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synch.py

Timestamp:

06/18/07 11:48:27 (2 years ago)

Author:

jdunck

Message:

gis: Merged revisions 4786-5490 via svnmerge from
http://code.djangoproject.com/svn/django/trunk

Files:

django/branches/gis
- Property svnmerge-integrated changed from /django/trunk:1-4785,4796-4797,4799-4809 to /django/trunk:1-5490

r4265	r5492
1	1	"""
2	2	Synchronization primitives:
3
	3
4	4	- reader-writer lock (preference to writers)
5	5
…	…
15	15	"""
16	16	Classic implementation of reader-writer lock with preference to writers.
17
	17
18	18	Readers can access a resource simultaneously.
19	19	Writers get an exclusive access.
20
	20
21	21	API is self-descriptive:
22	22	reader_enters()
…	…
25	25	writer_leaves()
26	26	"""
27
28	27	def __init__(self):
29	28	self.mutex = threading.RLock()
…	…
34	33	self.waiting_readers = 0
35	34	self.waiting_writers = 0
36
	35
37	36	def reader_enters(self):
38	37	self.mutex.acquire()
…	…
46	45	self.mutex.release()
47	46	self.can_read.acquire()
48
	47
49	48	def reader_leaves(self):
50	49	self.mutex.acquire()
…	…
57	56	finally:
58	57	self.mutex.release()
59
	58
60	59	def writer_enters(self):
61	60	self.mutex.acquire()
…	…
69	68	self.mutex.release()
70	69	self.can_write.acquire()
71
	70
72	71	def writer_leaves(self):
73	72	self.mutex.acquire()