Add synchronization to TestWatchLocation.

[chaoren]

Summary

There was no guarantee that the three threads haven't already exited by the
time the watchpoint is set.

[ovyalov]

Please see my comments.

test/functionalities/watchpoint/hello_watchlocation/main.cpp

20 ↗

(On Diff #20786)

Please follow the existing naming convention here - g_barrier ?

85 ↗

(On Diff #20786)

My understanding the watchpoint is set for g_char_ptr variable but I don't see any command to set watchpoint - is watchpoint here set implicitly by lldb?

85 ↗

(On Diff #20786)

Very minor unrelated thing - do we need to free this memory?

[chaoren]

Fix memory leak.

[chaoren]

test/functionalities/watchpoint/hello_watchlocation/main.cpp

85 ↗

(On Diff #20786)

TestWatchLocation.py breaks on the printf and does "watchpoint set expression -w write -x 1 -- g_char_ptr".

85 ↗

(On Diff #20786)

Yeah, there's a memory leak. I'll fix that too.

[ovyalov]

Looks good.

test/functionalities/watchpoint/hello_watchlocation/main.cpp

21 ↗

(On Diff #20789)

Please rename to g_barrier before submitting.

lldb/trunk/test/functionalities/watchpoint/hello_watchlocation/main.cpp

 #include <stdint.h>
 #include <stdlib.h>
 #include <unistd.h>
 
 pthread_t g_thread_1 = NULL;
 pthread_t g_thread_2 = NULL;
 pthread_t g_thread_3 = NULL;
 
+pthread_barrier_t g_barrier;
+
 char *g_char_ptr = NULL;
 
 void
 do_bad_thing_with_location(char *char_ptr, char new_val)
 {
     unsigned what = new_val;
     printf("new value written to location(%p) = %u\n", char_ptr, what);
     *char_ptr = new_val;

 }
 
 void *
 thread_func (void *arg)
 {
     uint32_t thread_index = *((uint32_t *)arg);
     printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index);
 
+    pthread_barrier_wait(&g_barrier);
+
     uint32_t count = 0;
     uint32_t val;
     while (count++ < 15)
     {
         // random micro second sleep from zero to 3 seconds
         int usec = ::rand() % 3000000;
         printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
         ::usleep (usec);
int main (int argc, char const *argv[])
     void *thread_result = NULL;
     uint32_t thread_index_1 = 1;
     uint32_t thread_index_2 = 2;
     uint32_t thread_index_3 = 3;
 
     g_char_ptr = (char *)malloc (1);
     *g_char_ptr = 0;
 
+    pthread_barrier_init(&g_barrier, NULL, 4);
+
     // Create 3 threads
     err = ::pthread_create (&g_thread_1, NULL, thread_func, &thread_index_1);
     err = ::pthread_create (&g_thread_2, NULL, thread_func, &thread_index_2);
     err = ::pthread_create (&g_thread_3, NULL, thread_func, &thread_index_3);
 
     printf ("Before turning all three threads loose...\n"); // Set break point at this line.
+    pthread_barrier_wait(&g_barrier);
 
     // Join all of our threads
     err = ::pthread_join (g_thread_1, &thread_result);
     err = ::pthread_join (g_thread_2, &thread_result);
     err = ::pthread_join (g_thread_3, &thread_result);
 
+    pthread_barrier_destroy(&g_barrier);
+    free(g_char_ptr);
+
     return 0;
 }