47c2a22fd6
there's no sense in using a powerful lock in exit, because it will never be unlocked. a thread that arrives at exit while exit is already in progress just needs to hang forever. use the pause syscall for this because it's cheap and easy and universally available.
33 lines
693 B
C
33 lines
693 B
C
#include <stdlib.h>
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#include <unistd.h>
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#include <stdio.h>
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#include "libc.h"
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#include "atomic.h"
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#include "syscall.h"
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static void dummy()
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{
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}
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/* __towrite.c and atexit.c override these */
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weak_alias(dummy, __funcs_on_exit);
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weak_alias(dummy, __fflush_on_exit);
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void exit(int code)
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{
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static int lock;
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/* If more than one thread calls exit, hang until _Exit ends it all */
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while (a_swap(&lock, 1)) __syscall(SYS_pause);
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/* Only do atexit & stdio flush if they were actually used */
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__funcs_on_exit();
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__fflush_on_exit();
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/* Destructor s**t is kept separate from atexit to avoid bloat */
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if (libc.fini) libc.fini();
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if (libc.ldso_fini) libc.ldso_fini();
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_Exit(code);
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for(;;);
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}
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