/* * Copyright 2007 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* * include/k5-thread.h * * Copyright 2004,2005,2006 by the Massachusetts Institute of Technology. * All Rights Reserved. * * Export of this software from the United States of America may * require a specific license from the United States Government. * It is the responsibility of any person or organization contemplating * export to obtain such a license before exporting. * * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and * distribute this software and its documentation for any purpose and * without fee is hereby granted, provided that the above copyright * notice appear in all copies and that both that copyright notice and * this permission notice appear in supporting documentation, and that * the name of M.I.T. not be used in advertising or publicity pertaining * to distribution of the software without specific, written prior * permission. Furthermore if you modify this software you must label * your software as modified software and not distribute it in such a * fashion that it might be confused with the original M.I.T. software. * M.I.T. makes no representations about the suitability of * this software for any purpose. It is provided "as is" without express * or implied warranty. * * * Preliminary thread support. */ #ifndef K5_THREAD_H #define K5_THREAD_H #pragma ident "%Z%%M% %I% %E% SMI" #ifdef _KERNEL #include typedef kmutex_t k5_mutex_t; #define K5_MUTEX_PARTIAL_INITIALIZER {0} /* ARGSUSED */ static void k5_mutex_assert_locked(k5_mutex_t *m) { } static int k5_mutex_lock(k5_mutex_t *m) { mutex_enter(m); return (0); } static int k5_mutex_unlock(k5_mutex_t *m) { mutex_exit(m); return(0); } #else /* _KERNEL */ #include "autoconf.h" #ifndef KRB5_CALLCONV # define KRB5_CALLCONV #endif #ifndef KRB5_CALLCONV_C # define KRB5_CALLCONV_C #endif /* Interface (tentative): Mutex support: // Between these two, we should be able to do pure compile-time // and pure run-time initialization. // POSIX: partial initializer is PTHREAD_MUTEX_INITIALIZER, // finish does nothing // Windows: partial initializer is an invalid handle, // finish does the real initialization work // debug: partial initializer sets one magic value, // finish verifies and sets a new magic value for // lock/unlock to check k5_mutex_t foo_mutex = K5_MUTEX_PARTIAL_INITIALIZER; int k5_mutex_finish_init(k5_mutex_t *); // for dynamic allocation int k5_mutex_init(k5_mutex_t *); // Must work for both kinds of alloc, even if it means adding flags. int k5_mutex_destroy(k5_mutex_t *); // As before. int k5_mutex_lock(k5_mutex_t *); int k5_mutex_unlock(k5_mutex_t *); In each library, one new function to finish the static mutex init, and any other library-wide initialization that might be desired. On POSIX, this function would be called via the second support function (see below). On Windows, it would be called at library load time. These functions, or functions they calls, should be the only places that k5_mutex_finish_init gets called. A second function or macro called at various possible "first" entry points which either calls pthread_once on the first function (POSIX), or checks some flag set by the first function (Windows, debug support), and possibly returns an error. (In the non-threaded case, a simple flag can be used to avoid multiple invocations, and the mutexes don't need run-time initialization anyways.) A third function for library termination calls mutex_destroy on each mutex for the library. This function would be called automatically at library unload time. If