motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-07-27 12:23:53 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

Fix qapi code generation wrt parallel build

Browse source 
Make's multiple output syntax

  x.c x.h: x.template
       gen < x.template

actually invokes the command once for x.c and once for x.h (with differing $@
in each invocation).  During a parallel build, the two commands may be invoked
in parallel; this opens up a race, where the second invocation trashes a file
supposedly produced during the first, and now in use by a dependent command.

The various qapi code generators are susceptible to this; fix by making them
generate just one file per invocation.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Avi Kivity 2011-12-27 16:02:16 +02:00 • committed by Anthony Liguori
parent 4e1ea514f9
commit 8d3bc5178f
4 changed files with 86 additions and 18 deletions
Download patch file Download diff file Expand all files Collapse all files

30
scripts/qapi-commands.py
View file

@ -372,7 +372,9 @@ def gen_command_def_prologue(prefix="", proxy=False):
try:
opts, args = getopt.gnu_getopt(sys.argv[1:], "p:o:m", ["prefix=", "output-dir=", "type=", "middle"])
opts, args = getopt.gnu_getopt(sys.argv[1:], "chp:o:m",
["source", "header", "prefix=",
"output-dir=", "type=", "middle"])
except getopt.GetoptError, err:
print str(err)
sys.exit(1)
@ -384,6 +386,9 @@ c_file = 'qmp-marshal.c'
h_file = 'qmp-commands.h'
middle_mode = False
do_c = False
do_h = False
for o, a in opts:
if o in ("-p", "--prefix"):
prefix = a
@ -393,10 +398,29 @@ for o, a in opts:
dispatch_type = a
elif o in ("-m", "--middle"):
middle_mode = True
elif o in ("-c", "--source"):
do_h = True
elif o in ("-h", "--header"):
do_c = True
if not do_c and not do_h:
do_c = True
do_h = True
c_file = output_dir + prefix + c_file
h_file = output_dir + prefix + h_file
def maybe_open(really, name, opt):
class Null(object):
def write(self, str):
pass
def read(self):
return ''
if really:
return open(name, opt)
else:
return Null()
try:
os.makedirs(output_dir)
except os.error, e:
@ -408,8 +432,8 @@ commands = filter(lambda expr: expr.has_key('command'), exprs)
commands = filter(lambda expr: not expr.has_key('gen'), commands)
if dispatch_type == "sync":
fdecl = open(h_file, 'w')
fdef = open(c_file, 'w')
fdecl = maybe_open(do_h, h_file, 'w')
fdef = maybe_open(do_c, c_file, 'w')
ret = gen_command_decl_prologue(header=basename(h_file), guard=guardname(h_file), prefix=prefix)
fdecl.write(ret)
ret = gen_command_def_prologue(prefix=prefix)