This commit substantially refactors the JITLinkMemoryManager API to: (1) add
asynchronous versions of key operations, (2) give memory manager implementations
full control over link graph address layout, (3) enable more efficient tracking
of allocated memory, and (4) support "allocation actions" and finalize-lifetime
memory.
Together these changes provide a more usable API, and enable more powerful and
efficient memory manager implementations.
To support these changes the JITLinkMemoryManager::Allocation inner class has
been split into two new classes: InFlightAllocation, and FinalizedAllocation.
The allocate method returns an InFlightAllocation that tracks memory (both
working and executor memory) prior to finalization. The finalize method returns
a FinalizedAllocation object, and the InFlightAllocation is discarded. Breaking
Allocation into InFlightAllocation and FinalizedAllocation allows
InFlightAllocation subclassses to be written more naturally, and FinalizedAlloc
to be implemented and used efficiently (see (3) below).
In addition to the memory manager changes this commit also introduces a new
MemProt type to represent memory protections (MemProt replaces use of
sys::Memory::ProtectionFlags in JITLink), and a new MemDeallocPolicy type that
can be used to indicate when a section should be deallocated (see (4) below).
Plugin/pass writers who were using sys::Memory::ProtectionFlags will have to
switch to MemProt -- this should be straightworward. Clients with out-of-tree
memory managers will need to update their implementations. Clients using
in-tree memory managers should mostly be able to ignore it.
Major features:
(1) More asynchrony:
The allocate and deallocate methods are now asynchronous by default, with
synchronous convenience wrappers supplied. The asynchronous versions allow
clients (including JITLink) to request and deallocate memory without blocking.
(2) Improved control over graph address layout:
Instead of a SegmentRequestMap, JITLinkMemoryManager::allocate now takes a
reference to the LinkGraph to be allocated. The memory manager is responsible
for calculating the memory requirements for the graph, and laying out the graph
(setting working and executor memory addresses) within the allocated memory.
This gives memory managers full control over JIT'd memory layout. For clients
that don't need or want this degree of control the new "BasicLayout" utility can
be used to get a segment-based view of the graph, similar to the one provided by
SegmentRequestMap. Once segment addresses are assigned the BasicLayout::apply
method can be used to automatically lay out the graph.
(3) Efficient tracking of allocated memory.
The FinalizedAlloc type is a wrapper for an ExecutorAddr and requires only
64-bits to store in the controller. The meaning of the address held by the
FinalizedAlloc is left up to the memory manager implementation, but the
FinalizedAlloc type enforces a requirement that deallocate be called on any
non-default values prior to destruction. The deallocate method takes a
vector<FinalizedAlloc>, allowing for bulk deallocation of many allocations in a
single call.
Memory manager implementations will typically store the address of some
allocation metadata in the executor in the FinalizedAlloc, as holding this
metadata in the executor is often cheaper and may allow for clean deallocation
even in failure cases where the connection with the controller is lost.
(4) Support for "allocation actions" and finalize-lifetime memory.
Allocation actions are pairs (finalize_act, deallocate_act) of JITTargetAddress
triples (fn, arg_buffer_addr, arg_buffer_size), that can be attached to a
finalize request. At finalization time, after memory protections have been
applied, each of the "finalize_act" elements will be called in order (skipping
any elements whose fn value is zero) as
((char*(*)(const char *, size_t))fn)((const char *)arg_buffer_addr,
(size_t)arg_buffer_size);
At deallocation time the deallocate elements will be run in reverse order (again
skipping any elements where fn is zero).
The returned char * should be null to indicate success, or a non-null
heap-allocated string error message to indicate failure.
These actions allow finalization and deallocation to be extended to include
operations like registering and deregistering eh-frames, TLS sections,
initializer and deinitializers, and language metadata sections. Previously these
operations required separate callWrapper invocations. Compared to callWrapper
invocations, actions require no extra IPC/RPC, reducing costs and eliminating
a potential source of errors.
Finalize lifetime memory can be used to support finalize actions: Sections with
finalize lifetime should be destroyed by memory managers immediately after
finalization actions have been run. Finalize memory can be used to support
finalize actions (e.g. with extra-metadata, or synthesized finalize actions)
without incurring permanent memory overhead.
In SimpleRemoteEPC, calls to from callWrapperAsync to sendMessage may fail.
