Changeset 96c30c8 in mainline for kernel/generic/src/ipc/sysipc.c

Timestamp:

2018-06-28T15:45:37Z (7 years ago)

Author:

Jiří Zárevúcky <jiri.zarevucky@…>

Branches:

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

Children:

331d024

Parents:

82453b29

git-author:

Jiří Zárevúcky <jiri.zarevucky@…> (2018-06-28 15:36:29)

git-committer:

Jiří Zárevúcky <jiri.zarevucky@…> (2018-06-28 15:45:37)

Message:

Turn ipc_poke() into a regular wakeup on the waitq.

With prior behavior of ignoring the poke when no thread is blocking,
a thread could go to sleep just after a poke meant for it and sleep
indefinitely despite there being work to do.

After the change, worst case scenario, thread enters ipc wait, exits
immediately due to a previous poke, finds no work to do and enters ipc wait
again (possibly repeating the spurious wakeup a few times).

File:

• kernel/generic/src/ipc/sysipc.c (modified) (1 diff)

kernel/generic/src/ipc/sysipc.c

@@ -856 +856 @@
 sys_errno_t sys_ipc_poke(void)
 {
-        waitq_unsleep(&TASK->answerbox.wq);
+        waitq_wakeup(&TASK->answerbox.wq, WAKEUP_FIRST);
         return EOK;
 }