metal : free metal objects (#5161)

* Releasing MTLFunction references after Metal pipeline construction

* Keeping the `ggml_metal_kernel` structure

* Spacing fix

* Whitespace fix

Author: ptsochantaris

ggml-metal.m

@@ -24,10 +24,7 @@
 
 #define UNUSED(x) (void)(x)
 
-#define GGML_METAL_MAX_KERNELS 256
-
 struct ggml_metal_kernel {
-    id<MTLFunction>             function;
     id<MTLComputePipelineState> pipeline;
 };
 
@@ -159,11 +156,10 @@
 
     id<MTLDevice>       device;
     id<MTLCommandQueue> queue;
-    id<MTLLibrary>      library;
 
     dispatch_queue_t d_queue;
 
-    struct ggml_metal_kernel kernels[GGML_METAL_MAX_KERNELS];
+    struct ggml_metal_kernel kernels[GGML_METAL_KERNEL_TYPE_COUNT];
 
     bool support_simdgroup_reduction;
     bool support_simdgroup_mm;
@@ -246,6 +242,8 @@ static void ggml_metal_log(enum ggml_log_level level, const char * format, ...){
     ctx->queue  = [ctx->device newCommandQueue];
     ctx->d_queue = dispatch_queue_create("ggml-metal", DISPATCH_QUEUE_CONCURRENT);
 
+    id<MTLLibrary> metal_library;
+
     // load library
     {
         NSBundle * bundle = nil;
@@ -260,7 +258,7 @@ static void ggml_metal_log(enum ggml_log_level level, const char * format, ...){
             // pre-compiled library found
             NSURL * libURL = [NSURL fileURLWithPath:libPath];
             GGML_METAL_LOG_INFO("%s: loading '%s'\n", __func__, [libPath UTF8String]);
-            ctx->library = [ctx->device newLibraryWithURL:libURL error:&error];
+            metal_library = [ctx->device newLibraryWithURL:libURL error:&error];
             if (error) {
                 GGML_METAL_LOG_ERROR("%s: error: %s\n", __func__, [[error description] UTF8String]);
                 return NULL;
@@ -302,7 +300,7 @@ static void ggml_metal_log(enum ggml_log_level level, const char * format, ...){
 
                 //[options setFastMathEnabled:false];
 
-                ctx->library = [ctx->device newLibraryWithSource:src options:options error:&error];
+                metal_library = [ctx->device newLibraryWithSource:src options:options error:&error];
                 if (error) {
                     GGML_METAL_LOG_ERROR("%s: error: %s\n", __func__, [[error description] UTF8String]);
                     return NULL;
@@ -367,8 +365,7 @@ static void ggml_metal_log(enum ggml_log_level level, const char * format, ...){
     {
         NSError * error = nil;
 
-        for (int i = 0; i < GGML_METAL_MAX_KERNELS; ++i) {
-            ctx->kernels[i].function = nil;
+        for (int i = 0; i < GGML_METAL_KERNEL_TYPE_COUNT; ++i) {
             ctx->kernels[i].pipeline = nil;
         }
 
@@ -380,10 +377,12 @@ static void ggml_metal_log(enum ggml_log_level level, const char * format, ...){
 #define GGML_METAL_ADD_KERNEL(e, name, supported) \
         if (supported) { \
             struct ggml_metal_kernel * kernel = &ctx->kernels[e]; \
-            kernel->function = [ctx->library newFunctionWithName:@"kernel_"#name]; \
-            kernel->pipeline = [ctx->device newComputePipelineStateWithFunction:kernel->function error:&error]; \
+            id<MTLFunction> metal_function = [metal_library newFunctionWithName:@"kernel_"#name]; \
+            kernel->pipeline = [ctx->device newComputePipelineStateWithFunction:metal_function error:&error]; \
+            [metal_function release]; \
             if (error) { \
                 GGML_METAL_LOG_ERROR("%s: error: load pipeline error: %s\n", __func__, [[error description] UTF8String]); \
+                [metal_library release]; \
                 return NULL; \
             } \
         } else { \
@@ -512,23 +511,17 @@ static void ggml_metal_log(enum ggml_log_level level, const char * format, ...){
         GGML_METAL_ADD_KERNEL(GGML_METAL_KERNEL_TYPE_SUM_ROWS,                  sum_rows,               true);
     }
 
+    [metal_library release];
     return ctx;
 }
 
 static void ggml_metal_free(struct ggml_metal_context * ctx) {
     GGML_METAL_LOG_INFO("%s: deallocating\n", __func__);
 
-    for (int i = 0; i < GGML_METAL_MAX_KERNELS; ++i) {
-        if (ctx->kernels[i].pipeline) {
-            [ctx->kernels[i].pipeline release];
-        }
-
-        if (ctx->kernels[i].function) {
-            [ctx->kernels[i].function release];
-        }
+    for (int i = 0; i < GGML_METAL_KERNEL_TYPE_COUNT; ++i) {
+        [ctx->kernels[i].pipeline release];
     }
 
-    [ctx->library release];
     [ctx->queue release];
     [ctx->device release];