Skip to content

P
protobuf
Commit 6b228f35 authored by Thomas Van Lenten's avatar Thomas Van Lenten
Browse files
Options

Merge pull request #1060 from thomasvl/drop_spinlocks 

Drop all use of OSSpinLock
parents 9e1777f4 d6590d65
Expand all Hide whitespace changes
Inline Side-by-side
Showing with 42 additions and 43 deletions
Makefile.am
View file @ 6b228f35
......@@ -468,7 +468,6 @@ objectivec_EXTRA_DIST= \
objectivec/Tests/GPBMessageTests.m \
objectivec/Tests/GPBObjectiveCPlusPlusTest.mm \
objectivec/Tests/GPBPerfTests.m \
objectivec/Tests/GPBStringTests.m \
objectivec/Tests/GPBSwiftTests.swift \
objectivec/Tests/GPBTestUtilities.h \
objectivec/Tests/GPBTestUtilities.m \
......
objectivec/GPBCodedInputStream.m
View file @ 6b228f35
This diff is collapsed.
objectivec/GPBCodedInputStream_PackagePrivate.h
View file @ 6b228f35
......@@ -39,19 +39,6 @@
@class GPBUnknownFieldSet;
@class GPBFieldDescriptor;
// GPBString is a string subclass that avoids the overhead of initializing
// a full NSString until it is actually needed. Lots of protocol buffers contain
// strings, and instantiating all of those strings and having them parsed to
// verify correctness when the message was being read was expensive, when many
// of the strings were never being used.
//
// Note for future-self. I tried implementing this using a NSProxy.
// Turned out the performance was horrible in client apps because folks
// like to use libraries like SBJSON that grab characters one at a time.
// The proxy overhead was a killer.
@interface GPBString : NSString
@end
typedef struct GPBCodedInputStreamState {
const uint8_t *bytes;
size_t bufferSize;
......@@ -92,10 +79,6 @@ typedef struct GPBCodedInputStreamState {
CF_EXTERN_C_BEGIN
// Returns a GPBString with a +1 retain count.
GPBString *GPBCreateGPBStringWithUTF8(const void *bytes, NSUInteger length)
__attribute__((ns_returns_retained));
int32_t GPBCodedInputStreamReadTag(GPBCodedInputStreamState *state);
double GPBCodedInputStreamReadDouble(GPBCodedInputStreamState *state);
......
objectivec/GPBMessage.m
View file @ 6b228f35
......@@ -568,13 +568,13 @@ static id GetArrayIvarWithField(GPBMessage *self, GPBFieldDescriptor *field) {
id array = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
if (!array) {
// Check again after getting the lock.
OSSpinLockLock(&self->readOnlyMutex_);
dispatch_semaphore_wait(self->readOnlySemaphore_, DISPATCH_TIME_FOREVER);
array = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
if (!array) {
array = CreateArrayForField(field, self);
GPBSetAutocreatedRetainedObjectIvarWithField(self, field, array);
}
OSSpinLockUnlock(&self->readOnlyMutex_);
dispatch_semaphore_signal(self->readOnlySemaphore_);
}
return array;
}
......@@ -598,13 +598,13 @@ static id GetMapIvarWithField(GPBMessage *self, GPBFieldDescriptor *field) {
id dict = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
if (!dict) {
// Check again after getting the lock.
OSSpinLockLock(&self->readOnlyMutex_);
dispatch_semaphore_wait(self->readOnlySemaphore_, DISPATCH_TIME_FOREVER);
dict = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
if (!dict) {
dict = CreateMapForField(field, self);
GPBSetAutocreatedRetainedObjectIvarWithField(self, field, dict);
}
OSSpinLockUnlock(&self->readOnlyMutex_);
dispatch_semaphore_signal(self->readOnlySemaphore_);
}
return dict;
}
......@@ -810,7 +810,7 @@ static GPBUnknownFieldSet *GetOrMakeUnknownFields(GPBMessage *self) {
messageStorage_ = (GPBMessage_StoragePtr)(
((uint8_t *)self) + class_getInstanceSize([self class]));
readOnlyMutex_ = OS_SPINLOCK_INIT;
readOnlySemaphore_ = dispatch_semaphore_create(1);
}
return self;
......@@ -1723,7 +1723,7 @@ static GPBUnknownFieldSet *GetOrMakeUnknownFields(GPBMessage *self) {
}
// Check for an autocreated value.
