]> git.proxmox.com Git - mirror_zfs.git/blobdiff - lib/libzpool/kernel.c
Simplify threads, mutexs, cvs and rwlocks
[mirror_zfs.git] / lib / libzpool / kernel.c
index 3fc7337e8eca8b52937ee482bf43b85a5e3017b6..c4b600d03876f8b23c0dc595dff339d36b3fc97f 100644 (file)
@@ -64,104 +64,29 @@ struct proc p0;
  * =========================================================================
  * threads
  * =========================================================================
+ *
+ * TS_STACK_MIN is dictated by the minimum allowed pthread stack size.  While
+ * TS_STACK_MAX is somewhat arbitrary, it was selected to be large enough for
+ * the expected stack depth while small enough to avoid exhausting address
+ * space with high thread counts.
  */
+#define        TS_STACK_MIN    MAX(PTHREAD_STACK_MIN, 32768)
+#define        TS_STACK_MAX    (256 * 1024)
 
-pthread_cond_t kthread_cond = PTHREAD_COND_INITIALIZER;
-pthread_mutex_t kthread_lock = PTHREAD_MUTEX_INITIALIZER;
-pthread_key_t kthread_key;
-int kthread_nr = 0;
-
-static void
-thread_init(void)
-{
-       kthread_t *kt;
-
-       VERIFY3S(pthread_key_create(&kthread_key, NULL), ==, 0);
-
-       /* Create entry for primary kthread */
-       kt = umem_zalloc(sizeof (kthread_t), UMEM_NOFAIL);
-       kt->t_tid = pthread_self();
-       kt->t_func = NULL;
-
-       VERIFY3S(pthread_setspecific(kthread_key, kt), ==, 0);
-
-       /* Only the main thread should be running at the moment */
-       ASSERT3S(kthread_nr, ==, 0);
-       kthread_nr = 1;
-}
-
-static void
-thread_fini(void)
-{
-       kthread_t *kt = curthread;
-
-       ASSERT(pthread_equal(kt->t_tid, pthread_self()));
-       ASSERT3P(kt->t_func, ==, NULL);
-
-       umem_free(kt, sizeof (kthread_t));
-
-       /* Wait for all threads to exit via thread_exit() */
-       VERIFY3S(pthread_mutex_lock(&kthread_lock), ==, 0);
-
-       kthread_nr--; /* Main thread is exiting */
-
-       while (kthread_nr > 0)
-               VERIFY0(pthread_cond_wait(&kthread_cond, &kthread_lock));
-
-       ASSERT3S(kthread_nr, ==, 0);
-       VERIFY3S(pthread_mutex_unlock(&kthread_lock), ==, 0);
-
-       VERIFY3S(pthread_key_delete(kthread_key), ==, 0);
-}
-
-kthread_t *
-zk_thread_current(void)
-{
-       kthread_t *kt = pthread_getspecific(kthread_key);
-
-       ASSERT3P(kt, !=, NULL);
-
-       return (kt);
-}
-
-void *
-zk_thread_helper(void *arg)
-{
-       kthread_t *kt = (kthread_t *)arg;
-
-       VERIFY3S(pthread_setspecific(kthread_key, kt), ==, 0);
-
-       VERIFY3S(pthread_mutex_lock(&kthread_lock), ==, 0);
-       kthread_nr++;
-       VERIFY3S(pthread_mutex_unlock(&kthread_lock), ==, 0);
-       (void) setpriority(PRIO_PROCESS, 0, kt->t_pri);
-
-       kt->t_tid = pthread_self();
-       ((thread_func_arg_t)kt->t_func)(kt->t_arg);
-
-       /* Unreachable, thread must exit with thread_exit() */
-       abort();
-
-       return (NULL);
-}
-
+/*ARGSUSED*/
 kthread_t *
-zk_thread_create(caddr_t stk, size_t stksize, thread_func_t func, void *arg,
-    uint64_t len, proc_t *pp, int state, pri_t pri, int detachstate)
+zk_thread_create(void (*func)(void *), void *arg, size_t stksize, int state)
 {
-       kthread_t *kt;
        pthread_attr_t attr;
+       pthread_t tid;
        char *stkstr;
+       int detachstate = PTHREAD_CREATE_DETACHED;
 
