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waf/playground/maxjobs2/compute/wscript

104 lines
2.6 KiB
Python

#! /usr/bin/env python
# The following example shows how several build processes can collaborate
# to stop spawning new processes when a special task of type K is executed
# this may be useful for link tasks for example
def options(opt):
opt.add_option('--loops', action='store', type='int', default=5, help='amount of cpu-intensive loops to perform')
def configure(conf):
busy = conf.path.find_node('look_busy.py').abspath()
conf.env.NOT_BUSY = ('%s 0' % busy).split()
conf.env.VERY_BUSY = ('%s %d' % (busy, conf.options.loops)).split()
def build(bld):
bld.link_limit = 1
bld.lockfile = bld.path.parent.make_node('busy_lock.txt').abspath()
for i in range(2):
for k in range(5):
bld(rule='${NOT_BUSY}', always=True)
bld(rule='${VERY_BUSY}', always=True, exclusive=True)
for k in range(10):
bld(rule='${NOT_BUSY}', always=True)
import os, fcntl, threading, errno, time
from waflib import Task
lock = threading.Lock()
def lock_maxjob(self):
# lock the file, telling other build processes to avoid spawining tasks during that time
while True:
try:
self.lockfd = os.open(self.generator.bld.lockfile, os.O_TRUNC | os.O_CREAT | os.O_RDWR)
fcntl.flock(self.lockfd, fcntl.LOCK_EX | fcntl.LOCK_NB)
except EnvironmentError as e:
if e.errno in (errno.EACCES, errno.EAGAIN):
time.sleep(0.3)
continue
raise
os.write(self.lockfd, "%d" % os.getpid())
self.start_time = time.time()
break
def release_maxjob(self):
# release the lock file
print("> long task %d" % (time.time() - self.start_time))
try:
os.remove(self.generator.bld.lockfile)
os.close(self.lockfd)
except OSError, e:
# of someone else has removed the lock... bad luck! but do not fail here
print "unexpected failure", e
pass
def wait_maxjob(self):
# wait on the lock file.. up to a certain limit
while True:
try:
ini = os.stat(self.generator.bld.lockfile).st_mtime
except OSError, e:
return
diff = time.time() - ini
if diff > 300: # stale lock file? wait 5 minutes
return
time.sleep(0.5)
# the method process is called by threads...
def process2(self):
if getattr(self.generator, 'exclusive', False):
lock.acquire()
try:
self.lock_maxjob()
finally:
lock.release()
else:
self.wait_maxjob()
ret = self.process_bound_maxjobs()
if getattr(self.generator, 'exclusive', False):
lock.acquire()
try:
self.release_maxjob()
finally:
lock.release()
return ret
def process(self):
try:
process2(self)
except Exception, e:
print type(e), e
Task.Task.process_bound_maxjobs = Task.Task.process
Task.Task.process = process
Task.Task.lock_maxjob = lock_maxjob
Task.Task.release_maxjob = release_maxjob
Task.Task.wait_maxjob = wait_maxjob