Cosmopolitan now supports mremap(), which is only supported on Linux and
NetBSD. First, it allows memory mappings to be relocated without copying
them; this can dramatically speed up data structures like std::vector if
the array size grows larger than 256kb. The mremap() system call is also
10x faster than munmap() when shrinking large memory mappings.
There's now two functions, getpagesize() and getgransize() which help to
write portable code that uses mmap(MAP_FIXED). Alternative sysconf() may
be called with our new _SC_GRANSIZE. The madvise() system call now has a
better wrapper with improved documentation.
It's now possible to create thousands of thousands of sparse independent
memory mappings, without any slowdown. The memory manager is better with
tracking memory protection now, particularly on Windows in a precise way
that can be restored during fork(). You now have the highest quality mem
manager possible. It's even better than some OSes like XNU, where mmap()
is implemented as an O(n) operation which means sadly things aren't much
improved over there. With this change the llamafile HTTP server endpoint
at /tokenize with a prompt of 50 tokens is now able to handle 2.6m r/sec
- Ensure SIGTHR isn't blocked in newly created threads
- Use TIB rather than thread_local for thread atexits
- Make POSIX thread keys atomic within thread
- Don't bother logging prctl() to --strace
- Log thread destructor names to --strace
The way to use double linked lists, is to remove all the things you want
to work on, insert them into a new list on the stack. Then once you have
all the work items, you release the lock, do your work, and then lock it
again, to add the shelled out items back to a global freelist.
This fixes a regression in mmap(MAP_FIXED) on Windows caused by a recent
revision. This change also fixes ZipOS so it no longer needs a MAP_FIXED
mapping to open files from the PKZIP store. The memory mapping mutex was
implemented incorrectly earlier which meant that ftrace and strace could
cause cause crashes. This lock and other recursive mutexes are rewritten
so that it should be provable that recursive mutexes in cosmopolitan are
asynchronous signal safe.
This change introduces accumulate, addressof, advance, all_of, distance,
array, enable_if, allocator_traits, back_inserter, bad_alloc, is_signed,
any_of, copy, exception, fill, fill_n, is_same, is_same_v, out_of_range,
lexicographical_compare, is_integral, uninitialized_fill_n, is_unsigned,
numeric_limits, uninitialized_fill, iterator_traits, move_backward, min,
max, iterator_tag, move_iterator, reverse_iterator, uninitialized_move_n
This change experiments with rewriting the ctl::vector class to make the
CTL design more similar to the STL. So far it has not slowed things down
to have 42 #include lines rather than 2, since it's still almost nothing
compared to LLVM's code. In fact the closer we can flirt with being just
like libcxx, the better chance we might have of discovering exactly what
makes it so slow to compile. It would be an enormous discovery if we can
find one simple trick to solving the issue there instead.
This also fixes a bug in `ctl::string(const string &s)` when `s` is big.
We now have a C++ red-black tree implementation that implements standard
template library compatible APIs while compiling 10x faster than libcxx.
It's not as beautiful as the red-black tree implementation in Plinko but
this will get the job done and the test proves it upholds all invariants
This change also restores CheckForMemoryLeaks() support and fixes a real
actual bug I discovered with Doug Lea's dlmalloc_inspect_all() function.
It hasn't been helpful enough to be justify the maintenance burden. What
actually does help is mprotect(), kprintf(), --ftrace and --strace which
can always be counted upon to work correctly. We aren't losing much with
this change. Support for ASAN on AARCH64 was never implemented. Applying
ASAN to the core libc runtimes was disabled many months ago. If there is
some way to have an ASAN runtime for user programs that is less invasive
we can potentially consider reintroducing support. But now is premature.
Actually Portable Executable now supports Android. Cosmo's old mmap code
required a 47 bit address space. The new implementation is very agnostic
and supports both smaller address spaces (e.g. embedded) and even modern
56-bit PML5T paging for x86 which finally came true on Zen4 Threadripper
Cosmopolitan no longer requires UNIX systems to observe the Windows 64kb
granularity; i.e. sysconf(_SC_PAGE_SIZE) will now report the host native
page size. This fixes a longstanding POSIX conformance issue, concerning
file mappings that overlap the end of file. Other aspects of conformance
have been improved too, such as the subtleties of address assignment and
and the various subtleties surrounding MAP_FIXED and MAP_FIXED_NOREPLACE
On Windows, mappings larger than 100 megabytes won't be broken down into
thousands of independent 64kb mappings. Support for MAP_STACK is removed
by this change; please use NewCosmoStack() instead.
Stack overflow avoidance is now being implemented using the POSIX thread
APIs. Please use GetStackBottom() and GetStackAddr(), instead of the old
error-prone GetStackAddr() and HaveStackMemory() APIs which are removed.
