]> git.sur5r.net Git - bacula/bacula/blobdiff - bacula/src/lib/jcr.c
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[bacula/bacula] / bacula / src / lib / jcr.c
index ee0c5040505c13518bdea2f150cfd3a9b98176cb..8c2c241ba982b8e65b8011acba6a1cceb2482fbb 100755 (executable)
@@ -1,5 +1,6 @@
 /*
- * Manipulation routines for Job Control Records
+ * Manipulation routines for Job Control Records and
+ *  handling of last_jobs_list.
  *
  *  Kern E. Sibbald, December 2000
  *
  *
  *  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) 2000-2003 Kern Sibbald and John Walker
+   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 as
-   published by the Free Software Foundation; either version 2 of
-   the License, or (at your option) any later version.
+   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 GNU
-   General Public License for more details.
-
-   You should have received a copy of the GNU General Public
-   License along with this program; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
-   MA 02111-1307, USA.
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
+   the file LICENSE for additional details.
 
  */
 
 #include "bacula.h"
 #include "jcr.h"
 
-struct s_last_job last_job;          /* last job run by this daemon */
+/* 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);
+}
 
-static JCR *jobs = NULL;             /* pointer to JCR chain */
-static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+/* 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
@@ -45,29 +218,51 @@ static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 JCR *new_jcr(int size, JCR_free_HANDLER *daemon_free_jcr)
 {
    JCR *jcr;
+   MQUEUE_ITEM *item = NULL;
+   struct sigaction sigtimer;
 
-   Dmsg0(200, "Enter new_jcr\n");
-   jcr = (JCR *) malloc(size);
+   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->use_count = 1;
-   pthread_mutex_init(&(jcr->mutex), NULL);
+   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);
 
-   P(mutex);
-   jcr->prev = NULL;
-   jcr->next = jobs;
-   if (jobs) {
-      jobs->prev = jcr;
+   /*
+    * 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));
    }
-   jobs = jcr;
-   V(mutex);
+   jcrs->append(jcr);
+   unlock_jcr_chain();
+   unlock_jobs();
+
    return jcr;
 }
 
@@ -75,53 +270,69 @@ JCR *new_jcr(int size, JCR_free_HANDLER *daemon_free_jcr)
 /*
  * Remove a JCR from the chain
  * NOTE! The chain must be locked prior to calling
- *      this routine.
+ *       this routine.
  */
 static void remove_jcr(JCR *jcr)
 {
-   Dmsg0(150, "Enter remove_jcr\n");
+   Dmsg0(3400, "Enter remove_jcr\n");
    if (!jcr) {
-      Emsg0(M_ABORT, 0, "NULL jcr.\n");
-   }
-   if (!jcr->prev) {                 /* if no prev */
-      jobs = jcr->next;              /* set new head */
-   } else {
-      jcr->prev->next = jcr->next;    /* update prev */
-   }
-   if (jcr->next) {
-      jcr->next->prev = jcr->prev;
+      Emsg0(M_ABORT, 0, _("NULL jcr.\n"));
    }
-   Dmsg0(150, "Leave remove_jcr\n");
+   jcrs->remove(jcr);
+   Dmsg0(3400, "Leave remove_jcr\n");
 }
 
 /*
- * Free stuff common to all JCRs
+ * 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:
-        last_job.NumJobs++;
-        last_job.JobType = jcr->JobType;
-        last_job.JobId = jcr->JobId;
-        last_job.VolSessionId = jcr->VolSessionId;
-        last_job.VolSessionTime = jcr->VolSessionTime;
-        strcpy(last_job.Job, jcr->Job);
-        last_job.JobFiles = jcr->JobFiles;
-        last_job.JobBytes = jcr->JobBytes;
-        last_job.JobStatus = jcr->JobStatus;
-        last_job.start_time = jcr->start_time;
-        last_job.end_time = time(NULL);
-        break;
-      default:
-        break;
-   }
-   pthread_mutex_destroy(&jcr->mutex);
-
-   close_msg(jcr);                   /* close messages for this job */
+   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) {
@@ -129,8 +340,12 @@ static void free_common_jcr(JCR *jcr)
       jcr->client_name = NULL;
    }
 
