| 1 | #!/usr/local/bin/python |
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| 2 | |
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| 3 | import logging |
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| 4 | import time |
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| 5 | from threading import Lock, Thread, Condition |
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| 6 | from service_error import service_error |
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| 7 | |
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| 8 | class thread_pool: |
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| 9 | """ |
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| 10 | A class to keep track of a set of threads all invoked for the same |
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| 11 | task. Manages the mutual exclusion of the states. |
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| 12 | """ |
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| 13 | def __init__(self, nthreads): |
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| 14 | """ |
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| 15 | Start a pool. |
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| 16 | """ |
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| 17 | self.changed = Condition() |
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| 18 | self.started = 0 |
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| 19 | self.terminated = 0 |
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| 20 | self.nthreads = nthreads |
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| 21 | |
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| 22 | def acquire(self): |
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| 23 | """ |
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| 24 | Get the pool's lock. |
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| 25 | """ |
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| 26 | self.changed.acquire() |
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| 27 | |
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| 28 | def release(self): |
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| 29 | """ |
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| 30 | Release the pool's lock. |
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| 31 | """ |
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| 32 | self.changed.release() |
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| 33 | |
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| 34 | def wait(self, timeout = None): |
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| 35 | """ |
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| 36 | Wait for a pool thread to start or stop. |
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| 37 | """ |
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| 38 | self.changed.wait(timeout) |
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| 39 | |
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| 40 | def start(self): |
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| 41 | """ |
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| 42 | Called by a pool thread to report starting. |
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| 43 | """ |
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| 44 | self.changed.acquire() |
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| 45 | self.started += 1 |
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| 46 | self.changed.notifyAll() |
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| 47 | self.changed.release() |
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| 48 | |
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| 49 | def terminate(self): |
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| 50 | """ |
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| 51 | Called by a pool thread to report finishing. |
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| 52 | """ |
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| 53 | self.changed.acquire() |
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| 54 | self.terminated += 1 |
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| 55 | self.changed.notifyAll() |
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| 56 | self.changed.release() |
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| 57 | |
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| 58 | def clear(self): |
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| 59 | """ |
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| 60 | Clear all pool data. |
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| 61 | """ |
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| 62 | self.changed.acquire() |
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| 63 | self.started = 0 |
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| 64 | self.terminated =0 |
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| 65 | self.changed.notifyAll() |
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| 66 | self.changed.release() |
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| 67 | |
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| 68 | def wait_for_slot(self): |
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| 69 | """ |
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| 70 | Wait until we have a free slot to start another pooled thread |
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| 71 | """ |
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| 72 | self.acquire() |
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| 73 | while self.started - self.terminated >= self.nthreads: |
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| 74 | self.wait() |
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| 75 | self.release() |
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| 76 | |
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| 77 | def wait_for_all_done(self, timeout=None): |
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| 78 | """ |
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| 79 | Wait until all active threads finish (and at least one has |
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| 80 | started). If a timeout is given, return after waiting that long |
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| 81 | for termination. If all threads are done (and one has started in |
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| 82 | the since the last clear()) return True, otherwise False. |
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| 83 | """ |
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| 84 | if timeout: |
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| 85 | deadline = time.time() + timeout |
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| 86 | self.acquire() |
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| 87 | while self.started == 0 or self.started > self.terminated: |
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| 88 | self.wait(timeout) |
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| 89 | if timeout: |
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| 90 | if time.time() > deadline: |
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| 91 | break |
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| 92 | timeout = deadline - time.time() |
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| 93 | self.release() |
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| 94 | return not (self.started == 0 or self.started > self.terminated) |
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| 95 | |
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| 96 | class pooled_thread(Thread): |
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| 97 | """ |
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| 98 | One of a set of threads dedicated to a specific task. Uses the |
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| 99 | thread_pool class above for coordination. |
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| 100 | """ |
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| 101 | def __init__(self, group=None, target=None, name=None, args=(), |
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| 102 | kwargs={}, pdata=None, trace_file=None): |
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| 103 | Thread.__init__(self, group, target, name, args, kwargs) |
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| 104 | self.rv = None # Return value of the ops in this thread |
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| 105 | self.exception = None # Exception that terminated this thread |
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| 106 | self.target=target # Target function to run on start() |
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| 107 | self.args = args # Args to pass to target |
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| 108 | self.kwargs = kwargs # Additional kw args |
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| 109 | self.pdata = pdata # thread_pool for this class |
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| 110 | # Logger for this thread |
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| 111 | self.log = logging.getLogger("fedd.experiment_control") |
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| 112 | |
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| 113 | def run(self): |
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| 114 | """ |
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| 115 | Emulate Thread.run, except add pool data manipulation and error |
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| 116 | logging. |
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| 117 | """ |
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| 118 | if self.pdata: |
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| 119 | self.pdata.start() |
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| 120 | |
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| 121 | if self.target: |
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| 122 | try: |
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| 123 | self.rv = self.target(*self.args, **self.kwargs) |
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| 124 | except service_error, s: |
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| 125 | self.exception = s |
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| 126 | self.log.error("Thread exception: %s %s" % \ |
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| 127 | (s.code_string(), s.desc)) |
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| 128 | except: |
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| 129 | self.exception = sys.exc_info()[1] |
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| 130 | self.log.error(("Unexpected thread exception: %s" +\ |
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| 131 | "Trace %s") % (self.exception,\ |
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| 132 | traceback.format_exc())) |
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| 133 | if self.pdata: |
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| 134 | self.pdata.terminate() |
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