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authorDimitry Andric <dim@FreeBSD.org>2019-08-20 18:01:57 +0000
committerDimitry Andric <dim@FreeBSD.org>2019-08-20 18:01:57 +0000
commit88c643b6fec27eec436c8d138fee6346e92337d6 (patch)
tree82cd13b2f3cde1c9e5f79689ba4e6ba67694843f /packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c
parent94994d372d014ce4c8758b9605d63fae651bd8aa (diff)
Notes
Diffstat (limited to 'packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c')
-rw-r--r--packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c80
1 files changed, 0 insertions, 80 deletions
diff --git a/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c b/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c
deleted file mode 100644
index fae9979611d5..000000000000
--- a/packages/Python/lldbsuite/test/functionalities/expr-doesnt-deadlock/locking.c
+++ /dev/null
@@ -1,80 +0,0 @@
-#include <pthread.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdio.h>
-
-pthread_mutex_t contended_mutex = PTHREAD_MUTEX_INITIALIZER;
-
-pthread_mutex_t control_mutex = PTHREAD_MUTEX_INITIALIZER;
-pthread_cond_t control_condition;
-
-pthread_mutex_t thread_started_mutex = PTHREAD_MUTEX_INITIALIZER;
-pthread_cond_t thread_started_condition;
-
-// This function runs in a thread. The locking dance is to make sure that
-// by the time the main thread reaches the pthread_join below, this thread
-// has for sure acquired the contended_mutex. So then the call_me_to_get_lock
-// function will block trying to get the mutex, and only succeed once it
-// signals this thread, then lets it run to wake up from the cond_wait and
-// release the mutex.
-
-void *
-lock_acquirer_1 (void *input)
-{
- pthread_mutex_lock (&contended_mutex);
-
- // Grab this mutex, that will ensure that the main thread
- // is in its cond_wait for it (since that's when it drops the mutex.
-
- pthread_mutex_lock (&thread_started_mutex);
- pthread_mutex_unlock(&thread_started_mutex);
-
- // Now signal the main thread that it can continue, we have the contended lock
- // so the call to call_me_to_get_lock won't make any progress till this
- // thread gets a chance to run.
-
- pthread_mutex_lock (&control_mutex);
-
- pthread_cond_signal (&thread_started_condition);
-
- pthread_cond_wait (&control_condition, &control_mutex);
-
- pthread_mutex_unlock (&contended_mutex);
- return NULL;
-}
-
-int
-call_me_to_get_lock ()
-{
- pthread_cond_signal (&control_condition);
- pthread_mutex_lock (&contended_mutex);
- return 567;
-}
-
-int main ()
-{
- pthread_t thread_1;
-
- pthread_cond_init (&control_condition, NULL);
- pthread_cond_init (&thread_started_condition, NULL);
-
- pthread_mutex_lock (&thread_started_mutex);
-
- pthread_create (&thread_1, NULL, lock_acquirer_1, NULL);
-
- pthread_cond_wait (&thread_started_condition, &thread_started_mutex);
-
- pthread_mutex_lock (&control_mutex);
- pthread_mutex_unlock (&control_mutex);
-
- // Break here. At this point the other thread will have the contended_mutex,
- // and be sitting in its cond_wait for the control condition. So there is
- // no way that our by-hand calling of call_me_to_get_lock will proceed
- // without running the first thread at least somewhat.
-
- call_me_to_get_lock();
- pthread_join (thread_1, NULL);
-
- return 0;
-
-}