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