1 // Copyright 2020 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include <linux/futex.h>
16 #include <syscall.h>
17 #include <uv.h>
18
19 #include <iostream>
20
21 #include "absl/flags/flag.h"
22 #include "absl/log/initialize.h"
23 #include "uv_sapi.sapi.h" // NOLINT(build/include)
24
25 namespace {
26
27 class UVSapiIdleBasicSandbox : public uv::UVSandbox {
28 private:
ModifyPolicy(sandbox2::PolicyBuilder *)29 std::unique_ptr<sandbox2::Policy> ModifyPolicy(
30 sandbox2::PolicyBuilder*) override {
31 return sandbox2::PolicyBuilder()
32 .AllowDynamicStartup()
33 .AllowExit()
34 .AllowFutexOp(FUTEX_WAKE_PRIVATE)
35 .AllowEpoll()
36 .AllowSyscall(__NR_eventfd2)
37 .AllowPipe()
38 .AllowWrite()
39 .BuildOrDie();
40 }
41 };
42
IdleBasic()43 absl::Status IdleBasic() {
44 // Initialize sandbox2 and sapi
45 UVSapiIdleBasicSandbox sandbox;
46 SAPI_RETURN_IF_ERROR(sandbox.Init());
47 uv::UVApi api(&sandbox);
48
49 // Get remote pointer to the IdleCallback method
50 void* function_ptr;
51 SAPI_RETURN_IF_ERROR(
52 sandbox.rpc_channel()->Symbol("IdleCallback", &function_ptr));
53 sapi::v::RemotePtr idle_callback(function_ptr);
54
55 // Allocate memory for the uv_idle_t object
56 void* idle_voidptr;
57 SAPI_RETURN_IF_ERROR(
58 sandbox.rpc_channel()->Allocate(sizeof(uv_idle_t), &idle_voidptr));
59 sapi::v::RemotePtr idler(idle_voidptr);
60
61 int return_code;
62
63 // Get default loop
64 SAPI_ASSIGN_OR_RETURN(void* loop_voidptr, api.sapi_uv_default_loop());
65 sapi::v::RemotePtr loop(loop_voidptr);
66
67 // Initialize idler
68 SAPI_ASSIGN_OR_RETURN(return_code, api.sapi_uv_idle_init(&loop, &idler));
69 if (return_code != 0) {
70 return absl::UnavailableError("sapi_uv_idle_init returned error " +
71 return_code);
72 }
73
74 // Start idler
75 SAPI_ASSIGN_OR_RETURN(return_code,
76 api.sapi_uv_idle_start(&idler, &idle_callback));
77 if (return_code != 0) {
78 return absl::UnavailableError("sapi_uv_idle_start returned error " +
79 return_code);
80 }
81
82 // Run loop
83 SAPI_ASSIGN_OR_RETURN(return_code, api.sapi_uv_run(&loop, UV_RUN_DEFAULT));
84 if (return_code != 0) {
85 return absl::UnavailableError("uv_run returned error " + return_code);
86 }
87
88 // Close idler
89 sapi::v::NullPtr null_ptr;
90 SAPI_RETURN_IF_ERROR(api.sapi_uv_close(&idler, &null_ptr));
91
92 // Close loop
93 SAPI_ASSIGN_OR_RETURN(return_code, api.sapi_uv_loop_close(&loop));
94 // UV_EBUSY is accepted because it is the return code of uv_loop_close
95 // in the original example
96 if (return_code != 0 && return_code != UV_EBUSY) {
97 return absl::UnavailableError("uv_loop_close returned error " +
98 return_code);
99 }
100
101 return absl::OkStatus();
102 }
103
104 } // namespace
105
main(int argc,char * argv[])106 int main(int argc, char* argv[]) {
107 absl::ParseCommandLine(argc, argv);
108 absl::InitializeLog();
109
110 if (absl::Status status = IdleBasic(); !status.ok()) {
111 LOG(ERROR) << "IdleBasic failed: " << status.ToString();
112 return EXIT_FAILURE;
113 }
114
115 return EXIT_SUCCESS;
116 }
117