The handlers may or may not be sent failure messages by handleDisconnect,
depending on when that method is run. This patch adds a check for an un-failed
handler, and if it finds one sends it a failure message.
On the controller-side, handle `Hangup` messages from the executor. The executor passed `Error::success()` or a failure message as payload.
Hangups cause an immediate disconnect of the transport layer. The disconnect function may be called later again and so implementations should be prepared. `FDSimpleRemoteEPCTransport::disconnect()` already has a flag to check that:
cd1bd95d87/llvm/lib/ExecutionEngine/Orc/Shared/SimpleRemoteEPCUtils.cpp (L112)
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D111527
Adds LLVMOrcCreateStaticLibrarySearchGeneratorForPath and
LLVMOrcCreateDynamicLibrarySearchGeneratorForPath functions to create generators
for static and dynamic libraries.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D108535
The callWrapperAsync and callSPSWrapperAsync methods take a handler object
that is run on the return value of the call when it is ready. The new RunPolicy
parameters allow clients to control how these handlers are run. If no policy is
specified then the handler will be packaged as a GenericNamedTask and dispatched
using the ExecutorProcessControl's TaskDispatch member. Callers can use the
ExecutorProcessControl::RunInPlace policy to cause the handler to be run
directly instead, which may be preferrable for simple handlers, or they can
write their own policy object (e.g. to dispatch as some other kind of Task,
rather than GenericNamedTask).
f3411616896 introduced a dependence (for builds with LLVM_ENABLE_THREADS) on
pthreads. This commit updates the CMakeLists.txt file to include a LINK_LIBS
entry for pthreads.
ExecutorProcessControl objects will now have a TaskDispatcher member which
should be used to dispatch work (in particular, handling incoming packets in
the implementation of remote EPC implementations like SimpleRemoteEPC).
The GenericNamedTask template can be used to wrap function objects that are
callable as 'void()' (along with an optional name to describe the task).
The makeGenericNamedTask functions can be used to create GenericNamedTask
instances without having to name the function object type.
In a future patch ExecutionSession will be updated to use the
ExecutorProcessControl's dispatcher, instead of its DispatchTaskFunction.
The callee address is now the first parameter and the 'SendResult' function
the second. This change improves consistentency with the non-async functions
where the callee is the first address and the return value the second.
There is a bug reported at https://bugs.llvm.org/show_bug.cgi?id=48938
After looking through the glibc, I found the `atexit(f)` is the same as `__cxa_atexit(f, NULL, NULL)`. In orc runtime, we identify different JITDylib by their dso_handle value, so that a NULL dso_handle is invalid. So in this patch, I added a `PlatformJDDSOHandle` to ELFNixRuntimeState, and functions which are registered by atexit will be registered at PlatformJD.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D111413
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.
This allows us to ensure that Support doesn't have includes from MC/*.
Differential Revision: https://reviews.llvm.org/D111454
This reverts commit dfd74db9813b0c7c64038c303726ba43f335e07a.
SimpleRemoteEPC should share dispatch with the ExecutionSession, rather than
having two different dispatch systems on the controller side.
SimpleRemoteEPCServer::Dispatch doesn't need to be shared.
Renames SimpleRemoteEPCServer::Dispatcher to SimpleRemoteEPCDispatcher and
moves it into OrcShared. SimpleRemoteEPCServer::ThreadDispatcher is similarly
moved and renamed to DynamicThreadPoolSimpleRemoteEPCDispatcher.
This will allow these classes to be reused by SimpleRemoteEPC on the controller
side of the connection.
With the removal of OrcRPCExecutorProcessControl and OrcRPCTPCServer in
6aeed7b19c4 the ORC RPC library no longer has any in-tree users.
Clients needing serialization for ORC should move to Simple Packed
Serialization (usually by adopting SimpleRemoteEPC for remote JITing).
The getPerDylibResources method may be called concurrently from multiple
threads, so we need to protect access to the underlying map.
Possible for fix https://llvm.org/PR51064
Adds a 'start' method to SimpleRemoteEPCTransport to defer transport startup
until the client has been configured. This avoids races on client members if the
first messages arrives while the client is being configured.
Also fixes races on the file descriptors in FDSimpleRemoteEPCTransport.
This reintroduces "[ORC] Introduce EPCGenericRTDyldMemoryManager."
