Add TLS support to libGL and, by virtue of using glthread.h and GL_CALL, all
DRI drivers. A TLS enabled libGL can load a TLS or a non-TLS DRI driver,
but a TLS DRI driver requires a TLS enabled libGL.
This fixes bug #1822.
diff --git a/src/mesa/glapi/glapi.c b/src/mesa/glapi/glapi.c
index bbc0a96..8ed8330 100644
--- a/src/mesa/glapi/glapi.c
+++ b/src/mesa/glapi/glapi.c
@@ -61,6 +61,10 @@
static GLboolean WarnFlag = GL_FALSE;
static _glapi_warning_func warning_func;
+static void init_glapi_relocs(void);
+
+static _glapi_proc generate_entrypoint(GLuint functionOffset);
+static void fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset);
/*
* Enable/disable printing of warning messages.
@@ -133,6 +137,28 @@
#if defined(THREADS)
+#if defined(GLX_USE_TLS)
+
+__thread struct _glapi_table * _glapi_tls_Dispatch
+ __attribute__((tls_model("initial-exec")))
+ = (struct _glapi_table *) __glapi_noop_table;
+
+static __thread struct _glapi_table * _glapi_tls_RealDispatch
+ __attribute__((tls_model("initial-exec")))
+ = (struct _glapi_table *) __glapi_noop_table;
+
+__thread void * _glapi_tls_Context
+ __attribute__((tls_model("initial-exec")));
+
+/**
+ * Legacy per-thread dispatch pointer. This is only needed to support
+ * non-TLS DRI drivers.
+ */
+
+_glthread_TSD _gl_DispatchTSD;
+
+#else
+
/**
* \name Multi-threaded control support variables
*
@@ -166,6 +192,7 @@
static _glthread_TSD ContextTSD; /**< Per-thread context pointer */
/*@}*/
+#endif /* defined(GLX_USE_TLS) */
#define DISPATCH_TABLE_NAME __glapi_threadsafe_table
#define UNUSED_TABLE_NAME __unused_threadsafe_functions
@@ -184,6 +211,29 @@
/***** END THREAD-SAFE DISPATCH *****/
+#if defined(GLX_USE_TLS)
+
+/**
+ * \name Old dispatch pointers
+ *
+ * Very old DRI based drivers assume that \c _glapi_Dispatch will never be
+ * \c NULL. Becuase of that, special "thread-safe" dispatch functions are
+ * needed here. Slightly more recent drivers detect the multi-threaded case
+ * by \c _glapi_DispatchTSD being \c NULL.
+ *
+ * \deprecated
+ *
+ * \warning
+ * \c _glapi_RealDispatch does not exist in TLS builds. I don't think it was
+ * ever used outside libGL.so, so this should be safe.
+ */
+/*@{*/
+PUBLIC const struct _glapi_table *_glapi_Dispatch = (struct _glapi_table *) __glapi_threadsafe_table;
+PUBLIC const struct _glapi_table *_glapi_DispatchTSD = NULL;
+PUBLIC const void *_glapi_Context = NULL;
+/*@}*/
+
+#else
PUBLIC struct _glapi_table *_glapi_Dispatch = (struct _glapi_table *) __glapi_noop_table;
#if defined( THREADS )
@@ -191,10 +241,11 @@
#endif
PUBLIC struct _glapi_table *_glapi_RealDispatch = (struct _glapi_table *) __glapi_noop_table;
-
/* Used when thread safety disabled */
PUBLIC void *_glapi_Context = NULL;
+#endif /* defined(GLX_USE_TLS) */
+
static GLboolean DispatchOverride = GL_FALSE;
@@ -224,7 +275,7 @@
PUBLIC void
_glapi_check_multithread(void)
{
-#if defined(THREADS)
+#if defined(THREADS) && !defined(GLX_USE_TLS)
if (!ThreadSafe) {
static unsigned long knownID;
static GLboolean firstCall = GL_TRUE;
@@ -255,7 +306,9 @@
_glapi_set_context(void *context)
{
(void) __unused_noop_functions; /* silence a warning */
