Changeset a879d73 in mainline

Timestamp:

2012-11-23T22:58:42Z (12 years ago)

Author:

Adam Hraska <adam.hraska+hos@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

d04e46e

Parents:

29b8138

Message:

urcu: Added sanity test of forceful rcu unlock upon fibril exit.

File:

• uspace/app/rcutest/rcutest.c (modified) (9 diffs)

uspace/app/rcutest/rcutest.c

@@ -74 +74 @@
 static bool basic_sanity_check(void);
 static bool dont_wait_for_new_reader(void);
-
+static bool wait_for_exiting_reader(void);
 
 static test_desc_t test_desc[] = {
@@ -104 +104 @@
                 .func = basic_sanity_check,
                 .name = "basic-sanity",
-                .desc = "Locks/unlocks and syncs in a single fibril, no contention.",
+                .desc = "Locks/unlocks and syncs in 1 fibril, no contention.",
         },
         {
@@ -118 +118 @@
                 .func = dont_wait_for_new_reader,
                 .name = "ignore-new-r",
-                .desc = "Syncs with preexisting reader but ignores new reader.",
+                .desc = "Syncs with preexisting reader; ignores new reader.",
+        },
+        {
+                .aggregate = false,
+                .type = T_SANITY,
+                .func = wait_for_exiting_reader,
+                .name = "dereg-unlocks",
+                .desc = "Lets deregister_fibril unlock the reader section.",
         },
         {
@@ -269 +276 @@
         bool synching;
         bool synched;
+        size_t failed;
 } one_reader_info_t;
 
@@ -278 +286 @@
         printf("lock{");
         rcu_read_lock();
+        rcu_read_lock();
         arg->entered_cs = true;
+        rcu_read_unlock();
 
         printf("r-sleep{");
@@ -286 +296 @@
         printf("}");
         
+        if (arg->synched) {
+                arg->failed = 1;
+                printf("Error: rcu_sync exited prematurely.\n");
+        }
+        
         arg->exited_cs = true;
         rcu_read_unlock();
@@ -318 +333 @@
         memory_barrier();
         
-        if (!info.exited_cs) {
+        if (!info.exited_cs || info.failed) {
                 printf("Error: rcu_sync() returned before the reader exited its CS.\n");
                 /* 
@@ -334 +349 @@
 /*--------------------------------------------------------------------*/
 
-#define WAIT_STEP_US  1000 * USECS_PER_MS
+#define WAIT_STEP_US  500 * USECS_PER_MS
 
 typedef struct two_reader_info {
@@ -496 +511 @@
 
 #undef WAIT_STEP_US
+
+/*--------------------------------------------------------------------*/
+#define WAIT_STEP_US  500 * USECS_PER_MS
+
+typedef struct exit_reader_info {
+        bool entered_cs;
+        bool exited_cs;
+        bool synching;
+        bool synched;
+} exit_reader_info_t;
+
+
+static int exiting_locked_reader(exit_reader_info_t *arg)
+{
+        rcu_register_fibril();
+        
+        printf("old-lock{");
+        rcu_read_lock();
+        rcu_read_lock();
+        rcu_read_lock();
+        arg->entered_cs = true;
+        
+        printf("wait-for-sync{");
+        /* Wait for rcu_sync() to start waiting for us. */
+        while (!arg->synching) {
+                async_usleep(WAIT_STEP_US);
+        }
+        printf(" }");
+        
+        rcu_read_unlock();
+        printf(" }");
+
+        arg->exited_cs = true;
+        /* Store exited_cs before unlocking reader section in deregister. */
+        memory_barrier();
+        
+        /* Deregister forcefully unlocks the reader section. */
+        rcu_deregister_fibril();
+        return 0;
+}
+
+
+static bool wait_for_exiting_reader(void)
+{
+        exit_reader_info_t info = { 0 };
+        
+        if (!create_fibril((fibril_func_t) exiting_locked_reader, &info))
+                return false;
+        
+        /* Waits for the preexisting_reader to enter its CS.*/
+        while (!info.entered_cs) {
+                async_usleep(WAIT_STEP_US);
+        }
+        
+        assert(!info.exited_cs);
+        
+        printf("sync[");
+        info.synching = true;
+        rcu_synchronize();
+        info.synched = true;
+        printf(" ]\n");
+        
+        /* Load info.exited_cs */
+        memory_barrier();
+        
+        if (!info.exited_cs) {
+                printf("Error: rcu_deregister_fibril did not unlock the CS.\n");
+                return false;
+        }       
+        
+        return true;
+}
+
+#undef WAIT_STEP_US
+
+
 /*--------------------------------------------------------------------*/
 /*--------------------------------------------------------------------*/