Add bitbake-dev to allow ease of testing and development of bitbake trunk

git-svn-id: https://svn.o-hand.com/repos/poky/trunk@5337 311d38ba-8fff-0310-9ca6-ca027cbcb966

1 files changed, 1157 insertions, 0 deletions

diff --git a/bitbake-dev/lib/bb/runqueue.py b/bitbake-dev/lib/bb/runqueue.py
new file mode 100644
index 0000000000..4130b50641
--- /dev/null
+++ b/bitbake-dev/lib/bb/runqueue.py
@@ -0,0 +1,1157 @@
+#!/usr/bin/env python
+# ex:ts=4:sw=4:sts=4:et
+# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
+"""
+BitBake 'RunQueue' implementation
+
+Handles preparation and execution of a queue of tasks
+"""
+
+# Copyright (C) 2006-2007  Richard Purdie
+#
+# 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
+# published by the Free Software Foundation.
+#
+# 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.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+from bb import msg, data, event, mkdirhier, utils
+from sets import Set 
+import bb, os, sys
+import signal
+import stat
+
+class TaskFailure(Exception):
+    """Exception raised when a task in a runqueue fails"""
+    def __init__(self, x): 
+        self.args = x
+
+
+class RunQueueStats:
+    """
+    Holds statistics on the tasks handled by the associated runQueue
+    """
+    def __init__(self, total):
+        self.completed = 0
+        self.skipped = 0
+        self.failed = 0
+        self.active = 0
+        self.total = total
+
+    def taskFailed(self):
+        self.active = self.active - 1
+        self.failed = self.failed + 1
+
+    def taskCompleted(self, number = 1):
+        self.active = self.active - number
+        self.completed = self.completed + number
+
+    def taskSkipped(self, number = 1):
+        self.active = self.active + number
+        self.skipped = self.skipped + number
+
+    def taskActive(self):
+        self.active = self.active + 1
+
+# These values indicate the next step due to be run in the 
+# runQueue state machine
+runQueuePrepare = 2
+runQueueRunInit = 3
+runQueueRunning = 4
+runQueueFailed = 6
+runQueueCleanUp = 7
+runQueueComplete = 8
+runQueueChildProcess = 9
+
+class RunQueueScheduler:
+    """
+    Control the order tasks are scheduled in.
+    """
+    def __init__(self, runqueue):
+        """
+        The default scheduler just returns the first buildable task (the 
+        priority map is sorted by task numer)
+        """
+        self.rq = runqueue
+        numTasks = len(self.rq.runq_fnid)
+
+        self.prio_map = []
+        self.prio_map.extend(range(numTasks))
+
+    def next(self):
+        """
+        Return the id of the first task we find that is buildable
+        """
+        for task1 in range(len(self.rq.runq_fnid)):
+            task = self.prio_map[task1]
+            if self.rq.runq_running[task] == 1:
+                continue
+            if self.rq.runq_buildable[task] == 1:
+                return task
+
+class RunQueueSchedulerSpeed(RunQueueScheduler):
+    """
+    A scheduler optimised for speed. The priority map is sorted by task weight,
+    heavier weighted tasks (tasks needed by the most other tasks) are run first.
+    """
+    def __init__(self, runqueue):
+        """
+        The priority map is sorted by task weight.
+        """
+        from copy import deepcopy
+
+        self.rq = runqueue
+
+        sortweight = deepcopy(self.rq.runq_weight)
+        sortweight.sort()
+        copyweight = deepcopy(self.rq.runq_weight)
+        self.prio_map = []
+
+        for weight in sortweight:
+            idx = copyweight.index(weight)
+            self.prio_map.append(idx)
+            copyweight[idx] = -1
+
+        self.prio_map.reverse()
+
+class RunQueueSchedulerCompletion(RunQueueSchedulerSpeed):
+    """
+    A scheduler optimised to complete .bb files are quickly as possible. The 
+    priority map is sorted by task weight, but then reordered so once a given 
+    .bb file starts to build, its completed as quickly as possible. This works
+    well where disk space is at a premium and classes like OE's rm_work are in 
+    force.
+    """
+    def __init__(self, runqueue):
+        RunQueueSchedulerSpeed.__init__(self, runqueue)
+        from copy import deepcopy
+
+        #FIXME - whilst this groups all fnids together it does not reorder the
+        #fnid groups optimally.
+ 
+        basemap = deepcopy(self.prio_map)
+        self.prio_map = []
+        while (len(basemap) > 0):
+            entry = basemap.pop(0)
+            self.prio_map.append(entry)
+            fnid = self.rq.runq_fnid[entry]
+            todel = []
+            for entry in basemap:
+                entry_fnid = self.rq.runq_fnid[entry]
+                if entry_fnid == fnid:
+                    todel.append(basemap.index(entry))
+                    self.prio_map.append(entry)
+            todel.reverse()
+            for idx in todel:
+                del basemap[idx]
+
+class RunQueue:
+    """
+    BitBake Run Queue implementation
+    """
+    def __init__(self, cooker, cfgData, dataCache, taskData, targets):
+        self.reset_runqueue()
+        self.cooker = cooker
+        self.dataCache = dataCache
+        self.taskData = taskData
+        self.cfgData = cfgData
+        self.targets = targets
+
+        self.number_tasks = int(bb.data.getVar("BB_NUMBER_THREADS", cfgData, 1) or 1)
+        self.multi_provider_whitelist = (bb.data.getVar("MULTI_PROVIDER_WHITELIST", cfgData, 1) or "").split()
+        self.scheduler = bb.data.getVar("BB_SCHEDULER", cfgData, 1) or "speed"
+        self.stamppolicy = bb.data.getVar("BB_STAMP_POLICY", cfgData, 1) or "perfile"
+        self.stampwhitelist = bb.data.getVar("BB_STAMP_WHITELIST", cfgData, 1) or ""
+
+    def reset_runqueue(self):
+        self.runq_fnid = []
+        self.runq_task = []
+        self.runq_depends = []
+        self.runq_revdeps = []
+
+        self.state = runQueuePrepare
+
+    def get_user_idstring(self, task):
+        fn = self.taskData.fn_index[self.runq_fnid[task]]
+        taskname = self.runq_task[task]
+        return "%s, %s" % (fn, taskname)
+
+    def get_task_id(self, fnid, taskname):
+        for listid in range(len(self.runq_fnid)):
+            if self.runq_fnid[listid] == fnid and self.runq_task[listid] == taskname:
+                return listid
+        return None
+
+    def circular_depchains_handler(self, tasks):
+        """
+        Some tasks aren't buildable, likely due to circular dependency issues.
