1//===------- SimpleEPCServer.cpp - EPC over simple abstract channel -------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/ExecutionEngine/Orc/TargetProcess/SimpleRemoteEPCServer.h"
10
11#include "llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h"
12#include "llvm/ExecutionEngine/Orc/Shared/TargetProcessControlTypes.h"
13#include "llvm/ExecutionEngine/Orc/TargetProcess/RegisterEHFrames.h"
14#include "llvm/Support/FormatVariadic.h"
15#include "llvm/Support/Process.h"
16#include "llvm/TargetParser/Host.h"
17
18#include "OrcRTBootstrap.h"
19
20#define DEBUG_TYPE "orc"
21
22using namespace llvm::orc::shared;
23
24namespace llvm {
25namespace orc {
26
27ExecutorBootstrapService::~ExecutorBootstrapService() = default;
28
29SimpleRemoteEPCServer::Dispatcher::~Dispatcher() = default;
30
31#if LLVM_ENABLE_THREADS
32void SimpleRemoteEPCServer::ThreadDispatcher::dispatch(
33 unique_function<void()> Work) {
34 {
35 std::lock_guard<std::mutex> Lock(DispatchMutex);
36 if (!Running)
37 return;
38 ++Outstanding;
39 }
40
41 std::thread([this, Work = std::move(Work)]() mutable {
42 Work();
43 std::lock_guard<std::mutex> Lock(DispatchMutex);
44 --Outstanding;
45 OutstandingCV.notify_all();
46 }).detach();
47}
48
49void SimpleRemoteEPCServer::ThreadDispatcher::shutdown() {
50 std::unique_lock<std::mutex> Lock(DispatchMutex);
51 Running = false;
52 OutstandingCV.wait(lock&: Lock, p: [this]() { return Outstanding == 0; });
53}
54#endif
55
56StringMap<ExecutorAddr> SimpleRemoteEPCServer::defaultBootstrapSymbols() {
57 StringMap<ExecutorAddr> DBS;
58 rt_bootstrap::addTo(M&: DBS);
59 return DBS;
60}
61
62Expected<SimpleRemoteEPCTransportClient::HandleMessageAction>
63SimpleRemoteEPCServer::handleMessage(SimpleRemoteEPCOpcode OpC, uint64_t SeqNo,
64 ExecutorAddr TagAddr,
65 SimpleRemoteEPCArgBytesVector ArgBytes) {
66
67 LLVM_DEBUG({
68 dbgs() << "SimpleRemoteEPCServer::handleMessage: opc = ";
69 switch (OpC) {
70 case SimpleRemoteEPCOpcode::Setup:
71 dbgs() << "Setup";
72 assert(SeqNo == 0 && "Non-zero SeqNo for Setup?");
73 assert(!TagAddr && "Non-zero TagAddr for Setup?");
74 break;
75 case SimpleRemoteEPCOpcode::Hangup:
76 dbgs() << "Hangup";
77 assert(SeqNo == 0 && "Non-zero SeqNo for Hangup?");
78 assert(!TagAddr && "Non-zero TagAddr for Hangup?");
79 break;
80 case SimpleRemoteEPCOpcode::Result:
81 dbgs() << "Result";
82 assert(!TagAddr && "Non-zero TagAddr for Result?");
83 break;
84 case SimpleRemoteEPCOpcode::CallWrapper:
85 dbgs() << "CallWrapper";
86 break;
87 }
88 dbgs() << ", seqno = " << SeqNo << ", tag-addr = " << TagAddr
89 << ", arg-buffer = " << formatv("{0:x}", ArgBytes.size())
90 << " bytes\n";
91 });
92
93 using UT = std::underlying_type_t<SimpleRemoteEPCOpcode>;
94 if (static_cast<UT>(OpC) > static_cast<UT>(SimpleRemoteEPCOpcode::LastOpC))
95 return make_error<StringError>(Args: "Unexpected opcode",
96 Args: inconvertibleErrorCode());
97
98 // TODO: Clean detach message?
