[lldb-server] Update tests to use std::thread/mutex for all platforms

Summary:
Some cleanup suggested when bringing up lldb-server on Windows. 
Thanks to Hui Huang for the patch.

Reviewers: zturner, labath, jfb, Hui

Reviewed By: labath

Subscribers: clayborg, dexonsmith, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D60496

llvm-svn: 358265

lldb/packages/Python/lldbsuite/test/tools/lldb-server/main.cpp

@@ -6,19 +6,25 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include <atomic>
+#include <chrono>
 #include <cstdlib>
 #include <cstring>
 #include <errno.h>
 #include <inttypes.h>
 #include <memory>
+#include <mutex>
+#if !defined(_WIN32)
 #include <pthread.h>
-#include <setjmp.h>
 #include <signal.h>
+#include <unistd.h>
+#endif
+#include <setjmp.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
+#include <thread>
 #include <time.h>
-#include <unistd.h>
 #include <vector>
 
 #if defined(__APPLE__)
@@ -28,6 +34,8 @@ int pthread_threadid_np(pthread_t, __uint64_t *);
 #include <sys/syscall.h>
 #elif defined(__NetBSD__)
 #include <lwp.h>
+#elif defined(_WIN32)
+#include <windows.h>
 #endif
 
 static const char *const RETVAL_PREFIX = "retval:";
@@ -50,10 +58,10 @@ static const char *const THREAD_COMMAND_SEGFAULT = "segfault";
 static const char *const PRINT_PID_COMMAND = "print-pid";
 
 static bool g_print_thread_ids = false;
-static pthread_mutex_t g_print_mutex = PTHREAD_MUTEX_INITIALIZER;
+static std::mutex g_print_mutex;
 static bool g_threads_do_segfault = false;
 
-static pthread_mutex_t g_jump_buffer_mutex = PTHREAD_MUTEX_INITIALIZER;
+static std::mutex g_jump_buffer_mutex;
 static jmp_buf g_jump_buffer;
 static bool g_is_segfaulting = false;
 
@@ -63,7 +71,11 @@ static volatile char g_c1 = '0';
 static volatile char g_c2 = '1';
 
 static void print_pid() {
+#if defined(_WIN32)
+  fprintf(stderr, "PID: %d\n", ::GetCurrentProcessId());
+#else
   fprintf(stderr, "PID: %d\n", getpid());
+#endif
 }
 
 static void print_thread_id() {
@@ -81,12 +93,17 @@ static void print_thread_id() {
 #elif defined(__NetBSD__)
   // Technically lwpid_t is 32-bit signed integer
   printf("%" PRIx64, static_cast<uint64_t>(_lwp_self()));
+#elif defined(_WIN32)
+  printf("%" PRIx64, static_cast<uint64_t>(::GetCurrentThreadId()));
 #else
   printf("{no-tid-support}");
 #endif
 }
 
 static void signal_handler(int signo) {
+#if defined(_WIN32)
+  // No signal support on Windows.
+#else
   const char *signal_name = nullptr;
   switch (signo) {
   case SIGUSR1:
@@ -100,14 +117,15 @@ static void signal_handler(int signo) {
   }
 
   // Print notice that we received the signal on a given thread.
-  pthread_mutex_lock(&g_print_mutex);
-  if (signal_name)
-    printf("received %s on thread id: ", signal_name);
-  else
-    printf("received signo %d (%s) on thread id: ", signo, strsignal(signo));
-  print_thread_id();
-  printf("\n");
-  pthread_mutex_unlock(&g_print_mutex);
+  {
+    std::lock_guard<std::mutex> lock(g_print_mutex);
+    if (signal_name)
+      printf("received %s on thread id: ", signal_name);
+    else
+      printf("received signo %d (%s) on thread id: ", signo, strsignal(signo));
+    print_thread_id();
+    printf("\n");
+  }
 
   // Reset the signal handler if we're one of the expected signal handlers.
   switch (signo) {
@@ -136,6 +154,7 @@ static void signal_handler(int signo) {
     fprintf(stderr, "failed to set signal handler: errno=%d\n", errno);
     exit(1);
   }
+#endif
 }
 
 static void swap_chars() {
@@ -147,25 +166,18 @@ static void swap_chars() {
 }
 
 static void hello() {
-  pthread_mutex_lock(&g_print_mutex);
+  std::lock_guard<std::mutex> lock(g_print_mutex);
   printf("hello, world\n");
-  pthread_mutex_unlock(&g_print_mutex);
 }
 
 static void *thread_func(void *arg) {
-  static pthread_mutex_t s_thread_index_mutex = PTHREAD_MUTEX_INITIALIZER;
-  static int s_thread_index = 1;
-
-  pthread_mutex_lock(&s_thread_index_mutex);
+  static std::atomic<int> s_thread_index(1);
   const int this_thread_index = s_thread_index++;
-  pthread_mutex_unlock(&s_thread_index_mutex);
-
   if (g_print_thread_ids) {
-    pthread_mutex_lock(&g_print_mutex);
+    std::lock_guard<std::mutex> lock(g_print_mutex);
     printf("thread %d id: ", this_thread_index);
     print_thread_id();
     printf("\n");
-    pthread_mutex_unlock(&g_print_mutex);
   }
 
   if (g_threads_do_segfault) {
@@ -175,48 +187,48 @@ static void *thread_func(void *arg) {
     // trying to do is add predictability as to the timing of
     // signal generation by created threads.
     int sleep_seconds = 2 * (this_thread_index - 1);
-    while (sleep_seconds > 0)
-      sleep_seconds = sleep(sleep_seconds);
+    std::this_thread::sleep_for(std::chrono::seconds(sleep_seconds));
 
     // Test creating a SEGV.
-    pthread_mutex_lock(&g_jump_buffer_mutex);
-    g_is_segfaulting = true;
-    int *bad_p = nullptr;
-    if (setjmp(g_jump_buffer) == 0) {
-      // Force a seg fault signal on this thread.
-      *bad_p = 0;
-    } else {
-      // Tell the system we're no longer seg faulting.
-      // Used by the SIGUSR1 signal handler that we inject
-      // in place of the SIGSEGV so it only tries to
-      // recover from the SIGSEGV if this seg fault code
-      // was in play.
-      g_is_segfaulting = false;
+    {
+      std::lock_guard<std::mutex> lock(g_jump_buffer_mutex);
+      g_is_segfaulting = true;
+      int *bad_p = nullptr;
+      if (setjmp(g_jump_buffer) == 0) {
+        // Force a seg fault signal on this thread.
+        *bad_p = 0;
+      } else {
+        // Tell the system we're no longer seg faulting.
+        // Used by the SIGUSR1 signal handler that we inject
+        // in place of the SIGSEGV so it only tries to
+        // recover from the SIGSEGV if this seg fault code
+        // was in play.
+        g_is_segfaulting = false;
+      }
     }
-    pthread_mutex_unlock(&g_jump_buffer_mutex);
 
-    pthread_mutex_lock(&g_print_mutex);
-    printf("thread ");
-    print_thread_id();
-    printf(": past SIGSEGV\n");
-    pthread_mutex_unlock(&g_print_mutex);
+    {
+      std::lock_guard<std::mutex> lock(g_print_mutex);
+      printf("thread ");
+      print_thread_id();
+      printf(": past SIGSEGV\n");
+    }
   }
 
   int sleep_seconds_remaining = 60;
-  while (sleep_seconds_remaining > 0) {
-    sleep_seconds_remaining = sleep(sleep_seconds_remaining);
-  }
+  std::this_thread::sleep_for(std::chrono::seconds(sleep_seconds_remaining));
 
   return nullptr;
 }
 
 int main(int argc, char **argv) {
   lldb_enable_attach();
 
-  std::vector<pthread_t> threads;
+  std::vector<std::thread> threads;
   std::unique_ptr<uint8_t[]> heap_array_up;
   int return_value = 0;
 
+#if !defined(_WIN32)
   // Set the signal handler.
   sig_t sig_result = signal(SIGALRM, signal_handler);
   if (sig_result == SIG_ERR) {
@@ -235,6 +247,7 @@ int main(int argc, char **argv) {
     fprintf(stderr, "failed to set SIGUSR1 handler: errno=%d\n", errno);
     exit(1);
   }
+#endif
 
   // Process command line args.
   for (int i = 1; i < argc; ++i) {
@@ -251,11 +264,9 @@ int main(int argc, char **argv) {
       // Loop around, sleeping until all sleep time is used up.  Note that
       // signals will cause sleep to end early with the number of seconds
       // remaining.
-      for (int i = 0; sleep_seconds_remaining > 0; ++i) {
-        sleep_seconds_remaining = sleep(sleep_seconds_remaining);
-        // std::cout << "sleep result (call " << i << "): " <<
-        // sleep_seconds_remaining << std::endl;
-      }
+      std::this_thread::sleep_for(
+          std::chrono::seconds(sleep_seconds_remaining));
+
     } else if (std::strstr(argv[i], SET_MESSAGE_PREFIX)) {
       // Copy the contents after "set-message:" to the g_message buffer.
       // Used for reading inferior memory and verifying contents match
@@ -267,9 +278,8 @@ int main(int argc, char **argv) {
       g_message[sizeof(g_message) - 1] = '\0';
 
     } else if (std::strstr(argv[i], PRINT_MESSAGE_COMMAND)) {
-      pthread_mutex_lock(&g_print_mutex);
+      std::lock_guard<std::mutex> lock(g_print_mutex);
       printf("message: %s\n", g_message);
-      pthread_mutex_unlock(&g_print_mutex);
     } else if (std::strstr(argv[i], GET_DATA_ADDRESS_PREFIX)) {
       volatile void *data_p = nullptr;
 
