Applying D7950 to four near copies of the file.

[chaoren]

Summary

Using std::thread/random instead of pthread/rand.
Two of them also suffered from the synchronization problem in D7916.

[vharron]

https://www.youtube.com/watch?v=z1DzZ7oShl4

test/functionalities/stop-hook/multiple_threads/main.cpp

40

The test sets a breakpoint on this line. That seems not great because there is executable code on this line.

lldb/test/functionalities/stop-hook/multiple_threads/TestStopHookMultipleThreads.py:39

I think you should move the comment to the printf, but if it works it's up to you.

test/functionalities/watchpoint/multiple_threads/main.cpp

44–45

Same here

53

Good you replaced this. rand only goes from 0-32767 on Windows.

[ki.stfu]

lgtm. I'll check it on OS X later.

[chaoren]

test/functionalities/stop-hook/multiple_threads/main.cpp

40

I initially did move it to the printf, but the length of the line bothered me.
It should be identical anyway if breakpoints are behaving correctly. ¯\_(ツ)_/¯

[ki.stfu]

These tests pass on OS X.

[tberghammer]

Please update the Makefile for the tests where you replaced pthreads with std::threads to use ENABLE_STD_THREADS instead on ENABLE_THREADS

[chaoren]

Using ENABLE_STD_THREADS instead of ENABLE_THREADS.

test/functionalities/stop-hook/multiple_threads/Makefile

 LEVEL = ../../../make
 
 CXX_SOURCES := main.cpp
-ENABLE_THREADS := YES
+ENABLE_STD_THREADS := YES
 
 include $(LEVEL)/Makefile.rules

test/functionalities/stop-hook/multiple_threads/main.cpp

 //===-- main.cpp ------------------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
-// C includes
-#include <pthread.h>
-#include <stdio.h>
-#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;
+#include <chrono>
+#include <cstdio>
+#include <mutex>
+#include <random>
+#include <thread>
 
-uint32_t g_val = 0;
+std::default_random_engine g_random_engine{std::random_device{}()};
+std::uniform_int_distribution<> g_distribution{0, 3000000};
 
-uint32_t access_pool (uint32_t flag = 0);
+uint32_t g_val = 0;
 
 uint32_t
-access_pool (uint32_t flag)
+access_pool (bool flag = false)
 {
-    static pthread_mutex_t g_access_mutex = PTHREAD_MUTEX_INITIALIZER;
-    if (flag == 0)
-        ::pthread_mutex_lock (&g_access_mutex);
+    static std::mutex g_access_mutex;
+    if (!flag)
+        g_access_mutex.lock();
 
     uint32_t old_val = g_val;
-    if (flag != 0)
+    if (flag)
         g_val = old_val + 1;
 
-    if (flag == 0)
-        ::pthread_mutex_unlock (&g_access_mutex);
+    if (!flag)
+        g_access_mutex.unlock();
     return g_val;
 }
 
-void *
-thread_func (void *arg)
+void
+thread_func (uint32_t thread_index)
 {
-    uint32_t thread_index = *((uint32_t *)arg); // Break here to test that the stop-hook mechanism works for multiple threads.
+    // Break here to test that the stop-hook mechanism works for multiple threads.
     printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index);
 
     uint32_t count = 0;
     uint32_t val;
     while (count++ < 15)
     {
         // random micro second sleep from zero to 3 seconds
-        int usec = ::rand() % 3000000;
+        int usec = g_distribution(g_random_engine);
         printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
-        ::usleep (usec);
-        
+        std::this_thread::sleep_for(std::chrono::microseconds{usec});
         if (count < 7)
             val = access_pool ();
         else
-            val = access_pool (1);
-                
+            val = access_pool (true);
         printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count);
     }
     printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index);
-    return NULL;
 }
 
 
 int main (int argc, char const *argv[])
 {
-    int err;
-    void *thread_result = NULL;
-    uint32_t thread_index_1 = 1;
-    uint32_t thread_index_2 = 2;
-    uint32_t thread_index_3 = 3;
+    std::thread threads[3];
 
     printf ("Before turning all three threads loose...\n"); // Set break point at this line, and add a stop-hook.
     // 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);
+    for (auto &thread : threads)
+        thread = std::thread{thread_func, std::distance(threads, &thread)};
 