-       ASSERT0(state & ~TS_RUN);
-       ASSERT0(len);
+       VERIFY0(pthread_attr_init(&attr));
 
-       kt = umem_zalloc(sizeof (kthread_t), UMEM_NOFAIL);
-       kt->t_func = func;
-       kt->t_arg = arg;
-       kt->t_pri = pri;
+       if (state & TS_JOINABLE)
+               detachstate = PTHREAD_CREATE_JOINABLE;
 
-       VERIFY0(pthread_attr_init(&attr));
        VERIFY0(pthread_attr_setdetachstate(&attr, detachstate));
 
        /*
@@ -183,6 +108,7 @@ zk_thread_create(caddr_t stk, size_t stksize, thread_func_t func, void *arg,
 
        VERIFY3S(stksize, >, 0);
        stksize = P2ROUNDUP(MAX(stksize, TS_STACK_MIN), PAGESIZE);
+
        /*
         * If this ever fails, it may be because the stack size is not a
         * multiple of system page size.
@@ -190,36 +116,10 @@ zk_thread_create(caddr_t stk, size_t stksize, thread_func_t func, void *arg,
        VERIFY0(pthread_attr_setstacksize(&attr, stksize));
        VERIFY0(pthread_attr_setguardsize(&attr, PAGESIZE));
 
-       VERIFY0(pthread_create(&kt->t_tid, &attr, &zk_thread_helper, kt));
+       VERIFY0(pthread_create(&tid, &attr, (void *(*)(void *))func, arg));
        VERIFY0(pthread_attr_destroy(&attr));
 
-       return (kt);
-}
-
-void
-zk_thread_exit(void)
-{
-       kthread_t *kt = curthread;
-
-       ASSERT(pthread_equal(kt->t_tid, pthread_self()));
-
-       umem_free(kt, sizeof (kthread_t));
-
-       VERIFY0(pthread_mutex_lock(&kthread_lock));
-       kthread_nr--;
-       VERIFY0(pthread_mutex_unlock(&kthread_lock));
-
-       VERIFY0(pthread_cond_broadcast(&kthread_cond));
-       pthread_exit((void *)TS_MAGIC);
-}
-
-void
-zk_thread_join(kt_did_t tid)
-{
-       void *ret;
-
-       pthread_join((pthread_t)tid, &ret);
-       VERIFY3P(ret, ==, (void *)TS_MAGIC);
+       return ((void *)(uintptr_t)tid);
 }
 
 /*
@@ -291,46 +191,34 @@ kstat_set_raw_ops(kstat_t *ksp,
 void
 mutex_init(kmutex_t *mp, char *name, int type, void *cookie)
 {
-       ASSERT3S(type, ==, MUTEX_DEFAULT);
-       ASSERT3P(cookie, ==, NULL);
-       mp->m_owner = MTX_INIT;
-       mp->m_magic = MTX_MAGIC;
-       VERIFY3S(pthread_mutex_init(&mp->m_lock, NULL), ==, 0);
+       VERIFY0(pthread_mutex_init(&mp->m_lock, NULL));
+       memset(&mp->m_owner, 0, sizeof (pthread_t));
 }
 
 void
 mutex_destroy(kmutex_t *mp)
 {
-       ASSERT3U(mp->m_magic, ==, MTX_MAGIC);
-       ASSERT3P(mp->m_owner, ==, MTX_INIT);
-       ASSERT0(pthread_mutex_destroy(&(mp)->m_lock));
-       mp->m_owner = MTX_DEST;
-       mp->m_magic = 0;
+       VERIFY0(pthread_mutex_destroy(&mp->m_lock));
 }
 
