/* $OpenBSD: thread_private.h,v 1.28 2016/09/01 10:41:02 otto Exp $ */ /* PUBLIC DOMAIN: No Rights Reserved. Marco S Hyman */ #ifndef _THREAD_PRIVATE_H_ #define _THREAD_PRIVATE_H_ #include /* for FILE and __isthreaded */ #define _MALLOC_MUTEXES 4 void _malloc_init(int); /* * The callbacks needed by libc to handle the threaded case. * NOTE: Bump the version when you change the struct contents! * * tc_canceled: * If not NULL, what to do when canceled (otherwise _exit(0)) * * tc_flockfile, tc_ftrylockfile, and tc_funlockfile: * If not NULL, these implement the flockfile() family. * XXX In theory, you should be able to lock a FILE before * XXX loading libpthread and have that be a real lock on it, * XXX but that doesn't work without the libc base version * XXX tracking the recursion count. * * tc_malloc_lock and tc_malloc_unlock: * tc_atexit_lock and tc_atexit_unlock: * tc_atfork_lock and tc_atfork_unlock: * tc_arc4_lock and tc_arc4_unlock: * The locks used by the malloc, atexit, atfork, and arc4 subsystems. * These have to be ordered specially in the fork/vfork wrappers * and may be implemented differently than the general mutexes * in the callbacks below. * * tc_mutex_lock and tc_mutex_unlock: * Lock and unlock the given mutex. If the given mutex is NULL * a mutex is allocated and initialized automatically. * * tc_mutex_destroy: * Destroy/deallocate the given mutex. * * tc_tag_lock and tc_tag_unlock: * Lock and unlock the mutex associated with the given tag. * If the given tag is NULL a tag is allocated and initialized * automatically. * * tc_tag_storage: * Returns a pointer to per-thread instance of data associated * with the given tag. If the given tag is NULL a tag is * allocated and initialized automatically. * * tc_fork, tc_vfork: * If not NULL, they are called instead of the syscall stub, so that * the thread library can do necessary locking and reinitialization. * * * If doesn't define TCB_GET(), then locating the TCB in a * threaded process requires a syscall (__get_tcb(2)) which is too much * overhead for single-threaded processes. For those archs, there are two * additional callbacks, though they are placed first in the struct for * convenience in ASM: * * tc_errnoptr: * Returns the address of the thread's errno. * * tc_tcb: * Returns the address of the thread's TCB. */ struct thread_callbacks { int *(*tc_errnoptr)(void); /* MUST BE FIRST */ void *(*tc_tcb)(void); __dead void (*tc_canceled)(void); void (*tc_flockfile)(FILE *); int (*tc_ftrylockfile)(FILE *); void (*tc_funlockfile)(FILE *); void (*tc_malloc_lock)(int); void (*tc_malloc_unlock)(int); void (*tc_atexit_lock)(void); void (*tc_atexit_unlock)(void); void (*tc_atfork_lock)(void); void (*tc_atfork_unlock)(void); void (*tc_arc4_lock)(void); void (*tc_arc4_unlock)(void); void (*tc_mutex_lock)(void **); void (*tc_mutex_unlock)(void **); void (*tc_mutex_destroy)(void **); void (*tc_tag_lock)(void **); void (*tc_tag_unlock)(void **); void *(*tc_tag_storage)(void **, void *, size_t, void *); __pid_t (*tc_fork)(void); __pid_t (*tc_vfork)(void); }; __BEGIN_PUBLIC_DECLS /* * Set the callbacks used by libc */ void _thread_set_callbacks(const struct thread_callbacks *_cb, size_t _len); __END_PUBLIC_DECLS #ifdef __LIBC__ __BEGIN_HIDDEN_DECLS /* the current set */ extern