summaryrefslogtreecommitdiff
path: root/src/sim/eventq.hh
AgeCommit message (Collapse)Author
2015-09-01sim: Remove broken AutoSerialize support from the event queueAndreas Sandberg
Event auto-serialization no longer in use and has been broken ever since the introduction of PDES support almost two years ago. Additionally, serializing the individual event queues is undesirable since it exposes the thread structure of the simulator. What this means in practice is that the number of threads in the simulator must be the same when taking a checkpoint and when loading the checkpoint. This changeset removes support for the AutoSerialize event flag and the associated serialization code.
2015-08-07sim: Flag EventQueue::getCurTick() as constAndreas Sandberg
2015-08-03sim: function for testing for auto deletionTimothy Jones
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-08-03uby: Fix checkpointing and restoreTimothy Jones
There are 2 problems with the existing checkpoint and restore code in ruby. The first is that when the event queue is altered by ruby during serialization, some events that are currently scheduled cannot be found (e.g. the event to stop simulation that always lives on the queue), causing a panic. The second is that ruby is sometimes serialized after the memory system, meaning that the dirty data in its cache is flushed back to memory too late and so isn't included in the checkpoint. These are fixed by implementing memory writeback in ruby, using the same technique of hijacking the event queue, but first descheduling all events that are currently on it. They are saved, along with their scheduled time, so that the event queue can be faithfully reconstructed after writeback has finished. Events with the AutoDelete flag set will delete themselves when they are descheduled, causing an error when attempting to schedule them again. This is fixed by simply not recording them when taking them off the queue. Writeback is still implemented using flushing, so the cache recorder object, that is created to generate the trace and manage flushing, is kept around and used during serialization to write the trace to disk. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-07-07sim: Fix broken event unserializationAndreas Sandberg
Events expected to be unserialized using an event-specific unserializeEvent call. This call was never actually used, which meant the events relying on it never got unserialized (or scheduled after unserialization). Instead of relying on a custom call, we now use the normal serialization code again. In order to schedule the event correctly, the parrent object is expected to use the EventQueue::checkpointReschedule() call. This happens automatically for events that are serialized using the AutoSerialize mechanism.
2015-07-07sim: Refactor the serialization base classAndreas Sandberg
Objects that are can be serialized are supposed to inherit from the Serializable class. This class is meant to provide a unified API for such objects. However, so far it has mainly been used by SimObjects due to some fundamental design limitations. This changeset redesigns to the serialization interface to make it more generic and hide the underlying checkpoint storage. Specifically: * Add a set of APIs to serialize into a subsection of the current object. Previously, objects that needed this functionality would use ad-hoc solutions using nameOut() and section name generation. In the new world, an object that implements the interface has the methods serializeSection() and unserializeSection() that serialize into a named /subsection/ of the current object. Calling serialize() serializes an object into the current section. * Move the name() method from Serializable to SimObject as it is no longer needed for serialization. The fully qualified section name is generated by the main serialization code on the fly as objects serialize sub-objects. * Add a scoped ScopedCheckpointSection helper class. Some objects need to serialize data structures, that are not deriving from Serializable, into subsections. Previously, this was done using nameOut() and manual section name generation. To simplify this, this changeset introduces a ScopedCheckpointSection() helper class. When this class is instantiated, it adds a new /subsection/ and subsequent serialization calls during the lifetime of this helper class happen inside this section (or a subsection in case of nested sections). * The serialize() call is now const which prevents accidental state manipulation during serialization. Objects that rely on modifying state can use the serializeOld() call instead. The default implementation simply calls serialize(). Note: The old-style calls need to be explicitly called using the serializeOld()/serializeSectionOld() style APIs. These are used by default when serializing SimObjects. * Both the input and output checkpoints now use their own named types. This hides underlying checkpoint implementation from objects that need checkpointing and makes it easier to change the underlying checkpoint storage code.
2015-02-03sim: Remove test for non-NULL this in EventAndreas Sandberg
The method Event::initialized() tests if this != NULL as a part of the expression that tests if an event is initialized. The only case when this check could be false is if the method is called on a null pointer, which is illegal and leads to undefined behavior (such as eating your pets) according to the C++ standard. Because of this, modern compilers (specifically, recent versions of clang) warn about this which we treat as an error. This changeset removes the redundant check to fix said warning.