it turns out to be needed at exit time for libraries that don't get unloaded, perhaps we should also use atexit(). Any static mutexes should be cleaned up with k5_mutex_destroy here. How does that second support function invoke the first support function only once? Through something modelled on pthread_once that I haven't written up yet. Probably: k5_once_t foo_once = K5_ONCE_INIT; k5_once(k5_once_t *, void (*)(void)); For POSIX: Map onto pthread_once facility. For non-threaded case: A simple flag. For Windows: Not needed; library init code takes care of it. XXX: A general k5_once mechanism isn't possible for Windows, without faking it through named mutexes or mutexes initialized at startup. I was only using it in one place outside these headers, so I'm dropping the general scheme. Eventually the existing uses in k5-thread.h and k5-platform.h will be converted to pthread_once or static variables. Thread-specific data: // TSD keys are limited in number in gssapi/krb5/com_err; enumerate // them all. This allows support code init to allocate the // necessary storage for pointers all at once, and avoids any // possible error in key creation. enum { ... } k5_key_t; // Register destructor function. Called in library init code. int k5_key_register(k5_key_t, void (*destructor)(void *)); // Returns NULL or data. void *k5_getspecific(k5_key_t); // Returns error if key out of bounds, or the pointer table can't // be allocated. A call to k5_key_register must have happened first. // This may trigger the calling of pthread_setspecific on POSIX. int k5_setspecific(k5_key_t, void *); // Called in library termination code. // Trashes data in all threads, calling the registered destructor // (but calling it from the current thread). int k5_key_delete(k5_key_t); For the non-threaded version, the support code will have a static array indexed by k5_key_t values, and get/setspecific simply access the array elements. The TSD destructor table is global state, protected by a mutex if threads are enabled. Debug support: Not much. Might check if k5_key_register has been called and abort if not. Any actual external symbols will use the krb5int_ prefix. The k5_ names will be simple macros or inline functions to rename the external symbols, or slightly more complex ones to expand the implementation inline (e.g., map to POSIX versions and/or debug code using __FILE__ and the like). More to be added, perhaps. */ #undef DEBUG_THREADS /* SUNW14resync XXX */ #undef DEBUG_THREADS_LOC /* SUNW14resync XXX */ #undef DEBUG_THREADS_SLOW /* debugging stuff that'll slow things down? */ #undef DEBUG_THREADS_STATS #ifndef _KERNEL #include #include #define ASSERT assert #endif /* For tracking locations, of (e.g.) last lock or unlock of mutex. */ #ifdef DEBUG_THREADS_LOC typedef struct { const char *filename; int lineno; } k5_debug_loc; #define K5_DEBUG_LOC_INIT { __FILE__, __LINE__ } #if __GNUC__ >= 2 #define K5_DEBUG_LOC (__extension__ (k5_debug_loc)K5_DEBUG_LOC_INIT) #else static inline k5_debug_loc k5_debug_make_loc(const char *file, short line) { k5_debug_loc l; l.filename = file; l.lineno = line; return l; } #define K5_DEBUG_LOC (k5_debug_make_loc(__FILE__,__LINE__)) #endif #else /* ! DEBUG_THREADS_LOC */ typedef char k5_debug_loc; #define K5_DEBUG_LOC_INIT 0 #define K5_DEBUG_LOC 0 #endif #define k5_debug_update_loc(L) ((L) = K5_DEBUG_LOC) /* Statistics gathering: Currently incomplete, don't try enabling it. Eventually: Report number of times locked, total and standard deviation of the time the lock was held, total and std dev time spent