OSSpinLockLock(&readOnlyMutex_);
dispatch_semaphore_wait(readOnlySemaphore_, DISPATCH_TIME_FOREVER);
value = [autocreatedExtensionMap_ objectForKey:extension];
if (!value) {
// Auto create the message extensions to match normal fields.
......@@ -1740,7 +1740,7 @@ static GPBUnknownFieldSet *GetOrMakeUnknownFields(GPBMessage *self) {
[value release];
}
OSSpinLockUnlock(&readOnlyMutex_);
dispatch_semaphore_signal(readOnlySemaphore_);
return value;
}
......
objectivec/GPBMessage_PackagePrivate.h
View file @ 6b228f35
......@@ -62,7 +62,12 @@ typedef struct GPBMessage_Storage *GPBMessage_StoragePtr;
// by *read* operations such as getters (autocreation of message fields and
// message extensions, not setting of values). Used to guarantee thread safety
// for concurrent reads on the message.
OSSpinLock readOnlyMutex_;
// NOTE: OSSpinLock may seem like a good fit here but Apple engineers have
// pointed out that they are vulnerable to live locking on iOS in cases of
// priority inversion:
// http://mjtsai.com/blog/2015/12/16/osspinlock-is-unsafe/
// https://lists.swift.org/pipermail/swift-dev/Week-of-Mon-20151214/000372.html
dispatch_semaphore_t readOnlySemaphore_;
}
// Gets an extension value without autocreating the result if not found. (i.e.
......
objectivec/GPBRootObject.m
View file @ 6b228f35
......@@ -31,7 +31,6 @@
#import "GPBRootObject_PackagePrivate.h"
#import <objc/runtime.h>
#import <libkern/OSAtomic.h>
#import <CoreFoundation/CoreFoundation.h>
......@@ -96,13 +95,19 @@ static CFHashCode GPBRootExtensionKeyHash(const void *value) {
return jenkins_one_at_a_time_hash(key);
}
static OSSpinLock gExtensionSingletonDictionaryLock_ = OS_SPINLOCK_INIT;
// NOTE: OSSpinLock may seem like a good fit here but Apple engineers have
// pointed out that they are vulnerable to live locking on iOS in cases of
// priority inversion:
// http://mjtsai.com/blog/2015/12/16/osspinlock-is-unsafe/
// https://lists.swift.org/pipermail/swift-dev/Week-of-Mon-20151214/000372.html
static dispatch_semaphore_t gExtensionSingletonDictionarySemaphore;
static CFMutableDictionaryRef gExtensionSingletonDictionary = NULL;
static GPBExtensionRegistry *gDefaultExtensionRegistry = NULL;
+ (void)initialize {
// Ensure the global is started up.
if (!gExtensionSingletonDictionary) {
gExtensionSingletonDictionarySemaphore = dispatch_semaphore_create(1);
CFDictionaryKeyCallBacks keyCallBacks = {
// See description above for reason for using custom dictionary.