99 switch (OpC) {
100 case SimpleRemoteEPCOpcode::Setup:
101 return make_error<StringError>(Args: "Unexpected Setup opcode",
102 Args: inconvertibleErrorCode());
103 case SimpleRemoteEPCOpcode::Hangup:
104 return SimpleRemoteEPCTransportClient::EndSession;
105 case SimpleRemoteEPCOpcode::Result:
106 if (auto Err = handleResult(SeqNo, TagAddr, ArgBytes: std::move(ArgBytes)))
107 return std::move(Err);
108 break;
109 case SimpleRemoteEPCOpcode::CallWrapper:
110 handleCallWrapper(RemoteSeqNo: SeqNo, TagAddr, ArgBytes: std::move(ArgBytes));
111 break;
112 }
113 return ContinueSession;
114}
115
116Error SimpleRemoteEPCServer::waitForDisconnect() {
117 std::unique_lock<std::mutex> Lock(ServerStateMutex);
118 ShutdownCV.wait(lock&: Lock, p: [this]() { return RunState == ServerShutDown; });
119 return std::move(ShutdownErr);
120}
121
122void SimpleRemoteEPCServer::handleDisconnect(Error Err) {
123 PendingJITDispatchResultsMap TmpPending;
124
125 {
126 std::lock_guard<std::mutex> Lock(ServerStateMutex);
127 std::swap(a&: TmpPending, b&: PendingJITDispatchResults);
128 RunState = ServerShuttingDown;
129 }
130
131 // Send out-of-band errors to any waiting threads.
132 for (auto &KV : TmpPending)
133 KV.second->set_value(
134 shared::WrapperFunctionResult::createOutOfBandError(Msg: "disconnecting"));
135
136 // Wait for dispatcher to clear.
137 D->shutdown();
138
139 // Shut down services.
140 while (!Services.empty()) {
141 ShutdownErr =
142 joinErrors(E1: std::move(ShutdownErr), E2: Services.back()->shutdown());
143 Services.pop_back();
144 }
145
146 std::lock_guard<std::mutex> Lock(ServerStateMutex);
147 ShutdownErr = joinErrors(E1: std::move(ShutdownErr), E2: std::move(Err));
148 RunState = ServerShutDown;
149 ShutdownCV.notify_all();
150}
151
152Error SimpleRemoteEPCServer::sendMessage(SimpleRemoteEPCOpcode OpC,
153 uint64_t SeqNo, ExecutorAddr TagAddr,
154 ArrayRef<char> ArgBytes) {
155
156 LLVM_DEBUG({
157 dbgs() << "SimpleRemoteEPCServer::sendMessage: opc = ";
158 switch (OpC) {
159 case SimpleRemoteEPCOpcode::Setup:
160 dbgs() << "Setup";
161 assert(SeqNo == 0 && "Non-zero SeqNo for Setup?");
162 assert(!TagAddr && "Non-zero TagAddr for Setup?");
163 break;
164 case SimpleRemoteEPCOpcode::Hangup:
165 dbgs() << "Hangup";
166 assert(SeqNo == 0 && "Non-zero SeqNo for Hangup?");
167 assert(!TagAddr && "Non-zero TagAddr for Hangup?");
168 break;
169 case SimpleRemoteEPCOpcode::Result:
170 dbgs() << "Result";
171 assert(!TagAddr && "Non-zero TagAddr for Result?");
172 break;
173 case SimpleRemoteEPCOpcode::CallWrapper:
174 dbgs() << "CallWrapper";
175 break;
176 }
177 dbgs() << ", seqno = " << SeqNo << ", tag-addr = " << TagAddr
178 << ", arg-buffer = " << formatv("{0:x}", ArgBytes.size())
179 << " bytes\n";
180 });
181 auto Err = T->sendMessage(OpC, SeqNo, TagAddr, ArgBytes);
182 LLVM_DEBUG({
183 if (Err)
184 dbgs() << " \\--> SimpleRemoteEPC::sendMessage failed\n";
185 });
186 return Err;
187}
188
189Error SimpleRemoteEPCServer::sendSetupMessage(
190 StringMap<std::vector<char>> BootstrapMap,
191 StringMap<ExecutorAddr> BootstrapSymbols) {
192
193 using namespace SimpleRemoteEPCDefaultBootstrapSymbolNames;
194
195 std::vector<char> SetupPacket;
196 SimpleRemoteEPCExecutorInfo EI;
197 EI.TargetTriple = sys::getProcessTriple();
198 if (auto PageSize = sys::Process::getPageSize())
199 EI.PageSize = *PageSize;
200 else
201 return PageSize.takeError();
202 EI.BootstrapMap = std::move(BootstrapMap);
203 EI.BootstrapSymbols = std::move(BootstrapSymbols);
204
205 assert(!EI.BootstrapSymbols.count(ExecutorSessionObjectName) &&
206 "Dispatch context name should not be set");
207 assert(!EI.BootstrapSymbols.count(DispatchFnName) &&
208 "Dispatch function name should not be set");