2014-10-16sim: EventQueue wakeup on events scheduled outside the event loopAndreas Hansson
This patch adds a 'wakeup' member function to EventQueue which should be called on an event queue whenever an event is scheduled on the event queue from outside code within the call tree of the gem5 event loop. This clearly isn't necessary for normal gem5 EventQueue operation but becomes the minimum necessary interface to allow hosting gem5's event loop onto other schedulers where there may be calls into gem5 from external code which schedules events onto an EventQueue between the current time and the time of the next scheduled event. The use case I have in mind is a SystemC hosting where the event loop is: while (more events) { wait(time_to_next_event or wakeup) setCurTick service events at this time } where the 'wait' needs to be woken up if time_to_next_event becomes shorter due to a scheduled event from SystemC arriving in a gem5 object. Requiring 'wakeup' to be called is a more efficient interface than requiring all gem5 event scheduling actions to affect the host scheduler. This interface could be located elsewhere, say on another global object, or by being passed by the host scheduler to objects which will schedule such events, but it seems cleanest to put it on EventQueue as it is actually a signal to the queue. EventQueue::wakeup is called for async_event events on event queue 0 as it's only important that *some* queue be triggered for such events.
2014-09-27misc: Fix a bunch of minor issues identified by static analysisAndreas Hansson
Add some missing initialisation, and fix a handful benign resource leaks (including some false positives).
2014-09-09misc: Fix a number of unitialised variables and membersAndreas Hansson
Static analysis unearther a bunch of uninitialised variables and members, and this patch addresses the problem. In all cases these omissions seem benign in the end, but at least fixing them means less false positives next time round.
2014-06-30power: Add basic DVFS support for gem5Stephan Diestelhorst
Adds DVFS capabilities to gem5, by allowing users to specify lists for frequencies and voltages in SrcClockDomains and VoltageDomains respectively. A separate component, DVFSHandler, provides a small interface to change operating points of the associated domains. Clock domains will be linked to voltage domains and thus allow separate clock, but shared voltage lines. Currently all the valid performance-level updates are performed with a fixed transition latency as specified for the domain. Config file example: ... vd = VoltageDomain(voltage = ['1V','0.95V','0.90V','0.85V']) tsys.cluster1.clk_domain.clock = ['1GHz','700MHz','400MHz','230MHz'] tsys.cluster2.clk_domain.clock = ['1GHz','700MHz','400MHz','230MHz'] tsys.cluster1.clk_domain.domain_id = 0 tsys.cluster2.clk_domain.domain_id = 1 tsys.cluster1.clk_domain.voltage_domain = vd tsys.cluster2.clk_domain.voltage_domain = vd tsys.dvfs_handler.domains = [tsys.cluster1.clk_domain, tsys.cluster2.clk_domain] tsys.dvfs_handler.enable = True
2014-04-03sim: Add the ability to lock and migrate between event queuesAndreas Sandberg
We need the ability to lock event queues to enable device accesses across threads. The serviceOne() method now takes a service lock prior to handling a new event. By locking an event queue, a different thread/eq can effectively execute in the context of the locked event queue. To simplify temporary event queue migrations, this changeset introduces the EventQueue::ScopedMigration class that unlocks the current event queue, locks a new event queue, and updates the current event queue variable. In order to prevent deadlocks, event queues need to be released when waiting on barriers. This is implemented using the EventQueue::ScopedRelease class. An instance of this class is, for example, used in the BaseGlobalEvent class to release the event queue when waiting on the synchronization barrier. The intended use for this functionality is when devices need to be accessed across thread boundaries. For example, when fast-forwarding, it might be useful to run devices and CPUs in separate threads. In such a case, the CPU locks the device queue whenever it needs to perform IO. This functionality is primarily intended for KVM. Note: Migrating between event queues can lead to non-deterministic timing. Use with extreme care! --HG-- extra : rebase_source : 23e3a741a1fd73861d1339782dbbe1bc76285315
2013-11-25sim: simulate with multiple threads and event queuesSteve Reinhardt ext:(%2C%20Nilay%20Vaish%20%3Cnilay%40cs.wisc.edu%3E%2C%20Ali%20Saidi%20%3CAli.Saidi%40ARM.com%3E)
This patch adds support for simulating with multiple threads, each of which operates on an event queue. Each sim object specifies which eventq is would like to be on. A custom barrier implementation is being added using which eventqs synchronize. The patch was tested in two different configurations: 1. ruby_network_test.py: in this simulation L1 cache controllers receive requests from the cpu. The requests are replied to immediately without any communication taking place with any other level. 2. twosys-tsunami-simple-atomic: this configuration simulates a client-server system which are connected by an ethernet link. We still lack the ability to communicate using message buffers or ports. But other things like simulation start and end, synchronizing after every quantum are working. Committed by: Nilay Vaish
2013-11-12sim: fix event priority name for debug-start optionAnthony Gutierrez
2013-02-19scons: Add warning for missing declarationsAndreas Hansson
This patch enables warnings for missing declarations. To avoid issues with SWIG-generated code, the warning is only applied to non-SWIG code.
