Pthread Cleanup Push Syntax Error

PTHREAD_CLEANUP_PUSH(3) NAME top pthread_cleanup_push, pthread_cleanup_pop - push and pop thread can‐ cellation clean-up handlers SYNOPSIS top #include pthread_cleanup_push example void pthread_cleanup_push(void (*routine)(void *), void *arg); void pthread_cleanup_pop(int execute); Compile

Pthread_cleanup_pop

and link with -pthread. DESCRIPTION top These functions manipulate the calling thread's stack pthread atexit of thread- cancellation clean-up handlers. A clean-up handler is a function that is automatically executed when a thread is canceled (or in various other circumstances described below); it might, pthread_cleanup_pop(1) for example, unlock a mutex so that it becomes available to other threads in the process. The pthread_cleanup_push() function pushes routine onto the top of the stack of clean-up handlers. When routine is later invoked, it will be given arg as its argument. The pthread_cleanup_pop() function removes the routine at the top of the stack of clean-up handlers,

Pthread_cleanup_pop Example

and optionally executes it if execute is nonzero. A cancellation clean-up handler is popped from the stack and executed in the following circumstances: 1. When a thread is canceled, all of the stacked clean-up handlers are popped and executed in the reverse of the order in which they were pushed onto the stack. 2. When a thread terminates by calling pthread_exit(3), all clean-up handlers are executed as described in the preceding point. (Clean-up handlers are not called if the thread terminates by performing a return from the thread start function.) 3. When a thread calls pthread_cleanup_pop() with a nonzero execute argument, the top-most clean-up handler is popped and executed. POSIX.1 permits pthread_cleanup_push() and pthread_cleanup_pop() to be implemented as macros that expand to text containing '{' and '}', respectively. For this reason, the caller must ensure that calls to these functions are paired within the same function, and at the same lexical nesting level. (In other words, a clean-up handler is established only during the execution of a specified section of code.)

establish cancellation handlers SYNOPSIS ^[THR] #include <pthread.h>

void pthread_cleanup_pop(int execute);
void pthread_cleanup_push(void (*routine)(void*), void *arg); pthread_cancel cleanup handler DESCRIPTION The pthread_cleanup_pop() function shall remove the routine at

Pthread_cleanup_pop(0)

the top of the calling thread's cancellation cleanup stack and optionally invoke it (if execute is non-zero). The pthread_cleanup_push() function shall push the specified http://man7.org/linux/man-pages/man3/pthread_cleanup_push.3.html cancellation cleanup handler routine onto the calling thread's cancellation cleanup stack. The cancellation cleanup handler shall be popped from the cancellation cleanup stack and invoked with the argument arg when: The thread exits (that is, calls pthread_exit()). The thread acts upon a cancellation request. The thread calls pthread_cleanup_pop() with http://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_cleanup_pop.html a non-zero execute argument. These functions may be implemented as macros. The application shall ensure that they appear as statements, and in pairs within the same lexical scope (that is, the pthread_cleanup_push() macro may be thought to expand to a token list whose first token is '{' with pthread_cleanup_pop() expanding to a token list whose last token is the corresponding '}' ). The effect of calling longjmp() or siglongjmp() is undefined if there have been any calls to pthread_cleanup_push() or pthread_cleanup_pop() made without the matching call since the jump buffer was filled. The effect of calling longjmp() or siglongjmp() from inside a cancellation cleanup handler is also undefined unless the jump buffer was also filled in the cancellation cleanup handler. The effect of the use of return, break, continue, and goto to prematurely leave a code block described by a pair of pthread_cleanup_push(