+        Identify the circular dependencies and print them in a user readable format.
+        """
+        from copy import deepcopy
+
+        valid_chains = []
+        explored_deps = {}
+        msgs = []
+
+        def chain_reorder(chain):
+            """
+            Reorder a dependency chain so the lowest task id is first
+            """
+            lowest = 0
+            new_chain = []
+            for entry in range(len(chain)):
+                if chain[entry] < chain[lowest]:
+                    lowest = entry
+            new_chain.extend(chain[lowest:])
+            new_chain.extend(chain[:lowest])
+            return new_chain
+
+        def chain_compare_equal(chain1, chain2):
+            """
+            Compare two dependency chains and see if they're the same
+            """
+            if len(chain1) != len(chain2):
+                return False
+            for index in range(len(chain1)):
+                if chain1[index] != chain2[index]:
+                    return False
+            return True
+            
+        def chain_array_contains(chain, chain_array):
+            """
+            Return True if chain_array contains chain
+            """
+            for ch in chain_array:
+                if chain_compare_equal(ch, chain):
+                    return True
+            return False
+
+        def find_chains(taskid, prev_chain):
+            prev_chain.append(taskid)
+            total_deps = []
+            total_deps.extend(self.runq_revdeps[taskid])
+            for revdep in self.runq_revdeps[taskid]:
+                if revdep in prev_chain:
+                    idx = prev_chain.index(revdep)
+                    # To prevent duplicates, reorder the chain to start with the lowest taskid
+                    # and search through an array of those we've already printed
+                    chain = prev_chain[idx:]
+                    new_chain = chain_reorder(chain)
+                    if not chain_array_contains(new_chain, valid_chains):
+                        valid_chains.append(new_chain)
+                        msgs.append("Dependency loop #%d found:\n" % len(valid_chains))
+                        for dep in new_chain:
+                            msgs.append("  Task %s (%s) (depends: %s)\n" % (dep, self.get_user_idstring(dep), self.runq_depends[dep]))
+                        msgs.append("\n")
+                    if len(valid_chains) > 10:
+                        msgs.append("Aborted dependency loops search after 10 matches.\n")
+                        return msgs
+                    continue
+                scan = False
+                if revdep not in explored_deps:
+                    scan = True
+                elif revdep in explored_deps[revdep]:
+                    scan = True
+                else:
+                    for dep in prev_chain:
+                        if dep in explored_deps[revdep]:
+                            scan = True
+                if scan:
+                    find_chains(revdep, deepcopy(prev_chain))
+                for dep in explored_deps[revdep]:
+                    if dep not in total_deps:
+                        total_deps.append(dep)
+
+            explored_deps[taskid] = total_deps
+
+        for task in tasks:
+            find_chains(task, [])
+
+        return msgs
+
+    def calculate_task_weights(self, endpoints):
+        """
+        Calculate a number representing the "weight" of each task. Heavier weighted tasks 
+        have more dependencies and hence should be executed sooner for maximum speed.
+
+        This function also sanity checks the task list finding tasks that its not
+        possible to execute due to circular dependencies.
+        """
+
+        numTasks = len(self.runq_fnid)
+        weight = []
+        deps_left = []
+        task_done = []
+
+        for listid in range(numTasks):
+            task_done.append(False)
+            weight.append(0)
+            deps_left.append(len(self.runq_revdeps[listid]))
+
+        for listid in endpoints:
+            weight[listid] = 1
+            task_done[listid] = True
+
+        while 1:
+            next_points = []
+            for listid in endpoints:
+                for revdep in self.runq_depends[listid]:
+                    weight[revdep] = weight[revdep] + weight[listid]
+                    deps_left[revdep] = deps_left[revdep] - 1
+                    if deps_left[revdep] == 0:
+                        next_points.append(revdep)
+                        task_done[revdep] = True
+            endpoints = next_points
+            if len(next_points) == 0:
+                break      
+
+        # Circular dependency sanity check
+        problem_tasks = []
+        for task in range(numTasks):
+            if task_done[task] is False or deps_left[task] != 0:
+                problem_tasks.append(task)
+                bb.msg.debug(2, bb.msg.domain.RunQueue, "Task %s (%s) is not buildable\n" % (task, self.get_user_idstring(task)))
+                bb.msg.debug(2, bb.msg.domain.RunQueue, "(Complete marker was %s and the remaining dependency count was %s)\n\n" % (task_done[task], deps_left[task]))
+
+        if problem_tasks:
+            message = "Unbuildable tasks were found.\n"
+            message = message + "These are usually caused by circular dependencies and any circular dependency chains found will be printed below. Increase the debug level to see a list of unbuildable tasks.\n\n"
+            message = message + "Identifying dependency loops (this may take a short while)...\n"
+            bb.msg.error(bb.msg.domain.RunQueue, message)
+
+            msgs = self.circular_depchains_handler(problem_tasks)
+
+            message = "\n"
+            for msg in msgs:
+                message = message + msg
+            bb.msg.fatal(bb.msg.domain.RunQueue, message)
+
+        return weight
+
+    def prepare_runqueue(self):
+        """
+        Turn a set of taskData into a RunQueue and compute data needed 
+        to optimise the execution order.