waiting for the lock. "Report" will probably mean "write a line to a file if a magic environment variable is set." */ #ifdef DEBUG_THREADS_STATS #if HAVE_TIME_H && (!defined(HAVE_SYS_TIME_H) || defined(TIME_WITH_SYS_TIME)) # include #endif #if HAVE_SYS_TIME_H # include #endif #ifdef HAVE_STDINT_H # include #endif /* for memset */ #include /* for uint64_t */ #include typedef uint64_t k5_debug_timediff_t; /* or long double */ typedef struct timeval k5_debug_time_t; static inline k5_debug_timediff_t timediff(k5_debug_time_t t2, k5_debug_time_t t1) { return (t2.tv_sec - t1.tv_sec) * 1000000 + (t2.tv_usec - t1.tv_usec); } struct k5_timediff_stats { k5_debug_timediff_t valmin, valmax, valsum, valsqsum; }; typedef struct { int count; k5_debug_time_t time_acquired, time_created; struct k5_timediff_stats lockwait, lockheld; } k5_debug_mutex_stats; #define k5_mutex_init_stats(S) \ (memset((S), 0, sizeof(struct k5_debug_mutex_stats)), 0) #define k5_mutex_finish_init_stats(S) (0) #define K5_MUTEX_STATS_INIT { 0, {0}, {0}, {0}, {0} } #else typedef char k5_debug_mutex_stats; #define k5_mutex_init_stats(S) (*(S) = 's', 0) #define k5_mutex_finish_init_stats(S) (0) #define K5_MUTEX_STATS_INIT 's' #endif /* Define the OS mutex bit. */ /* First, if we're not actually doing multiple threads, do we want the debug support or not? */ #ifdef DEBUG_THREADS enum k5_mutex_init_states { K5_MUTEX_DEBUG_PARTLY_INITIALIZED = 0x12, K5_MUTEX_DEBUG_INITIALIZED, K5_MUTEX_DEBUG_DESTROYED }; enum k5_mutex_flag_states { K5_MUTEX_DEBUG_UNLOCKED = 0x23, K5_MUTEX_DEBUG_LOCKED }; typedef struct { enum k5_mutex_init_states initialized; enum k5_mutex_flag_states locked; } k5_os_nothread_mutex; # define K5_OS_NOTHREAD_MUTEX_PARTIAL_INITIALIZER \ { K5_MUTEX_DEBUG_PARTLY_INITIALIZED, K5_MUTEX_DEBUG_UNLOCKED } # define k5_os_nothread_mutex_finish_init(M) \ (ASSERT((M)->initialized != K5_MUTEX_DEBUG_INITIALIZED), \ ASSERT((M)->initialized == K5_MUTEX_DEBUG_PARTLY_INITIALIZED), \ ASSERT((M)->locked == K5_MUTEX_DEBUG_UNLOCKED), \ (M)->initialized = K5_MUTEX_DEBUG_INITIALIZED, 0) # define k5_os_nothread_mutex_init(M) \ ((M)->initialized = K5_MUTEX_DEBUG_INITIALIZED, \ (M)->locked = K5_MUTEX_DEBUG_UNLOCKED, 0) # define k5_os_nothread_mutex_destroy(M) \ (ASSERT((M)->initialized == K5_MUTEX_DEBUG_INITIALIZED), \ (M)->initialized = K5_MUTEX_DEBUG_DESTROYED, 0) # define k5_os_nothread_mutex_lock(M) \ (k5_os_nothread_mutex_assert_unlocked(M), \ (M)->locked = K5_MUTEX_DEBUG_LOCKED, 0) # define k5_os_nothread_mutex_unlock(M) \ (k5_os_nothread_mutex_assert_locked(M), \ (M)->locked = K5_MUTEX_DEBUG_UNLOCKED, 0) # define k5_os_nothread_mutex_assert_locked(M) \ (ASSERT((M)->initialized == K5_MUTEX_DEBUG_INITIALIZED), \ ASSERT((M)->locked != K5_MUTEX_DEBUG_UNLOCKED), \ ASSERT((M)->locked == K5_MUTEX_DEBUG_LOCKED)) # define k5_os_nothread_mutex_assert_unlocked(M) \ (ASSERT((M)->initialized == K5_MUTEX_DEBUG_INITIALIZED), \ ASSERT((M)->locked != K5_MUTEX_DEBUG_LOCKED), \ ASSERT((M)->locked == K5_MUTEX_DEBUG_UNLOCKED)) #else /* threads disabled and not debugging */ typedef char k5_os_nothread_mutex; # define K5_OS_NOTHREAD_MUTEX_PARTIAL_INITIALIZER 0 /* Empty inline functions avoid the "statement with no effect" warnings, and do better type-checking than functions that don't use their arguments. */ /* SUNW 1.4resync, remove "inline" to avoid warning */ /* ARGSUSED */ /* LINTED */ static int k5_os_nothread_mutex_finish_init(k5_os_nothread_mutex *m) { return 0; } /* ARGSUSED */ /* LINTED */ static int k5_os_nothread_mutex_init(k5_os_nothread_mutex *m) { return 0; } /* ARGSUSED */ /* LINTED */ static int k5_os_nothread_mutex_destroy(k5_os_nothread_mutex *m) { return 0; } /* ARGSUSED */ /* LINTED */ static int k5_os_nothread_mutex_lock(k5_os_nothread_mutex *m) { return 0; } /* ARGSUSED */ /* LINTED */ static int k5_os_nothread_mutex_unlock(k5_os_nothread_mutex *m) { return 0; } # define k5_os_nothread_mutex_assert_locked(M) ((void)0) # define k5_os_nothread_mutex_assert_unlocked(M) ((void)0) #endif /* Values: 2 - function has not been run 3 - function has been run 4 - function is being run -- deadlock detected */ typedef unsigned char k5_os_nothread_once_t; # define K5_OS_NOTHREAD_ONCE_INIT 2 # define k5_os_nothread_once(O,F) \ (*(O) == 3 ? 0 \ : *(O) == 2 ? (*(O) = 4, (F)(), *(O) = 3, 0) \ : (ASSERT(*(O) != 4), ASSERT(*(O) == 2 || *(O) == 3), 0)) #ifndef ENABLE_THREADS typedef k5_os_nothread_mutex k5_os_mutex; # define K5_OS_MUTEX_PARTIAL_INITIALIZER \ K5_OS_NOTHREAD_MUTEX_PARTIAL_INITIALIZER # define k5_os_mutex_finish_init k5_os_nothread_mutex_finish_init # define k5_os_mutex_init k5_os_nothread_mutex_init # define k5_os_mutex_destroy k5_os_nothread_mutex_destroy # define k5_os_mutex_lock k5_os_nothread_mutex_lock # define k5_os_mutex_unlock k5_os_nothread_mutex_unlock # define k5_os_mutex_assert_locked k5_os_nothread_mutex_assert_locked # define k5_os_mutex_assert_unlocked k5_os_nothread_mutex_assert_unlocked # define k5_once_t k5_os_nothread_once_t # define K5_ONCE_INIT K5_OS_NOTHREAD_ONCE_INIT # define k5_once k5_os_nothread_once #elif HAVE_PTHREAD # include /* Weak reference support, etc. Linux: Stub mutex routines exist, but pthread_once does not. Solaris: In libc there's a pthread_once that doesn't seem to do anything. Bleah. But pthread_mutexattr_setrobust_np is defined only in libpthread. IRIX 6.5 stub pthread support in libc is really annoying. The pthread_mutex_lock function returns ENOSYS for a program not linked against -lpthread. No link-time failure, no weak symbols, etc. The C library doesn't provide pthread_once; we can use weak reference support for that. If weak references are not available, then for now, we assume that the pthread support routines will always be available -- either the real thing, or functional stubs that merely prohibit creating threads. If we find a platform with non-functional stubs and no weak references, we may have to resort to some hack like dlsym on the symbol tables of the current process. */ #ifdef HAVE_PRAGMA_WEAK_REF # pragma weak pthread_once # pragma weak pthread_mutex_lock # pragma weak pthread_mutex_unlock # pragma weak pthread_mutex_destroy # pragma weak pthread_mutex_init # pragma weak pthread_self # pragma weak pthread_equal # ifdef HAVE_PTHREAD_MUTEXATTR_SETROBUST_NP_IN_THREAD_LIB # pragma weak pthread_mutexattr_setrobust_np # endif # if !defined HAVE_PTHREAD_ONCE # define K5_PTHREADS_LOADED (&pthread_once != 0) # elif !defined HAVE_PTHREAD_MUTEXATTR_SETROBUST_NP \ && defined HAVE_PTHREAD_MUTEXATTR_SETROBUST_NP_IN_THREAD_LIB # define K5_PTHREADS_LOADED (&pthread_mutexattr_setrobust_np != 0) # else # define K5_PTHREADS_LOADED (1) # endif #else /* no pragma weak support */ # define K5_PTHREADS_LOADED (1) #endif #if defined(__mips) && defined(__sgi) && (defined(_SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4__)) /* IRIX 6.5 stub pthread support in libc is really annoying. The pthread_mutex_lock function returns ENOSYS for a program not linked against -lpthread. No link-time failure, no weak reference tests, etc. The C library doesn't provide pthread_once; we can use weak reference support for that. */ # ifndef