209 EI.BootstrapSymbols[ExecutorSessionObjectName] = ExecutorAddr::fromPtr(Ptr: this);
210 EI.BootstrapSymbols[DispatchFnName] = ExecutorAddr::fromPtr(Ptr: jitDispatchEntry);
211 EI.BootstrapSymbols[rt::RegisterEHFrameSectionWrapperName] =
212 ExecutorAddr::fromPtr(Ptr: &llvm_orc_registerEHFrameSectionWrapper);
213 EI.BootstrapSymbols[rt::DeregisterEHFrameSectionWrapperName] =
214 ExecutorAddr::fromPtr(Ptr: &llvm_orc_deregisterEHFrameSectionWrapper);
215
216 using SPSSerialize =
217 shared::SPSArgList<shared::SPSSimpleRemoteEPCExecutorInfo>;
218 auto SetupPacketBytes =
219 shared::WrapperFunctionResult::allocate(Size: SPSSerialize::size(Arg: EI));
220 shared::SPSOutputBuffer OB(SetupPacketBytes.data(), SetupPacketBytes.size());
221 if (!SPSSerialize::serialize(OB, Arg: EI))
222 return make_error<StringError>(Args: "Could not send setup packet",
223 Args: inconvertibleErrorCode());
224
225 return sendMessage(OpC: SimpleRemoteEPCOpcode::Setup, SeqNo: 0, TagAddr: ExecutorAddr(),
226 ArgBytes: {SetupPacketBytes.data(), SetupPacketBytes.size()});
227}
228
229Error SimpleRemoteEPCServer::handleResult(
230 uint64_t SeqNo, ExecutorAddr TagAddr,
231 SimpleRemoteEPCArgBytesVector ArgBytes) {
232 std::promise<shared::WrapperFunctionResult> *P = nullptr;
233 {
234 std::lock_guard<std::mutex> Lock(ServerStateMutex);
235 auto I = PendingJITDispatchResults.find(Val: SeqNo);
236 if (I == PendingJITDispatchResults.end())
237 return make_error<StringError>(Args: "No call for sequence number " +
238 Twine(SeqNo),
239 Args: inconvertibleErrorCode());
240 P = I->second;
241 PendingJITDispatchResults.erase(I);
242 releaseSeqNo(SeqNo);
243 }
244 auto R = shared::WrapperFunctionResult::allocate(Size: ArgBytes.size());
245 memcpy(dest: R.data(), src: ArgBytes.data(), n: ArgBytes.size());
246 P->set_value(std::move(R));
247 return Error::success();
248}
249
250void SimpleRemoteEPCServer::handleCallWrapper(
251 uint64_t RemoteSeqNo, ExecutorAddr TagAddr,
252 SimpleRemoteEPCArgBytesVector ArgBytes) {
253 D->dispatch(Work: [this, RemoteSeqNo, TagAddr, ArgBytes = std::move(ArgBytes)]() {
254 using WrapperFnTy =
255 shared::CWrapperFunctionResult (*)(const char *, size_t);
256 auto *Fn = TagAddr.toPtr<WrapperFnTy>();
257 shared::WrapperFunctionResult ResultBytes(
258 Fn(ArgBytes.data(), ArgBytes.size()));
259 if (auto Err = sendMessage(OpC: SimpleRemoteEPCOpcode::Result, SeqNo: RemoteSeqNo,
260 TagAddr: ExecutorAddr(),
261 ArgBytes: {ResultBytes.data(), ResultBytes.size()}))
262 ReportError(std::move(Err));
263 });
264}
265
266shared::WrapperFunctionResult
267SimpleRemoteEPCServer::doJITDispatch(const void *FnTag, const char *ArgData,
268 size_t ArgSize) {
269 uint64_t SeqNo;
270 std::promise<shared::WrapperFunctionResult> ResultP;
271 auto ResultF = ResultP.get_future();
272 {
273 std::lock_guard<std::mutex> Lock(ServerStateMutex);
274 if (RunState != ServerRunning)
275 return shared::WrapperFunctionResult::createOutOfBandError(
276 Msg: "jit_dispatch not available (EPC server shut down)");
277
278 SeqNo = getNextSeqNo();
279 assert(!PendingJITDispatchResults.count(SeqNo) && "SeqNo already in use");
280 PendingJITDispatchResults[SeqNo] = &ResultP;
281 }
282
283 if (auto Err = sendMessage(OpC: SimpleRemoteEPCOpcode::CallWrapper, SeqNo,
284 TagAddr: ExecutorAddr::fromPtr(Ptr: FnTag), ArgBytes: {ArgData, ArgSize}))
285 ReportError(std::move(Err));
286
287 return ResultF.get();
288}
289
290shared::CWrapperFunctionResult
291SimpleRemoteEPCServer::jitDispatchEntry(void *DispatchCtx, const void *FnTag,
292 const char *ArgData, size_t ArgSize) {
293 return reinterpret_cast<SimpleRemoteEPCServer *>(DispatchCtx)
294 ->doJITDispatch(FnTag, ArgData, ArgSize)
295 .release();
296}
297
298} // end namespace orc
299} // end namespace llvm
300