+        """
+
+        depends = []
+        runq_build = []
+        recursive_tdepends = {}
+
+        taskData = self.taskData
+
+        if len(taskData.tasks_name) == 0:
+            # Nothing to do
+            return
+
+        bb.msg.note(1, bb.msg.domain.RunQueue, "Preparing runqueue")
+
+        # Step A - Work out a list of tasks to run
+        #
+        # Taskdata gives us a list of possible providers for a every target 
+        # ordered by priority (build_targets, run_targets). It also gives
+        # information on each of those providers.
+        #
+        # To create the actual list of tasks to execute we fix the list of 
+        # providers and then resolve the dependencies into task IDs. This 
+        # process is repeated for each type of dependency (tdepends, deptask, 
+        # rdeptast, recrdeptask, idepends).
+
+        for task in range(len(taskData.tasks_name)):
+            fnid = taskData.tasks_fnid[task]
+            fn = taskData.fn_index[fnid]
+            task_deps = self.dataCache.task_deps[fn]
+
+            if fnid not in taskData.failed_fnids:
+
+                # Resolve task internal dependencies 
+                #
+                # e.g. addtask before X after Y
+                depends = taskData.tasks_tdepends[task]
+
+                # Resolve 'deptask' dependencies 
+                #
+                # e.g. do_sometask[deptask] = "do_someothertask"
+                # (makes sure sometask runs after someothertask of all DEPENDS)
+                if 'deptask' in task_deps and taskData.tasks_name[task] in task_deps['deptask']:
+                    tasknames = task_deps['deptask'][taskData.tasks_name[task]].split()
+                    for depid in taskData.depids[fnid]:
+                        # Won't be in build_targets if ASSUME_PROVIDED
+                        if depid in taskData.build_targets:
+                            depdata = taskData.build_targets[depid][0]
+                            if depdata is not None:
+                                dep = taskData.fn_index[depdata]
+                                for taskname in tasknames:
+                                    depends.append(taskData.gettask_id(dep, taskname))
+
+                # Resolve 'rdeptask' dependencies 
+                #
+                # e.g. do_sometask[rdeptask] = "do_someothertask"
+                # (makes sure sometask runs after someothertask of all RDEPENDS)
+                if 'rdeptask' in task_deps and taskData.tasks_name[task] in task_deps['rdeptask']:
+                    taskname = task_deps['rdeptask'][taskData.tasks_name[task]]
+                    for depid in taskData.rdepids[fnid]:
+                        if depid in taskData.run_targets:
+                            depdata = taskData.run_targets[depid][0]
+                            if depdata is not None:
+                                dep = taskData.fn_index[depdata]
+                                depends.append(taskData.gettask_id(dep, taskname))
+
+                # Resolve inter-task dependencies 
+                #
+                # e.g. do_sometask[depends] = "targetname:do_someothertask"
+                # (makes sure sometask runs after targetname's someothertask)
+                idepends = taskData.tasks_idepends[task]
+                for (depid, idependtask) in idepends:
+                    if depid in taskData.build_targets:
+                        # Won't be in build_targets if ASSUME_PROVIDED
+                        depdata = taskData.build_targets[depid][0]
+                        if depdata is not None:
+                            dep = taskData.fn_index[depdata]
+                            depends.append(taskData.gettask_id(dep, idependtask))
+
+                # Create a list of recursive dependent tasks (from tdepends) and cache
+                def get_recursive_tdepends(task):
+                    if not task:
+                        return []
+                    if task in recursive_tdepends:
+                        return recursive_tdepends[task]
+
+                    fnid = taskData.tasks_fnid[task]
+                    taskids = taskData.gettask_ids(fnid)
+
+                    rectdepends = taskids
+                    nextdeps = taskids
+                    while len(nextdeps) != 0:
+                        newdeps = []
+                        for nextdep in nextdeps:
+                            for tdepend in taskData.tasks_tdepends[nextdep]:
+                                if tdepend not in rectdepends:
+                                    rectdepends.append(tdepend)
+                                    newdeps.append(tdepend)
+                        nextdeps = newdeps
+                    recursive_tdepends[task] = rectdepends
+                    return rectdepends
+
+                # Using the list of tdepends for this task create a list of 
+                # the recursive idepends we have
+                def get_recursive_idepends(task):
+                    if not task:
+                        return []
+                    rectdepends = get_recursive_tdepends(task)
+
+                    recidepends = []
+                    for tdepend in rectdepends:
+                        for idepend in taskData.tasks_idepends[tdepend]:
+                            recidepends.append(idepend)
+                    return recidepends
+
+                def add_recursive_build(depid, depfnid):
+                    """
+                    Add build depends of depid to depends
+                    (if we've not see it before)
+                    (calls itself recursively)
+                    """
+                    if str(depid) in dep_seen:
+                        return
+                    dep_seen.append(depid)
+                    if depid in taskData.build_targets:
+                        depdata = taskData.build_targets[depid][0]
+                        if depdata is not None:
+                            dep = taskData.fn_index[depdata]
+                            # Need to avoid creating new tasks here
+                            taskid = taskData.gettask_id(dep, taskname, False)
+                            if taskid is not None:
+                                depends.append(taskid)
+                                fnid = taskData.tasks_fnid[taskid]
+                                #print "Added %s (%s) due to %s" % (taskid, taskData.fn_index[fnid], taskData.fn_index[depfnid])
