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add std.process.totalSystemMemory

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This commit is contained in:
Andrew Kelley
2023-03-06 00:19:32 -07:00
parent 6377aad23a
commit 3b29d00c98
2 changed files with 38 additions and 0 deletions
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3
lib/std/os/windows/kernel32.zig
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@@ -67,6 +67,7 @@ const RUNTIME_FUNCTION = windows.RUNTIME_FUNCTION;
const KNONVOLATILE_CONTEXT_POINTERS = windows.KNONVOLATILE_CONTEXT_POINTERS;
const EXCEPTION_ROUTINE = windows.EXCEPTION_ROUTINE;
const MODULEENTRY32 = windows.MODULEENTRY32;
const ULONGLONG = windows.ULONGLONG;
pub extern "kernel32" fn AddVectoredExceptionHandler(First: c_ulong, Handler: ?VECTORED_EXCEPTION_HANDLER) callconv(WINAPI) ?*anyopaque;
pub extern "kernel32" fn RemoveVectoredExceptionHandler(Handle: HANDLE) callconv(WINAPI) c_ulong;
@@ -457,3 +458,5 @@ pub extern "kernel32" fn RegOpenKeyExW(
samDesired: REGSAM,
phkResult: *HKEY,
) callconv(WINAPI) LSTATUS;
pub extern "kernel32" fn GetPhysicallyInstalledSystemMemory(TotalMemoryInKilobytes: *ULONGLONG) BOOL;

35
lib/std/process.zig
View File

@@ -1169,3 +1169,38 @@ pub fn execve(
return os.execvpeZ_expandArg0(.no_expand, argv_buf.ptr[0].?, argv_buf.ptr, envp);
}
pub const TotalSystemMemoryError = error{
UnknownTotalSystemMemory,
};
/// Returns the total system memory, in bytes.
pub fn totalSystemMemory() TotalSystemMemoryError!usize {
switch (builtin.os.tag) {
.linux => {
return totalSystemMemoryLinux() catch return error.UnknownTotalSystemMemory;
},
.windows => {
var kilobytes: std.os.windows.ULONGLONG = undefined;
assert(std.os.windows.kernel32.GetPhysicallyInstalledSystemMemory(&kilobytes) == std.os.windows.TRUE);
return kilobytes * 1024;
},
else => return error.UnknownTotalSystemMemory,
}
}
fn totalSystemMemoryLinux() !usize {
var file = try std.fs.openFileAbsoluteZ("/proc/meminfo", .{});
defer file.close();
var buf: [50]u8 = undefined;
const amt = try file.read(&buf);
if (amt != 50) return error.Unexpected;
var it = std.mem.tokenize(u8, buf[0..amt], " \n");
const label = it.next().?;
if (!std.mem.eql(u8, label, "MemTotal:")) return error.Unexpected;
const int_text = it.next() orelse return error.Unexpected;
const units = it.next() orelse return error.Unexpected;
if (!std.mem.eql(u8, units, "kB")) return error.Unexpected;
const kilobytes = try std.fmt.parseInt(usize, int_text, 10);
return kilobytes * 1024;
}