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    /* $OpenBSD: rthread_libc.c,v 1.2 2017/09/05 02:40:54 guenther Exp $ */  | 
    
    
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    /* PUBLIC DOMAIN: No Rights Reserved. Marco S Hyman <marc@snafu.org> */  | 
    
    
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    #include <pthread.h>  | 
    
    
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    #include <stdlib.h>  | 
    
    
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    #include <string.h>  | 
    
    
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    #include "rthread.h"  | 
    
    
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    #include "rthread_cb.h"  | 
    
    
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    /*  | 
    
    
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     * A thread tag is a pointer to a structure of this type.  An opaque  | 
    
    
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     * tag is used to decouple libc from the thread library.  | 
    
    
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     */  | 
    
    
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    struct _thread_tag { | 
    
    
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    	pthread_mutex_t	m;	/* the tag's mutex */  | 
    
    
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    	pthread_key_t	k;	/* a key for private data */  | 
    
    
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    };  | 
    
    
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    /*  | 
    
    
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     * local mutex to protect against tag creation races.  | 
    
    
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     */  | 
    
    
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    static pthread_mutex_t	_thread_tag_mutex = PTHREAD_MUTEX_INITIALIZER;  | 
    
    
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    /*  | 
    
    
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     * Initialize a thread tag structure once.   This function is called  | 
    
    
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     * if the tag is null.  Allocation and initialization are controlled  | 
    
    
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     * by a mutex.   If the tag is not null when the mutex is obtained  | 
    
    
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     * the caller lost a race -- some other thread initialized the tag.  | 
    
    
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     * This function will never return NULL.  | 
    
    
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     */  | 
    
    
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    static void  | 
    
    
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    _thread_tag_init(void **tag)  | 
    
    
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    { | 
    
    
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    	struct _thread_tag *tt;  | 
    
    
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    	int result;  | 
    
    
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    	result = pthread_mutex_lock(&_thread_tag_mutex);  | 
    
    
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    	if (result == 0) { | 
    
    
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    		if (*tag == NULL) { | 
    
    
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    			tt = malloc(sizeof *tt);  | 
    
    
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    			if (tt != NULL) { | 
    
    
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    				result = pthread_mutex_init(&tt->m, NULL);  | 
    
    
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    				result |= pthread_key_create(&tt->k, free);  | 
    
    
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    				*tag = tt;  | 
    
    
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    			}  | 
    
    
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    		}  | 
    
    
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    		result |= pthread_mutex_unlock(&_thread_tag_mutex);  | 
    
    
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    	}  | 
    
    
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    	if (result != 0)  | 
    
    
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    		_rthread_debug(1, "tag init failure");  | 
    
    
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    }  | 
    
    
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    /*  | 
    
    
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     * lock the mutex associated with the given tag  | 
    
    
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     */  | 
    
    
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    void  | 
    
    
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    _thread_tag_lock(void **tag)  | 
    
    
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    { | 
    
    
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    	struct _thread_tag *tt;  | 
    
    
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    	if (__isthreaded) { | 
    
    
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    		if (*tag == NULL)  | 
    
    
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    			_thread_tag_init(tag);  | 
    
    
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    		tt = *tag;  | 
    
    
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    		if (pthread_mutex_lock(&tt->m) != 0)  | 
    
    
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    			_rthread_debug(1, "tag mutex lock failure");  | 
    
    
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    	}  | 
    
    
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    }  | 
    
    
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    /*  | 
    
    
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     * unlock the mutex associated with the given tag  | 
    
    
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     */  | 
    
    
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    void  | 
    
    
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    _thread_tag_unlock(void **tag)  | 
    
    
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    { | 
    
    
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    	struct _thread_tag *tt;  | 
    
    
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    	if (__isthreaded) { | 
    
    
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    		if (*tag == NULL)  | 
    
    
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    			_thread_tag_init(tag);  | 
    
    
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    		tt = *tag;  | 
    
    
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    		if (pthread_mutex_unlock(&tt->m) != 0)  | 
    
    
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    			_rthread_debug(1, "tag mutex unlock failure");  | 
    
    
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    	}  | 
    
    
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    }  | 
    
    
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    /*  | 
    
    
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     * return the thread specific data for the given tag.   If there  | 
    
    
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     * is no data for this thread initialize it from 'storage'.  | 
    
    
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     * On any error return 'err'.  | 
    
    
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     */  | 
    
    
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    void *  | 
    
    
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    _thread_tag_storage(void **tag, void *storage, size_t sz, void *err)  | 
    