+                            else:
+                                fnid = taskData.getfn_id(dep)
+                            for nextdepid in taskData.depids[fnid]:
+                                if nextdepid not in dep_seen:
+                                    add_recursive_build(nextdepid, fnid)
+                            for nextdepid in taskData.rdepids[fnid]:
+                                if nextdepid not in rdep_seen:
+                                    add_recursive_run(nextdepid, fnid)
+                            for (idependid, idependtask) in get_recursive_idepends(taskid):
+                                if idependid not in dep_seen:
+                                    add_recursive_build(idependid, fnid)
+
+                def add_recursive_run(rdepid, depfnid):
+                    """
+                    Add runtime depends of rdepid to depends
+                    (if we've not see it before)
+                    (calls itself recursively)
+                    """
+                    if str(rdepid) in rdep_seen:
+                        return
+                    rdep_seen.append(rdepid)
+                    if rdepid in taskData.run_targets:
+                        depdata = taskData.run_targets[rdepid][0]
+                        if depdata is not None:
+                            dep = taskData.fn_index[depdata]
+                            # Need to avoid creating new tasks here
+                            taskid = taskData.gettask_id(dep, taskname, False)
+                            if taskid is not None:
+                                depends.append(taskid)
+                                fnid = taskData.tasks_fnid[taskid]
+                                #print "Added %s (%s) due to %s" % (taskid, taskData.fn_index[fnid], taskData.fn_index[depfnid])
+                            else:
+                                fnid = taskData.getfn_id(dep)
+                            for nextdepid in taskData.depids[fnid]:
+                                if nextdepid not in dep_seen:
+                                    add_recursive_build(nextdepid, fnid)
+                            for nextdepid in taskData.rdepids[fnid]:
+                                if nextdepid not in rdep_seen:
+                                    add_recursive_run(nextdepid, fnid)
+                            for (idependid, idependtask) in get_recursive_idepends(taskid):
+                                if idependid not in dep_seen:
+                                    add_recursive_build(idependid, fnid)
+
+                # Resolve recursive 'recrdeptask' dependencies 
+                #
+                # e.g. do_sometask[recrdeptask] = "do_someothertask"
+                # (makes sure sometask runs after someothertask of all DEPENDS, RDEPENDS and intertask dependencies, recursively)
+                if 'recrdeptask' in task_deps and taskData.tasks_name[task] in task_deps['recrdeptask']:
+                    for taskname in task_deps['recrdeptask'][taskData.tasks_name[task]].split():
+                        dep_seen = []
+                        rdep_seen = []
+                        idep_seen = []
+                        for depid in taskData.depids[fnid]:
+                            add_recursive_build(depid, fnid)
+                        for rdepid in taskData.rdepids[fnid]:
+                            add_recursive_run(rdepid, fnid)
+                        deptaskid = taskData.gettask_id(fn, taskname, False)
+                        for (idependid, idependtask) in get_recursive_idepends(deptaskid):
+                            add_recursive_build(idependid, fnid)
+
+                # Rmove all self references
+                if task in depends:
+                    newdep = []
+                    bb.msg.debug(2, bb.msg.domain.RunQueue, "Task %s (%s %s) contains self reference! %s" % (task, taskData.fn_index[taskData.tasks_fnid[task]], taskData.tasks_name[task], depends))
+                    for dep in depends:
+                       if task != dep:
+                          newdep.append(dep)
+                    depends = newdep
+
+
+            self.runq_fnid.append(taskData.tasks_fnid[task])
+            self.runq_task.append(taskData.tasks_name[task])
+            self.runq_depends.append(Set(depends))
+            self.runq_revdeps.append(Set())
+
+            runq_build.append(0)
+
+        # Step B - Mark all active tasks
+        #
+        # Start with the tasks we were asked to run and mark all dependencies
+        # as active too. If the task is to be 'forced', clear its stamp. Once
+        # all active tasks are marked, prune the ones we don't need.
+
+        bb.msg.note(2, bb.msg.domain.RunQueue, "Marking Active Tasks")
+
+        def mark_active(listid, depth):
+            """
+            Mark an item as active along with its depends
+            (calls itself recursively)
+            """
+
+            if runq_build[listid] == 1:
+                return
+
+            runq_build[listid] = 1
+
+            depends = self.runq_depends[listid]
+            for depend in depends:
+                mark_active(depend, depth+1)
+
+        self.target_pairs = []
+        for target in self.targets:
+            targetid = taskData.getbuild_id(target[0])
+
+            if targetid not in taskData.build_targets:
+                continue
+
+            if targetid in taskData.failed_deps:
+                continue
+
+            fnid = taskData.build_targets[targetid][0]
+            fn = taskData.fn_index[fnid]
+            self.target_pairs.append((fn, target[1]))
+
+            # Remove stamps for targets if force mode active
+            if self.cooker.configuration.force:
+                bb.msg.note(2, bb.msg.domain.RunQueue, "Remove stamp %s, %s" % (target[1], fn))
+                bb.build.del_stamp(target[1], self.dataCache, fn)
+
+            if fnid in taskData.failed_fnids:
+                continue
+
+            if target[1] not in taskData.tasks_lookup[fnid]:
+                bb.msg.fatal(bb.msg.domain.RunQueue, "Task %s does not exist for target %s" % (target[1], target[0]))
+
+            listid = taskData.tasks_lookup[fnid][target[1]]
+
+            mark_active(listid, 1)
+
+        # Step C - Prune all inactive tasks
+        #
+        # Once all active tasks are marked, prune the ones we don't need.
