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Defined in header <cstdlib> | ||
| (1) | ||
int atexit(/* c-atexit-handler */* func); int atexit(/* atexit-handler */* func); | (until C++11) | |
int atexit(/* c-atexit-handler */* func)noexcept; int atexit(/* atexit-handler */* func)noexcept; | (since C++11) | |
extern"C"using/* c-atexit-handler */=void(); extern"C++"using/* atexit-handler */=void(); | (2) | (exposition only*) |
Registers the function pointed to byfunc to be called on normal program termination (viastd::exit() or returning from themain function)
The functions will be called during the destruction of the static objects, in reverse order: if A was registered before B, then the call to B is made before the call to A. Same applies to the ordering between static object constructors and the calls to | (until C++11) |
The functions may be called concurrently with the destruction of the objects with static storage duration and with each other, maintaining the guarantee that if registration of A was sequenced-before the registration of B, then the call to B is sequenced-before the call to A, same applies to the sequencing between static object constructors and calls to | (since C++11) |
The same function may be registered more than once.
If a function exits via an exception,std::terminate is called.
atexit is thread-safe: calling the function from several threads does not induce a data race.
The implementation is guaranteed to support the registration of at least 32 functions. The exact limit is implementation-defined.
Contents |
| func | - | pointer to a function to be called on normal program termination |
0 if the registration succeeds, nonzero value otherwise.
The two overloads are distinct because the types of the parameterfunc are distinct (language linkage is part of its type).
#include <cstdlib>#include <iostream> void atexit_handler_1(){std::cout<<"At exit #1\n";} void atexit_handler_2(){std::cout<<"At exit #2\n";} int main(){constint result_1= std::atexit(atexit_handler_1);constint result_2= std::atexit(atexit_handler_2); if(result_1|| result_2){std::cerr<<"Registration failed!\n";returnEXIT_FAILURE;} std::cout<<"Returning from main...\n";returnEXIT_SUCCESS;}
Output:
Returning from main...At exit #2At exit #1
| causes abnormal program termination (without cleaning up) (function)[edit] | |
| causes normal program termination with cleaning up (function)[edit] | |
(C++11) | causes quick program termination without completely cleaning up (function)[edit] |
(C++11) | registers a function to be called onstd::quick_exit invocation (function)[edit] |
C documentation foratexit | |
