Changeset 1fa010c in mainline

Timestamp:

2010-10-19T20:12:14Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

12c38f5

Parents:

525df28

Message:

Implement simple deadlock detection for fibril mutexes.

The mechanism could be extended to rwlocks for the writer and first reader
cases. The current implementation will only build on ia32. In order to fix it,
we need a generic way to tell the frame pointer given fibril's ctx.

File:

• uspace/lib/c/generic/fibril_synch.c (modified) (3 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)
@@ -56 +58 @@
 }
 
+static bool check_for_deadlock(fibril_owner_info_t *oi)
+{
+        while (oi && oi->owned_by) {
+                if (oi->owned_by == (fibril_t *) fibril_get_id())
+                        return true;
+                oi = oi->owned_by->waits_for;
+        }
+
+        return false;
+}
+
+static void print_deadlock(fibril_owner_info_t *oi)
+{
+        fibril_t *f = (fibril_t *) fibril_get_id();
+
+        printf("Deadlock detected: ");
+
+        printf("Fibril %p waits for primitive %p.\n", f, oi);
+        stacktrace_print();
+
+        while (oi && oi->owned_by) {
+                printf(". ");
+                printf("Primitive %p is owned by fibril %p.\n",
+                    oi, oi->owned_by);
+                stacktrace_print_fp_pc(oi->owned_by->ctx.ebp,
+                    oi->owned_by->ctx.pc);
+                if (oi->owned_by == f)
+                        break;
+                printf("Fibril %p waits for primitive %p.\n",
+                     oi->owned_by, oi->owned_by->waits_for);
+                oi = oi->owned_by->waits_for;
+        }
+
+        abort();
+}
+
 void fibril_mutex_initialize(fibril_mutex_t *fm)
 {
@@ -77 +115 @@
                 list_append(&wdata.wu_event.link, &fm->waiters);
 
+                if (check_for_deadlock(&fm->oi))
+                        print_deadlock(&fm->oi);
                 f->waits_for = &fm->oi;