+
+        maps = []
+        delcount = 0
+        for listid in range(len(self.runq_fnid)):
+            if runq_build[listid-delcount] == 1:
+                maps.append(listid-delcount)
+            else:
+                del self.runq_fnid[listid-delcount]
+                del self.runq_task[listid-delcount]
+                del self.runq_depends[listid-delcount]
+                del runq_build[listid-delcount]
+                del self.runq_revdeps[listid-delcount]
+                delcount = delcount + 1
+                maps.append(-1)
+
+        #
+        # Step D - Sanity checks and computation
+        #
+
+        # Check to make sure we still have tasks to run
+        if len(self.runq_fnid) == 0:
+            if not taskData.abort:
+                bb.msg.fatal(bb.msg.domain.RunQueue, "All buildable tasks have been run but the build is incomplete (--continue mode). Errors for the tasks that failed will have been printed above.")
+            else:
+                bb.msg.fatal(bb.msg.domain.RunQueue, "No active tasks and not in --continue mode?! Please report this bug.")
+
+        bb.msg.note(2, bb.msg.domain.RunQueue, "Pruned %s inactive tasks, %s left" % (delcount, len(self.runq_fnid)))
+
+        # Remap the dependencies to account for the deleted tasks
+        # Check we didn't delete a task we depend on
+        for listid in range(len(self.runq_fnid)):
+            newdeps = []
+            origdeps = self.runq_depends[listid]
+            for origdep in origdeps:
+                if maps[origdep] == -1:
+                    bb.msg.fatal(bb.msg.domain.RunQueue, "Invalid mapping - Should never happen!")
+                newdeps.append(maps[origdep])
+            self.runq_depends[listid] = Set(newdeps)
+
+        bb.msg.note(2, bb.msg.domain.RunQueue, "Assign Weightings")
+
+        # Generate a list of reverse dependencies to ease future calculations
+        for listid in range(len(self.runq_fnid)):
+            for dep in self.runq_depends[listid]:
+                self.runq_revdeps[dep].add(listid)
+
+        # Identify tasks at the end of dependency chains
+        # Error on circular dependency loops (length two)
+        endpoints = []
+        for listid in range(len(self.runq_fnid)):
+            revdeps = self.runq_revdeps[listid]
+            if len(revdeps) == 0:
+                endpoints.append(listid)
+            for dep in revdeps:
+                if dep in self.runq_depends[listid]:
+                    #self.dump_data(taskData)
+                    bb.msg.fatal(bb.msg.domain.RunQueue, "Task %s (%s) has circular dependency on %s (%s)" % (taskData.fn_index[self.runq_fnid[dep]], self.runq_task[dep] , taskData.fn_index[self.runq_fnid[listid]], self.runq_task[listid]))
+
+        bb.msg.note(2, bb.msg.domain.RunQueue, "Compute totals (have %s endpoint(s))" % len(endpoints))
+
+        # Calculate task weights 
+        # Check of higher length circular dependencies
+        self.runq_weight = self.calculate_task_weights(endpoints)
+
+        # Decide what order to execute the tasks in, pick a scheduler
+        #self.sched = RunQueueScheduler(self)
+        if self.scheduler == "completion":
+            self.sched = RunQueueSchedulerCompletion(self)
+        else:
+            self.sched = RunQueueSchedulerSpeed(self)
+
+        # Sanity Check - Check for multiple tasks building the same provider
+        prov_list = {}
+        seen_fn = []
+        for task in range(len(self.runq_fnid)):
+            fn = taskData.fn_index[self.runq_fnid[task]]
+            if fn in seen_fn:
+                continue
+            seen_fn.append(fn)
+            for prov in self.dataCache.fn_provides[fn]:
+                if prov not in prov_list:
+                    prov_list[prov] = [fn]
+                elif fn not in prov_list[prov]: 
+                    prov_list[prov].append(fn)
+        error = False
+        for prov in prov_list:
+            if len(prov_list[prov]) > 1 and prov not in self.multi_provider_whitelist:
+                error = True
+                bb.msg.error(bb.msg.domain.RunQueue, "Multiple .bb files are due to be built which each provide %s (%s).\n This usually means one provides something the other doesn't and should." % (prov, " ".join(prov_list[prov])))
+        #if error:
+        #    bb.msg.fatal(bb.msg.domain.RunQueue, "Corrupted metadata configuration detected, aborting...")