    
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    { | 
    
    
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    	struct _thread_tag *tt;  | 
    
    
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    	void *ret;  | 
    
    
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    	if (*tag == NULL)  | 
    
    
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    		_thread_tag_init(tag);  | 
    
    
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    	tt = *tag;  | 
    
    
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    	ret = pthread_getspecific(tt->k);  | 
    
    
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    	if (ret == NULL) { | 
    
    
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    		ret = malloc(sz);  | 
    
    
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    		if (ret == NULL)  | 
    
    
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    			ret = err;  | 
    
    
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    		else { | 
    
    
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    			if (pthread_setspecific(tt->k, ret) == 0)  | 
    
    
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    				memcpy(ret, storage, sz);  | 
    
    
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    			else { | 
    
    
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    				free(ret);  | 
    
    
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    				ret = err;  | 
    
    
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    			}  | 
    
    
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    		}  | 
    
    
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    	}  | 
    
    
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    	return ret;  | 
    
    
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    }  | 
    
    
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    void  | 
    
    
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    _thread_mutex_lock(void **mutex)  | 
    
    
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    { | 
    
    
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    	pthread_mutex_t	*pmutex = (pthread_mutex_t *)mutex;  | 
    
    
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    	if (pthread_mutex_lock(pmutex) != 0)  | 
    
    
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    		_rthread_debug(1, "mutex lock failure");  | 
    
    
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    }  | 
    
    
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    void  | 
    
    
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    _thread_mutex_unlock(void **mutex)  | 
    
    
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    { | 
    
    
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    	pthread_mutex_t	*pmutex = (pthread_mutex_t *)mutex;  | 
    
    
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    	if (pthread_mutex_unlock(pmutex) != 0)  | 
    
    
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    		_rthread_debug(1, "mutex unlock failure");  | 
    
    
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    }  | 
    
    
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    void  | 
    
    
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    _thread_mutex_destroy(void **mutex)  | 
    
    
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    { | 
    
    
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    	pthread_mutex_t	*pmutex = (pthread_mutex_t *)mutex;  | 
    
    
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    	if (pthread_mutex_destroy(pmutex) != 0)  | 
    
    
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    		_rthread_debug(1, "mutex destroy failure");  | 
    
    
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    }  | 
    
    
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    /*  | 
    
    
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     * the malloc lock  | 
    
    
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     */  | 
    
    
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    #ifndef FUTEX  | 
    
    
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    #define MALLOC_LOCK_INITIALIZER(n) { \ | 
    
    
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    	_SPINLOCK_UNLOCKED,	\  | 
    
    
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    	TAILQ_HEAD_INITIALIZER(malloc_lock[n].lockers), \  | 
    
    
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    	PTHREAD_MUTEX_DEFAULT,	\  | 
    
    
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    	NULL,			\  | 
    
    
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    	0,			\  | 
    
    
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    	-1 }  | 
    
    
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    #else  | 
    
    
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    #define MALLOC_LOCK_INITIALIZER(n) { \ | 
    
    
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    	_SPINLOCK_UNLOCKED,	\  | 
    
    
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    	PTHREAD_MUTEX_DEFAULT,	\  | 
    
    
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    	NULL,			\  | 
    
    
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    	0,			\  | 
    
    
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    	-1 }  | 
    
    
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    #endif  | 
    
    
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    static struct pthread_mutex malloc_lock[_MALLOC_MUTEXES] = { | 
    
    
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    	MALLOC_LOCK_INITIALIZER(0),  | 
    
    
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    	MALLOC_LOCK_INITIALIZER(1),  | 
    
    
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    	MALLOC_LOCK_INITIALIZER(2),  | 
    
    
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    	MALLOC_LOCK_INITIALIZER(3)  | 
    
    
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    };  | 
    
    
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    static pthread_mutex_t malloc_mutex[_MALLOC_MUTEXES] = { | 
    
    
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    	&malloc_lock[0],  | 
    
    
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    	&malloc_lock[1],  | 
    
    
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    	&malloc_lock[2],  | 
    
    
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    	&malloc_lock[3]  | 
    
    
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    };  | 
    
    
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    void  | 
    
    
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    _thread_malloc_lock(int i)  | 
    
    
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    { | 
    
    
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    	pthread_mutex_lock(&malloc_mutex[i]);  | 
    
    
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    }  | 
    
    
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    void  | 
    
    
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    _thread_malloc_unlock(int i)  | 
    
    
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    { | 
    
    
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    	pthread_mutex_unlock(&malloc_mutex[i]);  | 
    
