iOS上的函数/方法级评测
是否有任何解决方案可以使用最新的Xcode（7.x）在iOS上进行函数/方法级评测 我的意思是，编译器在代码中注入性能日志。当苹果还在使用GCC时，我确实在iOS上成功地使用了iOS上的函数/方法级评测,ios,performance,profiling,Ios,Performance,Profiling,是否有任何解决方案可以使用最新的Xcode（7.x）在iOS上进行函数/方法级评测 我的意思是，编译器在代码中注入性能日志。当苹果还在使用GCC时，我确实在iOS上成功地使用了-pg和gprof，但似乎没有与clang相当的功能 我需要找出在某个场景中谁在微阻塞我的主线程（应用程序仍会做出反应，但阻塞会使滚动变得紧张）。不幸的是，Instruments的工具不能胜任这项任务：采样（停止应用程序并记录堆栈跟踪）对于我的需要来说太粗糙/不精确 所以我需要一种方法来精确地找出哪种方法在什么时间运行，运
-pggprof所以我需要一种方法来精确地找出哪种方法在什么时间运行，运行多长时间。唯一真正的方法是让编译器注入必要的代码（这就是
-pgNSCondition- (void)startWatchdog
{
static NSDate * lastIteration;
static BOOL hasHandled = NO;
NSCondition * condition = [[NSCondition alloc] init];
lastIteration = [NSDate date];
CFRunLoopObserverRef observer = CFRunLoopObserverCreateWithHandler(NULL,
kCFRunLoopBeforeTimers | kCFRunLoopBeforeWaiting, true, 0,
^(CFRunLoopObserverRef observer, CFRunLoopActivity activity) {
NSDate * now = [NSDate date];
if (activity == kCFRunLoopBeforeTimers) {
if (!hasHandled) {
[condition lock];
[condition signal];
[condition unlock];
}
lastIteration = now;
hasHandled = NO;
} else {
// About to wait for events. We might want tell the watchdog method
// that it's OK that there's going to be a timeout.
[condition lock];
[condition signal];
[condition unlock];
hasHandled = YES;
}
}
);
NSThread * watchdog = [[NSThread alloc] initWithTarget:self selector:@selector(watchdog:) object:condition];
[watchdog setThreadPriority:1];
[watchdog start];
CFRunLoopRef runloop = [[NSRunLoop currentRunLoop] getCFRunLoop];
CFRunLoopAddObserver(runloop, observer, kCFRunLoopCommonModes);
CFRunLoopAddObserver(runloop, observer, (CFStringRef)UITrackingRunLoopMode);
}
- (void)watchdog:(NSCondition *)condition
{
@autoreleasepool {
while (1) {
BOOL wasHandled;
NSDate * start = [NSDate date];
[condition lock];
wasHandled = [condition waitUntilDate:[start dateByAddingTimeInterval:0.2]];
[condition unlock];
if (!wasHandled) {
NSLog(@"-- Timeout: %f", [[NSDate date] timeIntervalSinceDate:start]);
}
}
}
}
@MikeDunlavey建议设置计时器对我来说是正确的解决方案。在我的例子中，一个真正的计时器是不起作用的，所以我使用了一个高优先级的后台线程和一个
NSCondition- (void)startWatchdog
{
static NSDate * lastIteration;
static BOOL hasHandled = NO;
NSCondition * condition = [[NSCondition alloc] init];
lastIteration = [NSDate date];
CFRunLoopObserverRef observer = CFRunLoopObserverCreateWithHandler(NULL,
kCFRunLoopBeforeTimers | kCFRunLoopBeforeWaiting, true, 0,
^(CFRunLoopObserverRef observer, CFRunLoopActivity activity) {
NSDate * now = [NSDate date];
if (activity == kCFRunLoopBeforeTimers) {
if (!hasHandled) {
[condition lock];
[condition signal];
[condition unlock];
}
lastIteration = now;
hasHandled = NO;
} else {
// About to wait for events. We might want tell the watchdog method
// that it's OK that there's going to be a timeout.
[condition lock];
[condition signal];
[condition unlock];
hasHandled = YES;
}
}
);
NSThread * watchdog = [[NSThread alloc] initWithTarget:self selector:@selector(watchdog:) object:condition];
[watchdog setThreadPriority:1];
[watchdog start];
CFRunLoopRef runloop = [[NSRunLoop currentRunLoop] getCFRunLoop];
CFRunLoopAddObserver(runloop, observer, kCFRunLoopCommonModes);
CFRunLoopAddObserver(runloop, observer, (CFStringRef)UITrackingRunLoopMode);
}
- (void)watchdog:(NSCondition *)condition
{
@autoreleasepool {
while (1) {
BOOL wasHandled;
NSDate * start = [NSDate date];
[condition lock];
wasHandled = [condition waitUntilDate:[start dateByAddingTimeInterval:0.2]];
[condition unlock];
if (!wasHandled) {
NSLog(@"-- Timeout: %f", [[NSDate date] timeIntervalSinceDate:start]);
}
}
}
}
-pg和gprof从来没有这样做过。他们所做的只是计算呼叫数，并对PC进行采样（这对阻塞是盲目的）。你不需要精确。您需要的是在正确的时间（即进程被阻止时）堆叠样本。大多数堆栈采样分析器在阻塞时不进行采样，因此这是不好的。（缩放可能有用？）我会试试。它可能需要相当数量的样本，但当你看到它时，你会认出正确的样本。@MikeDunlavey:谢谢你澄清了关于
gprofgprof