@@ -280,21 +290,19 @@ int main(int argc, char **argv) {
       else if (std::strstr(argv[i] + strlen(GET_DATA_ADDRESS_PREFIX), "g_c2"))
         data_p = &g_c2;
 
-      pthread_mutex_lock(&g_print_mutex);
+      std::lock_guard<std::mutex> lock(g_print_mutex);
       printf("data address: %p\n", data_p);
-      pthread_mutex_unlock(&g_print_mutex);
     } else if (std::strstr(argv[i], GET_HEAP_ADDRESS_COMMAND)) {
       // Create a byte array if not already present.
       if (!heap_array_up)
         heap_array_up.reset(new uint8_t[32]);
 
-      pthread_mutex_lock(&g_print_mutex);
+      std::lock_guard<std::mutex> lock(g_print_mutex);
       printf("heap address: %p\n", heap_array_up.get());
-      pthread_mutex_unlock(&g_print_mutex);
+
     } else if (std::strstr(argv[i], GET_STACK_ADDRESS_COMMAND)) {
-      pthread_mutex_lock(&g_print_mutex);
+      std::lock_guard<std::mutex> lock(g_print_mutex);
       printf("stack address: %p\n", &return_value);
-      pthread_mutex_unlock(&g_print_mutex);
     } else if (std::strstr(argv[i], GET_CODE_ADDRESS_PREFIX)) {
       void (*func_p)() = nullptr;
 
@@ -304,9 +312,8 @@ int main(int argc, char **argv) {
                            "swap_chars"))
         func_p = swap_chars;
 
-      pthread_mutex_lock(&g_print_mutex);
+      std::lock_guard<std::mutex> lock(g_print_mutex);
       printf("code address: %p\n", func_p);
-      pthread_mutex_unlock(&g_print_mutex);
     } else if (std::strstr(argv[i], CALL_FUNCTION_PREFIX)) {
       void (*func_p)() = nullptr;
 
@@ -317,36 +324,28 @@ int main(int argc, char **argv) {
                            "swap_chars") == 0)
         func_p = swap_chars;
       else {
-        pthread_mutex_lock(&g_print_mutex);
+        std::lock_guard<std::mutex> lock(g_print_mutex);
         printf("unknown function: %s\n",
                argv[i] + strlen(CALL_FUNCTION_PREFIX));
-        pthread_mutex_unlock(&g_print_mutex);
       }
       if (func_p)
         func_p();
     } else if (std::strstr(argv[i], THREAD_PREFIX)) {
       // Check if we're creating a new thread.
       if (std::strstr(argv[i] + strlen(THREAD_PREFIX), THREAD_COMMAND_NEW)) {
-        // Create a new thread.
-        pthread_t new_thread;
-        const int err =
-            ::pthread_create(&new_thread, nullptr, thread_func, nullptr);
-        if (err) {
-          fprintf(stderr, "pthread_create() failed with error code %d\n", err);
-          exit(err);
-        }
-        threads.push_back(new_thread);
+        threads.push_back(std::thread(thread_func, nullptr));
       } else if (std::strstr(argv[i] + strlen(THREAD_PREFIX),
                              THREAD_COMMAND_PRINT_IDS)) {
         // Turn on thread id announcing.
         g_print_thread_ids = true;
 
         // And announce us.
-        pthread_mutex_lock(&g_print_mutex);
-        printf("thread 0 id: ");
-        print_thread_id();
-        printf("\n");
-        pthread_mutex_unlock(&g_print_mutex);
+        {
+          std::lock_guard<std::mutex> lock(g_print_mutex);
+          printf("thread 0 id: ");
+          print_thread_id();
+          printf("\n");
+        }
       } else if (std::strstr(argv[i] + strlen(THREAD_PREFIX),
                              THREAD_COMMAND_SEGFAULT)) {
         g_threads_do_segfault = true;
@@ -355,21 +354,17 @@ int main(int argc, char **argv) {
         // Later use thread index and send command to thread.
       }
     } else if (std::strstr(argv[i], PRINT_PID_COMMAND)) {
-        print_pid();
+      print_pid();
     } else {
       // Treat the argument as text for stdout.
       printf("%s\n", argv[i]);
     }
   }
 
   // If we launched any threads, join them
-  for (std::vector<pthread_t>::iterator it = threads.begin();
-       it != threads.end(); ++it) {
-    void *thread_retval = nullptr;
-    const int err = ::pthread_join(*it, &thread_retval);
-    if (err != 0)
-      fprintf(stderr, "pthread_join() failed with error code %d\n", err);
-  }
+  for (std::vector<std::thread>::iterator it = threads.begin();
+       it != threads.end(); ++it)
+    it->join();
 
   return return_value;
 }