Fix Win32 multithread dispatching bugs.

meson.build

@@ -151,6 +151,8 @@ if libtype == 'shared'
     conf.set('EPOXY_PUBLIC', '__attribute__((visibility("default"))) extern')
     visibility_cflags += [ '-fvisibility=hidden' ]
   endif
+else
+  conf.set('EPOXY_STATIC_BUILD', true)
 endif
 
 # The inline keyword is available only for C++ in MSVC.

src/dispatch_common.h

@@ -22,7 +22,11 @@
  */
 
 #include "config.h"
-
+#ifdef __GNUC__
+#define EPOXY_THREADLOCAL __thread
+#elif defined (_MSC_VER)
+#define EPOXY_THREADLOCAL __declspec(thread)
+#endif
 #ifdef _WIN32
 #define PLATFORM_HAS_EGL ENABLE_EGL
 #define PLATFORM_HAS_GLX ENABLE_GLX

src/dispatch_wgl.c

@@ -27,8 +27,8 @@
 
 #include "dispatch_common.h"
 
-static bool first_context_current = false;
-static bool already_switched_to_dispatch_table = false;
+//static bool first_context_current = false;
+// static bool already_switched_to_dispatch_table = false;
 
 /**
  * If we can determine the WGL extension support from the current
@@ -75,70 +75,8 @@ epoxy_has_wgl_extension(HDC hdc, const char *ext)
 void
 epoxy_handle_external_wglMakeCurrent(void)
 {
-    if (!first_context_current) {
-        first_context_current = true;
-    } else {
-        if (!already_switched_to_dispatch_table) {
-            already_switched_to_dispatch_table = true;
-            gl_switch_to_dispatch_table();
-            wgl_switch_to_dispatch_table();
-        }
-
-        gl_init_dispatch_table();
-        wgl_init_dispatch_table();
-    }
-}
-
-/**
- * This global symbol is apparently looked up by Windows when loading
- * a DLL, but it doesn't declare the prototype.
- */
-BOOL WINAPI
-DllMain(HINSTANCE dll, DWORD reason, LPVOID reserved);
-
-BOOL WINAPI
-DllMain(HINSTANCE dll, DWORD reason, LPVOID reserved)
-{
-    void *data;
-
-    switch (reason) {
-    case DLL_PROCESS_ATTACH:
-        gl_tls_index = TlsAlloc();
-        if (gl_tls_index == TLS_OUT_OF_INDEXES)
-            return FALSE;
-        wgl_tls_index = TlsAlloc();
-        if (wgl_tls_index == TLS_OUT_OF_INDEXES)
-            return FALSE;
-
-        first_context_current = false;
-
-        /* FALLTHROUGH */
-
-    case DLL_THREAD_ATTACH:
-        data = LocalAlloc(LPTR, gl_tls_size);
-        TlsSetValue(gl_tls_index, data);
-
-        data = LocalAlloc(LPTR, wgl_tls_size);
-        TlsSetValue(wgl_tls_index, data);
-
-        break;
-
-    case DLL_THREAD_DETACH:
-    case DLL_PROCESS_DETACH:
-        data = TlsGetValue(gl_tls_index);
-        LocalFree(data);
-
-        data = TlsGetValue(wgl_tls_index);
-        LocalFree(data);
-
-        if (reason == DLL_PROCESS_DETACH) {
-            TlsFree(gl_tls_index);
-            TlsFree(wgl_tls_index);
-        }
-        break;
-    }
-
-    return TRUE;
+    gl_init_dispatch_table();
+    wgl_init_dispatch_table();
 }
 
 WRAPPER_VISIBILITY (BOOL)

src/gen_dispatch.py

@@ -639,7 +639,7 @@ def write_thunks(self, func):
                                                                        func.args_list))
 
     def write_function_pointer(self, func):
-        self.outln('{0} epoxy_{1} = epoxy_{1}_global_rewrite_ptr;'.format(func.ptr_type, func.wrapped_name))
+        self.outln('{0} epoxy_{1} = EPOXY_DISPATCH_PTR(epoxy_{1});'.format(func.ptr_type, func.wrapped_name))
         self.outln('')
 
     def write_provider_enums(self):
@@ -816,14 +816,22 @@ def write_source(self, f):
             self.write_thunks(func)
         self.outln('')
 
+        self.outln('#define EPOXY_DISPATCH_PTR(name) name##_global_rewrite_ptr')
+
         self.outln('#if USING_DISPATCH_TABLE')
 
+        self.outln('#undef EPOXY_DISPATCH_PTR')
+        self.outln('#define EPOXY_DISPATCH_PTR(name) name##_dispatch_table_thunk')
+
         self.outln('static struct dispatch_table resolver_table = {')
         for func in self.sorted_functions:
             self.outln('    epoxy_{0}_dispatch_table_rewrite_ptr, /* {0} */'.format(func.wrapped_name))
         self.outln('};')
         self.outln('')
+        """
+        self.outln('#ifdef EPOXY_STATIC_BUILD')
 
+        self.outln('#else')
         self.outln('uint32_t {0}_tls_index;'.format(self.target))
         self.outln('uint32_t {0}_tls_size = sizeof(struct dispatch_table);'.format(self.target))
         self.outln('')
@@ -833,8 +841,21 @@ def write_source(self, f):
         self.outln('{')
         self.outln('	return TlsGetValue({0}_tls_index);'.format(self.target))
         self.outln('}')
+        self.outln('#endif /* EPOXY_STATIC_BUILD */')
         self.outln('')
+        """
 
+        self.outln('EPOXY_THREADLOCAL struct dispatch_table {0}_tls_data = {{'.format(self.target))
+        for func in self.sorted_functions:
+            self.outln('    epoxy_{0}_dispatch_table_rewrite_ptr, /* {0} */'.format(func.wrapped_name))
+        self.outln('};')
+        self.outln('static inline struct dispatch_table *')
+        self.outln('get_dispatch_table(void)')
+        self.outln('{')
+        self.outln('	return &{0}_tls_data;'.format(self.target))
+        self.outln('}')
+        self.outln('')
+
         self.outln('void')
         self.outln('{0}_init_dispatch_table(void)'.format(self.target))
         self.outln('{')
@@ -843,14 +864,17 @@ def write_source(self, f):
         self.outln('}')
         self.outln('')
 
+        """
         self.outln('void')
         self.outln('{0}_switch_to_dispatch_table(void)'.format(self.target))
         self.outln('{')
-
+        
         for func in self.sorted_functions:
             self.outln('    epoxy_{0} = epoxy_{0}_dispatch_table_thunk;'.format(func.wrapped_name))
 
         self.outln('}')
+        """
+
         self.outln('')
 
         self.outln('#endif /* !USING_DISPATCH_TABLE */')