Detecting and causing unsafe latent accesses to a resource in multi-threaded ...

FIRST THREAD
_ /501

(DETERMINE THAT A RESOURCE CAN HAVE MULTIPLE UNSYCHRONIZED ACCESSES I /503 RECEIVE A REQUEST FROM A FIRST THREAD TO ACCESS THE RESOURCE *6 SECOND I /505 THREAD 507 SUSPEND THE FIRST THREAD \ RECEIVE A REQUEST FROM A . . SECOND THREAD T0 ACCESS THE RESOURCE 509\ l / 51 1 - _ AWAKEN THE FIRST THREAD LOG FOR A USER THAT UNSYNCHRONIZEDACCESSES I TO THE RESOURCE WERE 513 I PERFORMED \

1 /515 ACCESS THE RESOURCE ACCESS THE RESOURCE

Y

FIG. 6

613 /1315 NO @ j SET THREAD ID TO NULL I YES

FIG. 7A

r
E

I /623

I CHECK SHARED FLAG I
625 _ /629
N0 SET SHARED FLAG
TO TRUE

YES I I /631

INITIALIZE svuc OBJECT SET

TO SYNC OBJECTS HELD BY

THE THREAD

FIG. 7B