(jcr);
   Dmsg0(3400, "Leave remove_jcr\n");
}

/*
 * Free stuff common to all JCRs.  N.B. Be careful to include only
 *  generic stuff in the common part of the jcr.
 */
static void free_common_jcr(JCR *jcr)
{
   struct s_last_job *je, last_job;

   /* Keep some statistics */
   switch (jcr->JobType) {
   case JT_BACKUP:
   case JT_VERIFY:
   case JT_RESTORE:
   case JT_MIGRATE:
   case JT_COPY:
   case JT_ADMIN:
      num_jobs_run++;
      last_job.Errors = jcr->Errors;
      last_job.JobType = jcr->JobType;
      last_job.JobId = jcr->JobId;
      last_job.VolSessionId = jcr->VolSessionId;
      last_job.VolSessionTime = jcr->VolSessionTime;
      bstrncpy(last_job.Job, jcr->Job, sizeof(last_job.Job));
      last_job.JobFiles = jcr->JobFiles;
      last_job.JobBytes = jcr->JobBytes;
      last_job.JobStatus = jcr->JobStatus;
      last_job.JobLevel = jcr->JobLevel;
      last_job.start_time = jcr->start_time;
      last_job.end_time = time(NULL);
      /* Keep list of last jobs, but not Console where JobId==0 */
      if (last_job.JobId > 0) {
         je = (struct s_last_job *)malloc(sizeof(struct s_last_job));
         memcpy((char *)je, (char *)&last_job, sizeof(last_job));
         if (!last_jobs) {
            init_last_jobs_list();
         }
         last_jobs->append(je);
         if (last_jobs->size() > max_last_jobs) {
            je = (struct s_last_job *)last_jobs->first();
            last_jobs->remove(je);
            free(je);
         }
      }
      break;
   default:
      break;
   }
   jcr->destroy_mutex();

   delete jcr->msg_queue;
   close_msg(jcr);                    /* close messages for this job */

   /* do this after closing messages */
   if (jcr->client_name) {
      free_pool_memory(jcr->client_name);
      jcr->client_name = NULL;
   }

   if (jcr->attr) {
      free_pool_memory(jcr->attr);
      jcr->attr = NULL;
   }

   if (jcr->sd_auth_key) {
      free(jcr->sd_auth_key);
      jcr->sd_auth_key = NULL;
   }
   if (jcr->VolumeName) {
      free_pool_memory(jcr->VolumeName);
      jcr->VolumeName = NULL;
   }

   if (jcr->dir_bsock) {
      bnet_close(jcr->dir_bsock);
      jcr->dir_bsock = NULL;
   }
   if (jcr->errmsg) {
      free_pool_memory(jcr->errmsg);
      jcr->errmsg = NULL;
   }
   if (jcr->where) {
      free(jcr->where);
      jcr->where = NULL;
   }
   if (jcr->cached_path) {
      free_pool_memory(jcr->cached_path);
      jcr->cached_path = NULL;
      jcr->cached_pnl = 0;
   }
   free_getuser_cache();
   free_getgroup_cache();
   free(jcr);
}

/*
 * Global routine to free a jcr
 */
#ifdef DEBUG
void b_free_jcr(const char *file, int line, JCR *jcr)
{
   Dmsg3(3400, "Enter free_jcr 0x%x from %s:%d\n", jcr, file, line);

#else

void free_jcr(JCR *jcr)
{

   Dmsg2(3400, "Enter free_jcr 0x%x job=%d\n", jcr, jcr->JobId);

#endif

   dequeue_messages(jcr);
   lock_jcr_chain();
   jcr->dec_use_count();              /* decrement use count */
   if (jcr->use_count() < 0) {
      Emsg2(M_ERROR, 0, _("JCR use_count=%d JobId=%d\n"),
         jcr->use_count(), jcr->JobId);
   }
   Dmsg3(3400, "Dec free_jcr 0x%x use_count=%d jobid=%d\n", jcr, jcr->use_count(), jcr->JobId);
   if (jcr->use_count() > 0) {          /* if in use */
      unlock_jcr_chain();
      Dmsg3(3400, "free_jcr 0x%x job=%d use_count=%d\n", jcr, jcr->JobId, jcr->use_count());
      return;
   }

   remove_jcr(jcr);                   /* remove Jcr from chain */
   unlock_jcr_chain();

   job_end_pop(jcr);                  /* pop and call hooked routines */

   Dmsg1(3400, "End job=%d\n", jcr->JobId);
   if (jcr->daemon_free_jcr) {
      jcr->daemon_free_jcr(jcr);      /* call daemon free routine */
   }
   free_common_jcr(jcr);
   close_msg(NULL);                   /* flush any daemon messages */
   garbage_collect_memory_pool();
   Dmsg0(3400, "Exit free_jcr\n");
}


