Fix qapi code generation wrt parallel build

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

View File

@ -173,35 +173,37 @@ qapi-dir := $(BUILD_DIR)/qapi-generated
test-qmp-input-visitor.o test-qmp-output-visitor.o test-qmp-commands.o qemu-ga$(EXESUF): QEMU_CFLAGS += -I $(qapi-dir)
qemu-ga$(EXESUF): LIBS = $(LIBS_QGA)
gen-out-type = $(subst .,-,$@)
$(qapi-dir)/test-qapi-types.c $(qapi-dir)/test-qapi-types.h :\
$(SRC_PATH)/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-types.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-types.py -o "$(qapi-dir)" -p "test-" < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-types.py $(gen-out-type) -o "$(qapi-dir)" -p "test-" < $<, " GEN $@")
$(qapi-dir)/test-qapi-visit.c $(qapi-dir)/test-qapi-visit.h :\
$(SRC_PATH)/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-visit.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-visit.py -o "$(qapi-dir)" -p "test-" < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-visit.py $(gen-out-type) -o "$(qapi-dir)" -p "test-" < $<, " GEN $@")
$(qapi-dir)/test-qmp-commands.h $(qapi-dir)/test-qmp-marshal.c :\
$(SRC_PATH)/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-commands.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py -o "$(qapi-dir)" -p "test-" < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py $(gen-out-type) -o "$(qapi-dir)" -p "test-" < $<, " GEN $@")
$(qapi-dir)/qga-qapi-types.c $(qapi-dir)/qga-qapi-types.h :\
$(SRC_PATH)/qapi-schema-guest.json $(SRC_PATH)/scripts/qapi-types.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-types.py -o "$(qapi-dir)" -p "qga-" < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-types.py $(gen-out-type) -o "$(qapi-dir)" -p "qga-" < $<, " GEN $@")
$(qapi-dir)/qga-qapi-visit.c $(qapi-dir)/qga-qapi-visit.h :\
$(SRC_PATH)/qapi-schema-guest.json $(SRC_PATH)/scripts/qapi-visit.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-visit.py -o "$(qapi-dir)" -p "qga-" < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-visit.py $(gen-out-type) -o "$(qapi-dir)" -p "qga-" < $<, " GEN $@")
$(qapi-dir)/qga-qmp-commands.h $(qapi-dir)/qga-qmp-marshal.c :\
$(SRC_PATH)/qapi-schema-guest.json $(SRC_PATH)/scripts/qapi-commands.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py -o "$(qapi-dir)" -p "qga-" < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py $(gen-out-type) -o "$(qapi-dir)" -p "qga-" < $<, " GEN $@")
qapi-types.c qapi-types.h :\
$(SRC_PATH)/qapi-schema.json $(SRC_PATH)/scripts/qapi-types.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-types.py -o "." < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-types.py $(gen-out-type) -o "." < $<, " GEN $@")
qapi-visit.c qapi-visit.h :\
$(SRC_PATH)/qapi-schema.json $(SRC_PATH)/scripts/qapi-visit.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-visit.py -o "." < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-visit.py $(gen-out-type) -o "." < $<, " GEN $@")
qmp-commands.h qmp-marshal.c :\
$(SRC_PATH)/qapi-schema.json $(SRC_PATH)/scripts/qapi-commands.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py -m -o "." < $<, " GEN $@")
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py $(gen-out-type) -m -o "." < $<, " GEN $@")
test-qmp-output-visitor.o: $(addprefix $(qapi-dir)/, test-qapi-types.c test-qapi-types.h test-qapi-visit.c test-qapi-visit.h) $(qapi-obj-y)
test-qmp-output-visitor: test-qmp-output-visitor.o $(qobject-obj-y) $(qapi-obj-y) $(tools-obj-y) $(qapi-dir)/test-qapi-visit.o $(qapi-dir)/test-qapi-types.o

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)

View File

@ -163,7 +163,8 @@ void qapi_free_%(type)s(%(c_type)s obj)
try:
opts, args = getopt.gnu_getopt(sys.argv[1:], "p:o:", ["prefix=", "output-dir="])
opts, args = getopt.gnu_getopt(sys.argv[1:], "chp:o:",
["source", "header", "prefix=", "output-dir="])
except getopt.GetoptError, err:
print str(err)
sys.exit(1)
@ -173,11 +174,22 @@ prefix = ""
c_file = 'qapi-types.c'
h_file = 'qapi-types.h'
do_c = False
do_h = False
for o, a in opts:
if o in ("-p", "--prefix"):
prefix = a
elif o in ("-o", "--output-dir"):
output_dir = a + "/"
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
@ -188,8 +200,17 @@ except os.error, e:
if e.errno != errno.EEXIST:
raise
fdef = open(c_file, 'w')
fdecl = open(h_file, 'w')
def maybe_open(really, name, opt):
class Null(object):
def write(self, str):
pass
def read(self):
return ''
if really:
return open(name, opt)
fdef = maybe_open(do_c, c_file, 'w')
fdecl = maybe_open(do_h, h_file, 'w')
fdef.write(mcgen('''
/* AUTOMATICALLY GENERATED, DO NOT MODIFY */

View File

@ -139,7 +139,8 @@ void visit_type_%(name)s(Visitor *m, %(name)s * obj, const char *name, Error **e
name=name)
try:
opts, args = getopt.gnu_getopt(sys.argv[1:], "p:o:", ["prefix=", "output-dir="])
opts, args = getopt.gnu_getopt(sys.argv[1:], "chp:o:",
["source", "header", "prefix=", "output-dir="])
except getopt.GetoptError, err:
print str(err)
sys.exit(1)
@ -149,11 +150,22 @@ prefix = ""
c_file = 'qapi-visit.c'
h_file = 'qapi-visit.h'
do_c = False
do_h = False
for o, a in opts:
if o in ("-p", "--prefix"):
prefix = a
elif o in ("-o", "--output-dir"):
output_dir = a + "/"
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
@ -164,8 +176,17 @@ except os.error, e:
if e.errno != errno.EEXIST:
raise
fdef = open(c_file, 'w')
fdecl = open(h_file, 'w')
def maybe_open(really, name, opt):
class Null(object):
def write(self, str):
pass
def read(self):
return ''
if really:
return open(name, opt)
fdef = maybe_open(do_c, c_file, 'w')
fdecl = maybe_open(do_h, h_file, 'w')
fdef.write(mcgen('''
/* THIS FILE IS AUTOMATICALLY GENERATED, DO NOT MODIFY */