2013-01-31sim: remove unused struct priority_compareNilay Vaish
2012-11-16sim: have a curTick per eventqNilay Vaish
This patch adds a _curTick variable to an eventq. This variable is updated whenever an event is serviced in function serviceOne(), or all events upto a particular time are processed in function serviceEvents(). This change helps when there are eventqs that do not make use of curTick for scheduling events.
2012-08-21EventManager: Remove test for NULL pointer in constructorAndreas Hansson
This patch tidies up the EventManager constructor and prunes a corner case where the EventManager would initialise its eventq pointer to NULL. This would cause segmentation faults on actual use and should never happen.
2012-08-21Clock: Make Tick unsigned and remove UTickAndreas Hansson
This patch makes the Tick unsigned and removes the UTick typedef. The ticks should never be negative, and there was only one major issue with removing it, caused by the o3 CPU using a -1 as an initial value. The patch has no impact on any regressions.
2012-07-09EventManager: Rename queue accessor and remove cast operatorAndreas Hansson
This patch renames the queue() accessor to the less ambigious eventQueue, and also removes the cast operator. The queue() member function cause problems in derived classes that declare members with the same name, e.g. a MemObject subclass that has a packet queue on its own. The operator is not causing any harm at this point, but as it is not used there is little point in keeping it.
2012-06-05sim: Remove FastAllocAli Saidi
While FastAlloc provides a small performance increase (~1.5%) over regular malloc it isn't thread safe. After removing FastAlloc and using tcmalloc I've seen a performance increase of 12% over libc malloc when running twolf for ARM.
2012-05-10gem5: fix a number of use after free issuesAli Saidi
2012-03-19gcc: Clean-up of non-C++0x compliant code, first stepsAndreas Hansson
This patch cleans up a number of minor issues aiming to get closer to compliance with the C++0x standard as interpreted by gcc and clang (compile with std=c++0x and -pedantic-errors). In particular, the patch cleans up enums where the last item was succeded by a comma, namespaces closed by a curcly brace followed by a semi-colon, and the use of the GNU-extension typeof (replaced by templated functions). It does not address variable-length arrays, zero-size arrays, anonymous structs, range expressions in switch statements, and the use of long long. The generated CPU code also has a large number of issues that remain to be fixed, mainly related to overflows in implicit constant conversion (due to shifts).
2012-01-05eventq: add a function for replacing head of the queueNilay Vaish
This patch adds a function for replacing the event at the head of the queue with another event. This helps in running a different set of events. Events already scheduled can processed by replacing the original head event back. This function has been specifically added to support cache warmup and cooldown required for creating and restoring checkpoints. --HG-- extra : rebase_source : ed6e2905720b6bfdefd020fab76235ccf33d28d1
2011-09-22event: minor cleanupSteve Reinhardt
Initialize flags via the Event constructor instead of calling setFlags() in the body of the derived class's constructor. I forget exactly why, but this made life easier when implementing multi-queue support. Also rename Event::getFlags() to isFlagSet() to better match common usage, and get rid of some unused Event methods.
2011-04-15trace: reimplement the DTRACE function so it doesn't use a vectorNathan Binkert
At the same time, rename the trace flags to debug flags since they have broader usage than simply tracing. This means that --trace-flags is now --debug-flags and --trace-help is now --debug-help
2011-03-29sim: typecast Tick to UTick for eventQ assertKorey Sewell
2011-01-07Replace curTick global variable with accessor functions.Steve Reinhardt
This step makes it easy to replace the accessor functions (which still access a global variable) with ones that access per-thread curTick values.