     // 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);
+    for (auto &thread : threads)
+        thread.join();
 
     return 0;
 }

test/functionalities/watchpoint/hello_watchlocation/Makefile

 LEVEL = ../../../make
 
-ENABLE_THREADS := YES
+ENABLE_STD_THREADS := YES
 CXX_SOURCES := main.cpp
 
 include $(LEVEL)/Makefile.rules

test/functionalities/watchpoint/hello_watchlocation/main.cpp

thread_func (uint32_t thread_index)
     uint32_t count = 0;
     uint32_t val;
     while (count++ < 15)
     {
         // random micro second sleep from zero to 3 seconds
         int usec = g_distribution(g_random_engine);
         printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
         std::this_thread::sleep_for(std::chrono::microseconds{usec});
-        
         if (count < 7)
             val = access_pool ();
         else
             val = access_pool (true);
-                
         printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count);
     }
     printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index);
 }
 
 
 int main (int argc, char const *argv[])
 {
-    g_char_ptr = new char;
-    *g_char_ptr = 0;
-
-    std::thread threads[3];
     g_count = 4;
+    std::thread threads[3];
+
+    g_char_ptr = new char{};
 
     // Create 3 threads
     for (auto &thread : threads)
         thread = std::thread{thread_func, std::distance(threads, &thread)};
 
     printf ("Before turning all three threads loose...\n"); // Set break point at this line.
     barrier_wait();
 
     // Join all of our threads
     for (auto &thread : threads)
         thread.join();
 
     delete g_char_ptr;
 
     return 0;
 }

test/functionalities/watchpoint/multiple_threads/Makefile

 LEVEL = ../../../make
 
-ENABLE_THREADS := YES
+ENABLE_STD_THREADS := YES
 CXX_SOURCES := main.cpp
 
 include $(LEVEL)/Makefile.rules

test/functionalities/watchpoint/multiple_threads/main.cpp

 //===-- main.cpp ------------------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
-// C includes
-#include <pthread.h>
-#include <stdio.h>
-#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;
+#include <chrono>
+#include <cstdio>
+#include <mutex>
+#include <random>
+#include <thread>
+
+std::default_random_engine g_random_engine{std::random_device{}()};
+std::uniform_int_distribution<> g_distribution{0, 3000000};
 
 uint32_t g_val = 0;
 
-uint32_t access_pool (uint32_t flag = 0);
 
 uint32_t
-access_pool (uint32_t flag)
+access_pool (bool flag = false)
 {
-    static pthread_mutex_t g_access_mutex = PTHREAD_MUTEX_INITIALIZER;
-    if (flag == 0)
-        ::pthread_mutex_lock (&g_access_mutex);
+    static std::mutex g_access_mutex;
+    if (!flag)
+        g_access_mutex.lock();
 
     uint32_t old_val = g_val;
-    if (flag != 0) {
-        printf("changing g_val to %d...\n", (old_val + 1));
+    if (flag)
+    {
+        printf("changing g_val to %d...\n", old_val + 1);
         g_val = old_val + 1;
     }
 
-    if (flag == 0)
-        ::pthread_mutex_unlock (&g_access_mutex);
+    if (!flag)
+        g_access_mutex.unlock();
     return g_val;
 }
 
-void *
-thread_func (void *arg)
+void
+thread_func (uint32_t thread_index)
 {
-    uint32_t thread_index = *((uint32_t *)arg); // Break here in order to allow the thread
-                                                // to inherit the global watchpoint state.
+    // Break here in order to allow the thread
     printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index);
 
     uint32_t count = 0;
     uint32_t val;
     while (count++ < 15)
     {
         // random micro second sleep from zero to 3 seconds
-        int usec = ::rand() % 3000000;
+        int usec = g_distribution(g_random_engine);
         printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
-        ::usleep (usec);
-        
+        std::this_thread::sleep_for(std::chrono::microseconds{usec});
         if (count < 7)
             val = access_pool ();
         else
-            val = access_pool (1);
-                
+            val = access_pool (true);
         printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count);
     }
     printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index);
-    return NULL;
 }
 
 
 int main (int argc, char const *argv[])
 {
-    int err;
-    void *thread_result = NULL;
-    uint32_t thread_index_1 = 1;
-    uint32_t thread_index_2 = 2;
-    uint32_t thread_index_3 = 3;
+    std::thread threads[3];
 
     printf ("Before turning all three threads loose...\n"); // Set break point at this line,
                                                             // in order to set our watchpoint.
     // 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);
+    for (auto &thread : threads)
+        thread = std::thread{thread_func, std::distance(threads, &thread)};
 
