Changes in uspace/lib/c/generic/fibril_synch.c [9414abc:63f8966] in mainline

File:

• uspace/lib/c/generic/fibril_synch.c (modified) (17 diffs)

uspace/lib/c/generic/fibril_synch.c

@@ -42 +42 @@
 #include <errno.h>
 #include <assert.h>
-#include <stacktrace.h>
-#include <stdlib.h>
 
 static void optimize_execution_power(void)
@@ -58 +56 @@
 }
 
-static void print_deadlock(fibril_owner_info_t *oi)
-{
-        fibril_t *f = (fibril_t *) fibril_get_id();
-
-        printf("Deadlock detected.\n");
-        stacktrace_print();
-
-        printf("Fibril %p waits for primitive %p.\n", f, oi);
-
-        while (oi && oi->owned_by) {
-                printf("Primitive %p is owned by fibril %p.\n",
-                    oi, oi->owned_by);
-                if (oi->owned_by == f)
-                        break;
-                stacktrace_print_fp_pc(context_get_fp(&oi->owned_by->ctx),
-                    oi->owned_by->ctx.pc);
-                printf("Fibril %p waits for primitive %p.\n",
-                     oi->owned_by, oi->owned_by->waits_for);
-                oi = oi->owned_by->waits_for;
-        }
-}
-
-
-static void check_for_deadlock(fibril_owner_info_t *oi)
-{
-        while (oi && oi->owned_by) {
-                if (oi->owned_by == (fibril_t *) fibril_get_id()) {
-                        print_deadlock(oi);
-                        abort();
-                }
-                oi = oi->owned_by->waits_for;
-        }
-}
-
-
 void fibril_mutex_initialize(fibril_mutex_t *fm)
 {
-        fm->oi.owned_by = NULL;
         fm->counter = 1;
         list_initialize(&fm->waiters);
@@ -102 +64 @@
 void fibril_mutex_lock(fibril_mutex_t *fm)
 {
-        fibril_t *f = (fibril_t *) fibril_get_id();
-
         futex_down(&async_futex);
         if (fm->counter-- <= 0) {
@@ -113 +73 @@
                 link_initialize(&wdata.wu_event.link);
                 list_append(&wdata.wu_event.link, &fm->waiters);
-                check_for_deadlock(&fm->oi);
-                f->waits_for = &fm->oi;
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
-                fm->oi.owned_by = f;
                 futex_up(&async_futex);
         }
@@ -129 +86 @@
         if (fm->counter > 0) {
                 fm->counter--;
-                fm->oi.owned_by = (fibril_t *) fibril_get_id();
                 locked = true;
         }
@@ -143 +99 @@
                 link_t *tmp;
                 awaiter_t *wdp;
-                fibril_t *f;
         
                 assert(!list_empty(&fm->waiters));
@@ -150 +105 @@
                 wdp->active = true;
                 wdp->wu_event.inlist = false;
-
-                f = (fibril_t *) wdp->fid;
-                fm->oi.owned_by = f;
-                f->waits_for = NULL;
-
                 list_remove(&wdp->wu_event.link);
                 fibril_add_ready(wdp->fid);
                 optimize_execution_power();
-        } else {
-                fm->oi.owned_by = NULL;
         }
 }
@@ -172 +120 @@
 void fibril_rwlock_initialize(fibril_rwlock_t *frw)
 {
-        frw->oi.owned_by = NULL;
         frw->writers = 0;
         frw->readers = 0;
@@ -180 +127 @@
 void fibril_rwlock_read_lock(fibril_rwlock_t *frw)
 {
-        fibril_t *f = (fibril_t *) fibril_get_id();
-        
         futex_down(&async_futex);
         if (frw->writers) {
+                fibril_t *f = (fibril_t *) fibril_get_id();
                 awaiter_t wdata;
 
@@ -192 +138 @@
                 f->flags &= ~FIBRIL_WRITER;
                 list_append(&wdata.wu_event.link, &frw->waiters);
-                check_for_deadlock(&frw->oi);
-                f->waits_for = &frw->oi;
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
-                /* Consider the first reader the owner. */
-                if (frw->readers++ == 0)
-                        frw->oi.owned_by = f;
+                frw->readers++;
                 futex_up(&async_futex);
         }
@@ -205 +147 @@
 void fibril_rwlock_write_lock(fibril_rwlock_t *frw)
 {
-        fibril_t *f = (fibril_t *) fibril_get_id();
-        
         futex_down(&async_futex);
         if (frw->writers || frw->readers) {
+                fibril_t *f = (fibril_t *) fibril_get_id();
                 awaiter_t wdata;
 
@@ -217 +158 @@
                 f->flags |= FIBRIL_WRITER;
                 list_append(&wdata.wu_event.link, &frw->waiters);
-                check_for_deadlock(&frw->oi);
-                f->waits_for = &frw->oi;
                 fibril_switch(FIBRIL_TO_MANAGER);
         } else {
-                frw->oi.owned_by = f;
                 frw->writers++;
                 futex_up(&async_futex);
@@ -232 +170 @@
         assert(frw->readers || (frw->writers == 1));
         if (frw->readers) {
-                if (--frw->readers) {
-                        if (frw->oi.owned_by == (fibril_t *) fibril_get_id()) {
-                                /*
-                                 * If this reader firbril was considered the
-                                 * owner of this rwlock, clear the ownership
-                                 * information even if there are still more
-                                 * readers.
-                                 *
-                                 * This is the limitation of the detection
-                                 * mechanism rooted in the fact that tracking
-                                 * all readers would require dynamically
-                                 * allocated memory for keeping linkage info.
-                                 */
-                                frw->oi.owned_by = NULL;
-                        }
+                if (--frw->readers)
                         goto out;
-                }
         } else {
                 frw->writers--;
@@ -254 +177 @@
         
         assert(!frw->readers && !frw->writers);
-        
-        frw->oi.owned_by = NULL;
         
         while (!list_empty(&frw->waiters)) {
@@ -264 +185 @@
                 wdp = list_get_instance(tmp, awaiter_t, wu_event.link);
                 f = (fibril_t *) wdp->fid;
-                
-                f->waits_for = NULL;
                 
                 if (f->flags & FIBRIL_WRITER) {
@@ -275 +194 @@
                         fibril_add_ready(wdp->fid);
                         frw->writers++;
-                        frw->oi.owned_by = f;
                         optimize_execution_power();
                         break;
@@ -283 +201 @@
                         list_remove(&wdp->wu_event.link);
                         fibril_add_ready(wdp->fid);
-                        if (frw->readers++ == 0) {
-                                /* Consider the first reader the owner. */
-                                frw->oi.owned_by = f;
-                        }
+                        frw->readers++;
                         optimize_execution_power();
                 }