fix DRW instruction, add arena to iui so I don't need to manage label buffers

1 files changed, 139 insertions, 0 deletions

diff --git a/sources/mem.c b/sources/mem.c
new file mode 100644
index 0000000..3b111f7
--- /dev/null
+++ b/sources/mem.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2025 dwlr <dweller@cabin.digital>
+ *
+ * BSD 3-Clause License (BSD-3-Clause)
+ * See LICENSE for details
+ */
+
+
+typedef struct
+{
+    u8*   base;
+    u8* cursor;
+    usize size;
+
+} arena;
+
+
+typedef struct
+{
+    u8*   base;
+    ssize pages;
+
+} do_pagefault_args;
+void* do_pagefault(void* arg)
+{
+    ssize i = 0;
+    ssize p = mm_pagesize();
+    do_pagefault_args* args = (do_pagefault_args*)arg;
+    if(!args)
+    {
+        report(ERR, "do_pagefault() with NULL args!\n");
+        return NULL;
+    }
+
+    for(i = 0; i < args->pages; i++) args->base[p * i] = 0;
+
+    return NULL;
+}
+
+bool ar_create(usize size, bool prefault, arena* ar)
+{
+    ssize p = mm_pagesize();
+
+    if(!ar) return false;
+    if(size <= 0) return false;
+
+    size += (size % p) ? (p - (size % p)) : 0;
+
+    ar->base = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
+    if(ar->base == MAP_FAILED) return false;
+    ar->size = size;
+    ar->cursor = ar->base;
+
+    if(prefault)
+    {
+        ssize i = 0;
+        ssize cpus = cpu_count();
+        pthread_t* t = NULL;
+        do_pagefault_args* args = NULL;
+
+        t = calloc(cpus, sizeof(t[0]));
+        if(!t) report(FATAL, "ar_create()/prefault/calloc(t) failed!\n");
+        else
+        {
+            args = calloc(cpus, sizeof(args[0]));
+            if(!args)
+            {
+                free(t);
+                report(FATAL, "ar_create()/prefault/calloc(args) failed!\n");
+            }
+        }
+
+        for(i = 1; i < cpus; i++)
+        {
+            args[i].base  = ar->base + ((size / cpus) * i);
+            args[i].pages = ((size / p) / cpus);
+            pthread_create(&t[i], NULL, do_pagefault, &args[i]);
+        }
+
+        args[0].base  = ar->base;
+        args[0].pages = ((size / p) / cpus);
+        do_pagefault(&args[0]);
+
+        for(i = 1; i < cpus; i++) pthread_join(t[i], NULL);
+
+        free(args);
+        free(t);
+    }
+
+    return true;
+}
+
+#define ar_push(ar, sz) ar_pusha((ar), (sz), sizeof(int), true)
+void* ar_pusha(arena* ar, usize size, usize alignment, bool zero)
+{
+    usize cur, ovfl;
+
+    if(!ar) return NULL;
+    else
+    {
+        cur = align((usize)ar->cursor, alignment);
+        ovfl = (cur + size);
+        if(ovfl < cur) return NULL;
+
+        if(ovfl <= (usize)(ar->base + ar->size))
+        {
+            ar->cursor = (u8*)ovfl;
+
+            if(zero) memset((u8*)cur, 0, size);
+            return (u8*)cur;
+        }
+        else
+        {
+            report(ERR, "arena(%P): overflow @ %P x %llu\n", ar, cur, size);
+            return NULL;
+        }
+    }
+}
+
+void ar_pop(arena* ar, usize size)
+{
+    if(!ar) return;
+    else    ar->cursor = min(ar->base, ar->cursor - size);
+}
+
+void ar_clear(arena* ar)
+{
+    if(ar) ar->cursor = ar->base;
+}
+
+void ar_destroy(arena* ar)
+{
+    if(!ar) return;
+
+    munmap(ar->base, ar->size);
+    ar->base = ar->cursor = NULL;
+    ar->size = 0;
+}
+