0,
......@@ -134,9 +139,10 @@ static GPBExtensionRegistry *gDefaultExtensionRegistry = NULL;
+ (void)globallyRegisterExtension:(GPBExtensionDescriptor *)field {
const char *key = [field singletonNameC];
OSSpinLockLock(&gExtensionSingletonDictionaryLock_);
dispatch_semaphore_wait(gExtensionSingletonDictionarySemaphore,
DISPATCH_TIME_FOREVER);
CFDictionarySetValue(gExtensionSingletonDictionary, key, field);
OSSpinLockUnlock(&gExtensionSingletonDictionaryLock_);
dispatch_semaphore_signal(gExtensionSingletonDictionarySemaphore);
}
static id ExtensionForName(id self, SEL _cmd) {
......@@ -166,14 +172,24 @@ static id ExtensionForName(id self, SEL _cmd) {
key[classNameLen] = '_';
memcpy(&key[classNameLen + 1], selName, selNameLen);
key[classNameLen + 1 + selNameLen] = '\0';
OSSpinLockLock(&gExtensionSingletonDictionaryLock_);
// NOTE: Even though this method is called from another C function,
// gExtensionSingletonDictionarySemaphore and gExtensionSingletonDictionary
// will always be initialized. This is because this call flow is just to
// lookup the Extension, meaning the code is calling an Extension class
// message on a Message or Root class. This guarantees that the class was
// initialized and Message classes ensure their Root was also initialized.
NSAssert(gExtensionSingletonDictionary, @"Startup order broken!");
dispatch_semaphore_wait(gExtensionSingletonDictionarySemaphore,
DISPATCH_TIME_FOREVER);
id extension = (id)CFDictionaryGetValue(gExtensionSingletonDictionary, key);
if (extension) {
// The method is getting wired in to the class, so no need to keep it in
// the dictionary.
CFDictionaryRemoveValue(gExtensionSingletonDictionary, key);
}
OSSpinLockUnlock(&gExtensionSingletonDictionaryLock_);
dispatch_semaphore_signal(gExtensionSingletonDictionarySemaphore);
return extension;
}
......
objectivec/GPBUtilities.m
View file @ 6b228f35
......@@ -411,7 +411,7 @@ id GPBGetObjectIvarWithField(GPBMessage *self, GPBFieldDescriptor *field) {
return field.defaultValue.valueMessage;
}
OSSpinLockLock(&self->readOnlyMutex_);
dispatch_semaphore_wait(self->readOnlySemaphore_, DISPATCH_TIME_FOREVER);
GPBMessage *result = GPBGetObjectIvarWithFieldNoAutocreate(self, field);
if (!result) {
// For non repeated messages, create the object, set it and return it.
......@@ -420,7 +420,7 @@ id GPBGetObjectIvarWithField(GPBMessage *self, GPBFieldDescriptor *field) {
result = GPBCreateMessageWithAutocreator(field.msgClass, self, field);
GPBSetAutocreatedRetainedObjectIvarWithField(self, field, result);
}
OSSpinLockUnlock(&self->readOnlyMutex_);
dispatch_semaphore_signal(self->readOnlySemaphore_);
return result;
}
......
objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj
View file @ 6b228f35
......@@ -28,7 +28,6 @@
8B8B615D17DF7056002EE618 /* GPBARCUnittestProtos.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B8B615C17DF7056002EE618 /* GPBARCUnittestProtos.m */; settings = {COMPILER_FLAGS = "-fobjc-arc"; }; };
8B96157414C8C38C00A2AC0B /* GPBDescriptor.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B96157314C8C38C00A2AC0B /* GPBDescriptor.m */; };
8B96157514CA019D00A2AC0B /* Descriptor.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = 8BD3982214BE5B0C0081D629 /* Descriptor.pbobjc.m */; };
8BA9364518DA5F4C0056FA2A /* GPBStringTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 8BA9364418DA5F4B0056FA2A /* GPBStringTests.m */; };
8BBEA4A9147C727D00C4ADB7 /* GPBCodedInputStreamTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 7461B69B0F94FDF800A0C422 /* GPBCodedInputStreamTests.m */; };
8BBEA4AA147C727D00C4ADB7 /* GPBCodedOuputStreamTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 7461B69D0F94FDF800A0C422 /* GPBCodedOuputStreamTests.m */; };
8BBEA4AC147C727D00C4ADB7 /* GPBMessageTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 7461B6A30F94FDF800A0C422 /* GPBMessageTests.m */; };
......@@ -158,7 +157,6 @@
8B8B615C17DF7056002EE618 /* GPBARCUnittestProtos.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GPBARCUnittestProtos.m; sourceTree = "<group>"; };
8B96157214C8B06000A2AC0B /* GPBDescriptor.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBDescriptor.h; sourceTree = "<group>"; };
8B96157314C8C38C00A2AC0B /* GPBDescriptor.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GPBDescriptor.m; sourceTree = "<group>"; };
8BA9364418DA5F4B0056FA2A /* GPBStringTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GPBStringTests.m; sourceTree = "<group>"; };
8BBD9DB016DD1DC8008E1EC1 /* unittest_lite.proto */ = {isa = PBXFileReference; lastKnownFileType = text; name = unittest_lite.proto; path = ../../src/google/protobuf/unittest_lite.proto; sourceTree = "<group>"; };
8BBEA4A6147C727100C4ADB7 /* UnitTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = UnitTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
8BCF338814ED799900BC5317 /* GPBProtocolBuffers.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = GPBProtocolBuffers.m; sourceTree = "<group>"; };
......@@ -419,7 +417,6 @@
F4487C7E1AAF62CD00531423 /* GPBMessageTests+Serialization.m */,
F4B51B1D1BBC610700744318 /* GPBObjectiveCPlusPlusTest.mm */,
F41C175C1833D3310064ED4D /* GPBPerfTests.m */,
8BA9364418DA5F4B0056FA2A /* GPBStringTests.m */,
8B4248BA1A8C256A00BC1EC6 /* GPBSwiftTests.swift */,
7461B6AB0F94FDF800A0C422 /* GPBTestUtilities.h */,
7461B6AC0F94FDF800A0C422 /* GPBTestUtilities.m */,
......@@ -689,7 +686,6 @@
F41C175D1833D3310064ED4D /* GPBPerfTests.m in Sources */,
F4353D341AC06F10005A6198 /* GPBDictionaryTests+Bool.m in Sources */,
F4487C831AAF6AB300531423 /* GPBMessageTests+Merge.m in Sources */,
8BA9364518DA5F4C0056FA2A /* GPBStringTests.m in Sources */,
8BBEA4B6147C727D00C4ADB7 /* GPBUnknownFieldSetTest.m in Sources */,
F4353D371AC06F10005A6198 /* GPBDictionaryTests+String.m in Sources */,
F4353D381AC06F10005A6198 /* GPBDictionaryTests+UInt32.m in Sources */,
......
objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj
View file @ 6b228f35
......@@ -36,7 +36,6 @@
8B9A5EB41831993600A9D33B /* AppDelegate.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B9A5EB31831993600A9D33B /* AppDelegate.m */; };
8B9A5EB61831993600A9D33B /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 8B9A5EB51831993600A9D33B /* Images.xcassets */; };
8B9A5EEC18330A0F00A9D33B /* UIKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 8B9A5E9F1831913D00A9D33B /* UIKit.framework */; };
8BA9364518DA5F4C0056FA2A /* GPBStringTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 8BA9364418DA5F4B0056FA2A /* GPBStringTests.m */; };
