objective c usleep

Objetive-C learning _ Block learning notes, objetive-c_block Block: an anonymous function with an automatic variable (local variable. Block: used to save a piece of code and can be called when appropriate. Block essence: struct, which contains a function pointer Block application scenarios: animation, multithreading, set traversal, and network request callback Block format: ^ return value type parameter li

The pre-write code encounters a situation where usleep will die under multiple threads.Look at the log is the thread stuck, so gdb went in to see, but did not find the deadlock, or normal stay in the usleep, and finally found that it is usleep in the back.At the end of the week, an experiment was made, and it seemed that the machine had something to do with the o

instancevi. Relationship between OC instance object class object meta-Object(1) Each object is an instance of a class.(2) Each object has a pointer to the object named Isa, which points to its class.(3) Each class describes the characteristics of a series of its instances, including a list of member variables, a list of member functions, and so on.(4) Each object can accept the message, and the message list that the object can receive is saved in the class it corresponds to. Copyright NOTICE: T

Some time ago, during sokcet communication under Objetive-C, when the C ++ program was used as the server, everything was normal. When Java was used as the server, neither party received the data, after reading some documents, sort out the notes 1. Press enter and line feed at the end of the message. When Objetive-C sends data, add "\ r \ n" to the end" _ Datatosend = [nsdata datawithbytes: "This is a

atomic operation. If multipleWhen a thread calls the setter at the same time, one thread does not appear before the entire setter statement is executed, and the otherWhen a thread starts executing a setter, it is the same as the method ends with a lock.Nonatomic: The atomicity of Setter/getter is not guaranteed, and data may be problematic in multithreaded situations.nonatomic, non-atomic access, non-synchronous, multi-threaded concurrent access improves performance. First release the originalv

 Description of Use The Usleep command is used to delay the time in microseconds (sleep some number of microseconds), which actually does not reach this precision (Probably not accurate on many machines the mic Rosecond. Count on precision only to-4 or maybe-5.). If there is no usleep command in the system, you can use the Sleep command, and the Sleep command can specify a time delay with a decimal. 1 s

PHP sleep () function, usleep () function, sleepusleep PHP sleep () function Definition and usage The sleep () function delays code execution for several seconds.Syntax sleep (seconds)Seconds required. The pause time in seconds.Return Value If the call succeeds, 0 is returned. Otherwise, false is returned.Error/exception If the specified description seconds is a negative number, this function generates an E_WARNING. Example Output: 12:00:08 12:00:18

Tag: equals class CPU style note Code strong log IntegerPause code Execution in PHP for a certain time, there are two functions can be implemented, one is sleep (), the other is Usleep (), their parameters are an integer value. Sleep () is how many seconds are paused, and usleep () is how many microseconds are paused.Note: the Usleep () unit is in microseconds, 1

1:sleep ()The minimum unit of seconds.When using Sleep/ulseep/select, because the thread will go to sleep state, and then wake up, if the single execution problem is not small, if the number of cycles executed more, then the difference is very large.2:ulseep ()The smallest unit of microseconds.3:select ()Minimum units of microseconds, which need to be assigned each time they are used in the body.4:RTC ()Use the IOCTL control.5: Examples of use of the above four methods#include #include#includest

1. PHP Sleep () function Definition and usage The sleep () function delays code execution for several seconds.Grammar Sleep (seconds)seconds required. The pause time in seconds.return value If successful, returns 0, otherwise false.Error/exception If the specified description seconds is a negative number, the function generates a e_warning. Example Output: 12:00:08-12:00:18 2. PHP Usleep () function Definition and usage The

The use and difference of sleep () and Usleep () for Linux [Date: 2013-03-23] Source: Linux Community Fireroll [Font: Big Small] Function Name: SleepHeader file: #include #include Function: Execution suspend specified number of secondsSyntax: unsigned sleep (unsigned seconds);Example:#include #include int main (){int A;A=1;printf ("Hello");Sleep (a); /* VC Use sleep*/printf ("World");return 0;}Function Name: Usleep

PHP Sleep () function Definitions and usage The sleep () function delays code execution for several seconds.Grammar Sleep (seconds)seconds required. The pause time in seconds.return value If successful, returns 0, otherwise returns false.Error/exception If the specified description seconds is a negative number, the function generates a e_warning. Example Output: 12:00:08 12:00:18 PHP usleep () function Definitions and usage Th

This article mainly introduces the PHPsleep () function and usleep () function. if you need it, refer to the PHP sleep () function. Definition and usage The sleep () function delays code execution for several seconds.Syntax sleep (seconds)Seconds required. The pause time in seconds.Return value If the call succeeds, 0 is returned. otherwise, false is returned.Error/exception If the specified description seconds is a negative number, this function gen

Http://blog.chinaunix.net/space.php? Uid = 488742 Do = Blog cuid = 1276208 Root @ James-desktop:/opt/marvell_test/sleep_test #./x86_test_sleepFunction time (USEC) realtime reduce-------------------------------------------------------------------Usleep 500000 500640 640Nanosleep 500000 500998 998Select 500000 500929 929Usleep 100000 101256 1256Nanosleep 100000 100715 715Select 100000 100887 887Usleep 50000 51001 1001Nanosleep 50000 51049 1049Sele

Definition and usage The Usleep () function delays code execution for several microseconds. Grammar Usleep (microseconds) Parameter description microseconds required. Pause time in microseconds. return value no return value. Hints and Notes Note: This function does not work on Windows systems until PHP 5.Note: One microsecond equals one out of 10,000 seconds. Example echo date('h:i:s') . "";//

[RK_2014_0918] in linux, test the impact of usleep function on CPU usage. rk_2014_0918usleep 1. Local Environment CPU information Intel (R) Core (TM) i3 cpu m 350 @ 2.27 GHz Intel(R) Core(TM) i3 CPU M 350 @ 2.27GHz Intel(R) Core(TM) i3 CPU M 350 @ 2.27GHz Intel(R) Core(TM) i3 CPU M 350 @ 2.27GHz Memory InformationMemTotal: 1990228 kB 2. Build Test code 1. Test code #include while (1) { //uslee