+
+
+        # Create a whitelist usable by the stamp checks
+        stampfnwhitelist = []
+        for entry in self.stampwhitelist.split():
+            entryid = self.taskData.getbuild_id(entry)
+            if entryid not in self.taskData.build_targets:
+                continue
+            fnid = self.taskData.build_targets[entryid][0]
+            fn = self.taskData.fn_index[fnid]
+            stampfnwhitelist.append(fn)
+        self.stampfnwhitelist = stampfnwhitelist
+
+        #self.dump_data(taskData)
+
+        self.state = runQueueRunInit
+
+    def check_stamps(self):
+        unchecked = {}
+        current = []
+        notcurrent = []
+        buildable = []
+
+        if self.stamppolicy == "perfile":
+            fulldeptree = False
+        else:
+            fulldeptree = True
+            stampwhitelist = []
+            if self.stamppolicy == "whitelist":
+                stampwhitelist = self.self.stampfnwhitelist
+
+        for task in range(len(self.runq_fnid)):
+            unchecked[task] = ""
+            if len(self.runq_depends[task]) == 0:
+                buildable.append(task)
+
+        def check_buildable(self, task, buildable):
+             for revdep in self.runq_revdeps[task]:
+                alldeps = 1
+                for dep in self.runq_depends[revdep]:
+                    if dep in unchecked:
+                        alldeps = 0
+                if alldeps == 1:
+                    if revdep in unchecked:
+                        buildable.append(revdep)
+
+        for task in range(len(self.runq_fnid)):
+            if task not in unchecked:
+                continue
+            fn = self.taskData.fn_index[self.runq_fnid[task]]
+            taskname = self.runq_task[task]
+            stampfile = "%s.%s" % (self.dataCache.stamp[fn], taskname)
+            # If the stamp is missing its not current
+            if not os.access(stampfile, os.F_OK):
+                del unchecked[task]
+                notcurrent.append(task)
+                check_buildable(self, task, buildable)
+                continue
+            # If its a 'nostamp' task, it's not current
+            taskdep = self.dataCache.task_deps[fn]
+            if 'nostamp' in taskdep and task in taskdep['nostamp']:
+                del unchecked[task]
+                notcurrent.append(task)
+                check_buildable(self, task, buildable)
+                continue
+
+        while (len(buildable) > 0):
+            nextbuildable = []
+            for task in buildable:
+                if task in unchecked:
+                    fn = self.taskData.fn_index[self.runq_fnid[task]]
+                    taskname = self.runq_task[task]
+                    stampfile = "%s.%s" % (self.dataCache.stamp[fn], taskname)
+                    iscurrent = True
+
+                    t1 = os.stat(stampfile)[stat.ST_MTIME]
+                    for dep in self.runq_depends[task]:
+                        if iscurrent:
+                            fn2 = self.taskData.fn_index[self.runq_fnid[dep]]
+                            taskname2 = self.runq_task[dep]
+                            stampfile2 = "%s.%s" % (self.dataCache.stamp[fn2], taskname2)
+                            if fn == fn2 or (fulldeptree and fn2 not in stampwhitelist):
+                                if dep in notcurrent:
+                                    iscurrent = False
+                                else:
+                                    t2 = os.stat(stampfile2)[stat.ST_MTIME]
+                                    if t1 < t2:
+                                        iscurrent = False
+                    del unchecked[task]
+                    if iscurrent:
+                        current.append(task)
+                    else:
+                        notcurrent.append(task)
+
+                check_buildable(self, task, nextbuildable)
+
+            buildable = nextbuildable
+
+        #for task in range(len(self.runq_fnid)):
+        #    fn = self.taskData.fn_index[self.runq_fnid[task]]
+        #    taskname = self.runq_task[task]
+        #    print "%s %s.%s" % (task, taskname, fn)
+
+        #print "Unchecked: %s" % unchecked
+        #print "Current: %s" % current
+        #print "Not current: %s" % notcurrent
+
+        if len(unchecked) > 0:
+            bb.fatal("check_stamps fatal internal error")
+        return current
+
+    def check_stamp_task(self, task):
+
+        if self.stamppolicy == "perfile":
+            fulldeptree = False
+        else:
+            fulldeptree = True
+            stampwhitelist = []
+            if self.stamppolicy == "whitelist":
+                stampwhitelist = self.stampfnwhitelist
+
+        fn = self.taskData.fn_index[self.runq_fnid[task]]
+        taskname = self.runq_task[task]
+        stampfile = "%s.%s" % (self.dataCache.stamp[fn], taskname)
+        # If the stamp is missing its not current
+        if not os.access(stampfile, os.F_OK):
+            bb.msg.debug(2, bb.msg.domain.RunQueue, "Stampfile %s not available\n" % stampfile)
+            return False
+        # If its a 'nostamp' task, it's not current
+        taskdep = self.dataCache.task_deps[fn]
+        if 'nostamp' in taskdep and task in taskdep['nostamp']:
+            bb.msg.debug(2, bb.msg.domain.RunQueue, "%s.%s is nostamp\n" % (fn, taskname))
+            return False
+
+        iscurrent = True
+        t1 =  os.stat(stampfile)[stat.ST_MTIME]
+        for dep in self.runq_depends[task]:
+            if iscurrent:
+                fn2 = self.taskData.fn_index[self.runq_fnid[dep]]
+                taskname2 = self.runq_task[dep]
+                stampfile2 = "%s.%s" % (self.dataCache.stamp[fn2], taskname2)
+                if fn == fn2 or (fulldeptree and fn2 not in stampwhitelist):
+                    try:
+                        t2 = os.stat(stampfile2)[stat.ST_MTIME]
+                        if t1 < t2:
+                            bb.msg.debug(2, bb.msg.domain.RunQueue, "Stampfile %s < %s" % (stampfile,stampfile2))
+                            iscurrent = False
+                    except:
+                        bb.msg.debug(2, bb.msg.domain.RunQueue, "Exception reading %s for %s" % (stampfile2 ,stampfile))