8BBEA4A9147C727D00C4ADB7 /* GPBCodedInputStreamTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 7461B69B0F94FDF800A0C422 /* GPBCodedInputStreamTests.m */; };
8BBEA4AA147C727D00C4ADB7 /* GPBCodedOuputStreamTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 7461B69D0F94FDF800A0C422 /* GPBCodedOuputStreamTests.m */; };
8BBEA4AC147C727D00C4ADB7 /* GPBMessageTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 7461B6A30F94FDF800A0C422 /* GPBMessageTests.m */; };
......@@ -179,7 +178,6 @@
8B9A5EAD1831993600A9D33B /* en */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = en; path = en.lproj/InfoPlist.strings; sourceTree = "<group>"; };
8B9A5EB31831993600A9D33B /* AppDelegate.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = AppDelegate.m; sourceTree = "<group>"; };
8B9A5EB51831993600A9D33B /* Images.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Images.xcassets; sourceTree = "<group>"; };
8BA9364418DA5F4B0056FA2A /* GPBStringTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GPBStringTests.m; sourceTree = "<group>"; };
8BBD9DB016DD1DC8008E1EC1 /* unittest_lite.proto */ = {isa = PBXFileReference; lastKnownFileType = text; name = unittest_lite.proto; path = ../../src/google/protobuf/unittest_lite.proto; sourceTree = "<group>"; };
8BBEA4A6147C727100C4ADB7 /* UnitTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = UnitTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
8BCF338814ED799900BC5317 /* GPBProtocolBuffers.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = GPBProtocolBuffers.m; sourceTree = "<group>"; };
......@@ -457,7 +455,6 @@
F4487C801AAF62FC00531423 /* GPBMessageTests+Serialization.m */,
F4B51B1B1BBC5C7100744318 /* GPBObjectiveCPlusPlusTest.mm */,
F41C175C1833D3310064ED4D /* GPBPerfTests.m */,
8BA9364418DA5F4B0056FA2A /* GPBStringTests.m */,
8B4248B31A8BD96E00BC1EC6 /* GPBSwiftTests.swift */,
7461B6AB0F94FDF800A0C422 /* GPBTestUtilities.h */,
7461B6AC0F94FDF800A0C422 /* GPBTestUtilities.m */,
......@@ -785,7 +782,6 @@
F41C175D1833D3310064ED4D /* GPBPerfTests.m in Sources */,
F4353D421AC06F31005A6198 /* GPBDictionaryTests+Bool.m in Sources */,
F4487C851AAF6AC500531423 /* GPBMessageTests+Merge.m in Sources */,
8BA9364518DA5F4C0056FA2A /* GPBStringTests.m in Sources */,
8BBEA4B6147C727D00C4ADB7 /* GPBUnknownFieldSetTest.m in Sources */,
F4353D451AC06F31005A6198 /* GPBDictionaryTests+String.m in Sources */,
F4353D461AC06F31005A6198 /* GPBDictionaryTests+UInt32.m in Sources */,
......
objectivec/Tests/GPBCodedInputStreamTests.m
View file @ 6b228f35
......@@ -266,6 +266,9 @@
}
// Verifies fix for b/10315336.
// Note: Now that there isn't a custom string class under the hood, this test
// isn't as critical, but it does cover bad input and if a custom class is added
// again, it will help validate that class' handing of bad utf8.
- (void)testReadMalformedString {
NSOutputStream* rawOutput = [NSOutputStream outputStreamToMemory];
GPBCodedOutputStream* output =
......@@ -276,7 +279,7 @@
[output writeRawVarint32:tag];
[output writeRawVarint32:5];
// Create an invalid utf-8 byte array.
uint8_t bytes[5] = {0xc2, 0xf2};
uint8_t bytes[] = {0xc2, 0xf2, 0x0, 0x0, 0x0};
[output writeRawData:[NSData dataWithBytes:bytes length:sizeof(bytes)]];
[output flush];
......@@ -286,6 +289,7 @@
TestAllTypes* message = [TestAllTypes parseFromCodedInputStream:input
extensionRegistry:nil
error:NULL];
XCTAssertNotNil(message);
// Make sure we can read string properties twice without crashing.
XCTAssertEqual([message.defaultString length], (NSUInteger)0);
XCTAssertEqualObjects(@"", message.defaultString);
......
objectivec/Tests/GPBStringTests.m deleted 100644 → 0
View file @ 9e1777f4
This diff is collapsed.
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment