/** * @file * * @ingroup rtems_bsd_rtems * * @brief TODO. */ /* * Copyright (c) 2009-2014 embedded brains GmbH. All rights reserved. * * embedded brains GmbH * Dornierstr. 4 * 82178 Puchheim * Germany * * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #ifndef INVARIANTS #define _sx_assert(sx, what, file, line) #endif static void assert_sx(struct lock_object *lock, int what); static void lock_sx(struct lock_object *lock, int how); #ifdef KDTRACE_HOOKS static int owner_sx(struct lock_object *lock, struct thread **owner); #endif static int unlock_sx(struct lock_object *lock); struct lock_class lock_class_sx = { .lc_name = "sx", .lc_flags = LC_SLEEPLOCK | LC_SLEEPABLE | LC_RECURSABLE | LC_UPGRADABLE, .lc_assert = assert_sx, #ifdef DDB .lc_ddb_show = db_show_sx, #endif .lc_lock = lock_sx, .lc_unlock = unlock_sx, #ifdef KDTRACE_HOOKS .lc_owner = owner_sx, #endif }; void assert_sx(struct lock_object *lock, int what) { sx_assert((struct sx *)lock, what); } void lock_sx(struct lock_object *lock, int how) { sx_xlock((struct sx *)lock); } int unlock_sx(struct lock_object *lock) { sx_xunlock((struct sx *)lock); return (0); } #ifdef KDTRACE_HOOKS int owner_sx(struct lock_object *lock, struct thread **owner) { struct sx *sx = (struct sx *)lock; uintptr_t x = sx->sx_lock; *owner = (struct thread *)SX_OWNER(x); return ((x & SX_LOCK_SHARED) != 0 ? (SX_SHARERS(x) != 0) : (*owner != NULL)); } #endif void sx_sysinit(void *arg) { struct sx_args *sargs = arg; sx_init(sargs->sa_sx, sargs->sa_desc); } void sx_init_flags(struct sx *sx, const char *description, int opts) { int flags; flags = LO_SLEEPABLE | LO_UPGRADABLE; if (opts & SX_RECURSE) flags |= LO_RECURSABLE; rtems_bsd_mutex_init(&sx->lock_object, &sx->mutex, &lock_class_sx, description, NULL, flags); } void sx_destroy(struct sx *sx) { rtems_bsd_mutex_destroy(&sx->lock_object, &sx->mutex); } int _sx_xlock(struct sx *sx, int opts, const char *file, int line) { rtems_bsd_mutex_lock(&sx->lock_object, &sx->mutex); return (0); } int _sx_try_xlock(struct sx *sx, const char *file, int line) { return (rtems_bsd_mutex_trylock(&sx->lock_object, &sx->mutex)); } void _sx_xunlock(struct sx *sx, const char *file, int line) { rtems_bsd_mutex_unlock(&sx->mutex); } int _sx_try_upgrade(struct sx *sx, const char *file, int line) { return (1); } void _sx_downgrade(struct sx *sx, const char *file, int line) { /* Do nothing */ } #ifdef INVARIANT_SUPPORT #ifndef INVARIANTS #undef _sx_assert #endif /* * In the non-WITNESS case, sx_assert() can only detect that at least * *some* thread owns an slock, but it cannot guarantee that *this* * thread owns an slock. */ void _sx_assert(struct sx *sx, int what, const char *file, int line) { #ifndef WITNESS int slocked = 0; #endif if (panicstr != NULL) return; switch (what) { case SA_SLOCKED: case SA_SLOCKED | SA_NOTRECURSED: case SA_SLOCKED | SA_RECURSED: #ifndef WITNESS slocked = 1; /* FALLTHROUGH */ #endif case SA_LOCKED: case SA_LOCKED | SA_NOTRECURSED: case SA_LOCKED | SA_RECURSED: #ifdef WITNESS witness_assert(&sx->lock_object, what, file, line); #else /* * If some other thread has an exclusive lock or we * have one and are asserting a shared lock, fail. * Also, if no one has a lock at all, fail. */ if (sx->sx_lock == SX_LOCK_UNLOCKED || (!(sx->sx_lock & SX_LOCK_SHARED) && (slocked || sx_xholder(sx) != curthread))) panic("Lock %s not %slocked @ %s:%d\n", sx->lock_object.lo_name, slocked ? "share " : "", file, line); if (!(sx->sx_lock & SX_LOCK_SHARED)) { if (sx_recursed(sx)) { if (what & SA_NOTRECURSED) panic("Lock %s recursed @ %s:%d\n", sx->lock_object.lo_name, file, line); } else if (what & SA_RECURSED) panic("Lock %s not recursed @ %s:%d\n", sx->lock_object.lo_name, file, line); } #endif break; case SA_XLOCKED: case SA_XLOCKED | SA_NOTRECURSED: case SA_XLOCKED | SA_RECURSED: if (sx_xholder(sx) != curthread) panic("Lock %s not exclusively locked @ %s:%d\n", sx->lock_object.lo_name, file, line); if (sx_recursed(sx)) { if (what & SA_NOTRECURSED) panic("Lock %s recursed @ %s:%d\n", sx->lock_object.lo_name, file, line); } else if (what & SA_RECURSED) panic("Lock %s not recursed @ %s:%d\n", sx->lock_object.lo_name, file, line); break; case SA_UNLOCKED: #ifdef WITNESS witness_assert(&sx->lock_object, what, file, line); #else /* * If we hold an exclusve lock fail. We can't * reliably check to see if we hold a shared lock or * not. */ if (sx_xholder(sx) == curthread) panic("Lock %s exclusively locked @ %s:%d\n", sx->lock_object.lo_name, file, line); #endif break; default: panic("Unknown sx lock assertion: %d @ %s:%d", what, file, line); } } #endif /* INVARIANT_SUPPORT */ int sx_xlocked(struct sx *sx) { return (rtems_bsd_mutex_owned(&sx->mutex)); }