Always truncate thread names on linux to 15 chars (16 with the null t…

…erminator).

On Linux it is an error for a thread name to exceed 16 bytes. Thus also changing the VM thread pool to use the shorter "DartWorker" name.

Change-Id: I4c5cc2bfb831a5593a8652d6435631b9d3803720
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/126163
Commit-Queue: Kirill Nikolaev <cyriln@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>

runtime/vm/os_thread_android.cc

@@ -8,7 +8,8 @@
 
 #include "vm/os_thread.h"
 
-#include <errno.h>     // NOLINT
+#include <errno.h>  // NOLINT
+#include <stdio.h>
 #include <sys/time.h>  // NOLINT
 
 #include "platform/address_sanitizer.h"
@@ -119,8 +120,10 @@ static void* ThreadStart(void* data_ptr) {
   uword parameter = data->parameter();
   delete data;
 
-  // Set the thread name.
-  pthread_setname_np(pthread_self(), name);
+  // Set the thread name. There is 16 bytes limit on the name (including \0).
+  char truncated_name[16];
+  snprintf(truncated_name, ARRAY_SIZE(truncated_name), "%s", name);
+  pthread_setname_np(pthread_self(), truncated_name);
 
   // Create new OSThread object and set as TLS for new thread.
   OSThread* thread = OSThread::CreateOSThread();

runtime/vm/os_thread_linux.cc

@@ -8,7 +8,8 @@
 
 #include "vm/os_thread.h"
 
-#include <errno.h>         // NOLINT
+#include <errno.h>  // NOLINT
+#include <stdio.h>
 #include <sys/resource.h>  // NOLINT
 #include <sys/syscall.h>   // NOLINT
 #include <sys/time.h>      // NOLINT
@@ -121,8 +122,10 @@ static void* ThreadStart(void* data_ptr) {
   uword parameter = data->parameter();
   delete data;
 
-  // Set the thread name.
-  pthread_setname_np(pthread_self(), name);
+  // Set the thread name. There is 16 bytes limit on the name (including \0).
+  char truncated_name[16];
+  snprintf(truncated_name, ARRAY_SIZE(truncated_name), "%s", name);
+  pthread_setname_np(pthread_self(), truncated_name);
 
   // Create new OSThread object and set as TLS for new thread.
   OSThread* thread = OSThread::CreateOSThread();

runtime/vm/thread_pool.cc

@@ -335,7 +335,7 @@ void ThreadPool::Worker::StartThread() {
     ASSERT(task_ != nullptr);
   }
 #endif
-  int result = OSThread::Start("Dart ThreadPool Worker", &Worker::Main,
+  int result = OSThread::Start("DartWorker", &Worker::Main,
                                reinterpret_cast<uword>(this));
   if (result != 0) {
     FATAL1("Could not start worker thread: result = %d.", result);