1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef ART_RUNTIME_EXEC_UTILS_H_
18 #define ART_RUNTIME_EXEC_UTILS_H_
19
20 #include <time.h>
21
22 #include <cstdint>
23 #include <functional>
24 #include <optional>
25 #include <string>
26 #include <vector>
27
28 #include "android-base/unique_fd.h"
29 #include "base/macros.h"
30
31 namespace art HIDDEN {
32
33 struct ProcessStat {
34 // The total wall time, in milliseconds, that the process spent, or 0 if failed to get the value.
35 int64_t wall_time_ms = 0;
36 // The total CPU time, in milliseconds, that the process and any waited-for children spent, or 0
37 // if failed to get the value.
38 int64_t cpu_time_ms = 0;
39 };
40
41 struct ExecCallbacks {
42 // Called in the parent process as soon as the child process is forked.
43 std::function<void(pid_t pid)> on_start = [](pid_t) {};
44 // Called in the parent process after the child process exits while still in a waitable state, no
45 // matter the child process succeeds or not.
46 std::function<void(pid_t pid)> on_end = [](pid_t) {};
47 };
48
49 struct ExecResult {
50 // This struct needs to be in sync with the ExecResultStatus enum contained within the
51 // OdrefreshReported atom in frameworks/proto_logging/atoms/art/odrefresh_extension_atoms.proto.
52 enum Status {
53 // Unable to get the status.
54 kUnknown = 0,
55 // Process exited normally with an exit code.
56 kExited = 1,
57 // Process terminated by a signal.
58 kSignaled = 2,
59 // Process timed out and killed.
60 kTimedOut = 3,
61 // Failed to start the process.
62 kStartFailed = 4,
63 kLast = kStartFailed
64 };
65
66 Status status = kUnknown;
67
68 // The process exit code, if `status` is `kExited`, or -1.
69 int exit_code = -1;
70
71 // The signal that terminated the process, if `status` is `kSignaled`, or 0.
72 int signal = 0;
73 };
74
75 // Wrapper on fork/execv to run a command in a subprocess.
76 // These spawn child processes using the environment as it was set when the single instance
77 // of the runtime (Runtime::Current()) was started. If no instance of the runtime was started, it
78 // will use the current environment settings.
79 class EXPORT ExecUtils {
80 public:
81 virtual ~ExecUtils() = default;
82
83 virtual bool Exec(const std::vector<std::string>& arg_vector,
84 /*out*/ std::string* error_msg) const;
85
86 virtual int ExecAndReturnCode(const std::vector<std::string>& arg_vector,
87 /*out*/ std::string* error_msg) const;
88
89 // Executes the command specified in `arg_vector` in a subprocess with a timeout.
90 // If `timeout_sec` is negative, blocks until the subprocess exits.
91 // Returns a structured result. If the status is not `kExited`, also returns a non-empty
92 // `error_msg`.
93 virtual ExecResult ExecAndReturnResult(const std::vector<std::string>& arg_vector,
94 int timeout_sec,
95 /*out*/ std::string* error_msg) const;
96
97 // Same as above, but also collects stat of the process, calls callbacks, and supports creating a
98 // new process group. The stat is collected no matter the child process succeeds or not.
99 //
100 // Programs used by artd (odrefresh, dex2oat, profman) should NOT set `new_process_group` to true
101 // when spawning child processes because artd needs to kill an entire process subtree by killing
102 // the process group.
103 virtual ExecResult ExecAndReturnResult(const std::vector<std::string>& arg_vector,
104 int timeout_sec,
105 const ExecCallbacks& callbacks,
106 bool new_process_group,
107 /*out*/ ProcessStat* stat,
108 /*out*/ std::string* error_msg) const;
109
110 protected:
111 virtual android::base::unique_fd PidfdOpen(pid_t pid) const;
112
113 // Returns the content of `/proc/<pid>/stat`, or an empty string if failed.
114 virtual std::string GetProcStat(pid_t pid) const;
115
116 virtual std::optional<int64_t> GetUptimeMs(std::string* error_msg) const;
117
118 virtual int64_t GetTicksPerSec() const;
119
120 private:
121 bool GetStat(pid_t pid, /*out*/ ProcessStat* stat, /*out*/ std::string* error_msg) const;
122 };
123
Exec(const std::vector<std::string> & arg_vector,std::string * error_msg)124 inline bool Exec(const std::vector<std::string>& arg_vector, /*out*/ std::string* error_msg) {
125 return ExecUtils().Exec(arg_vector, error_msg);
126 }
127
ExecAndReturnCode(const std::vector<std::string> & arg_vector,std::string * error_msg)128 inline int ExecAndReturnCode(const std::vector<std::string>& arg_vector,
129 /*out*/ std::string* error_msg) {
130 return ExecUtils().ExecAndReturnCode(arg_vector, error_msg);
131 }
132
133 } // namespace art
134
135 #endif // ART_RUNTIME_EXEC_UTILS_H_
136