Re: [Mesa-dev] [PATCH 03/21] glsl: protect anonymous struct id with a mutex

2014-05-04 Thread Chia-I Wu 
On Sat, May 3, 2014 at 1:33 AM, Ian Romanick i...@freedesktop.org wrote:
 On 04/22/2014 01:58 AM, Chia-I Wu wrote:
 There may be two contexts compiling shaders at the same time, and we want the
 anonymous struct id to be globally unique.

 I am not very excited about this.

 Is there any chance of getting stdatomic.h for the MSVC compilers that
 people care about?  I'd much rather have this code be...

if (identifier == NULL) {
   static volatile atomic_uint_t anon_count = ATOMIC_VAR_INIT(1);
   unsigned count;

   count = atomic_fetch_add(anon_count, 1);
   identifier = ralloc_asprintf(this, #anon_struct_%04x, count);
}
I could not find any portable stdatomic.h implementation from a quick
search.  One thing we may
do is to have

$ cat $mesa/include/c11/stdatomic.h
#if __STDC_VERSION__ = 201112L  !defined(__STDC_NO_ATOMICS__)
#include stdatomic.h
#else

/* a implementation that is good enough for us */
#include threads.h

#define ATOMIC_VAR_INIT(val) { _MTX_INITIALIZER_NP, (val) }

typedef struct atomic_uint_t {
   mtx_t mutex;
   unsigned int val;
} atomic_uint_t;

static inline unsigned int
atomic_fetch_add(volatile atomic_uint_t *a)
{
unsigned int val;

mtx_lock(a-mutex);
val = a-val++;
mtx_unlock(a-mutex);

return val;
}
#endif

Whoever needs more than reference counting with unsigned int will need
to extend it a bit on systems where there is no stdatomic.h.  And
maybe we are better off without naming it stdatomic.h.  Ideas?


 Signed-off-by: Chia-I Wu o...@lunarg.com
 ---
  src/glsl/glsl_parser_extras.cpp | 10 --
  1 file changed, 8 insertions(+), 2 deletions(-)

 diff --git a/src/glsl/glsl_parser_extras.cpp 
 b/src/glsl/glsl_parser_extras.cpp
 index 91c9285..30e284b 100644
 --- a/src/glsl/glsl_parser_extras.cpp
 +++ b/src/glsl/glsl_parser_extras.cpp
 @@ -1332,9 +1332,15 @@ ast_struct_specifier::ast_struct_specifier(const char 
 *identifier,
  ast_declarator_list 
 *declarator_list)
  {
 if (identifier == NULL) {
 +  static mtx_t mutex = _MTX_INITIALIZER_NP;
static unsigned anon_count = 1;
 -  identifier = ralloc_asprintf(this, #anon_struct_%04x, anon_count);
 -  anon_count++;
 +  unsigned count;
 +
 +  mtx_lock(mutex);
 +  count = anon_count++;
 +  mtx_unlock(mutex);
 +
 +  identifier = ralloc_asprintf(this, #anon_struct_%04x, count);
 }
 name = identifier;
 this-declarations.push_degenerate_list_at_head(declarator_list-link);





-- 
o...@lunarg.com
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Re: [Mesa-dev] [PATCH 03/21] glsl: protect anonymous struct id with a mutex

2014-05-04 Thread Matt Turner 
On Fri, May 2, 2014 at 10:33 AM, Ian Romanick i...@freedesktop.org wrote:
 On 04/22/2014 01:58 AM, Chia-I Wu wrote:
 There may be two contexts compiling shaders at the same time, and we want the
 anonymous struct id to be globally unique.

 I am not very excited about this.

 Is there any chance of getting stdatomic.h for the MSVC compilers that
 people care about?  I'd much rather have this code be...

if (identifier == NULL) {
   static volatile atomic_uint_t anon_count = ATOMIC_VAR_INIT(1);
   unsigned count;

   count = atomic_fetch_add(anon_count, 1);
   identifier = ralloc_asprintf(this, #anon_struct_%04x, count);
}

Note that gcc-4.9 is the first version to have stdatomic.h.

gcc has supported atomic built-ins for a long time though:
http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Atomic-Builtins.html
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Re: [Mesa-dev] [PATCH 03/21] glsl: protect anonymous struct id with a mutex

2014-05-02 Thread Ian Romanick 
On 04/22/2014 01:58 AM, Chia-I Wu wrote:
 There may be two contexts compiling shaders at the same time, and we want the
 anonymous struct id to be globally unique.

I am not very excited about this.

Is there any chance of getting stdatomic.h for the MSVC compilers that
people care about?  I'd much rather have this code be...

   if (identifier == NULL) {
  static volatile atomic_uint_t anon_count = ATOMIC_VAR_INIT(1);
  unsigned count;

  count = atomic_fetch_add(anon_count, 1);
  identifier = ralloc_asprintf(this, #anon_struct_%04x, count);
   }

 Signed-off-by: Chia-I Wu o...@lunarg.com
 ---
  src/glsl/glsl_parser_extras.cpp | 10 --
  1 file changed, 8 insertions(+), 2 deletions(-)
 
 diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
 index 91c9285..30e284b 100644
 --- a/src/glsl/glsl_parser_extras.cpp
 +++ b/src/glsl/glsl_parser_extras.cpp
 @@ -1332,9 +1332,15 @@ ast_struct_specifier::ast_struct_specifier(const char 
 *identifier,
  ast_declarator_list *declarator_list)
  {
 if (identifier == NULL) {
 +  static mtx_t mutex = _MTX_INITIALIZER_NP;
static unsigned anon_count = 1;
 -  identifier = ralloc_asprintf(this, #anon_struct_%04x, anon_count);
 -  anon_count++;
 +  unsigned count;
 +
 +  mtx_lock(mutex);
 +  count = anon_count++;
 +  mtx_unlock(mutex);
 +
 +  identifier = ralloc_asprintf(this, #anon_struct_%04x, count);
 }
 name = identifier;
 this-declarations.push_degenerate_list_at_head(declarator_list-link);
 

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[Mesa-dev] [PATCH 03/21] glsl: protect anonymous struct id with a mutex

2014-04-22 Thread Chia-I Wu 
There may be two contexts compiling shaders at the same time, and we want the
anonymous struct id to be globally unique.

Signed-off-by: Chia-I Wu o...@lunarg.com
---
 src/glsl/glsl_parser_extras.cpp | 10 --
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
index 91c9285..30e284b 100644
--- a/src/glsl/glsl_parser_extras.cpp
+++ b/src/glsl/glsl_parser_extras.cpp
@@ -1332,9 +1332,15 @@ ast_struct_specifier::ast_struct_specifier(const char 
*identifier,
   ast_declarator_list *declarator_list)
 {
if (identifier == NULL) {
+  static mtx_t mutex = _MTX_INITIALIZER_NP;
   static unsigned anon_count = 1;
-  identifier = ralloc_asprintf(this, #anon_struct_%04x, anon_count);
-  anon_count++;
+  unsigned count;
+
+  mtx_lock(mutex);
+  count = anon_count++;
+  mtx_unlock(mutex);
+
+  identifier = ralloc_asprintf(this, #anon_struct_%04x, count);
}
name = identifier;
this-declarations.push_degenerate_list_at_head(declarator_list-link);
-- 
1.8.5.3

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