struct thread_callbacks _thread_cb; __END_HIDDEN_DECLS #endif /* __LIBC__ */ /* * helper macro to make unique names in the thread namespace */ #define __THREAD_NAME(name) __CONCAT(_thread_tagname_,name) /* * Resolver code is special cased in that it uses global keys. */ extern void *__THREAD_NAME(_res); extern void *__THREAD_NAME(_res_ext); extern void *__THREAD_NAME(serv_mutex); /* * Macros used in libc to access thread mutex, keys, and per thread storage. * _THREAD_PRIVATE_KEY and _THREAD_PRIVATE_MUTEX are different macros for * historical reasons. They do the same thing, define a static variable * keyed by 'name' that identifies a mutex and a key to identify per thread * data. */ #define _THREAD_PRIVATE_KEY(name) \ static void *__THREAD_NAME(name) #define _THREAD_PRIVATE_MUTEX(name) \ static void *__THREAD_NAME(name) #ifndef __LIBC__ /* building some sort of reach around */ #define _THREAD_PRIVATE_MUTEX_LOCK(name) do {} while (0) #define _THREAD_PRIVATE_MUTEX_UNLOCK(name) do {} while (0) #define _THREAD_PRIVATE(keyname, storage, error) &(storage) #define _MUTEX_LOCK(mutex) do {} while (0) #define _MUTEX_UNLOCK(mutex) do {} while (0) #define _MUTEX_DESTROY(mutex) do {} while (0) #define _MALLOC_LOCK(n) do {} while (0) #define _MALLOC_UNLOCK(n) do {} while (0) #define _ATEXIT_LOCK() do {} while (0) #define _ATEXIT_UNLOCK() do {} while (0) #define _ATFORK_LOCK() do {} while (0) #define _ATFORK_UNLOCK() do {} while (0) #define _ARC4_LOCK() do {} while (0) #define _ARC4_UNLOCK() do {} while (0) #else /* building libc */ #define _THREAD_PRIVATE_MUTEX_LOCK(name) \ do { \ if (_thread_cb.tc_tag_lock != NULL) \ _thread_cb.tc_tag_lock(&(__THREAD_NAME(name))); \ } while (0) #define _THREAD_PRIVATE_MUTEX_UNLOCK(name) \ do { \ if (_thread_cb.tc_tag_unlock != NULL) \ _thread_cb.tc_tag_unlock(&(__THREAD_NAME(name))); \ } while (0) #define _THREAD_PRIVATE(keyname, storage, error) \ (_thread_cb.tc_tag_storage == NULL ? &(storage) : \ _thread_cb.tc_tag_storage(&(__THREAD_NAME(keyname)), \ &(storage), sizeof(storage), error)) /* * Macros used in libc to access mutexes. */ #define _MUTEX_LOCK(mutex) \ do { \ if (__isthreaded) \ _thread_cb.tc_mutex_lock(mutex); \ } while (0) #define _MUTEX_UNLOCK(mutex) \ do { \ if (__isthreaded) \ _thread_cb.tc_mutex_unlock(mutex); \ } while (0) #define _MUTEX_DESTROY(mutex) \ do { \ if (__isthreaded) \ _thread_cb.tc_mutex_destroy(mutex); \ } while (0) /* * malloc lock/unlock prototypes and definitions */ #define _MALLOC_LOCK(n) \ do { \ if (__isthreaded) \ _thread_cb.tc_malloc_lock(n); \ } while (0) #define _MALLOC_UNLOCK(n) \ do { \ if (__isthreaded) \ _thread_cb.tc_malloc_unlock(n); \ } while (0) #define _ATEXIT_LOCK() \ do { \ if (__isthreaded) \ _thread_cb.tc_atexit_lock(); \ } while (0) #define _ATEXIT_UNLOCK() \ do { \ if (__isthreaded) \ _thread_cb.tc_atexit_unlock(); \ } while (0) #define _ATFORK_LOCK() \ do { \ if (__isthreaded) \ _thread_cb.tc_atfork_lock(); \ } while (0) #define _ATFORK_UNLOCK() \ do { \ if (__isthreaded) \ _thread_cb.tc_atfork_unlock(); \ } while (0) #define _ARC4_LOCK() \ do { \ if (__isthreaded) \ _thread_cb.tc_arc4_lock(); \ } while (0) #define _ARC4_UNLOCK() \ do { \ if (__isthreaded) \ _thread_cb.tc_arc4_unlock(); \ } while (0) #endif /* __LIBC__ */ #endif /* _THREAD_PRIVATE_H_ */