+                        iscurrent = False
+
+        return iscurrent
+
+    def execute_runqueue(self):
+        """
+        Run the tasks in a queue prepared by prepare_runqueue
+        Upon failure, optionally try to recover the build using any alternate providers
+        (if the abort on failure configuration option isn't set)
+        """
+
+        if self.state is runQueuePrepare:
+            self.prepare_runqueue()
+
+        if self.state is runQueueRunInit:
+            bb.msg.note(1, bb.msg.domain.RunQueue, "Executing runqueue")
+            self.execute_runqueue_initVars()
+
+        if self.state is runQueueRunning:
+            self.execute_runqueue_internal()
+
+        if self.state is runQueueCleanUp:
+            self.finish_runqueue()
+
+        if self.state is runQueueFailed:
+            if self.taskData.abort:
+                raise bb.runqueue.TaskFailure(self.failed_fnids)
+            for fnid in self.failed_fnids:
+                self.taskData.fail_fnid(fnid)
+            self.reset_runqueue()
+
+        if self.state is runQueueComplete:
+            # All done
+            bb.msg.note(1, bb.msg.domain.RunQueue, "Tasks Summary: Attempted %d tasks of which %d didn't need to be rerun and %d failed." % (self.stats.completed, self.stats.skipped, self.stats.failed))
+            return False
+
+        if self.state is runQueueChildProcess:
+            print "Child process"
+            return False
+
+        # Loop
+        return True
+
+    def execute_runqueue_initVars(self):
+
+        self.stats = RunQueueStats(len(self.runq_fnid))
+
+        self.runq_buildable = []
+        self.runq_running = []
+        self.runq_complete = []
+        self.build_pids = {}
+        self.failed_fnids = []
+
+        # Mark initial buildable tasks
+        for task in range(self.stats.total):
+            self.runq_running.append(0)
+            self.runq_complete.append(0)
+            if len(self.runq_depends[task]) == 0:
+                self.runq_buildable.append(1)
+            else:
+                self.runq_buildable.append(0)
+
+        self.state = runQueueRunning
+
+        event.fire(bb.event.StampUpdate(self.target_pairs, self.dataCache.stamp, self.cfgData))
+
+    def task_complete(self, task):
+        """
+        Mark a task as completed
+        Look at the reverse dependencies and mark any task with 
+        completed dependencies as buildable
+        """
+        self.runq_complete[task] = 1
+        for revdep in self.runq_revdeps[task]:
+            if self.runq_running[revdep] == 1:
+                continue
+            if self.runq_buildable[revdep] == 1:
+                continue
+            alldeps = 1
+            for dep in self.runq_depends[revdep]:
+                if self.runq_complete[dep] != 1:
+                    alldeps = 0
+            if alldeps == 1:
+                self.runq_buildable[revdep] = 1
+                fn = self.taskData.fn_index[self.runq_fnid[revdep]]
+                taskname = self.runq_task[revdep]
+                bb.msg.debug(1, bb.msg.domain.RunQueue, "Marking task %s (%s, %s) as buildable" % (revdep, fn, taskname))
+
+    def task_fail(self, task, exitcode):
+        """
+        Called when a task has failed
+        Updates the state engine with the failure
+        """
+        bb.msg.error(bb.msg.domain.RunQueue, "Task %s (%s) failed with %s" % (task, self.get_user_idstring(task), exitcode))
+        self.stats.taskFailed()
+        fnid = self.runq_fnid[task]
+        self.failed_fnids.append(fnid)
+        bb.event.fire(runQueueTaskFailed(task, self.stats, self, self.cfgData))
+        if self.taskData.abort:
+            self.state = runQueueCleanup
+
+    def execute_runqueue_internal(self):
+        """
+        Run the tasks in a queue prepared by prepare_runqueue
+        """
+
+        if self.stats.total == 0:
+            # nothing to do
+            self.state = runQueueCleanup
+
+        while True:
+            task = None
+            if self.stats.active < self.number_tasks:
+                task = self.sched.next()
+            if task is not None:
+                fn = self.taskData.fn_index[self.runq_fnid[task]]
+
+                taskname = self.runq_task[task]
+                if self.check_stamp_task(task):
+                    bb.msg.debug(2, bb.msg.domain.RunQueue, "Stamp current task %s (%s)" % (task, self.get_user_idstring(task)))
+                    self.runq_running[task] = 1
+                    self.runq_buildable[task] = 1
+                    self.task_complete(task)
+                    self.stats.taskCompleted()
+                    self.stats.taskSkipped()
+                    continue
+
+                bb.event.fire(runQueueTaskStarted(task, self.stats, self, self.cfgData))
+                bb.msg.note(1, bb.msg.domain.RunQueue, "Running task %d of %d (ID: %s, %s)" % (self.stats.completed + self.stats.active + 1, self.stats.total, task, self.get_user_idstring(task)))
+                sys.stdout.flush()
+                sys.stderr.flush()
+                try: 
+                    pid = os.fork() 
+                except OSError, e: 
+                    bb.msg.fatal(bb.msg.domain.RunQueue, "fork failed: %d (%s)" % (e.errno, e.strerror))
+                if pid == 0:
+                    self.state = runQueueChildProcess
+                    # Make the child the process group leader
+                    os.setpgid(0, 0)
+                    newsi = os.open('/dev/null', os.O_RDWR)
+                    os.dup2(newsi, sys.stdin.fileno())
+                    self.cooker.configuration.cmd = taskname[3:]
+                    bb.data.setVar("__RUNQUEUE_DO_NOT_USE_EXTERNALLY", self, self.cooker.configuration.data)
+                    try:
+                        self.cooker.tryBuild(fn)
+                    except bb.build.EventException:
+                        bb.msg.error(bb.msg.domain.Build, "Build of " + fn + " " + taskname + " failed")
+                        sys.exit(1)
+                    except:
+                        bb.msg.error(bb.msg.domain.Build, "Build of " + fn + " " + taskname + " failed")
+                        raise
+                    sys.exit(0)
+                self.build_pids[pid] = task
