Files
Odin/core/mem/virtual/virtual_posix.odin
2024-08-14 01:44:37 +02:00

70 lines
2.2 KiB
Odin

//+build darwin, netbsd, freebsd, openbsd
//+private
package mem_virtual
import "core:sys/posix"
// Define non-posix needed flags:
when ODIN_OS == .Darwin || ODIN_OS == .FreeBSD {
MAP_ANONYMOUS :: 0x1000 /* allocated from memory, swap space */
MADV_FREE :: 5 /* pages unneeded, discard contents */
} else when ODIN_OS == .OpenBSD || ODIN_OS == .NetBSD {
MAP_ANONYMOUS :: 0x1000
MADV_FREE :: 6
}
_reserve :: proc "contextless" (size: uint) -> (data: []byte, err: Allocator_Error) {
flags := posix.Map_Flags{ .PRIVATE } + transmute(posix.Map_Flags)i32(MAP_ANONYMOUS)
result := posix.mmap(nil, size, {}, flags)
if result == posix.MAP_FAILED {
return nil, .Out_Of_Memory
}
return ([^]byte)(uintptr(result))[:size], nil
}
_commit :: proc "contextless" (data: rawptr, size: uint) -> Allocator_Error {
if posix.mprotect(data, size, { .READ, .WRITE }) != .OK {
return .Out_Of_Memory
}
return nil
}
_decommit :: proc "contextless" (data: rawptr, size: uint) {
posix.mprotect(data, size, {})
posix.posix_madvise(data, size, transmute(posix.MAdvice)i32(MADV_FREE))
}
_release :: proc "contextless" (data: rawptr, size: uint) {
posix.munmap(data, size)
}
_protect :: proc "contextless" (data: rawptr, size: uint, flags: Protect_Flags) -> bool {
#assert(i32(posix.Prot_Flag_Bits.READ) == i32(Protect_Flag.Read))
#assert(i32(posix.Prot_Flag_Bits.WRITE) == i32(Protect_Flag.Write))
#assert(i32(posix.Prot_Flag_Bits.EXEC) == i32(Protect_Flag.Execute))
return posix.mprotect(data, size, transmute(posix.Prot_Flags)flags) == .OK
}
_platform_memory_init :: proc() {
DEFAULT_PAGE_SIZE = posix.PAGE_SIZE
// is power of two
assert(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) {
#assert(i32(posix.Prot_Flag_Bits.READ) == i32(Map_File_Flag.Read))
#assert(i32(posix.Prot_Flag_Bits.WRITE) == i32(Map_File_Flag.Write))
addr := posix.mmap(nil, uint(size), transmute(posix.Prot_Flags)flags, { .SHARED }, posix.FD(fd))
if addr == posix.MAP_FAILED || addr == nil {
return nil, .Map_Failure
}
return ([^]byte)(addr)[:size], nil
}