2010-04-18event: Allow EventWrapper to take an object referenceNathan Binkert
2010-04-15eventq: move EventQueue constructor to cc fileNathan Binkert
Also make copy constructor and assignment operator private.
2010-04-02eventq: allow an implicit cast from an EventManager to an EventQueue *Nathan Binkert
2010-04-02eventq: Clean up some flagsNathan Binkert
- Make the initialized flag always available, not just in debug mode. - Make the Initialized flag actually use several bits so it is very unlikely that something that's uninitialized accidentally looks initialized. - Add an initialized() function that tells you if the current event is indeed initialized. - Clear the flags on delete so it can't be accidentally thought of as initialized. - Fix getFlags assert statement. "How did this ever work?"
2010-04-02eventq: Make priorities just an integer instead of an enum.Nathan Binkert
Symbolic names should still be used, but this makes it easier to do things like: Event::Priority MyObject_Pri = Event::Default_Pri + 1 Remember that higher numbers are lower priority (should we fix this?)
2010-03-12eventq: rearrange a little bit so I can add some stuffNathan Binkert
2010-03-12eventq: remove some unused includesNathan Binkert
2010-02-26events: Give EventWrapped a default name and descriptionNathan Binkert
2009-11-04build: fix compile problems pointed out by gcc 4.4Nathan Binkert
2009-05-17includes: sort includes againNathan Binkert
2009-05-17types: Move stuff for global types into src/base/types.hhNathan Binkert
--HG-- rename : src/sim/host.hh => src/base/types.hh
2008-12-08eventq: Add some debugging code to the eventq.Nathan Binkert
2008-12-06eventq: use the flags data structureNathan Binkert
2008-12-06eventq: move virtual function definitiions to the .cc file.Nathan Binkert
2008-11-10python: Fix the reference counting for python events placed on the eventq.Nathan Binkert
We need to add a reference when an object is put on the C++ queue, and remove a reference when the object is removed from the queue. This was not happening before and caused a memory problem.
2008-10-09eventq: Major API change for the Event and EventQueue structures.Nathan Binkert
Since the early days of M5, an event needed to know which event queue it was on, and that data was required at the time of construction of the event object. In the future parallelized M5, this sort of requirement does not work well since the proper event queue will not always be known at the time of construction of an event. Now, events are created, and the EventQueue itself has the schedule function, e.g. eventq->schedule(event, when). To simplify the syntax, I created a class called EventManager which holds a pointer to an EventQueue and provides the schedule interface that is a proxy for the EventQueue. The intent is that objects that frequently schedule events can be derived from EventManager and then they have the schedule interface. SimObject and Port are examples of objects that will become EventManagers. The end result is that any SimObject can just call schedule(event, when) and it will just call that SimObject's eventq->schedule function. Of course, some objects may have more than one EventQueue, so this interface might not be perfect for those, but they should be relatively few.
2008-10-09eventq: Don't use inline friend function when a static function will do.Nathan Binkert
Another good reason to avoid this is that swig will try to wrap the friend, but it won't try to wrap a private static function.
2008-09-29Fix EVENTQ_DEBUG vs DEBUG_EVENTQ #define inconsistency.Steve Reinhardt
2008-09-19Use the proper version of C++ headersNathan Binkert
2008-09-10style: Remove non-leading tabs everywhere they shouldn't be. Developers ↵Ali Saidi
should configure their editors to not insert tabs
2008-07-11eventq: change the event datastructure back to LIFO.Nathan Binkert
The status quo is preferred since it is less likely that people will rely on LIFO than FIFO, and when we move to a parallelized M5, no ordering between events of the same time/priority will be guaranteed.
2008-07-11eventq: new eventq data structure. The new data structure is singlyNathan Binkert
linked list sorted by time and priority. For things of the same time and priority, a second, circularly linked list maintains the data structure. Events of the same time and priority are now inserted in FIFO order instead of LIFO order. This dramatically improves the performance of systems that schedule multiple events at the same time. The FIFO order version is not preferred to LIFO (because it may cause people to rely on it), but I'm going to commit it anyway and immediately commit the preferred LIFO version on top.