HAVE_PRAGMA_WEAK_REF # if defined(__GNUC__) && __GNUC__ < 3 # error "Please update to a newer gcc with weak symbol support, or switch to native cc, reconfigure and recompile." # else # error "Weak reference support is required" # endif # endif # define USE_PTHREAD_LOCK_ONLY_IF_LOADED #endif #if !defined(HAVE_PTHREAD_MUTEX_LOCK) && !defined(USE_PTHREAD_LOCK_ONLY_IF_LOADED) # define USE_PTHREAD_LOCK_ONLY_IF_LOADED #endif #ifdef HAVE_PRAGMA_WEAK_REF /* Can't rely on useful stubs -- see above regarding Solaris. */ typedef struct { pthread_once_t o; k5_os_nothread_once_t n; } k5_once_t; # define K5_ONCE_INIT { PTHREAD_ONCE_INIT, K5_OS_NOTHREAD_ONCE_INIT } # define k5_once(O,F) (K5_PTHREADS_LOADED \ ? pthread_once(&(O)->o,F) \ : k5_os_nothread_once(&(O)->n,F)) #else typedef pthread_once_t k5_once_t; # define K5_ONCE_INIT PTHREAD_ONCE_INIT # define k5_once pthread_once #endif typedef struct { pthread_mutex_t p; #ifdef DEBUG_THREADS pthread_t owner; #endif #ifdef USE_PTHREAD_LOCK_ONLY_IF_LOADED k5_os_nothread_mutex n; #endif } k5_os_mutex; #ifdef DEBUG_THREADS # ifdef __GNUC__ # define k5_pthread_mutex_lock(M) \ ({ \ k5_os_mutex *_m2 = (M); \ int _r2 = pthread_mutex_lock(&_m2->p); \ if (_r2 == 0) _m2->owner = pthread_self(); \ _r2; \ }) # else static inline int k5_pthread_mutex_lock(k5_os_mutex *m) { int r = pthread_mutex_lock(&m->p); if (r) return r; m->owner = pthread_self(); return 0; } # endif # define k5_pthread_assert_locked(M) \ (K5_PTHREADS_LOADED \ ? ASSERT(pthread_equal((M)->owner, pthread_self())) \ : (void)0) # define k5_pthread_mutex_unlock(M) \ (k5_pthread_assert_locked(M), \ (M)->owner = (pthread_t) 0, \ pthread_mutex_unlock(&(M)->p)) #else # define k5_pthread_mutex_lock(M) pthread_mutex_lock(&(M)->p) /* LINTED */ static void k5_pthread_assert_locked(k5_os_mutex *m) { } # define k5_pthread_mutex_unlock(M) pthread_mutex_unlock(&(M)->p) #endif /* Define as functions to: (1) eliminate "statement with no effect" warnings for "0" (2) encourage type-checking in calling code */ /* LINTED */ static void k5_pthread_assert_unlocked(pthread_mutex_t *m) { } #if defined(DEBUG_THREADS_SLOW) && HAVE_SCHED_H && (HAVE_SCHED_YIELD || HAVE_PRAGMA_WEAK_REF) # include # if !HAVE_SCHED_YIELD # pragma weak sched_yield # define MAYBE_SCHED_YIELD() ((void)((&sched_yield != NULL) ? sched_yield() : 0)) # else # define MAYBE_SCHED_YIELD() ((void)sched_yield()) # endif #else # define MAYBE_SCHED_YIELD() ((void)0) #endif /* It may not be obvious why this function is desirable. I want to call pthread_mutex_lock, then sched_yield, then look at the return code from pthread_mutex_lock. That can't be implemented in a macro without a temporary variable, or GNU C extensions. There used to be an inline function which did it, with both functions called from the inline function. But that messes with the debug information on a lot of configurations, and you can't tell where the inline function was called from. (Typically, gdb gives you the name of the function from which the inline function was called, and a line number within the inline function itself.) With this auxiliary function, pthread_mutex_lock can be called at the invoking site via a macro; once it returns, the inline function is called (with messed-up line-number info for gdb hopefully localized to just that call). */ #ifdef __GNUC__ #define return_after_yield(R) \ __extension__ ({ \ int _r = (R); \ MAYBE_SCHED_YIELD(); \ _r; \ }) #else static int return_after_yield(int r) { MAYBE_SCHED_YIELD(); return r; } #endif #ifdef USE_PTHREAD_LOCK_ONLY_IF_LOADED # if