mem.virtual -> os2

core/mem/virtual/doc.odin

@@ -1,7 +1,6 @@
 /*
 A platform agnostic way to reserve/commit/decommit virtual memory.
 
-
 virtual.Arena usage
 
 Example:
@@ -56,7 +55,21 @@ Example:
 		vmem.arena_destroy(&arena)
 	}
 
+virtual.map_file usage
 
+Example:
+	// Source: https://github.com/odin-lang/examples/blob/master/arena_allocator/arena_allocator.odin
+	import "core:fmt"
+
+	// virtual package implements cross-platform file memory mapping
+	import vmem "core:mem/virtual"
+
+	main :: proc() {
+		data, err := virtual.map_file_from_path(#file, {.Read})
+		defer virtual.unmap_file(data)
+		fmt.printfln("Error: %v", err)
+		fmt.printfln("Data:  %s", data)
+	}
 */
 package mem_virtual
 

core/mem/virtual/file.odin

@@ -1,6 +1,6 @@
 package mem_virtual
 
-import "core:os"
+import os "core:os/os2"
 
 Map_File_Error :: enum {
 	None,
@@ -19,21 +19,20 @@ Map_File_Flags :: distinct bit_set[Map_File_Flag; u32]
 
 map_file :: proc{
 	map_file_from_path,
-	map_file_from_file_descriptor,
+	map_file_from_file,
 }
 
 map_file_from_path :: proc(filename: string, flags: Map_File_Flags) -> (data: []byte, error: Map_File_Error) {
-	fd, err := os.open(filename, os.O_RDWR)
+	f, err := os.open(filename, os.O_RDWR)
 	if err != nil {
 		return nil, .Open_Failure
 	}
-	defer os.close(fd)
-
-	return map_file_from_file_descriptor(uintptr(fd), flags)
+	defer os.close(f)
+	return map_file_from_file(f, flags)
 }
 
-map_file_from_file_descriptor :: proc(fd: uintptr, flags: Map_File_Flags) -> (data: []byte, error: Map_File_Error) {
-	size, os_err := os.file_size(os.Handle(fd))
+map_file_from_file :: proc(f: ^os.File, flags: Map_File_Flags) -> (data: []byte, error: Map_File_Error) {
+	size, os_err := os.file_size(f)
 	if os_err != nil {
 		return nil, .Stat_Failure
 	}
@@ -43,5 +42,12 @@ map_file_from_file_descriptor :: proc(fd: uintptr, flags: Map_File_Flags) -> (da
 	if size != i64(int(size)) {
 		return nil, .Too_Large_Size
 	}
+	fd := os.fd(f)
 	return _map_file(fd, size, flags)
 }
+
+unmap_file :: proc(data: []byte) {
+	if raw_data(data) != nil {
+		_unmap_file(data)
+	}
+}

core/mem/virtual/virtual_linux.odin

@@ -49,7 +49,6 @@ _platform_memory_init :: proc "contextless" () {
 	assert_contextless(DEFAULT_PAGE_SIZE != 0 && (DEFAULT_PAGE_SIZE & (DEFAULT_PAGE_SIZE-1)) == 0)
 }
 
-
 _map_file :: proc "contextless" (fd: uintptr, size: i64, flags: Map_File_Flags) -> (data: []byte, error: Map_File_Error) {
 	prot: linux.Mem_Protection
 	if .Read in flags {
@@ -66,3 +65,7 @@ _map_file :: proc "contextless" (fd: uintptr, size: i64, flags: Map_File_Flags)
 	}
 	return ([^]byte)(addr)[:size], nil
 }
+
+_unmap_file :: proc "contextless" (data: []byte) {
+	_release(raw_data(data), uint(len(data)))
+}

core/mem/virtual/virtual_other.odin

@@ -26,8 +26,13 @@ _protect :: proc "contextless" (data: rawptr, size: uint, flags: Protect_Flags)
 }
 
 _platform_memory_init :: proc "contextless" () {
+
 }
 
-_map_file :: proc "contextless" (fd: uintptr, size: i64, flags: Map_File_Flags) -> (data: []byte, error: Map_File_Error) {
+_map_file :: proc "contextless" (f: any, size: i64, flags: Map_File_Flags) -> (data: []byte, error: Map_File_Error) {
 	return nil, .Map_Failure
 }
+
+_unmap_file :: proc "contextless" (data: []byte) {
+
+}

core/mem/virtual/virtual_posix.odin

@@ -47,3 +47,7 @@ _map_file :: proc "contextless" (fd: uintptr, size: i64, flags: Map_File_Flags)
 	}
 	return ([^]byte)(addr)[:size], nil
 }
+
+_unmap_file :: proc "contextless" (data: []byte) {
+	_release(raw_data(data), uint(len(data)))
+}

core/mem/virtual/virtual_windows.odin

@@ -82,6 +82,8 @@ foreign Kernel32 {
 		dwFileOffsetLow:      u32,
 		dwNumberOfBytesToMap: uint,
 	) -> rawptr ---
+
+	UnmapViewOfFile :: proc(lpBaseAddress: rawptr) -> b32 ---
 }
 
 @(no_sanitize_address)
@@ -185,3 +187,8 @@ _map_file :: proc "contextless" (fd: uintptr, size: i64, flags: Map_File_Flags)
 	file_data := MapViewOfFile(handle, desired_access, 0, 0, uint(size))
 	return ([^]byte)(file_data)[:size], nil
 }
+
+@(no_sanitize_address)
+_unmap_file :: proc "contextless" (data: []byte) {
+	UnmapViewOfFile(raw_data(data))
+}