(bef55a2b47a938ef35cbd7b61a1e5fa74e68c9ed) and "[lli] Add ChildTarget dependence
on OrcTargetProcess library." (7a219d801bf2c3006482cf3cbd3170b3b4ea2e1b) which were
reverted in 99951a56842d8e4cd0706cd17a04f77b5d0f6dd0 due to bot failures.
The root cause of the bot failures should be fixed by "[ORC] Fix uninitialized
variable." (0371049277912afc201da721fa659ecef7ab7fba) and "[ORC] Wait for
handleDisconnect to complete in SimpleRemoteEPC::disconnect."
(320832cc9b7e7fea5fc8afbed75c34c4a43287ba).
Disconnect should block until handleDisconnect completes, otherwise we might
destroy the SimpleRemoteEPC instance while it's still in use.
Thanks to Dave Blaikie for helping me track this down.
This reverts commit bef55a2b47a938ef35cbd7b61a1e5fa74e68c9ed while I investigate
failures on some bots. Also reverts "[lli] Add ChildTarget dependence on
OrcTargetProcess library." (7a219d801bf2c3006482cf3cbd3170b3b4ea2e1b) which was
a fallow-up to bef55a2b47a.
EPCGenericRTDyldMemoryMnaager is an EPC-based implementation of the
RuntimeDyld::MemoryManager interface. It enables remote-JITing via EPC (backed
by a SimpleExecutorMemoryManager instance on the executor side) for RuntimeDyld
clients.
The lli and lli-child-target tools are updated to use SimpleRemoteEPC and
SimpleRemoteEPCServer (rather than OrcRemoteTargetClient/Server), and
EPCGenericRTDyldMemoryManager for MCJIT tests.
By enabling remote-JITing for MCJIT and RuntimeDyld-based ORC clients,
EPCGenericRTDyldMemoryManager allows us to deprecate older remote-JITing
support, including OrcTargetClient/Server, OrcRPCExecutorProcessControl, and the
Orc RPC system itself. These will be removed in future patches.
Removing the 'ess' suffix improves the ergonomics without sacrificing clarity.
Since this class is likely to be used more frequently in the future it's worth
some short term pain to fix this now.
EPCGenericDylibManager provides an interface for loading dylibs and looking up
symbols in the executor, implemented using EPC-calls to functions in the
executor.
SimpleExecutorDylibManager is an executor-side service that provides the
functions used by EPCGenericDylibManager.
SimpleRemoteEPC is updated to use an EPCGenericDylibManager instance to
implement the ExecutorProcessControl loadDylib and lookup methods. In a future
commit these methods will be removed, and clients updated to use
EPCGenericDylibManagers directly.
This should have been included with ExecutorBootstrapService in 78b083dbb72,
but was accidentally left out. It give services a chance to release any
resources that they have acquired.
Two typos, one unsused include and some leftovers from the TargetProcessControl -> ExecutorProcessControl renaming
Reviewed By: xgupta
Differential Revision: https://reviews.llvm.org/D110260
Finalization and deallocation actions are a key part of the upcoming
JITLinkMemoryManager redesign: They generalize the existing finalization and
deallocate concepts (basically "copy-and-mprotect", and "munmap") to include
support for arbitrary registration and deregistration of parts of JIT linked
code. This allows us to register and deregister eh-frames, TLV sections,
language metadata, etc. using regular memory management calls with no additional
IPC/RPC overhead, which should both improve JIT performance and simplify
interactions between ORC and the ORC runtime.
The SimpleExecutorMemoryManager class provides executor-side support for memory
management operations, including finalization and deallocation actions.
This support is being added in advance of the rest of the memory manager
redesign as it will simplify the introduction of an EPC based
RuntimeDyld::MemoryManager (since eh-frame registration/deregistration will be
expressible as actions). The new RuntimeDyld::MemoryManager will in turn allow
us to remove older remote allocators that are blocking the rest of the memory
manager changes.
This is a small first step towards reorganization of the ORC libraries:
Declarations for types and function names (as strings) to be found in the
"ORC runtime bootstrap" set are moved into OrcRTBridge.h / OrcRTBridge.cpp.
The current implementation of the "ORC runtime bootstrap" functions is moved
into OrcRTBootstrap.h and OrcRTBootstrap.cpp. It is likely that this code will
eventually be moved into ORT-RT proper (in compiler RT).
