[PATCH 1/1] ntdll: Reimplement set_native_thread_name() for macOS

[Marc-Aurel Zent]

From: Marc-Aurel Zent

---
 dlls/ntdll/unix/thread.c | 91 ++++++++++++++++++++++++++++++----------
 1 file changed, 70 insertions(+), 21 deletions(-)

diff --git a/dlls/ntdll/unix/thread.c b/dlls/ntdll/unix/thread.c
index 9e84ec3cc96..37341416a9e 100644
--- a/dlls/ntdll/unix/thread.c
+++ b/dlls/ntdll/unix/thread.c
@@ -1911,39 +1911,88 @@ static void set_native_thread_name( HANDLE handle, const UNICODE_STRING *name )
         close( fd );
     }
 #elif defined(__APPLE__)
-    /* pthread_setname_np() silently fails if the name is longer than 63 characters + null terminator */
-    char nameA[64];
-    NTSTATUS status;
-    int unix_pid, unix_tid, len, current_tid;
+    extern int __proc_info( int callnum, int pid, int flavor, uint64_t arg, void *buffer, int buffersize );
+    static int pthread_name_offset = -1;
+    static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+    char nameA[MAXTHREADNAMESIZE];
+    char *pthread_name;
+    int len;
+    THREAD_BASIC_INFORMATION info;
+    struct ntdll_thread_data *thread_data;
+    pthread_t pthread_id;

-    SERVER_START_REQ( get_thread_times )
+    if (NtQueryInformationThread( handle, ThreadBasicInformation, &info, sizeof(info), NULL ))
+        return;
+
+    if (HandleToULong( info.ClientId.UniqueProcess ) != GetCurrentProcessId())
     {
-        req->handle = wine_server_obj_handle( handle );
-        status = wine_server_call( req );
-        if (status == STATUS_SUCCESS)
+        static int once;
+        if (!once++) FIXME("cross-process native thread naming not supported\n");
+        return;
+    }
+
+    pthread_mutex_lock( &lock );
+
+    if (pthread_name_offset == -1)
+    {
+        char current_thread_name[MAXTHREADNAMESIZE];
+        const char *test_name = "__WINE_THREAD_NAME_OFFSET_TEST__";
+        const int max_search_offset = 256;
+        int test_name_len, search_offset = 0;
+
+        pthread_getname_np( pthread_self(), current_thread_name, sizeof(current_thread_name) );
+        test_name_len = strlen( test_name );
+        pthread_setname_np( test_name );
+
+        for (; search_offset < max_search_offset; search_offset++)
         {
-            unix_pid = reply->unix_pid;
-            unix_tid = reply->unix_tid;
+            char *candidate = (char *)pthread_self() + search_offset;
+            if (!strncmp( candidate, test_name, test_name_len ))
+            {
+                pthread_name_offset = search_offset;
+                break;
+            }
+        }
+
+        pthread_setname_np( current_thread_name );
+
+        if (pthread_name_offset == -1)
+        {
+            static int once;
+            if (!once++) ERR("could not determine pthread_name struct offset\n");
+            goto out;
         }
     }
-    SERVER_END_REQ;

-    if (status != STATUS_SUCCESS || unix_pid == -1 || unix_tid == -1)
-        return;
+    thread_data = (struct ntdll_thread_data *)&((PTEB)(info.TebBaseAddress))->GdiTebBatch;
+    pthread_id = thread_data->pthread_id;
+    pthread_name = (char *)pthread_id + pthread_name_offset;

-    current_tid = mach_thread_self();
-    mach_port_deallocate(mach_task_self(), current_tid);
+    len = ntdll_wcstoumbs( name->Buffer, name->Length / sizeof(WCHAR), nameA, sizeof(nameA) - 1, FALSE );

-    if (unix_tid != current_tid)
+    if (len >= 0) 
+    {
+        nameA[len] = '\0';
+        strcpy( pthread_name, nameA );
+    } 
+    else 
+    {
+        bzero( pthread_name, MAXTHREADNAMESIZE );
+        goto out;
+    }
+
+    if (!pthread_equal( pthread_self(), pthread_id ))
     {
         static int once;
-        if (!once++) FIXME("setting other thread name not supported\n");
-        return;
+        if (!once++) FIXME("cross-thread native thread naming not visible cross-process\n");
+        goto out;
     }

-    len = ntdll_wcstoumbs( name->Buffer, name->Length / sizeof(WCHAR), nameA, sizeof(nameA) - 1, FALSE );
-    nameA[len] = '\0';
-    pthread_setname_np(nameA);
+    if (__proc_info( 5, getpid(), 2, (uint64_t)0, (void *)nameA, len ))
+        ERR("could not set native thread name kernel-side\n");
+
+out:
+    pthread_mutex_unlock( &lock );
 #else
     static int once;
     if (!once++) FIXME("not implemented on this platform\n");