+                self.runq_running[task] = 1
+                self.stats.taskActive()
+                if self.stats.active < self.number_tasks:
+                    continue
+            if self.stats.active > 0:
+                result = os.waitpid(-1, os.WNOHANG)
+                if result[0] is 0 and result[1] is 0:
+                    return
+                task = self.build_pids[result[0]]
+                del self.build_pids[result[0]]
+                if result[1] != 0:
+                    self.task_fail(task, result[1])
+                    return
+                self.task_complete(task)
+                self.stats.taskCompleted()
+                bb.event.fire(runQueueTaskCompleted(task, self.stats, self, self.cfgData))
+                continue
+
+            if len(self.failed_fnids) != 0:
+                self.state = runQueueFailed
+                return
+
+            # Sanity Checks
+            for task in range(self.stats.total):
+                if self.runq_buildable[task] == 0:
+                    bb.msg.error(bb.msg.domain.RunQueue, "Task %s never buildable!" % task)
+                if self.runq_running[task] == 0:
+                    bb.msg.error(bb.msg.domain.RunQueue, "Task %s never ran!" % task)
+                if self.runq_complete[task] == 0:
+                    bb.msg.error(bb.msg.domain.RunQueue, "Task %s never completed!" % task)
+            self.state = runQueueComplete
+            return
+
+    def finish_runqueue_now(self):
+        bb.msg.note(1, bb.msg.domain.RunQueue, "Sending SIGINT to remaining %s tasks" % self.stats.active)
+        for k, v in self.build_pids.iteritems():
+             try:
+                 os.kill(-k, signal.SIGINT)
+             except:
+                 pass
+
+    def finish_runqueue(self, now = False):
+        self.state = runQueueCleanUp
+        if now:
+            self.finish_runqueue_now()
+        try:
+            while self.stats.active > 0:
+                bb.event.fire(runQueueExitWait(self.stats.active, self.cfgData))
+                bb.msg.note(1, bb.msg.domain.RunQueue, "Waiting for %s active tasks to finish" % self.stats.active)
+                tasknum = 1
+                for k, v in self.build_pids.iteritems():
+                    bb.msg.note(1, bb.msg.domain.RunQueue, "%s: %s (%s)" % (tasknum, self.get_user_idstring(v), k))
+                    tasknum = tasknum + 1
+                result = os.waitpid(-1, os.WNOHANG)
+                if result[0] is 0 and result[1] is 0:
+                    return
+                task = self.build_pids[result[0]]
+                del self.build_pids[result[0]]
+                if result[1] != 0:
+                    self.task_fail(task, result[1])
+                else:
+                    self.stats.taskCompleted()
+                    bb.event.fire(runQueueTaskCompleted(task, self.stats, self, self.cfgData))
+        except:
+            self.finish_runqueue_now()
+            raise
+
+        if len(self.failed_fnids) != 0:
+            self.state = runQueueFailed
+            return
+
+        self.state = runQueueComplete
+        return
+
+    def dump_data(self, taskQueue):
+        """
+        Dump some debug information on the internal data structures
+        """
+        bb.msg.debug(3, bb.msg.domain.RunQueue, "run_tasks:")
+        for task in range(len(self.runq_task)):
+                bb.msg.debug(3, bb.msg.domain.RunQueue, " (%s)%s - %s: %s   Deps %s RevDeps %s" % (task, 
+                        taskQueue.fn_index[self.runq_fnid[task]], 
+                        self.runq_task[task], 
+                        self.runq_weight[task], 
+                        self.runq_depends[task], 
+                        self.runq_revdeps[task]))
+
+        bb.msg.debug(3, bb.msg.domain.RunQueue, "sorted_tasks:")
+        for task1 in range(len(self.runq_task)):
+            if task1 in self.prio_map:
+                task = self.prio_map[task1]
+                bb.msg.debug(3, bb.msg.domain.RunQueue, " (%s)%s - %s: %s   Deps %s RevDeps %s" % (task, 
+                        taskQueue.fn_index[self.runq_fnid[task]], 
+                        self.runq_task[task], 
+                        self.runq_weight[task], 
+                        self.runq_depends[task], 
+                        self.runq_revdeps[task]))
+
+
+class TaskFailure(Exception):
+    """
+    Exception raised when a task in a runqueue fails
+    """
+    def __init__(self, x): 
+        self.args = x
+
+
+class runQueueExitWait(bb.event.Event):
+    """
+    Event when waiting for task processes to exit
+    """
+
+    def __init__(self, remain, d):
+        self.remain = remain
+        self.message = "Waiting for %s active tasks to finish" % remain
+        bb.event.Event.__init__(self, d)
+
+class runQueueEvent(bb.event.Event):
+    """
+    Base runQueue event class
+    """
+    def __init__(self, task, stats, rq, d):
+        self.taskid = task
+        self.taskstring = rq.get_user_idstring(task)
+        self.stats = stats
+        bb.event.Event.__init__(self, d)
+
+class runQueueTaskStarted(runQueueEvent):
+    """
+    Event notifing a task was started
+    """
+    def __init__(self, task, stats, rq, d):
+        runQueueEvent.__init__(self, task, stats, rq, d)
+        self.message = "Running task %s (%d of %d) (%s)" % (task, stats.completed + stats.active + 1, self.stats.total, self.taskstring)
+
+class runQueueTaskFailed(runQueueEvent):
+    """
+    Event notifing a task failed
+    """
+    def __init__(self, task, stats, rq, d):
+        runQueueEvent.__init__(self, task, stats, rq, d)
+        self.message = "Task %s failed (%s)" % (task, self.taskstring)
+
+class runQueueTaskCompleted(runQueueEvent):
+    """
+    Event notifing a task completed
+    """
+    def __init__(self, task, stats, rq, d):
+        runQueueEvent.__init__(self, task, stats, rq, d)
+        self.message = "Task %s completed (%s)" % (task, self.taskstring)
+
+def check_stamp_fn(fn, taskname, d):
+    rq = bb.data.getVar("__RUNQUEUE_DO_NOT_USE_EXTERNALLY", d)
+    fnid = rq.taskData.getfn_id(fn)
+    taskid = rq.get_task_id(fnid, taskname)
+    if taskid is not None:
+        return rq.check_stamp_task(taskid)
+    return None