Revision b9768937
| b/lib/utils.py | ||
|---|---|---|
| 3258 | 3258 |
return wrap |
| 3259 | 3259 |
|
| 3260 | 3260 |
|
| 3261 |
class SignalWakeupFd(object): |
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| 3262 |
try: |
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| 3263 |
# This is only supported in Python 2.5 and above (some distributions |
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| 3264 |
# backported it to Python 2.4) |
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| 3265 |
_set_wakeup_fd_fn = signal.set_wakeup_fd |
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| 3266 |
except AttributeError: |
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| 3267 |
# Not supported |
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| 3268 |
def _SetWakeupFd(self, _): # pylint: disable-msg=R0201 |
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| 3269 |
return -1 |
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| 3270 |
else: |
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| 3271 |
def _SetWakeupFd(self, fd): |
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| 3272 |
return self._set_wakeup_fd_fn(fd) |
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| 3273 |
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| 3274 |
def __init__(self): |
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"""Initializes this class. |
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| 3276 |
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| 3277 |
""" |
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| 3278 |
(read_fd, write_fd) = os.pipe() |
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| 3279 |
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| 3280 |
# Once these succeeded, the file descriptors will be closed automatically. |
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| 3281 |
# Buffer size 0 is important, otherwise .read() with a specified length |
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| 3282 |
# might buffer data and the file descriptors won't be marked readable. |
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| 3283 |
self._read_fh = os.fdopen(read_fd, "r", 0) |
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| 3284 |
self._write_fh = os.fdopen(write_fd, "w", 0) |
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| 3285 |
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| 3286 |
self._previous = self._SetWakeupFd(self._write_fh.fileno()) |
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| 3287 |
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| 3288 |
# Utility functions |
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| 3289 |
self.fileno = self._read_fh.fileno |
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| 3290 |
self.read = self._read_fh.read |
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| 3291 |
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| 3292 |
def Reset(self): |
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| 3293 |
"""Restores the previous wakeup file descriptor. |
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| 3294 |
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| 3295 |
""" |
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| 3296 |
if hasattr(self, "_previous") and self._previous is not None: |
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| 3297 |
self._SetWakeupFd(self._previous) |
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| 3298 |
self._previous = None |
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| 3299 |
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| 3300 |
def Notify(self): |
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| 3301 |
"""Notifies the wakeup file descriptor. |
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| 3302 |
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| 3303 |
""" |
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| 3304 |
self._write_fh.write("\0")
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| 3305 |
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| 3306 |
def __del__(self): |
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| 3307 |
"""Called before object deletion. |
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| 3308 |
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| 3309 |
""" |
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| 3310 |
self.Reset() |
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| 3311 |
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| 3312 |
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| 3261 | 3313 |
class SignalHandler(object): |
| 3262 | 3314 |
"""Generic signal handler class. |
| 3263 | 3315 |
|
| ... | ... | |
| 3272 | 3324 |
@ivar called: tracks whether any of the signals have been raised |
| 3273 | 3325 |
|
| 3274 | 3326 |
""" |
| 3275 |
def __init__(self, signum, handler_fn=None): |
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| 3327 |
def __init__(self, signum, handler_fn=None, wakeup=None):
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|
| 3276 | 3328 |
"""Constructs a new SignalHandler instance. |
| 3277 | 3329 |
|
| 3278 | 3330 |
@type signum: int or list of ints |
| ... | ... | |
| 3287 | 3339 |
self.called = False |
| 3288 | 3340 |
|
| 3289 | 3341 |
self._handler_fn = handler_fn |
| 3342 |
self._wakeup = wakeup |
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| 3290 | 3343 |
|
| 3291 | 3344 |
self._previous = {}
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| 3292 | 3345 |
try: |
| ... | ... | |
| 3336 | 3389 |
# solution in Python -- there are no atomic types. |
| 3337 | 3390 |
self.called = True |
| 3338 | 3391 |
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| 3392 |
if self._wakeup: |
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| 3393 |
# Notify whoever is interested in signals |
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| 3394 |
self._wakeup.Notify() |
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| 3395 |
|
|
| 3339 | 3396 |
if self._handler_fn: |
| 3340 | 3397 |
self._handler_fn(signum, frame) |
| 3341 | 3398 |
|
Also available in: Unified diff