Skip to content

_forkserver_worker

genlm.eval.domains.ds1000._forkserver_worker

Warm fork-server for DS-1000 harness scripts: pre-imports the science libs (not tensorflow, fork-unsafe) and forks a child per request, or from a warm per-task session child. JSON lines in/out.

run_child(script, timeout, out_path, td)

Executed in the forked child. Never returns.

Source code in genlm/eval/domains/ds1000/_forkserver_worker.py 
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
def run_child(script: str, timeout: float, out_path: str, td: str) -> None:
    """Executed in the forked child. Never returns."""
    rc = 0
    try:
        fd = os.open(out_path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
        os.dup2(fd, 1)
        os.dup2(fd, 2)
        os.close(fd)
        _sandbox_into(td)
        signal.signal(signal.SIGALRM, signal.SIG_DFL)
        signal.alarm(max(1, int(timeout)))
        g = {"__name__": "__main__", "__builtins__": __builtins__}
        try:
            exec(compile(script, "<harness>", "exec"), g, g)
        except SystemExit:
            pass
        except BaseException:  # noqa: BLE001
            traceback.print_exc()
            rc = 1
    except BaseException:  # noqa: BLE001
        rc = 2
    finally:
        try:
            sys.stdout.flush()
            sys.stderr.flush()
        except Exception:  # noqa: BLE001
            pass
        os._exit(rc)

run_session(setup, cmd_r, res_w, td)

Session child: run setup once, then fork one grandchild per body.

Source code in genlm/eval/domains/ds1000/_forkserver_worker.py 
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
def run_session(setup: str, cmd_r: int, res_w: int, td: str) -> None:
    """Session child: run setup once, then fork one grandchild per body."""

    def send(obj):
        os.write(res_w, (json.dumps(obj) + "\n").encode())

    try:
        os.setsid()
        log_fd = os.open(os.path.join(td, "__session__.log"),
                         os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
        os.dup2(log_fd, 1)
        os.dup2(log_fd, 2)
        os.close(log_fd)
        _sandbox_into(td)
        signal.signal(signal.SIGALRM, signal.SIG_DFL)
        signal.alarm(SETUP_TIMEOUT)
        ns = {"__name__": "__main__", "__builtins__": __builtins__}
        try:
            exec(compile(setup, "<session-setup>", "exec"), ns, ns)
        except BaseException:  # noqa: BLE001
            traceback.print_exc()
            send({"setup_failed": 1})
            os._exit(0)
        signal.alarm(0)
        send({"ready": 1})

        buf = b""
        while True:
            chunk = os.read(cmd_r, 1 << 20)
            if not chunk:
                os._exit(0)
            buf += chunk
            while b"\n" in buf:
                line, buf = buf.split(b"\n", 1)
                if not line.strip():
                    continue
                req = json.loads(line)
                sys.stdout.flush()
                sys.stderr.flush()
                try:
                    pid = os.fork()
                except OSError:
                    send({"id": req["id"], "forkfail": 1})
                    continue
                if pid == 0:
                    os.close(cmd_r)
                    os.close(res_w)
                    run_child_in_ns(req["body"], req["timeout"], req["out"], ns)
                _, status = os.waitpid(pid, 0)
                send({"id": req["id"], "status": status})
    except BaseException:  # noqa: BLE001
        try:
            send({"setup_failed": 1})
        except Exception:  # noqa: BLE001
            pass
        os._exit(2)

run_child_in_ns(body, timeout, out_path, ns)

Grandchild: execute a body script in the session namespace.

Source code in genlm/eval/domains/ds1000/_forkserver_worker.py 
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
def run_child_in_ns(body: str, timeout: float, out_path: str, ns) -> None:
    """Grandchild: execute a body script in the session namespace."""
    rc = 0
    try:
        fd = os.open(out_path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
        os.dup2(fd, 1)
        os.dup2(fd, 2)
        os.close(fd)
        signal.signal(signal.SIGALRM, signal.SIG_DFL)
        signal.alarm(max(1, int(timeout)))
        try:
            exec(compile(body, "<harness-body>", "exec"), ns, ns)
        except SystemExit:
            pass
        except BaseException:  # noqa: BLE001
            traceback.print_exc()
            rc = 1
    except BaseException:  # noqa: BLE001
        rc = 2
    finally:
        try:
            sys.stdout.flush()
            sys.stderr.flush()
        except Exception:  # noqa: BLE001
            pass
        os._exit(rc)