From 21cd70dfc1a6dc90511bae55a460a3a55461339a Mon Sep 17 00:00:00 2001 From: Wenchao Xia Date: Wed, 18 Jun 2014 08:43:28 +0200 Subject: [PATCH] qapi script: add event support qapi-event.py will parse the schema and generate qapi-event.c, then the API in qapi-event.c can be used to handle events in qemu code. All API have prefix "qapi_event". The script mainly includes two parts: generate API for each event define, generate an enum type for all defined events. Since in some cases the real emit behavior may change, for example, qemu-img would not send a event, a callback layer is used to control the behavior. As a result, the stubs at compile time can be saved, the binding of block layer code and monitor code will become looser. Signed-off-by: Wenchao Xia Signed-off-by: Paolo Bonzini Reviewed-by: Eric Blake Signed-off-by: Luiz Capitulino --- Makefile | 11 +- Makefile.objs | 2 +- docs/qapi-code-gen.txt | 18 ++ scripts/qapi-event.py | 369 +++++++++++++++++++++++ scripts/qapi.py | 12 + tests/Makefile | 2 +- tests/qapi-schema/event-nest-struct.err | 1 + tests/qapi-schema/event-nest-struct.exit | 1 + tests/qapi-schema/event-nest-struct.json | 2 + tests/qapi-schema/event-nest-struct.out | 0 10 files changed, 413 insertions(+), 5 deletions(-) create mode 100644 scripts/qapi-event.py create mode 100644 tests/qapi-schema/event-nest-struct.err create mode 100644 tests/qapi-schema/event-nest-struct.exit create mode 100644 tests/qapi-schema/event-nest-struct.json create mode 100644 tests/qapi-schema/event-nest-struct.out diff --git a/Makefile b/Makefile index 800fbf32e7..f473cf5637 100644 --- a/Makefile +++ b/Makefile @@ -45,8 +45,8 @@ endif endif GENERATED_HEADERS = config-host.h qemu-options.def -GENERATED_HEADERS += qmp-commands.h qapi-types.h qapi-visit.h -GENERATED_SOURCES += qmp-marshal.c qapi-types.c qapi-visit.c +GENERATED_HEADERS += qmp-commands.h qapi-types.h qapi-visit.h qapi-event.h +GENERATED_SOURCES += qmp-marshal.c qapi-types.c qapi-visit.c qapi-event.c GENERATED_HEADERS += trace/generated-events.h GENERATED_SOURCES += trace/generated-events.c @@ -202,7 +202,7 @@ Makefile: $(version-obj-y) $(version-lobj-y) # Build libraries libqemustub.a: $(stub-obj-y) -libqemuutil.a: $(util-obj-y) qapi-types.o qapi-visit.o +libqemuutil.a: $(util-obj-y) qapi-types.o qapi-visit.o qapi-event.o block-modules = $(foreach o,$(block-obj-m),"$(basename $(subst /,-,$o))",) NULL util/module.o-cflags = -D'CONFIG_BLOCK_MODULES=$(block-modules)' @@ -259,6 +259,11 @@ $(qapi-modules) $(SRC_PATH)/scripts/qapi-visit.py $(qapi-py) $(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-visit.py \ $(gen-out-type) -o "." -b -i $<, \ " GEN $@") +qapi-event.c qapi-event.h :\ +$(qapi-modules) $(SRC_PATH)/scripts/qapi-event.py $(qapi-py) + $(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-event.py \ + $(gen-out-type) -o "." -b -i $<, \ + " GEN $@") qmp-commands.h qmp-marshal.c :\ $(qapi-modules) $(SRC_PATH)/scripts/qapi-commands.py $(qapi-py) $(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py \ diff --git a/Makefile.objs b/Makefile.objs index b897e1dc34..1f76cea569 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -12,7 +12,7 @@ block-obj-y += main-loop.o iohandler.o qemu-timer.o block-obj-$(CONFIG_POSIX) += aio-posix.o block-obj-$(CONFIG_WIN32) += aio-win32.o block-obj-y += block/ -block-obj-y += qapi-types.o qapi-visit.o +block-obj-y += qapi-types.o qapi-visit.o qapi-event.o block-obj-y += qemu-io-cmds.o block-obj-y += qemu-coroutine.o qemu-coroutine-lock.o qemu-coroutine-io.o diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt