add get core count

core/os/os_darwin.odin

@@ -314,6 +314,7 @@ foreign libc {
 	@(link_name="realpath") _unix_realpath :: proc(path: cstring, resolved_path: rawptr) -> rawptr ---
 
 	@(link_name="strerror") _darwin_string_error :: proc(num : c.int) -> cstring ---
+	@(link_name="sysctlbyname") _sysctlbyname    :: proc(path: cstring, oldp: rawptr, oldlenp: rawptr, newp: rawptr, newlen: int) -> c.int ---
 
 	@(link_name="exit")    _unix_exit :: proc(status: c.int) -> ! ---
 }
@@ -771,6 +772,17 @@ get_page_size :: proc() -> int {
 	return page_size
 }
 
+get_processor_thread_count :: proc() -> int {
+	count : int = 0
+	count_size := size_of(count)
+	if _sysctlbyname("hw.logicalcpu", rawptr(count), rawptr(count_size), 0, 0) == 0 {
+		if count > 0 {
+			return count
+		}
+	}
+
+	return 1
+}
 
 _alloc_command_line_arguments :: proc() -> []string {
 	res := make([]string, len(runtime.args__))

core/os/os_freebsd.odin

@@ -287,6 +287,7 @@ foreign libc {
 	
 	@(link_name="getenv")           _unix_getenv        :: proc(cstring) -> cstring ---
 	@(link_name="realpath")         _unix_realpath      :: proc(path: cstring, resolved_path: rawptr) -> rawptr ---
+	@(link_name="sysctlbyname")     _sysctlbyname       :: proc(path: cstring, oldp: rawptr, oldlenp: rawptr, newp: rawptr, newlen: int) -> c.int ---
 
 	@(link_name="exit")             _unix_exit          :: proc(status: c.int) -> ! ---
 }
@@ -702,6 +703,18 @@ get_page_size :: proc() -> int {
 	return page_size
 }
 
+get_processor_thread_count :: proc() -> int {
+	count : int = 0
+	count_size := size_of(count)
+	if _sysctlbyname("hw.logicalcpu", rawptr(count), rawptr(count_size), 0, 0) == 0 {
+		if count > 0 {
+			return count
+		}
+	}
+
+	return 1
+}
+
 
 _alloc_command_line_arguments :: proc() -> []string {
 	res := make([]string, len(runtime.args__))

core/os/os_linux.odin

@@ -404,6 +404,7 @@ foreign libc {
 	@(link_name="__errno_location") __errno_location    :: proc() -> ^int ---
 
 	@(link_name="getpagesize")      _unix_getpagesize   :: proc() -> c.int ---
+	@(link_name="get_nprocs")       _unix_get_nprocs    :: proc() -> c.int ---
 	@(link_name="fdopendir")        _unix_fdopendir     :: proc(fd: Handle) -> Dir ---
 	@(link_name="closedir")         _unix_closedir      :: proc(dirp: Dir) -> c.int ---
 	@(link_name="rewinddir")        _unix_rewinddir     :: proc(dirp: Dir) ---
@@ -878,6 +879,10 @@ get_page_size :: proc() -> int {
 	return page_size
 }
 
+get_processor_thread_count :: proc() -> int {
+	thread_count := int(_unix_get_nprocs())
+	return thread_count
+}
 
 _alloc_command_line_arguments :: proc() -> []string {
 	res := make([]string, len(runtime.args__))

core/os/os_windows.odin

@@ -126,6 +126,28 @@ get_page_size :: proc() -> int {
 	return page_size
 }
 
+get_processor_thread_count :: proc() -> int {
+	length : c.int = 0
+	result := windows.GetLogicalProcessorInformation(nil, &length)
+
+	thread_count := 0
+	if !result && win32.GetLastError() == 122 && length > 0 {
+		processors := make([]windows.SYSTEM_LOGICAL_PROCESSOR_INFORMATION, length, context.temp_allocator)
+
+		result = windows.GetLogicalProcessorInformation(&processors[0], &length)
+		if result {
+			core_count := 0
+			for processor in processors {
+				if processor.Relationship == windows.RelationProcessorCore {
+					thread := intrinsics.count_ones(processor.ProcessorMask)
+					thread_count += thread
+				}
+			}
+		}
+	}
+
+	return thread_count
+}
 
 
 exit :: proc "contextless" (code: int) -> ! {
@@ -214,4 +236,4 @@ is_windows_10 :: proc() -> bool {
 is_windows_11 :: proc() -> bool {
 	osvi := get_windows_version_w()
 	return (osvi.dwMajorVersion == 10 && osvi.dwMinorVersion == 0 && osvi.dwBuildNumber >= WINDOWS_11_BUILD_CUTOFF)
-}
+}