+   if (jcr->attr) {
+      free_pool_memory(jcr->attr);
+      jcr->attr = NULL;
+   }
+
    if (jcr->sd_auth_key) {
-      Dmsg0(200, "Free JCR sd_auth_key\n");
       free(jcr->sd_auth_key);
       jcr->sd_auth_key = NULL;
    }
@@ -147,157 +362,159 @@ static void free_common_jcr(JCR *jcr)
       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(char *file, int line, JCR *jcr)
+void b_free_jcr(const char *file, int line, JCR *jcr)
 {
-   Dmsg3(200, "Enter free_jcr 0x%x from %s:%d\n", jcr, file, line);
+   Dmsg3(3400, "Enter free_jcr 0x%x from %s:%d\n", jcr, file, line);
 
 #else
 
 void free_jcr(JCR *jcr)
 {
-   Dmsg1(200, "Enter free_jcr 0x%x\n", jcr);
+
+   Dmsg2(3400, "Enter free_jcr 0x%x job=%d\n", jcr, jcr->JobId);
 
 #endif
 
-   P(mutex);
-   jcr->use_count--;                 /* decrement use count */
-   Dmsg2(200, "Decrement jcr 0x%x use_count=%d\n", jcr, jcr->use_count);
-   if (jcr->use_count > 0) {         /* if in use */
-      V(mutex);
-      Dmsg2(200, "jcr 0x%x use_count=%d\n", jcr, jcr->use_count);
-      return;
+   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);
    }
-   remove_jcr(jcr);
-   V(mutex);
-
-   if (jcr->daemon_free_jcr) {
-      jcr->daemon_free_jcr(jcr);      /* call daemon free routine */
+   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;
    }
-   free_common_jcr(jcr);
 
-   P(mutex);
-   close_msg(NULL);                  /* flush any daemon messages */
-   V(mutex);
-   Dmsg0(200, "Exit free_jcr\n");
-}
+   remove_jcr(jcr);                   /* remove Jcr from chain */
+   unlock_jcr_chain();
 
+   job_end_pop(jcr);                  /* pop and call hooked routines */
 
-/* 
- * Global routine to free a jcr
- *  JCR chain is already locked
- */
-void free_locked_jcr(JCR *jcr)
-{
-   jcr->use_count--;                 /* decrement use count */
-   Dmsg2(200, "Decrement jcr 0x%x use_count=%d\n", jcr, jcr->use_count);
-   if (jcr->use_count > 0) {         /* if in use */
-      return;
+   Dmsg1(3400, "End job=%d\n", jcr->JobId);
+   if (jcr->daemon_free_jcr) {
+      jcr->daemon_free_jcr(jcr);      /* call daemon free routine */
    }
-   remove_jcr(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     
+ * Given a JobId, find the JCR
  *   Returns: jcr on success
- *           NULL on failure
+ *            NULL on failure
  */
 JCR *get_jcr_by_id(uint32_t JobId)
 {
-   JCR *jcr;      
+   JCR *jcr;
 
-   P(mutex);
-   for (jcr = jobs; jcr; jcr=jcr->next) {
+   foreach_jcr(jcr) {
       if (jcr->JobId == JobId) {
-        jcr->use_count++;
-         Dmsg2(200, "Increment jcr 0x%x use_count=%d\n", jcr, jcr->use_count);
-        break;
+         jcr->inc_use_count();
+         Dmsg2(3400, "Inc get_jcr 0x%x use_count=%d\n", jcr, jcr->use_count());
+         break;
       }
    }
-   V(mutex);
-   return jcr; 
+   endeach_jcr(jcr);
+   return jcr;
 }
 
 /*
- * Given a SessionId and SessionTime, find the JCR     
+ * Given a SessionId and SessionTime, find the JCR
  *   Returns: jcr on success
- *           NULL on failure
+ *            NULL on failure
  */
 JCR *get_jcr_by_session(uint32_t SessionId, uint32_t SessionTime)
 {
-   JCR *jcr;      
-
-   P(mutex);
-   for (jcr = jobs; jcr; jcr=jcr->next) {
-      if (jcr->VolSessionId == SessionId && 
-         jcr->VolSessionTime == SessionTime) {
-        jcr->use_count++;
-         Dmsg2(200, "Increment jcr 0x%x use_count=%d\n", jcr, jcr->use_count);
-        break;
+   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;
       }
    }
-   V(mutex);
-   return jcr; 
+   endeach_jcr(jcr);
+   return jcr;
 }
 