index dea0d505a7..3a0c99e1da 100644 --- a/docs/qapi-code-gen.txt +++ b/docs/qapi-code-gen.txt @@ -215,6 +215,24 @@ An example command is: 'data': { 'arg1': 'str', '*arg2': 'str' }, 'returns': 'str' } +=== Events === + +Events are defined with the keyword 'event'. When 'data' is also specified, +additional info will be carried on. Finally there will be C API generated +in qapi-event.h; when called by QEMU code, a message with timestamp will +be emitted on the wire. If timestamp is -1, it means failure to retrieve host +time. + +An example event is: + +{ 'event': 'EVENT_C', + 'data': { '*a': 'int', 'b': 'str' } } + +Resulting in this JSON object: + +{ "event": "EVENT_C", + "data": { "b": "test string" }, + "timestamp": { "seconds": 1267020223, "microseconds": 435656 } } == Code generation == diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py new file mode 100644 index 0000000000..3a1cd61914 --- /dev/null +++ b/scripts/qapi-event.py @@ -0,0 +1,369 @@ +# +# QAPI event generator +# +# Copyright (c) 2014 Wenchao Xia +# +# Authors: +# Wenchao Xia +# +# This work is licensed under the terms of the GNU GPL, version 2. +# See the COPYING file in the top-level directory. + +from ordereddict import OrderedDict +from qapi import * +import sys +import os +import getopt +import errno + +def _generate_event_api_name(event_name, params): + api_name = "void qapi_event_send_%s(" % c_fun(event_name).lower(); + l = len(api_name) + + if params: + for argname, argentry, optional, structured in parse_args(params): + if optional: + api_name += "bool has_%s,\n" % c_var(argname) + api_name += "".ljust(l) + + if argentry == "str": + api_name += "const " + api_name += "%s %s,\n" % (c_type(argentry), c_var(argname)) + api_name += "".ljust(l) + + api_name += "Error **errp)" + return api_name; + + +# Following are the core functions that generate C APIs to emit event. + +def generate_event_declaration(api_name): + return mcgen(''' + +%(api_name)s; +''', + api_name = api_name) + +def generate_event_implement(api_name, event_name, params): + # step 1: declare any variables + ret = mcgen(""" + +%(api_name)s +{ + QDict *qmp; + Error *local_err = NULL; + QMPEventFuncEmit emit; +""", + api_name = api_name) + + if params: + ret += mcgen(""" + QmpOutputVisitor *qov; + Visitor *v; + QObject *obj; + +""") + + # step 2: check emit function, create a dict + ret += mcgen(""" + emit = qmp_event_get_func_emit(); + if (!emit) { + return; + } + + qmp = qmp_event_build_dict("%(event_name)s"); + +""", + event_name = event_name) + + # step 3: visit the params if params != None + if params: + ret += mcgen(""" + qov = qmp_output_visitor_new(); + g_assert(qov); + + v = qmp_output_get_visitor(qov); + g_assert(v); + + /* Fake visit, as if all members are under a structure */ + visit_start_struct(v, NULL, "", "%(event_name)s", 0, &local_err); + if (local_err) { + goto clean; + } + +""", + event_name = event_name) + + for argname, argentry, optional, structured in parse_args(params): + if optional: + ret += mcgen(""" + if (has_%(var)s) { +""", + var = c_var(argname)) + push_indent() + + if argentry == "str": + var_type = "(char **)" + else: + var_type = "" + + ret += mcgen(""" + visit_type_%(type)s(v, %(var_type)s&%(var)s, "%(name)s", &local_err); + if (local_err) { + goto clean; + } +""", + var_type = var_type, + var = c_var(argname), + type = type_name(argentry), + name = argname) + + if optional: + pop_indent() + ret += mcgen(""" + } +""") + + ret += mcgen(""" + + visit_end_struct(v, &local_err); + if (local_err) { + goto clean; + } + + obj = qmp_output_get_qobject(qov); + g_assert(obj != NULL); + + qdict_put_obj(qmp, "data", obj); +""") + + # step 4: call qmp event api + ret += mcgen(""" + emit(%(event_enum_value)s, qmp, &local_err); + +""", + event_enum_value = event_enum_value) + + # step 5: clean up + if params: + ret += mcgen(""" + clean: + qmp_output_visitor_cleanup(qov); +""") + ret += mcgen(""" + error_propagate(errp, local_err); + QDECREF(qmp); +} +""") + + return ret + + +# Following are the functions that generate an enum type for all defined +# events, similar to qapi-types.py. Here we already have enum name and +# values which were generated before and recorded in event_enum_*. It also +# works around the issue that "import qapi-types" can't work. + +def generate_event_enum_decl(event_enum_name, event_enum_values): + lookup_decl = mcgen(''' + +extern const char *%(event_enum_name)s_lookup[]; +''', + event_enum_name = event_enum_name) + + enum_decl = mcgen(''' +typedef enum %(event_enum_name)s +{ +''', + event_enum_name = event_enum_name) + + # append automatically generated _MAX value + enum_max_value = generate_enum_full_value(event_enum_name, "MAX") + enum_values = event_enum_values + [ enum_max_value ] + + i = 0 + for value in enum_values: + enum_decl += mcgen(''' + %(value)s = %(i)d, +''', + value = value, + i = i) + i += 1 + + enum_decl += mcgen(''' +} %(event_enum_name)s; +''', + event_enum_name = event_enum_name) + + return lookup_decl + enum_decl + +def generate_event_enum_lookup(event_enum_name, event_enum_strings): + ret = mcgen(''' + +const char *%(event_enum_name)s_lookup[] = { +''', + event_enum_name = event_enum_name) + + i = 0 + for string in event_enum_strings: + ret += mcgen(''' + "%(string)s", +''', + string = string) + + ret += mcgen(''' + NULL, +}; +''') + return ret + + +# Start the real job + +try: + opts, args = getopt.gnu_getopt(sys.argv[1:], "chbp:i:o:", + ["source", "header", "builtins", "prefix=", + "input-file=", "output-dir="]) +except getopt.GetoptError, err: + print str(err) + sys.exit(1) + +input_file = "" +output_dir = "" +prefix = "" +c_file = 'qapi-event.c' +h_file = 'qapi-event.h' + +do_c = False +do_h = False +do_builtins = False + +for o, a in opts: + if o in ("-p", "--prefix"): + prefix = a + elif o in ("-i", "--input-file"): + input_file = a + elif o in ("-o", "--output-dir"): + output_dir = a + "/" + elif o in ("-c", "--source"): + do_c = True + elif o in ("-h", "--header"): + do_h = True + elif o in ("-b", "--builtins"): + do_builtins = 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 + +try: + os.makedirs(output_dir) +except os.error, e: + if e.errno != errno.EEXIST: + raise + +def maybe_open(really, name, opt): + if really: + return open(name, opt) + else: + import StringIO + return StringIO.StringIO() + +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 */ + +/* + * schema-defined QAPI event functions + * + * Copyright (c) 2014 Wenchao Xia + * + * Authors: + * Wenchao Xia + * + * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#include "qemu-common.h" +#include "%(header)s" +#include "%(prefix)sqapi-visit.h" +#include "qapi/qmp-output-visitor.h" +#include "qapi/qmp-event.h" + +''', + prefix=prefix, header=basename(h_file))) + +fdecl.write(mcgen(''' +/* THIS FILE IS AUTOMATICALLY GENERATED, DO NOT MODIFY */ + +/* + * schema-defined QAPI event functions + * + * Copyright (c) 2014 Wenchao Xia + * + * Authors: + * Wenchao Xia + * + * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#ifndef %(guard)s +#define %(guard)s + +#include "qapi/error.h" +#include "qapi/qmp/qdict.h" +#include "%(prefix)sqapi-types.h" + +''', + prefix=prefix, guard=guardname(h_file))) + +exprs = parse_schema(input_file) + +event_enum_name = prefix.upper().replace('-', '_') + "QAPIEvent" +event_enum_values = [] +event_enum_strings = [] + +for expr in exprs: + if expr.has_key('event'): + event_name = expr['event'] + params = expr.get('data') + if params and len(params) == 0: + params = None + + api_name = _generate_event_api_name(event_name, params) + ret = generate_event_declaration(api_name) + fdecl.write(ret) + + # We need an enum value per event + event_enum_value = generate_enum_full_value(event_enum_name, + event_name) + ret = generate_event_implement(api_name, event_name, params) + fdef.write(ret) + + # Record it, and generate enum later + event_enum_values.append(event_enum_value) + event_enum_strings.append(event_name) + +ret = generate_event_enum_decl(event_enum_name, event_enum_values) +fdecl.write(ret) +ret = generate_event_enum_lookup(event_enum_name, event_enum_strings) +fdef.write(ret) + +fdecl.write(''' +#endif +''') + +fdecl.flush() +fdecl.close() + +fdef.flush() +fdef.close() diff --git a/scripts/qapi.py b/scripts/qapi.py index 0079194169..54b97cb48e 100644 --- a/scripts/qapi.py +++ b/scripts/qapi.py @@ -248,6 +248,16 @@ def discriminator_find_enum_define(expr): return find_enum(discriminator_type) +def check_event(expr, expr_info): + params = expr.get('data') + if params: + for argname, argentry, optional, structured in parse_args(params): + if structured: + raise QAPIExprError(expr_info, + "Nested structure define in event is not " + "supported now, event '%s', argname '%s'" + % (expr['event'], argname)) + def check_union(expr, expr_info): name = expr['union'] base = expr.get('base') @@ -311,6 +321,8 @@ def check_exprs(schema): expr = expr_elem['expr'] if expr.has_key('union'): check_union(expr, expr_elem['info']) + if expr.has_key('event'): + check_event(expr, expr_elem['info']) def parse_schema(input_file): try: diff --git a/tests/Makefile b/tests/Makefile index 4caf7deb89..1fa38a18a8 100644 --- a/tests/Makefile +++ b/tests/Makefile @@ -199,7 +199,7 @@ check-qapi-schema-y := $(addprefix tests/qapi-schema/, \ include-simple.json include-relpath.json include-format-err.json \ include-non-file.json include-no-file.json include-before-err.json \ include-nested-err.json include-self-cycle.json include-cycle.json \ - include-repetition.json) + include-repetition.json event-nest-struct.json) GENERATED_HEADERS += tests/test-qapi-types.h tests/test-qapi-visit.h tests/test-qmp-commands.h diff --git a/tests/qapi-schema/event-nest-struct.err b/tests/qapi-schema/event-nest-struct.err new file mode 100644 index 0000000000..e4a0faac9c --- /dev/null +++ b/tests/qapi-schema/event-nest-struct.err @@ -0,0 +1 @@ +tests/qapi-schema/event-nest-struct.json:1: Nested structure define in event is not supported now, event 'EVENT_A', argname 'a' diff --git a/tests/qapi-schema/event-nest-struct.exit b/tests/qapi-schema/event-nest-struct.exit new file mode 100644 index 0000000000..d00491fd7e --- /dev/null +++ b/tests/qapi-schema/event-nest-struct.exit @@ -0,0 +1 @@ +1 diff --git a/tests/qapi-schema/event-nest-struct.json b/tests/qapi-schema/event-nest-struct.json new file mode 100644 index 0000000000..ee6f3ecb6f --- /dev/null +++ b/tests/qapi-schema/event-nest-struct.json @@ -0,0 +1,2 @@ +{ 'event': 'EVENT_A', + 'data': { 'a' : { 'string' : 'str', 'integer': 'int' }, 'b' : 'str' } } diff --git a/tests/qapi-schema/event-nest-struct.out b/tests/qapi-schema/event-nest-struct.out new file mode 100644 index 0000000000..e69de29bb2