/*
 * Given a JobId, find the JCR
 *   Returns: jcr on success
 *            NULL on failure
 */
JCR *get_jcr_by_id(uint32_t JobId)
{
   JCR *jcr;

   foreach_jcr(jcr) {
      if (jcr->JobId == JobId) {
         jcr->inc_use_count();
         Dmsg2(3400, "Inc get_jcr 0x%x use_count=%d\n", jcr, jcr->use_count());
         break;
      }
   }
   endeach_jcr(jcr);
   return jcr;
}

/*
 * Given a SessionId and SessionTime, find the JCR
 *   Returns: jcr on success
 *            NULL on failure
 */
JCR *get_jcr_by_session(uint32_t SessionId, uint32_t SessionTime)
{
   JCR *jcr;

   foreach_jcr(jcr) {
      if (jcr->VolSessionId == SessionId &&
          jcr->VolSessionTime == SessionTime) {
         jcr->inc_use_count();
         Dmsg2(3400, "Inc get_jcr 0x%x use_count=%d\n", jcr, jcr->use_count());
         break;
      }
   }
   endeach_jcr(jcr);
   return jcr;
}


/*
 * Given a Job, find the JCR
 *  compares on the number of characters in Job
 *  thus allowing partial matches.
 *   Returns: jcr on success
 *            NULL on failure
 */
JCR *get_jcr_by_partial_name(char *Job)
{
   JCR *jcr;
   int len;

   if (!Job) {
      return NULL;
   }
   len = strlen(Job);
   foreach_jcr(jcr) {
      if (strncmp(Job, jcr->Job, len) == 0) {
         jcr->inc_use_count();
         Dmsg2(3400, "Inc get_jcr 0x%x use_count=%d\n", jcr, jcr->use_count());
         break;
      }
   }
   endeach_jcr(jcr);
   return jcr;
}


/*
 * Given a Job, find the JCR
 *  requires an exact match of names.
 *   Returns: jcr on success
 *            NULL on failure
 */
JCR *get_jcr_by_full_name(char *Job)
{
   JCR *jcr;

   if (!Job) {
      return NULL;
   }
   foreach_jcr(jcr) {
      if (strcmp(jcr->Job, Job) == 0) {
         jcr->inc_use_count();
         Dmsg2(3400, "Inc get_jcr 0x%x use_count=%d\n", jcr, jcr->use_count());
         break;
      }
   }
   endeach_jcr(jcr);
   return jcr;
}

void set_jcr_job_status(JCR *jcr, int JobStatus)
{
   /*
    * For a set of errors, ... keep the current status
    *   so it isn't lost. For all others, set it.
    */
   switch (jcr->JobStatus) {
   case JS_ErrorTerminated:
   case JS_Error:
   case JS_FatalError:
   case JS_Differences:
   case JS_Canceled:
      break;
   default:
      jcr->JobStatus = JobStatus;
   }
}

#ifdef TRACE_JCR_CHAIN
static int lock_count = 0;
#endif

/*
 * Lock the chain
 */
#ifdef TRACE_JCR_CHAIN
static void b_lock_jcr_chain(const char *fname, int line)
#else
static void lock_jcr_chain()
#endif
{
#ifdef TRACE_JCR_CHAIN
   Dmsg3(3400, "Lock jcr chain %d from %s:%d\n", ++lock_count,
      fname, line);
#endif
   P(jcr_lock);
}

/*
 * Unlock the chain
 */
#ifdef TRACE_JCR_CHAIN
static void b_unlock_jcr_chain(const char *fname, int line)
#else
static void unlock_jcr_chain()
#endif
{
#ifdef TRACE_JCR_CHAIN
   Dmsg3(3400, "Unlock jcr chain %d from %s:%d\n", lock_count--,
      fname, line);
#endif
   V(jcr_lock);
}