-#if defined(THREADS)
+#if defined(GLX_USE_TLS)
+ _glapi_tls_Context = context;
+#elif defined(THREADS)
(void) __unused_threadsafe_functions; /* silence a warning */
_glthread_SetTSD(&ContextTSD, context);
_glapi_Context = (ThreadSafe) ? NULL : context;
@@ -274,7 +327,9 @@
PUBLIC void *
_glapi_get_context(void)
{
-#if defined(THREADS)
+#if defined(GLX_USE_TLS)
+ return _glapi_tls_Context;
+#elif defined(THREADS)
if (ThreadSafe) {
return _glthread_GetTSD(&ContextTSD);
}
@@ -294,6 +349,13 @@
PUBLIC void
_glapi_set_dispatch(struct _glapi_table *dispatch)
{
+#if defined(PTHREADS) || defined(GLX_USE_TLS)
+ static pthread_once_t once_control = PTHREAD_ONCE_INIT;
+
+
+ pthread_once( & once_control, init_glapi_relocs );
+#endif
+
if (!dispatch) {
/* use the no-op functions */
dispatch = (struct _glapi_table *) __glapi_noop_table;
@@ -304,7 +366,15 @@
}
#endif
-#if defined(THREADS)
+#if defined(GLX_USE_TLS)
+ if (DispatchOverride) {
+ _glapi_tls_RealDispatch = dispatch;
+ }
+ else {
+ _glthread_SetTSD(&_gl_DispatchTSD, (void *) dispatch);
+ _glapi_tls_Dispatch = dispatch;
+ }
+#elif defined(THREADS)
if (DispatchOverride) {
_glthread_SetTSD(&RealDispatchTSD, (void *) dispatch);
if (ThreadSafe)
@@ -342,7 +412,13 @@
PUBLIC struct _glapi_table *
_glapi_get_dispatch(void)
{
-#if defined(THREADS)
+#if defined(GLX_USE_TLS)
+ struct _glapi_table * api = (DispatchOverride)
+ ? _glapi_tls_RealDispatch : _glapi_tls_Dispatch;
+
+ assert( api != NULL );
+ return api;
+#elif defined(THREADS)
if (ThreadSafe) {
if (DispatchOverride) {
return (struct _glapi_table *) _glthread_GetTSD(&RealDispatchTSD);
@@ -399,7 +475,10 @@
_glapi_set_dispatch(real);
-#if defined(THREADS)
+#if defined(GLX_USE_TLS)
+ _glthread_SetTSD(&_gl_DispatchTSD, (void *) override);
+ _glapi_tls_Dispatch = override;
+#elif defined(THREADS)
_glthread_SetTSD(&_gl_DispatchTSD, (void *) override);
if ( ThreadSafe ) {
_glapi_Dispatch = (struct _glapi_table *) __glapi_threadsafe_table;
@@ -424,10 +503,14 @@
DispatchOverride = GL_FALSE;
_glapi_set_dispatch(real);
/* the rest of this isn't needed, just play it safe */
-#if defined(THREADS)
+#if defined(GLX_USE_TLS)
+ _glapi_tls_RealDispatch = NULL;
+#else
+# if defined(THREADS)
_glthread_SetTSD(&RealDispatchTSD, NULL);
-#endif
+# endif
_glapi_RealDispatch = NULL;
+#endif
}
@@ -439,7 +522,9 @@
}
else {
if (DispatchOverride) {
-#if defined(THREADS)
+#if defined(GLX_USE_TLS)
+ return (struct _glapi_table *) _glapi_tls_Dispatch;
+#elif defined(THREADS)
return (struct _glapi_table *) _glthread_GetTSD(&_gl_DispatchTSD);
#else
return _glapi_Dispatch;
@@ -498,9 +583,15 @@
#ifdef USE_X86_ASM
-extern const GLubyte gl_dispatch_functions_start[];
-# if defined(THREADS)
+#if defined( GLX_USE_TLS )
+extern GLubyte gl_dispatch_functions_start[];
+extern GLubyte gl_dispatch_functions_end[];
+#else
+extern const GLubyte gl_dispatch_functions_start[];
+#endif
+
+# if defined(THREADS) && !defined(GLX_USE_TLS)
# define X86_DISPATCH_FUNCTION_SIZE 32
# else
# define X86_DISPATCH_FUNCTION_SIZE 16
@@ -603,45 +694,20 @@
generate_entrypoint(GLuint functionOffset)
{
#if defined(USE_X86_ASM)
- /*
- * This x86 code contributed by Josh Vanderhoof.
