closes #3882

[arvados.git] / services / api / app / models / job.rb

diff --git a/services/api/app/models/job.rb b/services/api/app/models/job.rb
index ea9990d9e7a3e766c709d194f62aa84255a0d6e0..864e60832f4e8312307fd628ba333ba3e64a2dec 100644 (file)
--- a/services/api/app/models/job.rb
+++ b/services/api/app/models/job.rb
@@ -9,11 +9,12 @@ class Job < ArvadosModel
   before_create :ensure_unique_submit_id
   after_commit :trigger_crunch_dispatch_if_cancelled, :on => :update
   before_validation :set_priority
-  before_validation :update_timestamps_when_state_changes
   before_validation :update_state_from_old_state_attrs
   validate :ensure_script_version_is_commit
   validate :find_docker_image_locator
   validate :validate_status
+  validate :validate_state_change
+  before_save :update_timestamps_when_state_changes
 
   has_many :commit_ancestors, :foreign_key => :descendant, :primary_key => :script_version
   has_many(:nodes, foreign_key: :job_uuid, primary_key: :uuid)
@@ -70,16 +71,13 @@ class Job < ArvadosModel
   end
 
   def self.queue
-    self.where('started_at is ? and is_locked_by_uuid is ? and cancelled_at is ? and success is ?',
-               nil, nil, nil, nil).
-      order('priority desc, created_at')
+    self.where('state = ?', Queued).order('priority desc, created_at')
   end
 
   def queue_position
-    i = 0
-    Job::queue.each do |j|
-      if j[:uuid] == self.uuid
-        return i
+    Job::queue.each_with_index do |job, index|
+      if job[:uuid] == self.uuid
+        return index
       end
     end
     nil
@@ -94,7 +92,7 @@ class Job < ArvadosModel
     transaction do
       self.reload
       unless self.state == Queued and self.is_locked_by_uuid.nil?
-        raise ConflictError.new
+        raise AlreadyLockedError
       end
       self.state = Running
       self.is_locked_by_uuid = locked_by_uuid
@@ -263,6 +261,7 @@ class Job < ArvadosModel
 
   def update_timestamps_when_state_changes
     return if not (state_changed? or new_record?)
+
     case state
     when Running
       self.started_at ||= Time.now
@@ -330,4 +329,30 @@ class Job < ArvadosModel
     end
   end
 
+  def validate_state_change
+    ok = true
+    if self.state_changed?
+      ok = case self.state_was
+           when nil
+             # state isn't set yet
+             true
+           when Queued
+             # Permit going from queued to any state
+             true
+           when Running
+             # From running, may only transition to a finished state
+             [Complete, Failed, Cancelled].include? self.state
+           when Complete, Failed, Cancelled
+             # Once in a finished state, don't permit any more state changes
+             false
+           else
+             # Any other state transition is also invalid
+             false
+           end
+      if not ok
+        errors.add :state, "invalid change from #{self.state_was} to #{self.state}"
+      end
+    end
+    ok
+  end
 end