defined(PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP) && defined(DEBUG_THREADS) # define K5_OS_MUTEX_PARTIAL_INITIALIZER \ { PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, (pthread_t) 0, \ K5_OS_NOTHREAD_MUTEX_PARTIAL_INITIALIZER } # elif defined(DEBUG_THREADS) # define K5_OS_MUTEX_PARTIAL_INITIALIZER \ { PTHREAD_MUTEX_INITIALIZER, (pthread_t) 0, \ K5_OS_NOTHREAD_MUTEX_PARTIAL_INITIALIZER } # else # define K5_OS_MUTEX_PARTIAL_INITIALIZER \ { PTHREAD_MUTEX_INITIALIZER, K5_OS_NOTHREAD_MUTEX_PARTIAL_INITIALIZER } # endif # define k5_os_mutex_finish_init(M) \ k5_os_nothread_mutex_finish_init(&(M)->n) # define k5_os_mutex_init(M) \ (k5_os_nothread_mutex_init(&(M)->n), \ (K5_PTHREADS_LOADED \ ? pthread_mutex_init(&(M)->p, 0) \ : 0)) # define k5_os_mutex_destroy(M) \ (k5_os_nothread_mutex_destroy(&(M)->n), \ (K5_PTHREADS_LOADED \ ? pthread_mutex_destroy(&(M)->p) \ : 0)) # define k5_os_mutex_lock(M) \ return_after_yield(K5_PTHREADS_LOADED \ ? k5_pthread_mutex_lock(M) \ : k5_os_nothread_mutex_lock(&(M)->n)) # define k5_os_mutex_unlock(M) \ (MAYBE_SCHED_YIELD(), \ (K5_PTHREADS_LOADED \ ? k5_pthread_mutex_unlock(M) \ : k5_os_nothread_mutex_unlock(&(M)->n))) # define k5_os_mutex_assert_unlocked(M) \ (K5_PTHREADS_LOADED \ ? k5_pthread_assert_unlocked(&(M)->p) \ : k5_os_nothread_mutex_assert_unlocked(&(M)->n)) # define k5_os_mutex_assert_locked(M) \ (K5_PTHREADS_LOADED \ ? k5_pthread_assert_locked(M) \ : k5_os_nothread_mutex_assert_locked(&(M)->n)) #else # ifdef DEBUG_THREADS # ifdef PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP # define K5_OS_MUTEX_PARTIAL_INITIALIZER \ { PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, (pthread_t) 0 } # else # define K5_OS_MUTEX_PARTIAL_INITIALIZER \ { PTHREAD_MUTEX_INITIALIZER, (pthread_t) 0 } # endif # else # define K5_OS_MUTEX_PARTIAL_INITIALIZER \ { PTHREAD_MUTEX_INITIALIZER } # endif /* LINTED */ static int k5_os_mutex_finish_init(k5_os_mutex *m) { return 0; } # define k5_os_mutex_init(M) pthread_mutex_init(&(M)->p, 0) # define k5_os_mutex_destroy(M) pthread_mutex_destroy(&(M)->p) # define k5_os_mutex_lock(M) return_after_yield(k5_pthread_mutex_lock(M)) # define k5_os_mutex_unlock(M) (MAYBE_SCHED_YIELD(),k5_pthread_mutex_unlock(M)) # define k5_os_mutex_assert_unlocked(M) k5_pthread_assert_unlocked(&(M)->p) # define k5_os_mutex_assert_locked(M) k5_pthread_assert_locked(M) #endif /* is pthreads always available? */ #elif defined _WIN32 typedef struct { HANDLE h; int is_locked; } k5_os_mutex; # define K5_OS_MUTEX_PARTIAL_INITIALIZER { INVALID_HANDLE_VALUE, 0 } # define k5_os_mutex_finish_init(M) \ (ASSERT((M)->h == INVALID_HANDLE_VALUE), \ ((M)->h = CreateMutex(NULL, FALSE, NULL)) ? 0 : GetLastError()) # define k5_os_mutex_init(M) \ ((M)->is_locked = 0, \ ((M)->h = CreateMutex(NULL, FALSE, NULL)) ? 0 : GetLastError()) # define k5_os_mutex_destroy(M) \ (CloseHandle((M)->h) ? ((M)->h = 0, 0) : GetLastError()) static inline int k5_os_mutex_lock(k5_os_mutex *m) { DWORD res; res = WaitForSingleObject(m->h, INFINITE); if (res == WAIT_FAILED) return GetLastError(); /* Eventually these should be turned into some reasonable error code. */ ASSERT(res != WAIT_TIMEOUT); ASSERT(res != WAIT_ABANDONED); ASSERT(res == WAIT_OBJECT_0); /* Avoid locking twice. */ ASSERT(m->is_locked == 0); m->is_locked = 1; return 0; } # define k5_os_mutex_unlock(M) \ (ASSERT((M)->is_locked == 1), \ (M)->is_locked = 0, \ ReleaseMutex((M)->h) ? 