diff options
Diffstat (limited to 'db2/mutex/uts4_cc.s')
| -rw-r--r-- | db2/mutex/uts4_cc.s | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/db2/mutex/uts4_cc.s b/db2/mutex/uts4_cc.s new file mode 100644 index 0000000000..ee5f4143bd --- /dev/null +++ b/db2/mutex/uts4_cc.s @@ -0,0 +1,21 @@ + / + / int uts_lock ( int *p, int i ); + / Update the lock word pointed to by p with the + / value i, using compare-and-swap. + / Returns 0 if update was successful. + / Returns 1 if update failed. + / + entry uts_lock + uts_lock: + using .,r15 + st r2,8(sp) / Save R2 + l r2,64+0(sp) / R2 -> word to update + slr r0, r0 / R0 = current lock value must be 0 + l r1,64+4(sp) / R1 = new lock value + cs r0,r1,0(r2) / Try the update ... + be x / ... Success. Return 0 + la r0,1 / ... Failure. Return 1 + x: / + l r2,8(sp) / Restore R2 + b 2(,r14) / Return to caller + drop r15 |