Changes in uspace/lib/c/generic/rcu.c [ab6edb6:1433ecda] in mainline

File:

• uspace/lib/c/generic/rcu.c (modified) (14 diffs)

uspace/lib/c/generic/rcu.c

@@ -82 +82 @@
 #include <thread.h>
 
-#include "private/fibril.h"
-
 
 /** RCU sleeps for RCU_SLEEP_MS before polling an active RCU reader again. */
@@ -150 +148 @@
 
 
-static void wait_for_readers(size_t reader_group);
+static void wait_for_readers(size_t reader_group, blocking_mode_t blocking_mode);
 static void force_mb_in_all_threads(void);
 static bool is_preexisting_reader(const fibril_rcu_data_t *fib, size_t group);
 
-static void lock_sync(void);
+static void lock_sync(blocking_mode_t blocking_mode);
 static void unlock_sync(void);
-static void sync_sleep(void);
+static void sync_sleep(blocking_mode_t blocking_mode);
 
 static bool is_in_group(size_t nesting_cnt, size_t group);
@@ -172 +170 @@
         assert(!fibril_rcu.registered);
 
-        futex_lock(&rcu.list_futex);
+        futex_down(&rcu.list_futex);
         list_append(&fibril_rcu.link, &rcu.fibrils_list);
-        futex_unlock(&rcu.list_futex);
+        futex_up(&rcu.list_futex);
 
         fibril_rcu.registered = true;
@@ -197 +195 @@
         fibril_rcu.nesting_cnt = 0;
 
-        futex_lock(&rcu.list_futex);
+        futex_down(&rcu.list_futex);
         list_remove(&fibril_rcu.link);
-        futex_unlock(&rcu.list_futex);
+        futex_up(&rcu.list_futex);
 
         fibril_rcu.registered = false;
@@ -242 +240 @@
 
 /** Blocks until all preexisting readers exit their critical sections. */
-void rcu_synchronize(void)
+void _rcu_synchronize(blocking_mode_t blocking_mode)
 {
         assert(!rcu_read_locked());
@@ -252 +250 @@
         size_t gp_in_progress = ACCESS_ONCE(rcu.cur_gp);
 
-        lock_sync();
+        lock_sync(blocking_mode);
 
         /*
@@ -300 +298 @@
 
         size_t new_reader_group = get_other_group(rcu.reader_group);
-        wait_for_readers(new_reader_group);
+        wait_for_readers(new_reader_group, blocking_mode);
 
         /* Separates waiting for readers in new_reader_group from group flip. */
@@ -312 +310 @@
         memory_barrier();
 
-        wait_for_readers(old_reader_group);
+        wait_for_readers(old_reader_group, blocking_mode);
 
         /* MB_FORCE_U  */
@@ -332 +330 @@
 
 /** Waits for readers of reader_group to exit their readers sections. */
-static void wait_for_readers(size_t reader_group)
-{
-        futex_lock(&rcu.list_futex);
+static void wait_for_readers(size_t reader_group, blocking_mode_t blocking_mode)
+{
+        futex_down(&rcu.list_futex);
 
         list_t quiescent_fibrils;
@@ -345 +343 @@
 
                         if (is_preexisting_reader(fib, reader_group)) {
-                                futex_unlock(&rcu.list_futex);
-                                sync_sleep();
-                                futex_lock(&rcu.list_futex);
+                                futex_up(&rcu.list_futex);
+                                sync_sleep(blocking_mode);
+                                futex_down(&rcu.list_futex);
                                 /* Break to while loop. */
                                 break;
@@ -358 +356 @@
 
         list_concat(&rcu.fibrils_list, &quiescent_fibrils);
-        futex_unlock(&rcu.list_futex);
-}
-
-static void lock_sync(void)
-{
-        futex_lock(&rcu.sync_lock.futex);
+        futex_up(&rcu.list_futex);
+}
+
+static void lock_sync(blocking_mode_t blocking_mode)
+{
+        futex_down(&rcu.sync_lock.futex);
         if (rcu.sync_lock.locked) {
-                blocked_fibril_t blocked_fib;
-                blocked_fib.id = fibril_get_id();
-
-                list_append(&blocked_fib.link, &rcu.sync_lock.blocked_fibrils);
-
-                do {
-                        blocked_fib.is_ready = false;
-                        futex_unlock(&rcu.sync_lock.futex);
-                        futex_lock(&async_futex);
-                        fibril_switch(FIBRIL_FROM_BLOCKED);
-                        futex_unlock(&async_futex);
-                        futex_lock(&rcu.sync_lock.futex);
-                } while (rcu.sync_lock.locked);
-
-                list_remove(&blocked_fib.link);
-                rcu.sync_lock.locked = true;
+                if (blocking_mode == BM_BLOCK_FIBRIL) {
+                        blocked_fibril_t blocked_fib;
+                        blocked_fib.id = fibril_get_id();
+
+                        list_append(&blocked_fib.link, &rcu.sync_lock.blocked_fibrils);
+
+                        do {
+                                blocked_fib.is_ready = false;
+                                futex_up(&rcu.sync_lock.futex);
+                                fibril_switch(FIBRIL_TO_MANAGER);
+                                futex_down(&rcu.sync_lock.futex);
+                        } while (rcu.sync_lock.locked);
+
+                        list_remove(&blocked_fib.link);
+                        rcu.sync_lock.locked = true;
+                } else {
+                        assert(blocking_mode == BM_BLOCK_THREAD);
+                        rcu.sync_lock.blocked_thread_cnt++;
+                        futex_up(&rcu.sync_lock.futex);
+                        futex_down(&rcu.sync_lock.futex_blocking_threads);
+                }
         } else {
                 rcu.sync_lock.locked = true;
@@ -396 +399 @@
         if (0 < rcu.sync_lock.blocked_thread_cnt) {
                 --rcu.sync_lock.blocked_thread_cnt;
-                futex_unlock(&rcu.sync_lock.futex_blocking_threads);
+                futex_up(&rcu.sync_lock.futex_blocking_threads);
         } else {
                 /* Unlock but wake up any fibrils waiting for the lock. */
@@ -411 +414 @@
 
                 rcu.sync_lock.locked = false;
-                futex_unlock(&rcu.sync_lock.futex);
-        }
-}
-
-static void sync_sleep(void)
+                futex_up(&rcu.sync_lock.futex);
+        }
+}
+
+static void sync_sleep(blocking_mode_t blocking_mode)
 {
         assert(rcu.sync_lock.locked);
@@ -422 +425 @@
          * but keep sync locked.
          */
-        futex_unlock(&rcu.sync_lock.futex);
-        async_usleep(RCU_SLEEP_MS * 1000);
-        futex_lock(&rcu.sync_lock.futex);
+        futex_up(&rcu.sync_lock.futex);
+
+        if (blocking_mode == BM_BLOCK_FIBRIL) {
+                async_usleep(RCU_SLEEP_MS * 1000);
+        } else {
+                thread_usleep(RCU_SLEEP_MS * 1000);
+        }
+
+        futex_down(&rcu.sync_lock.futex);
 }