Fix build problems with API header and add shared_counter program

Author: fwsGonzo

compute.json

@@ -63,7 +63,6 @@
 		"filename": "/tmp/compute_gbcemu",
 		"max_memory": 128,
 		"max_request_memory": 64,
-		"shared_memory": 2,
 		"concurrency": 4,
 		"storage": true
 	},
@@ -124,11 +123,6 @@
 		"uri": "https://filebin.varnish-software.com/tinykvm_programs/minify.tar.xz",
 		"filename": "/tmp/compute_minify"
 	},
-	"rust": {
-		"group": "compute",
-		"uri": "https://filebin.varnish-software.com/tinykvm_programs/rustpng.tar.xz",
-		"filename": "/tmp/compute_rust"
-	},
 	"nim_storage": {
 		"group": "compute",
 		"uri": "https://filebin.varnish-software.com/tinykvm_programs/storage_example.tar.xz",
@@ -141,6 +135,17 @@
 		"filename": "/tmp/compute_nim_prefetch_task",
 		"storage": true
 	},
+	"rust": {
+		"group": "compute",
+		"uri": "https://filebin.varnish-software.com/tinykvm_programs/rustpng.tar.xz",
+		"filename": "/tmp/compute_rust"
+	},
+	"shared_counter": {
+		"group": "compute",
+		"uri": "https://filebin.varnish-software.com/tinykvm_programs/shared_counter.tar.xz",
+		"filename": "/tmp/compute_shared_counter",
+		"shared_memory": 2
+	},
 	"stable_diffusion": {
 		"group": "compute",
 		"uri": "https://filebin.varnish-software.com/tinykvm_programs/sdpp.tar.xz",

cpp/.gitignore

@@ -3,4 +3,5 @@ minimal/minimal
 minimal/storage
 collector/collector
 collector/storage
+shared_counter/shared_counter
 *.syms

cpp/shared_counter/build.sh

@@ -0,0 +1 @@
+g++ -O2 -static -std=c++20 shared_counter.cpp -o shared_counter

cpp/shared_counter/shared_counter.cpp

@@ -0,0 +1,24 @@
+#include "../../kvm_api.h"
+static uint64_t* shared_counter = nullptr;
+
+static void on_get(const char *url, const char*)
+{
+	uint64_t counter = __sync_fetch_and_add(shared_counter, 1);
+
+	const char ct[] = "text/plain";
+	char co[] = "Hell0 World, 000!";
+	co[ 4] = '0' + (counter / 1000) % 10;
+	co[13] = '0' + (counter / 100) % 10;
+	co[14] = '0' + (counter / 10) % 10;
+	co[15] = '0' + (counter / 1) % 10;
+	backend_response(200, ct, sizeof(ct)-1, co, sizeof(co)-1);
+}
+
+int main()
+{
+	// Allocate a shared counter in shared memory
+	shared_counter = SHM_ALLOC_TYPE(uint64_t);
+
+	set_backend_get(on_get);
+	wait_for_requests();
+}

kvm_api.h

@@ -427,7 +427,7 @@ struct virtbuffer {
  * static size_t cont_len = 0;
  *
  * static void
- * modify_content(size_t n, struct virtbuffer buffers[n], size_t res)
+ * modify_content(size_t n, struct virtbuffer buffers[], size_t res)
  * {
  *     // Allocate a new zero-terminated buffer from input
  *     char *new_buf = malloc(buffers[0].len + 1);
@@ -443,7 +443,7 @@ struct virtbuffer {
  *     storage_return_nothing();
  * }
  * static void
- * get_content(size_t n, struct virtbuffer buffers[n], size_t res)
+ * get_content(size_t n, struct virtbuffer buffers[], size_t res)
  * {
  *     storage_return(cont, cont_len);
  * }
@@ -472,15 +472,15 @@ struct virtbuffer {
  * from the function. This allows the system to copy the data back to the
  * request program before the function has returned and deallocated the data.
 **/
-typedef void (*storage_func) (size_t n, struct virtbuffer[n], size_t res);
+typedef void (*storage_func) (size_t n, struct virtbuffer[], size_t res);
 
 /* Returns true (1) if called from storage. */
 extern int
 sys_is_storage();
 
 /* Transfer an array of buffers to storage, transfer output into @dst. */
 extern long
-storage_callv(storage_func, size_t n, const struct virtbuffer[n], void* dst, size_t);
+storage_callv(storage_func, size_t n, const struct virtbuffer[], void* dst, size_t);
 
 /* Transfer an array to storage, transfer output into @dst. */
 static inline long
@@ -599,7 +599,13 @@ extern struct shared_memory_info shared_memory_area();
 
 /* Allocate pointers to shared memory with given size and alignment. */
 #define SHM_ALLOC_BYTES(x) internal_shm_alloc(x, 8)
-#define SHM_ALLOC_TYPE(x) (typeof(x) *)internal_shm_alloc(sizeof(x), _Alignof(x))
+#ifdef __cplusplus
+#define SHM_ALLOC_TYPE(x) (x *)internal_shm_alloc(sizeof(x), alignof(x))
+#define SHM_ALLOC(x) (decltype(x) *)internal_shm_alloc(sizeof(x), alignof(x))
+#else
+#define SHM_ALLOC_TYPE(x) (x *)internal_shm_alloc(sizeof(x), _Alignof(x))
+#define SHM_ALLOC(x) (typeof(x) *)internal_shm_alloc(sizeof(x), _Alignof(x))
+#endif
 static inline void * internal_shm_alloc(size_t size, size_t align) {
 	static struct shared_memory_info info;
 	if (info.ptr == 0x0) {