From d2a920ee6ee060bc2ae0e5e355d61ad1bf1a3092 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@chromium.org>
Date: Fri, 5 Mar 2021 15:49:17 -0800
Subject: [PATCH] util: Extract thread-id helpers from u_current

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9323>
---
 src/mapi/u_current.c | 45 +++++---------------------------------------
 src/util/u_thread.h  | 41 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 40 deletions(-)

diff --git a/src/mapi/u_current.c b/src/mapi/u_current.c
index 6904167f7d0..7a95e96f509 100644
--- a/src/mapi/u_current.c
+++ b/src/mapi/u_current.c
@@ -49,6 +49,7 @@
  */
 
 #include "c11/threads.h"
+#include "util/u_thread.h"
 #include "u_current.h"
 
 #ifndef MAPI_MODE_UTIL
@@ -150,42 +151,6 @@ u_current_init_tsd(void)
  */
 static mtx_t ThreadCheckMutex = _MTX_INITIALIZER_NP;
 
-
-#ifdef _WIN32
-typedef DWORD thread_id;
-#else
-typedef thrd_t thread_id;
-#endif
-
-
-static inline thread_id
-get_thread_id(void)
-{
-   /*
-    * XXX: Callers of of this function assume it is a lightweight function.
-    * But unfortunately C11's thrd_current() gives no such guarantees.  In
-    * fact, it's pretty hard to have a compliant implementation of
-    * thrd_current() on Windows with such characteristics.  So for now, we
-    * side-step this mess and use Windows thread primitives directly here.
-    */
-#ifdef _WIN32
-   return GetCurrentThreadId();
-#else
-   return thrd_current();
-#endif
-}
-
-
-static inline int
-thread_id_equal(thread_id t1, thread_id t2)
-{
-#ifdef _WIN32
-   return t1 == t2;
-#else
-   return thrd_equal(t1, t2);
-#endif
-}
-
 static thread_id knownID;
 
 /**
@@ -204,10 +169,10 @@ u_current_init(void)
    if (firstCall) {
       u_current_init_tsd();
 
-      knownID = get_thread_id();
+      knownID = util_get_thread_id();
       firstCall = 0;
    }
-   else if (!thread_id_equal(knownID, get_thread_id())) {
+   else if (!util_thread_id_equal(knownID, util_get_thread_id())) {
       ThreadSafe = 1;
       u_current_set_table(NULL);
       u_current_set_context(NULL);
@@ -257,7 +222,7 @@ u_current_get_context_internal(void)
 #else
    if (ThreadSafe)
       return tss_get(u_current_context_tsd);
-   else if (!thread_id_equal(knownID, get_thread_id()))
+   else if (!util_thread_id_equal(knownID, util_get_thread_id()))
       return NULL;
    else
       return u_current_context;
@@ -298,7 +263,7 @@ u_current_get_table_internal(void)
 #else
    if (ThreadSafe)
       return (struct _glapi_table *) tss_get(u_current_table_tsd);
-   else if (!thread_id_equal(knownID, get_thread_id()))
+   else if (!util_thread_id_equal(knownID, util_get_thread_id()))
       return (struct _glapi_table *) table_noop_array;
    else
       return (struct _glapi_table *) u_current_table;
diff --git a/src/util/u_thread.h b/src/util/u_thread.h
index c5f7fb69fd3..8366bfb6d49 100644
--- a/src/util/u_thread.h
+++ b/src/util/u_thread.h
@@ -319,4 +319,45 @@ static inline void util_barrier_wait(util_barrier *barrier)
 
 #endif
 
+/*
+ * Thread-id's.
+ *
+ * thrd_current() is not portable to windows (or at least not in a desirable
+ * way), so thread_id's provide an alternative mechanism
+ */
+
+#ifdef _WIN32
+typedef DWORD thread_id;
+#else
+typedef thrd_t thread_id;
+#endif
+
+static inline thread_id
+util_get_thread_id(void)
+{
+   /*
+    * XXX: Callers of of this function assume it is a lightweight function.
+    * But unfortunately C11's thrd_current() gives no such guarantees.  In
+    * fact, it's pretty hard to have a compliant implementation of
+    * thrd_current() on Windows with such characteristics.  So for now, we
+    * side-step this mess and use Windows thread primitives directly here.
+    */
+#ifdef _WIN32
+   return GetCurrentThreadId();
+#else
+   return thrd_current();
+#endif
+}
+
+
+static inline int
+util_thread_id_equal(thread_id t1, thread_id t2)
+{
+#ifdef _WIN32
+   return t1 == t2;
+#else
+   return thrd_equal(t1, t2);
+#endif
+}
+
 #endif /* U_THREAD_H_ */