 void
 mutex_enter(kmutex_t *mp)
 {
-       ASSERT3U(mp->m_magic, ==, MTX_MAGIC);
-       ASSERT3P(mp->m_owner, !=, MTX_DEST);
-       ASSERT3P(mp->m_owner, !=, curthread);
-       VERIFY3S(pthread_mutex_lock(&mp->m_lock), ==, 0);
-       ASSERT3P(mp->m_owner, ==, MTX_INIT);
-       mp->m_owner = curthread;
+       VERIFY0(pthread_mutex_lock(&mp->m_lock));
+       mp->m_owner = pthread_self();
 }
 
 int
 mutex_tryenter(kmutex_t *mp)
 {
-       int err;
-       ASSERT3U(mp->m_magic, ==, MTX_MAGIC);
-       ASSERT3P(mp->m_owner, !=, MTX_DEST);
-       if (0 == (err = pthread_mutex_trylock(&mp->m_lock))) {
-               ASSERT3P(mp->m_owner, ==, MTX_INIT);
-               mp->m_owner = curthread;
+       int error;
+
+       error = pthread_mutex_trylock(&mp->m_lock);
+       if (error == 0) {
+               mp->m_owner = pthread_self();
                return (1);
        } else {
-               VERIFY3S(err, ==, EBUSY);
+               VERIFY3S(error, ==, EBUSY);
                return (0);
        }
 }
@@ -338,23 +226,8 @@ mutex_tryenter(kmutex_t *mp)
 void
 mutex_exit(kmutex_t *mp)
 {
-       ASSERT3U(mp->m_magic, ==, MTX_MAGIC);
-       ASSERT3P(mutex_owner(mp), ==, curthread);
-       mp->m_owner = MTX_INIT;
-       VERIFY3S(pthread_mutex_unlock(&mp->m_lock), ==, 0);
-}
-
-void *
-mutex_owner(kmutex_t *mp)
-{
-       ASSERT3U(mp->m_magic, ==, MTX_MAGIC);
-       return (mp->m_owner);
-}
-
-int
-mutex_held(kmutex_t *mp)
-{
-       return (mp->m_owner == curthread);
+       memset(&mp->m_owner, 0, sizeof (pthread_t));
+       VERIFY0(pthread_mutex_unlock(&mp->m_lock));
 }
 
 /*
@@ -366,89 +239,60 @@ mutex_held(kmutex_t *mp)
 void
 rw_init(krwlock_t *rwlp, char *name, int type, void *arg)
 {
-       ASSERT3S(type, ==, RW_DEFAULT);
-       ASSERT3P(arg, ==, NULL);
-       VERIFY3S(pthread_rwlock_init(&rwlp->rw_lock, NULL), ==, 0);
-       rwlp->rw_owner = RW_INIT;
-       rwlp->rw_wr_owner = RW_INIT;
+       VERIFY0(pthread_rwlock_init(&rwlp->rw_lock, NULL));
        rwlp->rw_readers = 0;
-       rwlp->rw_magic = RW_MAGIC;
+       rwlp->rw_owner = 0;
 }
 
 void
 rw_destroy(krwlock_t *rwlp)
 {
-       ASSERT3U(rwlp->rw_magic, ==, RW_MAGIC);
-       ASSERT(rwlp->rw_readers == 0 && rwlp->rw_wr_owner == RW_INIT);
-       VERIFY3S(pthread_rwlock_destroy(&rwlp->rw_lock), ==, 0);
-       rwlp->rw_magic = 0;
+       VERIFY0(pthread_rwlock_destroy(&rwlp->rw_lock));
 }
 