     // 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);
+    for (auto &thread : threads)
+        thread.join();
 
     return 0;
 }

test/functionalities/watchpoint/watchpoint_set_command/Makefile

 LEVEL = ../../../make
 
-ENABLE_THREADS := YES
+ENABLE_STD_THREADS := YES
 CXX_SOURCES := main.cpp
 
 include $(LEVEL)/Makefile.rules

test/functionalities/watchpoint/watchpoint_set_command/main.cpp

 //===-- main.cpp ------------------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
-// C includes
-#include <pthread.h>
-#include <stdio.h>
-#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;
+#include <chrono>
+#include <condition_variable>
+#include <cstdio>
+#include <random>
+#include <thread>
+
+std::default_random_engine g_random_engine{std::random_device{}()};
+std::uniform_int_distribution<> g_distribution{0, 3000000};
+std::condition_variable g_condition_variable;
+std::mutex g_mutex;
+int g_count;
 
-char *g_char_ptr = NULL;
+char *g_char_ptr = nullptr;
+
+void
+barrier_wait()
+{
+    std::unique_lock<std::mutex> lock{g_mutex};
+    if (--g_count > 0)
+        g_condition_variable.wait(lock);
+    else
+        g_condition_variable.notify_all();
+}
 
 void
 do_bad_thing_with_location(unsigned index, char *char_ptr, char new_val)
 {
     unsigned what = new_val;
     printf("new value written to array(%p) and index(%u) = %u\n", char_ptr, index, what);
     char_ptr[index] = new_val;
 }
 
-uint32_t access_pool (uint32_t flag = 0);
-
 uint32_t
-access_pool (uint32_t flag)
+access_pool (bool flag = false)
 {
-    static pthread_mutex_t g_access_mutex = PTHREAD_MUTEX_INITIALIZER;
+    static std::mutex g_access_mutex;
     static unsigned idx = 0; // Well-behaving thread only writes into indexs from 0..6.
-    if (flag == 0)
-        ::pthread_mutex_lock (&g_access_mutex);
+    if (!flag)
+        g_access_mutex.lock();
 
     // idx valid range is [0, 6].
     if (idx > 6)
         idx = 0;
 
-    if (flag != 0) {
+    if (flag)
+    {
         // Write into a forbidden area.
         do_bad_thing_with_location(7, g_char_ptr, 99);
     }
 
     unsigned index = idx++;
 
-    if (flag == 0)
-        ::pthread_mutex_unlock (&g_access_mutex);
+    if (!flag)
+        g_access_mutex.unlock();
     return g_char_ptr[index];
 }
 
-void *
-thread_func (void *arg)
+void
+thread_func (uint32_t thread_index)
 {
-    uint32_t thread_index = *((uint32_t *)arg);
     printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index);
 
+    barrier_wait();
+
     uint32_t count = 0;
     uint32_t val;
     while (count++ < 15)
     {
         // random micro second sleep from zero to 3 seconds
-        int usec = ::rand() % 3000000;
+        int usec = g_distribution(g_random_engine);
         printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
-        ::usleep (usec);
-        
+        std::this_thread::sleep_for(std::chrono::microseconds{usec});
         if (count < 7)
             val = access_pool ();
         else
-            val = access_pool (1);
-                
+            val = access_pool (true);
         printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count);
     }
     printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index);
-    return NULL;
 }
 
 
 int main (int argc, char const *argv[])
 {
-    int err;
-    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 (10);
-    for (int i = 0; i < 10; ++i)
-        *g_char_ptr = 0;
+    g_count = 4;
+    std::thread threads[3];
+
+    g_char_ptr = new char[10]{};
 
     // 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);
+    for (auto &thread : threads)
+        thread = std::thread{thread_func, std::distance(threads, &thread)};
 
     struct {
         int a;
         int b;
         int c;
     } MyAggregateDataType;
 
     printf ("Before turning all three threads loose...\n"); // Set break point at this line.
+    barrier_wait();
 