    
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    }  | 
    
    
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    static void  | 
    
    
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    _thread_malloc_reinit(void)  | 
    
    
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    { | 
    
    
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    	int i;  | 
    
    
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    	for (i = 0; i < _MALLOC_MUTEXES; i++) { | 
    
    
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    		malloc_lock[i].lock = _SPINLOCK_UNLOCKED;  | 
    
    
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    #ifndef FUTEX  | 
    
    
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    		TAILQ_INIT(&malloc_lock[i].lockers);  | 
    
    
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    #endif  | 
    
    
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    		malloc_lock[i].owner = NULL;  | 
    
    
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    		malloc_lock[i].count = 0;  | 
    
    
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    	}  | 
    
    
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    }  | 
    
    
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    /*  | 
    
    
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     * atexit lock  | 
    
    
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     */  | 
    
    
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    static _atomic_lock_t atexit_lock = _SPINLOCK_UNLOCKED;  | 
    
    
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    void  | 
    
    
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    _thread_atexit_lock(void)  | 
    
    
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    { | 
    
    
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    	_spinlock(&atexit_lock);  | 
    
    
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    }  | 
    
    
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    void  | 
    
    
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    _thread_atexit_unlock(void)  | 
    
    
    222  | 
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    { | 
    
    
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    	_spinunlock(&atexit_lock);  | 
    
    
    224  | 
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    }  | 
    
    
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    226  | 
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    /*  | 
    
    
    227  | 
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     * atfork lock  | 
    
    
    228  | 
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     */  | 
    
    
    229  | 
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    static _atomic_lock_t atfork_lock = _SPINLOCK_UNLOCKED;  | 
    
    
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    231  | 
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    void  | 
    
    
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    _thread_atfork_lock(void)  | 
    
    
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    { | 
    
    
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    	_spinlock(&atfork_lock);  | 
    
    
    235  | 
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    }  | 
    
    
    236  | 
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    237  | 
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    void  | 
    
    
    238  | 
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    _thread_atfork_unlock(void)  | 
    
    
    239  | 
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    { | 
    
    
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    	_spinunlock(&atfork_lock);  | 
    
    
    241  | 
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    }  | 
    
    
    242  | 
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    243  | 
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    /*  | 
    
    
    244  | 
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     * arc4random lock  | 
    
    
    245  | 
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     */  | 
    
    
    246  | 
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    static _atomic_lock_t arc4_lock = _SPINLOCK_UNLOCKED;  | 
    
    
    247  | 
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    248  | 
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    void  | 
    
    
    249  | 
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    _thread_arc4_lock(void)  | 
    
    
    250  | 
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    { | 
    
    
    251  | 
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    	_spinlock(&arc4_lock);  | 
    
    
    252  | 
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    }  | 
    
    
    253  | 
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    254  | 
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    void  | 
    
    
    255  | 
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    _thread_arc4_unlock(void)  | 
    
    
    256  | 
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    { | 
    
    
    257  | 
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    	_spinunlock(&arc4_lock);  | 
    
    
    258  | 
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    }  | 
    
    
    259  | 
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    260  | 
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    pid_t  | 
    
    
    261  | 
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    _thread_dofork(pid_t (*sys_fork)(void))  | 
    
    
    262  | 
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    { | 
    
    
    263  | 
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    	int i;  | 
    
    
    264  | 
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    	pid_t newid;  | 
    
    
    265  | 
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    266  | 
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    	_thread_atexit_lock();  | 
    
    
    267  | 
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    	for (i = 0; i < _MALLOC_MUTEXES; i++)  | 
    
    
    268  | 
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    		_thread_malloc_lock(i);  | 
    
    
    269  | 
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    	_thread_arc4_lock();  | 
    
    
    270  | 
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    271  | 
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    	newid = sys_fork();  | 
    
    
    272  | 
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    273  | 
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    	_thread_arc4_unlock();  | 
    
    
    274  | 
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    	if (newid == 0)  | 
    
    
    275  | 
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    		_thread_malloc_reinit();  | 
    
    
    276  | 
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    	else  | 
    
    
    277  | 
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    		for (i = 0; i < _MALLOC_MUTEXES; i++)  | 
    
    
    278  | 
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     | 
    			_thread_malloc_unlock(i);  | 
    
    
    279  | 
     | 
     | 
    	_thread_atexit_unlock();  | 
    
    
    280  | 
     | 
     | 
     | 
    
    
    281  | 
     | 
     | 
    	return newid;  | 
    
    
    282  | 
     | 
     | 
    }  | 
    
    
    283  | 
     | 
     | 
     |