我想使用C函数启动一个新线程,而不是使用Objective-C方法.我试过了
[NSThread detachNewThreadSelector: @selector(func) toTarget: nil withObject: id(data)];
我在哪里
void func(void *data) {
// ...
}
和data是一个void *,但我在objc_msgSend中遇到运行时崩溃,调用来自
-[NSThread initWithTarget:selector:object:]
我该怎么做？它甚至可能吗？
解决方法
滚动你自己：
// In some .h file. #import to make the extension methods 'visible' to your code.
@interface NSThread (FunctionExtension)
+(void)detachNewThreadByCallingFunction:(void (*)(void *))function data:(void *)data;
-(id)initWithFunction:(void (*)(void *))function data:(void *)data;
@end
// In some .m file.
@implementation NSThread (FunctionExtension)
+(void)startBackgroundThreadUsingFunction:(id)object
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
void (*startThreadFunction)(void *) = (void (*)(void *))[[object objectForKey:@"function"] pointerValue];
void *startThreadData = (void *) [[object objectForKey:@"data"] pointerValue];
if(startThreadFunction != NULL) { startThreadFunction(startThreadData); }
[pool release];
pool = NULL;
}
+(void)detachNewThreadByCallingFunction:(void (*)(void *))function data:(void *)data
{
[[[[NSThread alloc] initWithFunction:function data:data] autorelease] start];
}
-(id)initWithFunction:(void (*)(void *))function data:(void *)data
{
return([self initWithTarget:[NSThread class] selector:@selector(startBackgroundThreadUsingFunction:) object:[NSDictionary dictionaryWithObjectsAndKeys:[NSValue valueWithPointer:function],@"function",[NSValue valueWithPointer:data],@"data",NULL]]);
}
@end
注意：我写了上面的代码,并将其放在公共领域. (有时律师喜欢这种东西)它也完全没有经过考验！
你可以随时删除NSAutoreleasePool位,如果你可以保证线程入口函数也创建一个…但它是无害的,没有任何速度惩罚,并使调用任意C函数更简单.我会说保持它在那里.
你可以像这样使用它：
void bgThreadFunction(void *data)
{
NSLog(@"bgThreadFunction STARTING!! Data: %p",data);
}
-(void)someMethod
{
// init and then start later...
NSThread *bgThread = [[[NSThread alloc] initWithFunction:bgThreadFunction data:(void *)0xdeadbeef] autorelease];
// ... assume other code/stuff here.
[bgThread start];
// Or,use the all in one convenience method.
[NSThread detachNewThreadByCallingFunction:bgThreadFunction data:(void *)0xcafebabe];
}
运行时：
2009-08-30 22:21:12.529 test[64146:1303] bgThreadFunction STARTING!! Data: 0xdeadbeef 2009-08-30 22:21:12.529 test[64146:2903] bgThreadFunction STARTING!! Data: 0xcafebabe