Award - Windows PowerShell practical guide to probation Pthread_cleanup_push/pop 09:44 2013-11-26 227 people read comment(0) Collection report Classification: C/C++(12) Author similar articleX UNIX(14) Author similar articleX operating system(10) Author similar articleX Pthread_cleanup_push void (void (*routine) () (void*), *arg void (); http://prog3.com/sbdm/blog/thisisbatman/article/details/16959669 Void pthread_cleanup_pop (int execute); / / int parameter here, 0 is the implementation of the http://docs.oracle.com/cd/E19048-01/chorus5/806-7021/6jfu393ab/index.html contents of push, non implementation of the 0. Prototype is very simple, with the function of atexit () almost, but one is a thread is a process. What you want to do when the thread exits in the push/pop. There are several points to pay attention to: 1, push and pop must be in pairs, in fact, push contains "{" and pop pthread cleanup contains "}", a little less. 2, push can have more than one, the same pop to the corresponding number, follow the "advanced" principle". Push functions may be implemented in the following three timing: 1, the display of the call pthread_exit (); or 2, the cancel point thread is cancel. or 3, pthread_cleanup_pop () parameters are not 0. All of the above actions are limited to the code that is covered by push/pop. In front of the two pthread cleanup push is better understood, the key is pthread cleanup pop parameter problem, in fact, int that is because C is not bool, this parameter only 0 and non-zero difference, the pthread cleanup pop, parameter is 5 and 10 are the same, is non-zero. We often see this code: Child void (*t void) { Pthread_cleanup_push (pthread_mutex_unlock, &mutex); Pthread_mutex_lock (&mutex); ... in... Pthread_mutex_unlock (&mutex); Pthread_cleanup_pop (0); } Why pthread_cleanup_pop is 0, he simply does not implement the function push in the function pointer to point to the function, yes, is not executed, really want to execute on the trouble. So why do you have to write it? That's because push and pop must be in pairs, not writing is a syntax error. Write so mainly in order to ensure a mutex can be unlock because, between the pthread mutex lock and pthread mutex unlock may anything can happen. For instance, the existence of N cancel points cause the thread to be main or other threads to cancel, cancel action is will not release the mutex, this lock to death. By pthread_cleanup_push to add a function pthread_mutex_unlock, referring to the timing of the above instructions, when the thread is cancel, you can release the lock to clean up the action. If the thread executing normally, until run to pthread cleanup pop, then the lock has been in the intermediate code pthread mutex unlo

DESCRIPTION | EXAMPLES - POSIX Threads Only | ATTRIBUTES | SEE ALSO NAME cancellation- overview of concepts related to POSIX thread cancellation API RESTRICTIONS The function or functions documented here may not be used safely in all application contexts with all APIs provided in the ChorusOS 5.0 product. See API(5FEA) for details. DESCRIPTION FUNCTIONACTION pthread_cancelCancels thread execution. pthread_setcancelstateSets the cancellation state of a thread. pthread_setcanceltypeSets the cancellation type of a thread. pthread_testcancelCreates a cancellation point in the calling thread. pthread_cleanup_pushPushes a cleanup handler routine. pthread_cleanup_popPops a cleanup handler routine. Cancellation Thread cancellation allows a thread to terminate the execution of any application thread in the process. Cancellation is useful when further operation of one or more threads is undesirable or unnecessary. An example of a situation that would benefit from using cancellation is an asynchronously-generated cancel condition such as a user requesting to close or exit some running operation. Another example is the completion of a task undertaken by a number of threads, such as solving a maze. With many threads searching for the solution, one of the threads might solve the puzzle while the others continue to operate. Since they are serving no purpose at that point, they should all be canceled. Planning Planning and programming for most cancellations follow this pattern: Identify which threads you want to cancel, and insert pthread_cancel(3POSIX) statements. Identify system-defined cancellation points where a thread that might be canceled could have changed a system or program state that should be restored. See the Cancellation Points for a list. When a thread changes the system or program state just before a cancellation point, and should restore that state before the thread is canceled, place a cleanup handler before the cancellation point with pthread_cleanup_push(3POSIX). Wherever a thread restores the changed state, pop the cleanup handler from the cleanup stack with pthread-cleanup-pop(3POSIX). Know whether the threads you are canceling call into cancel-unsafe libraries, and disable cancellation with pthread_setcancelstate(3POSIX) before the call into the library. See Cancellation State. To cancel a thread in a proce