Explicitly value-initializes the deleter, even though I have not found a
way to get the deleter to act like it’s been default-initialized in unit
tests so far.
Uses auto in reset. The static cast is apparently not needed (unless I’m
missing some case I didn’t think of.)
Implements the general move constructor - turns out that the reason this
didn’t work before was that default_delete<U> was not move constructible
from default_delete<T>.
Drop inline specifiers from functions defined entirely inside the struct
definition since they are implicitly inline.
* Cleans up reset to match spec
Remove the variants from the T[] specialization. Also follow the spec on
the order of operations in reset, which may matter if we are deleting an
object that has a reference to the unique_ptr that is being reset. (?)
* Tests Base/Derived reset.
* Adds some constexpr declarations.
* Adds default_delete specialization for T[].
* Makes parameters const.
Moves some isbig checks into string.h, enabling smarter optimizations to
be made on small strings. Also we no longer zero out our string prior to
calling the various constructors, buying back the performance we lost on
big strings when we made the small-string optimization. We further add a
little optimization to the big_string copy constructor: if the string is
using half or more of its capacity, then we don’t recompute capacity and
just take the old string’s. As well, the copy constructor always makes a
small string when it will fit, even if copied from a big string that got
truncated.
This also reworks the test to follow the idiom adopted elsewhere re stl,
and adds a helper function to tell if a string is small based on data().
* Add ctl utility.h
Implements forward, move, swap, and declval. This commit also adds a def
for nullptr_t to cxx.inc. We need it now because the CTL headers stopped
including anything from libc++, so we no longer get their basic types.
* Use ctl::swap in string
The STL spec says that swap is located in the string_view header anyawy.
Performance-wise this is a noop, but it’s slightly cleaner.
The way unique_ptr is supposed to work is as a purely compile-time check
that your raw pointers are getting deleted when they go out of scope. It
should ideally emit the same exact machine code as if you were using raw
pointers with manual deletes.
Part of what this means is that under normal circumstances, a unique_ptr
shouldn’t take up more space than a raw pointer - in other words, sizeof
unique_ptr<T> should == sizeof(T*).
The present PR doesn’t bother with the specialization for array types. I
also left a couple other parts of the STL API unimplemented. I’d love to
see someone else implement these, or I’ll get to them at some point.
🚨 clang-format changes output per version!
This is with version 19.0.0. The modifications seem to be fixing the old
version’s errors - mainly involving omitted whitespace around binary ops
and inserted whitespace between goto labels and colons (if followed by a
curly brace.)
Also fixes a few mistakes made by e.g. someone (ahem) forgetting to pass
his ctl/string.h modifications through it.
We should add this to .git-blame-ignore-revs once we have its final hash
on master.
This replaces the STL <new> header. Mainly, it defines a global operator
new and operator delete, as well as the placement versions of these. The
placement versions are required to not get compile errors when trying to
write a placement new statement.
Each of these operators is defined with many, many different variants. A
glance at new.cc is recommended followed by a chaser of the Alexandrescu
talk "std::allocator is to Allocation as std::vector is to Vexation". We
must provide a global-namespace source-level definition of each operator
and it is illegal for any of them to be marked inline, so here we are.
The upshot is that we no longer need to include <new>, and our optional/
vector headers are self-contained.
Manually manage the lifetime of `value_` by using an anonymous
`union`. This fixes a bunch of double-frees and double-constructs.
Additionally move the `present_` flag last. When `T` has padding
`present_` will be placed there saving `alignof(T)` bytes from
`sizeof(optional<T>)`.
There were a few errors in how capacity and memory was being handled for
small strings. The capacity errors meant that small strings would become
big strings too soon, and the memory error introduced undefined behavior
that was caught by CheckMemoryLeaks in our test file but only sometimes.
The crucial change is in reserve: we only copy n bytes into p2, and then
we manually set the null terminator instead of expecting it to have been
there already. (E.g. it might not be there for an empty small string.)
We also fix one other doozy in append when we were exactly at the small-
to-big string boundary: we set the last byte (i.e., the remainder field)
to 0, then decremented it, giving us size_t max. Whoops. We boneheadedly
fix this by setting the 0 byte after we've fixed up the remainder, so it
is at worst a no-op.
Otherwise, capacity now works the same for small strings as it does with
big strings: it's the amount of space available including the null byte.
We test all of this with a new test that only gets included if our class
under test is not std::string (presumably meaning it's ctl::string.) The
test manually verifies that the small string optimization behaves how we
expect.
Since this test checks against std::string, we go ahead and include that
other header from the STL.
Also modifies the new test we introduced to also run on std::string, but
it just does the append without expecting anything about how its data is
stored. We also check that the string has the right value afterwards.