 void
 rw_enter(krwlock_t *rwlp, krw_t rw)
 {
-       ASSERT3U(rwlp->rw_magic, ==, RW_MAGIC);
-       ASSERT3P(rwlp->rw_owner, !=, curthread);
-       ASSERT3P(rwlp->rw_wr_owner, !=, curthread);
-
        if (rw == RW_READER) {
-               VERIFY3S(pthread_rwlock_rdlock(&rwlp->rw_lock), ==, 0);
-               ASSERT3P(rwlp->rw_wr_owner, ==, RW_INIT);
-
+               VERIFY0(pthread_rwlock_rdlock(&rwlp->rw_lock));
                atomic_inc_uint(&rwlp->rw_readers);
        } else {
-               VERIFY3S(pthread_rwlock_wrlock(&rwlp->rw_lock), ==, 0);
-               ASSERT3P(rwlp->rw_wr_owner, ==, RW_INIT);
-               ASSERT3U(rwlp->rw_readers, ==, 0);
-
-               rwlp->rw_wr_owner = curthread;
+               VERIFY0(pthread_rwlock_wrlock(&rwlp->rw_lock));
+               rwlp->rw_owner = pthread_self();
        }
-
-       rwlp->rw_owner = curthread;
 }
 
 void
 rw_exit(krwlock_t *rwlp)
 {
-       ASSERT3U(rwlp->rw_magic, ==, RW_MAGIC);
-       ASSERT(RW_LOCK_HELD(rwlp));
-
        if (RW_READ_HELD(rwlp))
                atomic_dec_uint(&rwlp->rw_readers);
        else
-               rwlp->rw_wr_owner = RW_INIT;
+               rwlp->rw_owner = 0;
 
-       rwlp->rw_owner = RW_INIT;
-       VERIFY3S(pthread_rwlock_unlock(&rwlp->rw_lock), ==, 0);
+       VERIFY0(pthread_rwlock_unlock(&rwlp->rw_lock));
 }
 
 int
 rw_tryenter(krwlock_t *rwlp, krw_t rw)
 {
-       int rv;
-
-       ASSERT3U(rwlp->rw_magic, ==, RW_MAGIC);
+       int error;
 
        if (rw == RW_READER)
-               rv = pthread_rwlock_tryrdlock(&rwlp->rw_lock);
+               error = pthread_rwlock_tryrdlock(&rwlp->rw_lock);
        else
-               rv = pthread_rwlock_trywrlock(&rwlp->rw_lock);
-
-       if (rv == 0) {
-               ASSERT3P(rwlp->rw_wr_owner, ==, RW_INIT);
+               error = pthread_rwlock_trywrlock(&rwlp->rw_lock);
 
+       if (error == 0) {
                if (rw == RW_READER)
                        atomic_inc_uint(&rwlp->rw_readers);
-               else {
-                       ASSERT3U(rwlp->rw_readers, ==, 0);
-                       rwlp->rw_wr_owner = curthread;
-               }
+               else
+                       rwlp->rw_owner = pthread_self();
 
-               rwlp->rw_owner = curthread;
                return (1);
        }
 
-       VERIFY3S(rv, ==, EBUSY);
+       VERIFY3S(error, ==, EBUSY);
 
        return (0);
 }
@@ -456,8 +300,6 @@ rw_tryenter(krwlock_t *rwlp, krw_t rw)
 int
 rw_tryupgrade(krwlock_t *rwlp)
 {
-       ASSERT3U(rwlp->rw_magic, ==, RW_MAGIC);
-
        return (0);
 }
 
@@ -470,27 +312,21 @@ rw_tryupgrade(krwlock_t *rwlp)
 void
 cv_init(kcondvar_t *cv, char *name, int type, void *arg)
 {
-       ASSERT3S(type, ==, CV_DEFAULT);
-       cv->cv_magic = CV_MAGIC;
-       VERIFY0(pthread_cond_init(&cv->cv, NULL));
+       VERIFY0(pthread_cond_init(cv, NULL));
 }
 
 void
 cv_destroy(kcondvar_t *cv)
 {
-       ASSERT3U(cv->cv_magic, ==, CV_MAGIC);
-       VERIFY0(pthread_cond_destroy(&cv->cv));
-       cv->cv_magic = 0;
+       VERIFY0(pthread_cond_destroy(cv));
 }
 