     // 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);
+    for (auto &thread : threads)
+        thread.join();
+
+    delete[] g_char_ptr;
 
     return 0;
 }

test/python_api/watchpoint/watchlocation/Makefile

 LEVEL = ../../../make
 
-ENABLE_THREADS := YES
+ENABLE_STD_THREADS := YES
 CXX_SOURCES := main.cpp
 
 include $(LEVEL)/Makefile.rules

test/python_api/watchpoint/watchlocation/main.cpp

 //===-- main.cpp ------------------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
-// C includes
-#include <pthread.h>
-#include <stdio.h>
-#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;
+#include <chrono>
+#include <condition_variable>
+#include <cstdio>
+#include <random>
+#include <thread>
+
+std::default_random_engine g_random_engine{std::random_device{}()};
+std::uniform_int_distribution<> g_distribution{0, 3000000};
+std::condition_variable g_condition_variable;
+std::mutex g_mutex;
+int g_count;
 
-char *g_char_ptr = NULL;
+char *g_char_ptr = nullptr;
+
+void
+barrier_wait()
+{
+    std::unique_lock<std::mutex> lock{g_mutex};
+    if (--g_count > 0)
+        g_condition_variable.wait(lock);
+    else
+        g_condition_variable.notify_all();
+}
 
 void
 do_bad_thing_with_location(char *char_ptr, char new_val)
 {
     *char_ptr = new_val;
 }
 
-uint32_t access_pool (uint32_t flag = 0);
-
 uint32_t
-access_pool (uint32_t flag)
+access_pool (bool flag = false)
 {
-    static pthread_mutex_t g_access_mutex = PTHREAD_MUTEX_INITIALIZER;
-    if (flag == 0)
-        ::pthread_mutex_lock (&g_access_mutex);
+    static std::mutex g_access_mutex;
+    if (!flag)
+        g_access_mutex.lock();
 
     char old_val = *g_char_ptr;
-    if (flag != 0)
+    if (flag)
         do_bad_thing_with_location(g_char_ptr, old_val + 1);
 
-    if (flag == 0)
-        ::pthread_mutex_unlock (&g_access_mutex);
+    if (!flag)
+        g_access_mutex.unlock();
     return *g_char_ptr;
 }
 
-void *
-thread_func (void *arg)
+void
+thread_func (uint32_t thread_index)
 {
-    uint32_t thread_index = *((uint32_t *)arg);
     printf ("%s (thread index = %u) startng...\n", __FUNCTION__, thread_index);
 
+    barrier_wait();
+
     uint32_t count = 0;
     uint32_t val;
     while (count++ < 15)
     {
         // random micro second sleep from zero to 3 seconds
-        int usec = ::rand() % 3000000;
+        int usec = g_distribution(g_random_engine);
         printf ("%s (thread = %u) doing a usleep (%d)...\n", __FUNCTION__, thread_index, usec);
-        ::usleep (usec);
-        
+        std::this_thread::sleep_for(std::chrono::microseconds{usec});
         if (count < 7)
             val = access_pool ();
         else
-            val = access_pool (1);
-                
+            val = access_pool (true);
         printf ("%s (thread = %u) after usleep access_pool returns %d (count=%d)...\n", __FUNCTION__, thread_index, val, count);
     }
     printf ("%s (thread index = %u) exiting...\n", __FUNCTION__, thread_index);
-    return NULL;
 }
 
 
 int main (int argc, char const *argv[])
 {
-    int err;
-    void *thread_result = NULL;
-    uint32_t thread_index_1 = 1;
-    uint32_t thread_index_2 = 2;
-    uint32_t thread_index_3 = 3;
+    g_count = 4;
+    std::thread threads[3];
 
-    g_char_ptr = (char *)malloc (1);
-    *g_char_ptr = 0;
+    g_char_ptr = new char{};
 
     // 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);
+    for (auto &thread : threads)
+        thread = std::thread{thread_func, std::distance(threads, &thread)};
 
     printf ("Before turning all three threads loose...\n"); // Set break point at this line.
+    barrier_wait();
 
     // 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);
+    for (auto &thread : threads)
+        thread.join();
+
+    delete g_char_ptr;
 
     return 0;
 }