/*
 * Start walk of jcr chain
 * The proper way to walk the jcr chain is:
 *    JCR *jcr;
 *    foreach_jcr(jcr) {
 *      ...
 *    }
 *    endeach_jcr(jcr);
 *
 *  It is possible to leave out the endeach_jcr(jcr), but
 *   in that case, the last jcr referenced must be explicitly
 *   released with:
 *
 *    free_jcr(jcr);
 *  
 */
JCR *jcr_walk_start() 
{
   JCR *jcr;
   lock_jcr_chain();
   jcr = (JCR *)jcrs->first();
   if (jcr) {
      jcr->inc_use_count();
      Dmsg3(3400, "Inc jcr_walk_start 0x%x job=%d use_count=%d\n", jcr, 
            jcr->JobId, jcr->use_count());
   }
   unlock_jcr_chain();
   return jcr;
}

/*
 * Get next jcr from chain, and release current one
 */
JCR *jcr_walk_next(JCR *prev_jcr)
{
   JCR *jcr;

   lock_jcr_chain();
   jcr = (JCR *)jcrs->next(prev_jcr);
   if (jcr) {
      jcr->inc_use_count();
      Dmsg3(3400, "Inc jcr_walk_next 0x%x job=%d use_count=%d\n", jcr, 
         jcr->JobId, jcr->use_count());
   }
   unlock_jcr_chain();
   if (prev_jcr) {
      free_jcr(prev_jcr);
   }
   return jcr;
}

/*
 * Release last jcr referenced
 */
void jcr_walk_end(JCR *jcr)
{
   if (jcr) {
      free_jcr(jcr);
   }
}


/*
 * Setup to call the timeout check routine every 30 seconds
 *  This routine will check any timers that have been enabled.
 */
bool init_jcr_subsystem(void)
{
   watchdog_t *wd = new_watchdog();

   wd->one_shot = false;
   wd->interval = 30;   /* FIXME: should be configurable somewhere, even
                         if only with a #define */
   wd->callback = jcr_timeout_check;

   register_watchdog(wd);

   return true;
}

static void jcr_timeout_check(watchdog_t *self)
{
   JCR *jcr;
   BSOCK *fd;
   time_t timer_start;

   Dmsg0(3400, "Start JCR timeout checks\n");

   /* Walk through all JCRs checking if any one is
    * blocked for more than specified max time.
    */
   foreach_jcr(jcr) {
      Dmsg2(3400, "jcr_timeout_check JobId=%u jcr=0x%x\n", jcr->JobId, jcr);
      if (jcr->JobId == 0) {
         continue;
      }
      fd = jcr->store_bsock;
      if (fd) {
         timer_start = fd->timer_start;
         if (timer_start && (watchdog_time - timer_start) > fd->timeout) {
            fd->timer_start = 0;      /* turn off timer */
            fd->timed_out = true;
            Jmsg(jcr, M_ERROR, 0, _(
"Watchdog sending kill after %d secs to thread stalled reading Storage daemon.\n"),
                 watchdog_time - timer_start);
            pthread_kill(jcr->my_thread_id, TIMEOUT_SIGNAL);
         }
      }
      fd = jcr->file_bsock;
      if (fd) {
         timer_start = fd->timer_start;
         if (timer_start && (watchdog_time - timer_start) > fd->timeout) {
            fd->timer_start = 0;      /* turn off timer */
            fd->timed_out = true;
            Jmsg(jcr, M_ERROR, 0, _(
"Watchdog sending kill after %d secs to thread stalled reading File daemon.\n"),
                 watchdog_time - timer_start);
            pthread_kill(jcr->my_thread_id, TIMEOUT_SIGNAL);
         }
      }
      fd = jcr->dir_bsock;
      if (fd) {
         timer_start = fd->timer_start;
         if (timer_start && (watchdog_time - timer_start) > fd->timeout) {
            fd->timer_start = 0;      /* turn off timer */
            fd->timed_out = true;
            Jmsg(jcr, M_ERROR, 0, _(
"Watchdog sending kill after %d secs to thread stalled reading Director.\n"),
                 watchdog_time - timer_start);
            pthread_kill(jcr->my_thread_id, TIMEOUT_SIGNAL);
         }
      }
   }
   endeach_jcr(jcr);

   Dmsg0(3400, "Finished JCR timeout checks\n");
}

/*
 * Timeout signal comes here
 */
extern "C" void timeout_handler(int sig)
{
   return;                            /* thus interrupting the function */
}