 void
 cv_wait(kcondvar_t *cv, kmutex_t *mp)
 {
-       ASSERT3U(cv->cv_magic, ==, CV_MAGIC);
-       ASSERT3P(mutex_owner(mp), ==, curthread);
-       mp->m_owner = MTX_INIT;
-       VERIFY0(pthread_cond_wait(&cv->cv, &mp->m_lock));
-       mp->m_owner = curthread;
+       memset(&mp->m_owner, 0, sizeof (pthread_t));
+       VERIFY0(pthread_cond_wait(cv, &mp->m_lock));
+       mp->m_owner = pthread_self();
 }
 
 clock_t
@@ -501,8 +337,6 @@ cv_timedwait(kcondvar_t *cv, kmutex_t *mp, clock_t abstime)
        timestruc_t ts;
        clock_t delta;
 
-       ASSERT3U(cv->cv_magic, ==, CV_MAGIC);
-
        delta = abstime - ddi_get_lbolt();
        if (delta <= 0)
                return (-1);
@@ -516,10 +350,9 @@ cv_timedwait(kcondvar_t *cv, kmutex_t *mp, clock_t abstime)
                ts.tv_nsec -= NANOSEC;
        }
 
-       ASSERT3P(mutex_owner(mp), ==, curthread);
-       mp->m_owner = MTX_INIT;
-       error = pthread_cond_timedwait(&cv->cv, &mp->m_lock, &ts);
-       mp->m_owner = curthread;
+       memset(&mp->m_owner, 0, sizeof (pthread_t));
+       error = pthread_cond_timedwait(cv, &mp->m_lock, &ts);
+       mp->m_owner = pthread_self();
 
        if (error == ETIMEDOUT)
                return (-1);
@@ -548,7 +381,7 @@ cv_timedwait_hires(kcondvar_t *cv, kmutex_t *mp, hrtime_t tim, hrtime_t res,
        if (delta <= 0)
                return (-1);
 
-       VERIFY(gettimeofday(&tv, NULL) == 0);
+       VERIFY0(gettimeofday(&tv, NULL));
 
        ts.tv_sec = tv.tv_sec + delta / NANOSEC;
        ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC + (delta % NANOSEC);
@@ -557,10 +390,9 @@ cv_timedwait_hires(kcondvar_t *cv, kmutex_t *mp, hrtime_t tim, hrtime_t res,
                ts.tv_nsec -= NANOSEC;
        }
 
-       ASSERT(mutex_owner(mp) == curthread);
-       mp->m_owner = MTX_INIT;
-       error = pthread_cond_timedwait(&cv->cv, &mp->m_lock, &ts);
-       mp->m_owner = curthread;
+       memset(&mp->m_owner, 0, sizeof (pthread_t));
+       error = pthread_cond_timedwait(cv, &mp->m_lock, &ts);
+       mp->m_owner = pthread_self();
 
        if (error == ETIMEDOUT)
                return (-1);
@@ -573,15 +405,13 @@ cv_timedwait_hires(kcondvar_t *cv, kmutex_t *mp, hrtime_t tim, hrtime_t res,
 void
 cv_signal(kcondvar_t *cv)
 {
-       ASSERT3U(cv->cv_magic, ==, CV_MAGIC);
-       VERIFY0(pthread_cond_signal(&cv->cv));
+       VERIFY0(pthread_cond_signal(cv));
 }
 
 void
 cv_broadcast(kcondvar_t *cv)
 {
-       ASSERT3U(cv->cv_magic, ==, CV_MAGIC);
-       VERIFY0(pthread_cond_broadcast(&cv->cv));
+       VERIFY0(pthread_cond_broadcast(cv));
 }
 
 /*
@@ -1188,7 +1018,6 @@ kernel_init(int mode)
 
        VERIFY0(uname(&hw_utsname));
 
-       thread_init();
        system_taskq_init();
        icp_init();
 
@@ -1207,7 +1036,6 @@ kernel_fini(void)
 
        icp_fini();
        system_taskq_fini();
-       thread_fini();
 
        random_fini();
 }