0 : GetLastError()) # define k5_os_mutex_assert_unlocked(M) ((void)0) # define k5_os_mutex_assert_locked(M) ((void)0) #else # error "Thread support enabled, but thread system unknown" #endif typedef struct { k5_debug_loc loc_last, loc_created; k5_os_mutex os; k5_debug_mutex_stats stats; } k5_mutex_t; #define K5_MUTEX_PARTIAL_INITIALIZER \ { K5_DEBUG_LOC_INIT, K5_DEBUG_LOC_INIT, \ K5_OS_MUTEX_PARTIAL_INITIALIZER, K5_MUTEX_STATS_INIT } /* LINTED */ static int k5_mutex_init_1(k5_mutex_t *m, k5_debug_loc l) { int err = k5_os_mutex_init(&m->os); if (err) return err; m->loc_created = m->loc_last = l; err = k5_mutex_init_stats(&m->stats); ASSERT(err == 0); return 0; } #define k5_mutex_init(M) k5_mutex_init_1((M), K5_DEBUG_LOC) /* LINTED */ static int k5_mutex_finish_init_1(k5_mutex_t *m, k5_debug_loc l) { int err = k5_os_mutex_finish_init(&m->os); if (err) return err; m->loc_created = m->loc_last = l; err = k5_mutex_finish_init_stats(&m->stats); ASSERT(err == 0); return 0; } #define k5_mutex_finish_init(M) k5_mutex_finish_init_1((M), K5_DEBUG_LOC) #define k5_mutex_destroy(M) \ (k5_os_mutex_assert_unlocked(&(M)->os), \ k5_mutex_lock(M), (M)->loc_last = K5_DEBUG_LOC, k5_mutex_unlock(M), \ k5_os_mutex_destroy(&(M)->os)) #ifdef __GNUC__ #define k5_mutex_lock(M) \ __extension__ ({ \ int _err = 0; \ k5_mutex_t *_m = (M); \ _err = k5_os_mutex_lock(&_m->os); \ if (_err == 0) _m->loc_last = K5_DEBUG_LOC; \ _err; \ }) #else /* LINTED */ static int k5_mutex_lock_1(k5_mutex_t *m, k5_debug_loc l) { int err = 0; err = k5_os_mutex_lock(&m->os); if (err) return err; m->loc_last = l; return err; } #define k5_mutex_lock(M) k5_mutex_lock_1(M, K5_DEBUG_LOC) #endif #define k5_mutex_unlock(M) \ (k5_mutex_assert_locked(M), \ (M)->loc_last = K5_DEBUG_LOC, \ k5_os_mutex_unlock(&(M)->os)) #define k5_mutex_assert_locked(M) k5_os_mutex_assert_locked(&(M)->os) #define k5_mutex_assert_unlocked(M) k5_os_mutex_assert_unlocked(&(M)->os) #define k5_assert_locked k5_mutex_assert_locked #define k5_assert_unlocked k5_mutex_assert_unlocked /* Thread-specific data; implemented in a support file, because we'll need to keep track of some global data for cleanup purposes. Note that the callback function type is such that the C library routine free() is a valid callback. */ typedef enum { K5_KEY_COM_ERR, K5_KEY_GSS_KRB5_SET_CCACHE_OLD_NAME, K5_KEY_GSS_KRB5_CCACHE_NAME, K5_KEY_MAX } k5_key_t; /* rename shorthand symbols for export */ #define k5_key_register krb5int_key_register #define k5_getspecific krb5int_getspecific #define k5_setspecific krb5int_setspecific #define k5_key_delete krb5int_key_delete extern int k5_key_register(k5_key_t, void (*)(void *)); extern void *k5_getspecific(k5_key_t); extern int k5_setspecific(k5_key_t, void *); extern int k5_key_delete(k5_key_t); extern int KRB5_CALLCONV krb5int_mutex_alloc (k5_mutex_t **); extern void KRB5_CALLCONV krb5int_mutex_free (k5_mutex_t *); extern int KRB5_CALLCONV krb5int_mutex_lock (k5_mutex_t *); extern int KRB5_CALLCONV krb5int_mutex_unlock (k5_mutex_t *); /* In time, many of the definitions above should move into the support library, and this file should be greatly simplified. For type definitions, that'll take some work, since other data structures incorporate mutexes directly, and our mutex type is dependent on configuration options and system attributes. For most functions, though, it should be relatively easy. For now, plugins should use the exported functions, and not the above macros, and use krb5int_mutex_alloc for allocations. */ #ifdef PLUGIN #undef k5_mutex_lock #define k5_mutex_lock krb5int_mutex_lock #undef k5_mutex_unlock #define k5_mutex_unlock krb5int_mutex_unlock #endif #endif /* _KERNEL */ #endif /* multiple inclusion? */