- *
- * 0: a1 10 32 54 76 movl __glapi_Dispatch,%eax
- * 00 01 02 03 04
- * 5: 85 c0 testl %eax,%eax
- * 05 06
- * 7: 74 06 je f <entrypoint+0xf>
- * 07 08
- * 9: ff a0 10 32 54 76 jmp *0x76543210(%eax)
- * 09 0a 0b 0c 0d 0e
- * f: e8 fc ff ff ff call __glapi_get_dispatch
- * 0f 10 11 12 13
- * 14: ff a0 10 32 54 76 jmp *0x76543210(%eax)
- * 14 15 16 17 18 19
+ /* 32 is chosen as something of a magic offset. For x86, the dispatch
+ * at offset 32 is the first one where the offset in the
+ * "jmp OFFSET*4(%eax)" can't be encoded in a single byte.
*/
- static const unsigned char insn_template[] = {
- 0xa1, 0x00, 0x00, 0x00, 0x00,
- 0x85, 0xc0,
- 0x74, 0x06,
- 0xff, 0xa0, 0x00, 0x00, 0x00, 0x00,
- 0xe8, 0x00, 0x00, 0x00, 0x00,
- 0xff, 0xa0, 0x00, 0x00, 0x00, 0x00
- };
- unsigned char *code = (unsigned char *) malloc(sizeof(insn_template));
- unsigned int next_insn;
- if (code) {
- memcpy(code, insn_template, sizeof(insn_template));
+ const GLubyte * const template_func = gl_dispatch_functions_start
+ + (X86_DISPATCH_FUNCTION_SIZE * 32);
+ GLubyte * const code = (GLubyte *) malloc( X86_DISPATCH_FUNCTION_SIZE );
-#if defined( THREADS )
- *(unsigned int *)(code + 0x01) = (unsigned int)&_glapi_DispatchTSD;
-#else
- *(unsigned int *)(code + 0x01) = (unsigned int)&_glapi_Dispatch;
-#endif
- *(unsigned int *)(code + 0x0b) = (unsigned int)functionOffset * 4;
- next_insn = (unsigned int)(code + 0x14);
- *(unsigned int *)(code + 0x10) = (unsigned int)_glapi_get_dispatch - next_insn;
- *(unsigned int *)(code + 0x16) = (unsigned int)functionOffset * 4;
+
+ if ( code != NULL ) {
+ (void) memcpy( code, template_func, X86_DISPATCH_FUNCTION_SIZE );
+ fill_in_entrypoint_offset( (_glapi_proc) code, functionOffset );
}
+
return (_glapi_proc) code;
#elif defined(USE_SPARC_ASM)
@@ -707,10 +773,19 @@
fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
{
#if defined(USE_X86_ASM)
+ GLubyte * const code = (GLubyte *) entrypoint;
- unsigned char *code = (unsigned char *) entrypoint;
- *(unsigned int *)(code + 0x0b) = offset * 4;
- *(unsigned int *)(code + 0x16) = offset * 4;
+
+#if X86_DISPATCH_FUNCTION_SIZE == 32
+ *((unsigned int *)(code + 11)) = 4 * offset;
+ *((unsigned int *)(code + 22)) = 4 * offset;
+#elif X86_DISPATCH_FUNCTION_SIZE == 16 && defined( GLX_USE_TLS )
+ *((unsigned int *)(code + 8)) = 4 * offset;
+#elif X86_DISPATCH_FUNCTION_SIZE == 16
+ *((unsigned int *)(code + 7)) = 4 * offset;
+#else
+# error Invalid X86_DISPATCH_FUNCTION_SIZE!
+#endif
#elif defined(USE_SPARC_ASM)
@@ -1028,3 +1103,25 @@
(void) table;
#endif
}
+
+
+/**
+ * Perform platform-specific GL API entry-point fixups.
+ *
+ *
+ */
+static void
+init_glapi_relocs( void )
+{
+#if defined( USE_X86_ASM ) && defined( GLX_USE_TLS )
+ extern void * _x86_get_dispatch(void);
+ const GLubyte * const get_disp = (const GLubyte *) _x86_get_dispatch;
+ GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start;
+
+
+ while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) {
+ (void) memcpy( curr_func, get_disp, 6 );
+ curr_func += X86_DISPATCH_FUNCTION_SIZE;
+ }
+#endif /* defined( USE_X86_ASM ) && defined( GLX_USE_TLS ) */
+}