diff options
Diffstat (limited to 'lib/spack/llnl/util/tty/log.py')
| -rw-r--r-- | lib/spack/llnl/util/tty/log.py | 204 |
1 files changed, 96 insertions, 108 deletions
diff --git a/lib/spack/llnl/util/tty/log.py b/lib/spack/llnl/util/tty/log.py index b67edcf9cc..a4ba2a9bdf 100644 --- a/lib/spack/llnl/util/tty/log.py +++ b/lib/spack/llnl/util/tty/log.py @@ -24,11 +24,11 @@ ############################################################################## """Utility classes for logging the output of blocks of code. """ -import sys +import multiprocessing import os import re import select -import inspect +import sys import llnl.util.tty as tty import llnl.util.tty.color as color @@ -100,25 +100,29 @@ class keyboard_input(object): class log_output(object): - """Redirects output and error of enclosed block to a file. + """Spawns a daemon that reads from a pipe and writes to a file Usage: - with log_output(open('logfile.txt', 'w')): - # do things ... output will be logged. + # Spawns the daemon + with log_output('logfile.txt', 'w') as log_redirection: + # do things ... output is not redirected + with log_redirection: + # do things ... output will be logged or: - with log_output(open('logfile.txt', 'w'), echo=True): - # do things ... output will be logged - # and also printed to stdout. - - Closes the provided stream when done with the block. - If echo is True, also prints the output to stdout. + with log_output('logfile.txt', echo=True) as log_redirection: + # do things ... output is not redirected + with log_redirection: + # do things ... output will be logged + # and also printed to stdout. + + Opens a stream in 'w' mode at daemon spawning and closes it at + daemon joining. If echo is True, also prints the output to stdout. """ - def __init__(self, stream, echo=False, force_color=False, debug=False): - self.stream = stream - - # various output options + def __init__(self, filename, echo=False, force_color=False, debug=False): + self.filename = filename + # Various output options self.echo = echo self.force_color = force_color self.debug = debug @@ -126,70 +130,81 @@ class log_output(object): # Default is to try file-descriptor reassignment unless the system # out/err streams do not have an associated file descriptor self.directAssignment = False - - def trace(self, frame, event, arg): - """Jumps to __exit__ on the child process.""" - raise _SkipWithBlock() + self.read, self.write = os.pipe() + + # Sets a daemon that writes to file what it reads from a pipe + self.p = multiprocessing.Process( + target=self._spawn_writing_daemon, + args=(self.read,), + name='logger_daemon' + ) + self.p.daemon = True + # Needed to un-summon the daemon + self.parent_pipe, self.child_pipe = multiprocessing.Pipe() def __enter__(self): - """Redirect output from the with block to a file. - - This forks the with block as a separate process, with stdout - and stderr redirected back to the parent via a pipe. If - echo is set, also writes to standard out. - - """ - # remember these values for later. - self._force_color = color._force_color - self._debug = tty._debug - - read, write = os.pipe() - - self.pid = os.fork() - if self.pid: - # Parent: read from child, skip the with block. - os.close(write) - - read_file = os.fdopen(read, 'r', 0) - with self.stream as log_file: - with keyboard_input(sys.stdin): - while True: - rlist, w, x = select.select( - [read_file, sys.stdin], [], []) - if not rlist: + self.p.start() + return log_output.OutputRedirection(self) + + def __exit__(self, exc_type, exc_val, exc_tb): + self.parent_pipe.send(True) + self.p.join(60.0) # 1 minute to join the child + + def _spawn_writing_daemon(self, read): + # Parent: read from child, skip the with block. + read_file = os.fdopen(read, 'r', 0) + with open(self.filename, 'w') as log_file: + with keyboard_input(sys.stdin): + while True: + rlist, _, _ = select.select([read_file, sys.stdin], [], []) + if not rlist: + break + + # Allow user to toggle echo with 'v' key. + # Currently ignores other chars. + if sys.stdin in rlist: + if sys.stdin.read(1) == 'v': + self.echo = not self.echo + + # Handle output from the with block process. + if read_file in rlist: + line = read_file.readline() + if not line: + # For some reason we never reach this point... break - # Allow user to toggle echo with 'v' key. - # Currently ignores other chars. - if sys.stdin in rlist: - if sys.stdin.read(1) == 'v': - self.echo = not self.echo + # Echo to stdout if requested. + if self.echo: + sys.stdout.write(line) - # handle output from the with block process. - if read_file in rlist: - line = read_file.readline() - if not line: - break + # Stripped output to log file. + log_file.write(_strip(line)) + log_file.flush() - # Echo to stdout if requested. - if self.echo: - sys.stdout.write(line) + if self.child_pipe.poll(): + break - # Stripped output to log file. - log_file.write(_strip(line)) + def __del__(self): + """Closes the pipes""" + os.close(self.write) + os.close(self.read) - read_file.flush() - read_file.close() + class OutputRedirection(object): - # Set a trace function to skip the with block. - sys.settrace(lambda *args, **keys: None) - frame = inspect.currentframe(1) - frame.f_trace = self.trace + def __init__(self, other): + self.__dict__.update(other.__dict__) - else: - # Child: redirect output, execute the with block. - os.close(read) + def __enter__(self): + """Redirect output from the with block to a file. + Hijacks stdout / stderr and writes to the pipe + connected to the logger daemon + """ + # remember these values for later. + self._force_color = color._force_color + self._debug = tty._debug + # Redirect this output to a pipe + write = self.write try: # Save old stdout and stderr self._stdout = os.dup(sys.stdout.fileno()) @@ -205,53 +220,26 @@ class log_output(object): output_redirect = os.fdopen(write, 'w') sys.stdout = output_redirect sys.stderr = output_redirect - if self.force_color: color._force_color = True - if self.debug: tty._debug = True - def __exit__(self, exc_type, exception, traceback): - """Exits on child, handles skipping the with block on parent.""" - # Child should just exit here. - if self.pid == 0: + def __exit__(self, exc_type, exception, traceback): + """Plugs back the original file descriptors + for stdout and stderr + """ # Flush the log to disk. sys.stdout.flush() sys.stderr.flush() - - if exception: - # Restore stdout on the child if there's an exception, - # and let it be raised normally. - # - # This assumes that even if the exception is caught, - # the child will exit with a nonzero return code. If - # it doesn't, the child process will continue running. - # - # TODO: think about how this works outside install. - # TODO: ideally would propagate exception to parent... - if self.directAssignment: - sys.stdout = self._stdout - sys.stderr = self._stderr - else: - os.dup2(self._stdout, sys.stdout.fileno()) - os.dup2(self._stderr, sys.stderr.fileno()) - - return False - + if self.directAssignment: + # We seem to need this only to pass test/install.py + sys.stdout = self._stdout + sys.stderr = self._stderr else: - # Die quietly if there was no exception. - os._exit(0) - - else: - # If the child exited badly, parent also should exit. - pid, returncode = os.waitpid(self.pid, 0) - if returncode != 0: - os._exit(1) - - # restore output options. - color._force_color = self._force_color - tty._debug = self._debug + os.dup2(self._stdout, sys.stdout.fileno()) + os.dup2(self._stderr, sys.stderr.fileno()) - # Suppresses exception if it's our own. - return exc_type is _SkipWithBlock + # restore output options. + color._force_color = self._force_color + tty._debug = self._debug |