Changeset 235d31d in mainline for uspace/lib/c/generic/fibril.c

Timestamp:

2014-12-22T17:47:40Z (9 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

8c7d5ad

Parents:

eae91e0 (diff), 759ea0d (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge the CHT pre-integration branch

This branch contains:

• the merge of lp:~adam-hraska+lp/helenos/rcu, which brings:

• a new preemptible kernel RCU variant called A-RCU,
• a preemptible variant of Podzimek's non-preemptible kernel RCU and
• a new variant of usersace RCU,
• a new concurrent hash table (CHT) implementation based on RCU,
• a deployment of CHT in kernel futex handling,
• a deployment of the userspace RCU in the implementation of upgradable futexes,

all described in Adam Hraska's master thesis named Read-Copy-Update
for HelenOS, defended in 2013 at MFF UK; furthemore, the branch
fixes two synchronization bugs in condvars and waitq, respectively:

• revid:adam.hraska+hos@gmail.com-20121116144921-3to9u1tn1sg07rg7
• revid:adam.hraska+hos@gmail.com-20121116173623-km7gwtqixwudpe66

• build fixes required to pass make check
• overhaul of ia64 and sparc64 trap handling, to allow exc_dispatch() to be used now when the kernel is more picky about CPU state accounting
• an important fix of the sparc64/sun4v preemptible trap handler
• various other fixes of issues discovered on non-x86 architectures

File:

• uspace/lib/c/generic/fibril.c (modified) (11 diffs)

uspace/lib/c/generic/fibril.c

@@ -49 +49 @@
 #include <assert.h>
 #include <async.h>
+#include <futex.h>
+
+#ifdef FUTEX_UPGRADABLE
+#include <rcu.h>
+#endif
 
 /**
@@ -54 +59 @@
  * serialized_list and manager_list.
  */
-static atomic_t fibril_futex = FUTEX_INITIALIZER;
+static futex_t fibril_futex = FUTEX_INITIALIZER;
 
 static LIST_INITIALIZE(ready_list);
@@ -83 +88 @@
 {
         fibril_t *fibril = __tcb_get()->fibril_data;
+
+#ifdef FUTEX_UPGRADABLE
+        rcu_register_fibril();
+#endif
         
         /* Call the implementing function. */
@@ -146 +155 @@
         int retval = 0;
         
-        futex_down(&fibril_futex);
+        futex_lock(&fibril_futex);
         
         if (stype == FIBRIL_PREEMPT && list_empty(&ready_list))
@@ -168 +177 @@
         if ((stype == FIBRIL_TO_MANAGER) || (stype == FIBRIL_FROM_DEAD)) {
                 while (list_empty(&manager_list)) {
-                        futex_up(&fibril_futex);
+                        futex_unlock(&fibril_futex);
                         async_create_manager();
-                        futex_down(&fibril_futex);
+                        futex_lock(&fibril_futex);
                 }
         }
@@ -203 +212 @@
                         }
                         
-                        return 1;       /* futex_up already done here */
+                        return 1;       /* futex_unlock already done here */
                 }
                 
@@ -246 +255 @@
         list_remove(&dstf->link);
         
-        futex_up(&fibril_futex);
+        futex_unlock(&fibril_futex);
+        
+#ifdef FUTEX_UPGRADABLE
+        if (stype == FIBRIL_FROM_DEAD) {
+                rcu_deregister_fibril();
+        }
+#endif
+        
         context_restore(&dstf->ctx);
         /* not reached */
         
 ret_0:
-        futex_up(&fibril_futex);
+        futex_unlock(&fibril_futex);
         return retval;
 }
@@ -318 +334 @@
         fibril_t *fibril = (fibril_t *) fid;
         
-        futex_down(&fibril_futex);
+        futex_lock(&fibril_futex);
         
         if ((fibril->flags & FIBRIL_SERIALIZED))
@@ -325 +341 @@
                 list_append(&fibril->link, &ready_list);
         
-        futex_up(&fibril_futex);
+        futex_unlock(&fibril_futex);
 }
 
@@ -338 +354 @@
         fibril_t *fibril = (fibril_t *) fid;
         
-        futex_down(&fibril_futex);
+        futex_lock(&fibril_futex);
         list_append(&fibril->link, &manager_list);
-        futex_up(&fibril_futex);
+        futex_unlock(&fibril_futex);
 }
 
@@ -346 +362 @@
 void fibril_remove_manager(void)
 {
-        futex_down(&fibril_futex);
+        futex_lock(&fibril_futex);
         
         if (!list_empty(&manager_list))
                 list_remove(list_first(&manager_list));
         
-        futex_up(&fibril_futex);
+        futex_unlock(&fibril_futex);
 }