Changeset 1787e527 in mainline for uspace/lib/libc/generic/fibril_sync.c

Timestamp:

2009-11-16T21:22:54Z (14 years ago)

Author:

Lenka Trochtova <trochtova.lenka@…>

Branches:

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

Children:

5ebdf94

Parents:

fcbd1be (diff), 9c70ed6 (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:

merged with head (unstable)

File:

• uspace/lib/libc/generic/fibril_sync.c (modified) (8 diffs)

uspace/lib/libc/generic/fibril_sync.c

@@ -36 +36 @@
 #include <fibril.h>
 #include <async.h>
+#include <async_priv.h>
 #include <adt/list.h>
 #include <futex.h>
+#include <sys/time.h>
+#include <errno.h>
 #include <assert.h>
+
+static void optimize_execution_power(void)
+{
+        /*
+         * When waking up a worker fibril previously blocked in fibril
+         * synchronization, chances are that there is an idle manager fibril
+         * waiting for IPC, that could start executing the awakened worker
+         * fibril right away. We try to detect this and bring the manager
+         * fibril back to fruitful work.
+         */
+        if (atomic_get(&threads_in_ipc_wait) > 0)
+                ipc_poke();
+}
 
 void fibril_mutex_initialize(fibril_mutex_t *fm)
@@ -50 +66 @@
         futex_down(&async_futex);
         if (fm->counter-- <= 0) {
-                fibril_t *f = (fibril_t *) fibril_get_id();
-                list_append(&f->link, &fm->waiters);
+                awaiter_t wdata;
+
+                wdata.fid = fibril_get_id();
+                wdata.active = false;
+                wdata.wu_event.inlist = true;
+                link_initialize(&wdata.wu_event.link);
+                list_append(&wdata.wu_event.link, &fm->waiters);
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
@@ -77 +98 @@
         if (fm->counter++ < 0) {
                 link_t *tmp;
-                fibril_t *f;
+                awaiter_t *wdp;
         
                 assert(!list_empty(&fm->waiters));
                 tmp = fm->waiters.next;
-                f = list_get_instance(tmp, fibril_t, link);
-                list_remove(&f->link);
-                fibril_add_ready((fid_t) f);
+                wdp = list_get_instance(tmp, awaiter_t, wu_event.link);
+                wdp->active = true;
+                wdp->wu_event.inlist = false;
+                list_remove(&wdp->wu_event.link);
+                fibril_add_ready(wdp->fid);
+                optimize_execution_power();
         }
 }
@@ -106 +130 @@
         if (frw->writers) {
                 fibril_t *f = (fibril_t *) fibril_get_id();
+                awaiter_t wdata;
+
+                wdata.fid = (fid_t) f;
+                wdata.active = false;
+                wdata.wu_event.inlist = true;
+                link_initialize(&wdata.wu_event.link);
                 f->flags &= ~FIBRIL_WRITER;
-                list_append(&f->link, &frw->waiters);
+                list_append(&wdata.wu_event.link, &frw->waiters);
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
@@ -120 +150 @@
         if (frw->writers || frw->readers) {
                 fibril_t *f = (fibril_t *) fibril_get_id();
+                awaiter_t wdata;
+
+                wdata.fid = (fid_t) f;
+                wdata.active = false;
+                wdata.wu_event.inlist = true;
+                link_initialize(&wdata.wu_event.link);
                 f->flags |= FIBRIL_WRITER;
-                list_append(&f->link, &frw->waiters);
+                list_append(&wdata.wu_event.link, &frw->waiters);
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
@@ -144 +180 @@
         while (!list_empty(&frw->waiters)) {
                 link_t *tmp = frw->waiters.next;
-                fibril_t *f = list_get_instance(tmp, fibril_t, link);
+                awaiter_t *wdp;
+                fibril_t *f;
+                
+                wdp = list_get_instance(tmp, awaiter_t, wu_event.link);
+                f = (fibril_t *) wdp->fid;
                 
                 if (f->flags & FIBRIL_WRITER) {
                         if (frw->readers)
                                 break;
-                        list_remove(&f->link);
-                        fibril_add_ready((fid_t) f);
+                        wdp->active = true;
+                        wdp->wu_event.inlist = false;
+                        list_remove(&wdp->wu_event.link);
+                        fibril_add_ready(wdp->fid);
                         frw->writers++;
+                        optimize_execution_power();
                         break;
                 } else {
-                        list_remove(&f->link);
-                        fibril_add_ready((fid_t) f);
+                        wdp->active = true;
+                        wdp->wu_event.inlist = false;
+                        list_remove(&wdp->wu_event.link);
+                        fibril_add_ready(wdp->fid);
                         frw->readers++;
+                        optimize_execution_power();
                 }
         }
@@ -178 +224 @@
 }
 
-void fibril_condvar_wait(fibril_condvar_t *fcv, fibril_mutex_t *fm)
-{
-        fibril_t *f = (fibril_t *) fibril_get_id();
-
-        futex_down(&async_futex);
-        list_append(&f->link, &fcv->waiters);
+int
+fibril_condvar_wait_timeout(fibril_condvar_t *fcv, fibril_mutex_t *fm,
+    suseconds_t timeout)
+{
+        awaiter_t wdata;
+
+        if (timeout < 0)
+                return ETIMEOUT;
+
+        wdata.fid = fibril_get_id();
+        wdata.active = false;
+        
+        wdata.to_event.inlist = timeout > 0;
+        wdata.to_event.occurred = false;
+        link_initialize(&wdata.to_event.link);
+
+        wdata.wu_event.inlist = true;
+        link_initialize(&wdata.wu_event.link);
+
+        futex_down(&async_futex);
+        if (timeout) {
+                gettimeofday(&wdata.to_event.expires, NULL);
+                tv_add(&wdata.to_event.expires, timeout);
+                async_insert_timeout(&wdata);
+        }
+        list_append(&wdata.wu_event.link, &fcv->waiters);
         _fibril_mutex_unlock_unsafe(fm);
         fibril_switch(FIBRIL_TO_MANAGER);
         fibril_mutex_lock(fm);
+
+        /* async_futex not held after fibril_switch() */
+        futex_down(&async_futex);
+        if (wdata.to_event.inlist)
+                list_remove(&wdata.to_event.link);
+        if (wdata.wu_event.inlist)
+                list_remove(&wdata.wu_event.link);
+        futex_up(&async_futex);
+        
+        return wdata.to_event.occurred ? ETIMEOUT : EOK;
+}
+
+void fibril_condvar_wait(fibril_condvar_t *fcv, fibril_mutex_t *fm)
+{
+        int rc;
+
+        rc = fibril_condvar_wait_timeout(fcv, fm, 0);
+        assert(rc == EOK);
 }
 
@@ -192 +276 @@
 {
         link_t *tmp;
-        fibril_t *f;
+        awaiter_t *wdp;
 
         futex_down(&async_futex);
         while (!list_empty(&fcv->waiters)) {
                 tmp = fcv->waiters.next;
-                f = list_get_instance(tmp, fibril_t, link);
-                list_remove(&f->link);
-                fibril_add_ready((fid_t) f);
-                if (once)
-                        break;
+                wdp = list_get_instance(tmp, awaiter_t, wu_event.link);
+                list_remove(&wdp->wu_event.link);
+                wdp->wu_event.inlist = false;
+                if (!wdp->active) {
+                        wdp->active = true;
+                        fibril_add_ready(wdp->fid);
+                        optimize_execution_power();
+                        if (once)
+                                break;
+                }
         }
         futex_up(&async_futex);