 
 /*
- * Given a Job, find the 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
+ *            NULL on failure
  */
 JCR *get_jcr_by_partial_name(char *Job)
 {
-   JCR *jcr;      
+   JCR *jcr;
    int len;
 
-   P(mutex);
+   if (!Job) {
+      return NULL;
+   }
    len = strlen(Job);
-   for (jcr = jobs; jcr; jcr=jcr->next) {
+   foreach_jcr(jcr) {
       if (strncmp(Job, jcr->Job, len) == 0) {
-        jcr->use_count++;
-         Dmsg2(200, "Increment jcr 0x%x use_count=%d\n", jcr, jcr->use_count);
-        break;
+         jcr->inc_use_count();
+         Dmsg2(3400, "Inc get_jcr 0x%x use_count=%d\n", jcr, jcr->use_count());
+         break;
       }
    }
-   V(mutex);
-   return jcr; 
+   endeach_jcr(jcr);
+   return jcr;
 }
 
 
 /*
- * Given a Job, find the JCR     
+ * Given a Job, find the JCR
  *  requires an exact match of names.
  *   Returns: jcr on success
- *           NULL on failure
+ *            NULL on failure
  */
 JCR *get_jcr_by_full_name(char *Job)
 {
-   JCR *jcr;      
+   JCR *jcr;
 
-   P(mutex);
-   for (jcr = jobs; jcr; jcr=jcr->next) {
+   if (!Job) {
+      return NULL;
+   }
+   foreach_jcr(jcr) {
       if (strcmp(jcr->Job, Job) == 0) {
-        jcr->use_count++;
-         Dmsg2(200, "Increment jcr 0x%x use_count=%d\n", jcr, jcr->use_count);
-        break;
+         jcr->inc_use_count();
+         Dmsg2(3400, "Inc get_jcr 0x%x use_count=%d\n", jcr, jcr->use_count());
+         break;
       }
    }
-   V(mutex);
-   return jcr; 
+   endeach_jcr(jcr);
+   return jcr;
 }
 
 void set_jcr_job_status(JCR *jcr, int JobStatus)
@@ -318,35 +535,185 @@ void set_jcr_job_status(JCR *jcr, int JobStatus)
    }
 }
 
-/* 
+#ifdef TRACE_JCR_CHAIN
+static int lock_count = 0;
+#endif
+
+/*
  * Lock the chain
  */
-void lock_jcr_chain()
+#ifdef TRACE_JCR_CHAIN
+static void b_lock_jcr_chain(const char *fname, int line)
+#else
+static void lock_jcr_chain()
+#endif
 {
-   P(mutex);
+#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
  */
-void unlock_jcr_chain()
+#ifdef TRACE_JCR_CHAIN
+static void b_unlock_jcr_chain(const char *fname, int line)
+#else
+static void unlock_jcr_chain()
+#endif
 {
-   V(mutex);
+#ifdef TRACE_JCR_CHAIN
+   Dmsg3(3400, "Unlock jcr chain %d from %s:%d\n", lock_count--,
+      fname, line);
+#endif
+   V(jcr_lock);
 }
 
 
-JCR *get_next_jcr(JCR *jcr)
+/*
+ * 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 *rjcr;
+   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;
+}
 
-   if (jcr == NULL) {
-      rjcr = jobs;
-   } else {
-      rjcr = jcr->next;
+/*
+ * Release last jcr referenced
+ */
+void jcr_walk_end(JCR *jcr)
+{
+   if (jcr) {
+      free_jcr(jcr);
    }
-   if (rjcr) {
-      rjcr->use_count++;
-      Dmsg1(200, "Increment jcr use_count=%d\n", rjcr->use_count);
+}
+
+
+/*
+ * 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);
+         }
+      }
    }
-   return rjcr;
+   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 */
 }