The immediate goal of this change is to make these bootstrap functions usable
for clients other than SimpleRemoteEPC/SimpleRemoteEPCServer. The first planned
client is a new RuntimeDyld::MemoryManager that will run over EPC, which will
allow us to remove the old OrcRemoteTarget code.
This patch use the same way as the https://reviews.llvm.org/rGfe1fa43f16beac1506a2e73a9f7b3c81179744eb to handle the thread local variable.
It allocates 2 * pointerSize space in GOT to represent the thread key and data address. Instead of using the _tls_get_addr function, I customed a function __orc_rt_elfnix_tls_get_addr to get the address of thread local varible. Currently, this is a wip patch, only one TLS relocation R_X86_64_TLSGD is supported and I need to add the corresponding test cases.
To allocate the TLS descriptor in GOT, I need to get the edge kind information in PerGraphGOTAndPLTStubBuilder, So I add a `Edge::Kind K` argument in some functions in PerGraphGOTAndPLTStubBuilder.h. If it is not suitable, I can think further to solve this problem.
Differential Revision: https://reviews.llvm.org/D109293
Bootstrap symbols are symbols whose addresses may be required to bootstrap
the rest of the JIT. The bootstrap symbols map generalizes the existing
JITDispatchInfo class provide an arbitrary map of symbol names to addresses.
The JITDispatchInfo class will be replaced by bootstrap symbols with reserved
names in upcoming commits.
This reapplies bb27e4564355243e479cab40885d6e0f7f640572 (SimpleRemoteEPC
support) and 2269a941a450a0d395161cfb792be58870b2875b (#include <mutex>
fix) with further fixes to support building with LLVM_ENABLE_THREADS=Off.
This reverts commit 5629afea9109d3b72064cbe70e1ca91ffb9dc0a2 ("[ORC] Add missing
include."), and bb27e4564355243e479cab40885d6e0f7f640572 ("[ORC] Add
SimpleRemoteEPC: ExecutorProcessControl over SPS + abstract transport.").
The SimpleRemoteEPC patch currently assumes availability of threads, and needs
to be rewritten with LLVM_ENABLE_THREADS guards.
SimpleRemoteEPC is an ExecutorProcessControl implementation (with corresponding
new server class) that uses ORC SimplePackedSerialization (SPS) to serialize and
deserialize EPC-messages to/from byte-buffers. The byte-buffers are sent and
received via a new SimpleRemoteEPCTransport interface that can be implemented to
run SimpleRemoteEPC over whatever underlying transport system (IPC, RPC, network
sockets, etc.) best suits your use case.
The SimpleRemoteEPCServer class provides executor-side support. It uses a
customizable SimpleRemoteEPCServer::Dispatcher object to dispatch wrapper
function calls to prevent the RPC thread from being blocked (a problem in some
earlier remote-JIT server implementations). Almost all functionality (beyond the
bare basics needed to bootstrap) is implemented as wrapper functions to keep the
implementation simple and uniform.
Compared to previous remote JIT utilities (OrcRemoteTarget*,
OrcRPCExecutorProcessControl), more consideration has been given to
disconnection and error handling behavior: Graceful disconnection is now always
initiated by the ORC side of the connection, and failure at either end (or in
the transport) will result in Errors being delivered to both ends to enable
controlled tear-down of the JIT and Executor (in the Executor's case this means
"as controlled as the JIT'd code allows").
The introduction of SimpleRemoteEPC will allow us to remove other remote-JIT
support from ORC (including the legacy OrcRemoteTarget* code used by lli, and
the OrcRPCExecutorProcessControl and OrcRPCEPCServer classes), and then remove
ORC RPC itself.
The llvm-jitlink and llvm-jitlink-executor tools have been updated to use
SimpleRemoteEPC over file descriptors. Future commits will move lli and other
tools and example code to this system, and remove ORC RPC.
All ExecutorProcessControl subclasses must provide a JITLinkMemoryManager object
that can be used to allocate memory in the executor process. The
EPCGenericJITLinkMemoryManager class provides an off-the-shelf
JITLinkMemoryManager implementation for JITs that do not need (or cannot
provide) a specialized JITLinkMemoryManager implementation. This simplifies the
process of creating new ExecutorProcessControl implementations.
This should fix the bot error in
https://lab.llvm.org/buildbot/#/builders/112/builds/8599
which forced reversion of the ELFNixPlatform in 45ac5f54418.
This should allow us to re-enable the ELFNixPlatform in a follow-up patch.
