From 1411d79e24f818bc8ea22268b66bb40a4091c79a Mon Sep 17 00:00:00 2001
From: Yonggang Luo <luoyonggang@gmail.com>
Date: Tue, 18 Oct 2022 02:36:42 +0800
Subject: [PATCH] mapi: Use util_call_once to init exec_mem and mutex instead
 _MTX_INITIALIZER_NP

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19154>
---
 src/mapi/glapi/meson.build        |  4 ++--
 src/mapi/shared-glapi/meson.build |  2 +-
 src/mapi/u_execmem.c              | 23 ++++++++++++++++-------
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/mapi/glapi/meson.build b/src/mapi/glapi/meson.build
index d823482f2b5..c14c28b1f26 100644
--- a/src/mapi/glapi/meson.build
+++ b/src/mapi/glapi/meson.build
@@ -81,7 +81,7 @@ libglapi_bridge = static_library(
   bridge_glapi_files,
   include_directories : [inc_mesa, inc_include, inc_src, inc_mapi],
   c_args : [c_msvc_compat_args, bridge_glapi_args],
-  dependencies : [dep_thread, dep_selinux, idep_mesautilc11],
+  dependencies : [dep_thread, dep_selinux, idep_mesautilc11, idep_mesautil],
   build_by_default : false,
 )
 
@@ -93,7 +93,7 @@ else
     static_glapi_files,
     include_directories : [inc_mesa, inc_include, inc_src, inc_mapi],
     c_args : [c_msvc_compat_args, static_glapi_args],
-    dependencies : [dep_thread, dep_selinux, idep_mesautilc11],
+    dependencies : [dep_thread, dep_selinux, idep_mesautilc11, idep_mesautil],
     build_by_default : false,
   )
 endif
diff --git a/src/mapi/shared-glapi/meson.build b/src/mapi/shared-glapi/meson.build
index 26166d7ddbc..3db5646c7f4 100644
--- a/src/mapi/shared-glapi/meson.build
+++ b/src/mapi/shared-glapi/meson.build
@@ -54,7 +54,7 @@ libglapi = shared_library(
   gnu_symbol_visibility : 'hidden',
   link_args : [ld_args_gc_sections],
   include_directories : [inc_src, inc_include, inc_mapi],
-  dependencies : [dep_thread, dep_selinux, idep_mesautilc11],
+  dependencies : [dep_thread, dep_selinux, idep_mesautilc11, idep_mesautil],
   soversion : host_machine.system() == 'windows' ? '' : '0',
   version : '0.0.0',
   name_prefix : 'lib',
diff --git a/src/mapi/u_execmem.c b/src/mapi/u_execmem.c
index 60fe678e58c..4626c0f8b4a 100644
--- a/src/mapi/u_execmem.c
+++ b/src/mapi/u_execmem.c
@@ -33,12 +33,13 @@
 
 
 #include "c11/threads.h"
+#include "util/u_call_once.h"
 #include "u_execmem.h"
 
 
 #define EXEC_MAP_SIZE (4*1024)
 
-static mtx_t exec_mutex = _MTX_INITIALIZER_NP;
+static mtx_t exec_mutex;
 
 static unsigned int head = 0;
 
@@ -76,9 +77,8 @@ init_map(void)
    }
 #endif
 
-   if (!exec_mem)
-      exec_mem = mmap(NULL, EXEC_MAP_SIZE, PROT_EXEC | PROT_READ | PROT_WRITE,
-		      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+   exec_mem = mmap(NULL, EXEC_MAP_SIZE, PROT_EXEC | PROT_READ | PROT_WRITE,
+                   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
    return (exec_mem != MAP_FAILED);
 }
@@ -117,6 +117,14 @@ init_map(void)
 
 #endif
 
+static void
+u_execmem_init_once(void)
+{
+   if (!init_map())
+      exec_mem = NULL;
+   mtx_init(&exec_mutex, mtx_plain);
+}
+
 void *
 u_execmem_alloc(unsigned int size)
 {
@@ -125,12 +133,13 @@ u_execmem_alloc(unsigned int size)
    return NULL;
 #else
    void *addr = NULL;
+   static util_once_flag once = UTIL_ONCE_FLAG_INIT;
+   util_call_once(&once, u_execmem_init_once);
+   if (exec_mem == NULL)
+      return NULL;
 
    mtx_lock(&exec_mutex);
 
-   if (!init_map())
-      goto bail;
-
    /* free space check, assumes no integer overflow */
    if (head + size > EXEC_MAP_SIZE)
       goto bail;