From 72608ce01dfa8db72356fd4e47551ef7acb8fe60 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Tue, 18 Mar 2025 15:16:22 +0100
Subject: [PATCH] - Temp allocator now supports more than 2 in-flight stacks. -
 Printing stacktrace uses its own temp allocator. - `@pool` no longer takes an
 argument. - `Allocator` interface removes `mark` and `reset`. -
 DynamicArenaAllocator has changed init function. - Added
 `BackedArenaAllocator` which is allocated to a fixed size, then allocates on
 the backing allocator and supports mark/reset.

---
 lib/std/compression/qoi.c3                    |   2 +-
 lib/std/core/allocators/arena_allocator.c3    |   4 +-
 .../core/allocators/backed_arena_allocator.c3 | 210 ++++++++++++++++++
 lib/std/core/allocators/dynamic_arena.c3      |   5 +-
 lib/std/core/allocators/temp_allocator.c3     | 134 ++++++-----
 lib/std/core/builtin.c3                       |  11 +-
 lib/std/core/dstring.c3                       |   7 +-
 lib/std/core/mem.c3                           |  44 +---
 lib/std/core/mem_allocator.c3                 | 112 +++++-----
 lib/std/core/runtime_test.c3                  |   2 +-
 lib/std/core/string.c3                        |   4 +-
 lib/std/encoding/json.c3                      |   2 +-
 lib/std/io/io.c3                              |   2 +-
 lib/std/io/os/ls.c3                           |   4 +-
 lib/std/io/os/temp_directory.c3               |   2 +-
 lib/std/io/path.c3                            |  16 +-
 lib/std/net/url.c3                            |   6 +-
 lib/std/net/url_encoding.c3                   |   4 +-
 lib/std/os/env.c3                             |   4 +-
 lib/std/os/linux/linux.c3                     |   4 +-
 lib/std/os/macos/darwin.c3                    |   6 +-
 releasenotes.md                               |   6 +
 .../generic/generic_lambda_complex.c3t        |  25 ++-
 .../test_suite/macros/short_trailing_body.c3t | 113 ++++------
 test/test_suite/stdlib/map_linux.c3t          |  57 ++---
 test/test_suite/stdlib/map_macos.c3t          |  57 ++---
 test/unit/stdlib/mem/temp_mem.c3              |  10 +-
 27 files changed, 519 insertions(+), 334 deletions(-)
 create mode 100644 lib/std/core/allocators/backed_arena_allocator.c3

diff --git a/lib/std/compression/qoi.c3 b/lib/std/compression/qoi.c3
index a389d2a12..eecfa4dd9 100644
--- a/lib/std/compression/qoi.c3
+++ b/lib/std/compression/qoi.c3
@@ -95,7 +95,7 @@ fn usz? write(String filename, char[] input, QOIDesc* desc) => @pool()
  @param channels : `The channels to be used`
  @return? FILE_OPEN_FAILED, INVALID_DATA, TOO_MANY_PIXELS
 *>
-fn char[]? read(Allocator allocator, String filename, QOIDesc* desc, QOIChannels channels = AUTO) => @pool(allocator)
+fn char[]? read(Allocator allocator, String filename, QOIDesc* desc, QOIChannels channels = AUTO) => @pool()
 {
 	// read file
 	char[] data = file::load_temp(filename) ?? FILE_OPEN_FAILED?!;
diff --git a/lib/std/core/allocators/arena_allocator.c3 b/lib/std/core/allocators/arena_allocator.c3
index 672477dc6..4cc8631c6 100644
--- a/lib/std/core/allocators/arena_allocator.c3
+++ b/lib/std/core/allocators/arena_allocator.c3
@@ -50,8 +50,8 @@ fn void ArenaAllocator.release(&self, void* ptr, bool) @dynamic
 	}
 }
 
-fn usz ArenaAllocator.mark(&self) @dynamic => self.used;
-fn void ArenaAllocator.reset(&self, usz mark) @dynamic => self.used = mark;
+fn usz ArenaAllocator.mark(&self) => self.used;
+fn void ArenaAllocator.reset(&self, usz mark) => self.used = mark;
 
 <*
  @require !alignment || math::is_power_of_2(alignment)
diff --git a/lib/std/core/allocators/backed_arena_allocator.c3 b/lib/std/core/allocators/backed_arena_allocator.c3
new file mode 100644
index 000000000..62366b157
--- /dev/null
+++ b/lib/std/core/allocators/backed_arena_allocator.c3
@@ -0,0 +1,210 @@
+module std::core::mem::allocator;
+import std::io, std::math;
+
+struct AllocChunk @local
+{
+	usz size;
+	char[*] data;
+}
+
+struct BackedArenaAllocator (Allocator)
+{
+	Allocator backing_allocator;
+	ExtraPage* last_page;
+	usz used;
+	usz capacity;
+	char[*] data;
+}
+
+const usz PAGE_IS_ALIGNED @local = (usz)isz.max + 1u;
+
+struct ExtraPage @local
+{
+	ExtraPage* prev_page;
+	void* start;
+	usz mark;
+	usz size;
+	usz ident;
+	char[*] data;
+}
+
+macro usz ExtraPage.pagesize(&self) => self.size & ~PAGE_IS_ALIGNED;
+macro bool ExtraPage.is_aligned(&self) => self.size & PAGE_IS_ALIGNED == PAGE_IS_ALIGNED;
+
+<*
+ @require size >= 16
+*>
+fn BackedArenaAllocator*? new_backed_allocator(usz size, Allocator allocator)
+{
+	BackedArenaAllocator* temp = allocator::alloc_with_padding(allocator, BackedArenaAllocator, size)!;
+	temp.last_page = null;
+	temp.backing_allocator = allocator;
+	temp.used = 0;
+	temp.capacity = size;
+	return temp;
+}
+
+fn void BackedArenaAllocator.destroy(&self)
+{
+	self.reset(0);
+	if (self.last_page) (void)self._free_page(self.last_page);
+	allocator::free(self.backing_allocator, self);
+}
+
+fn usz BackedArenaAllocator.mark(&self) => self.used;
+
+fn void BackedArenaAllocator.release(&self, void* old_pointer, bool) @dynamic
+{
+	usz old_size = *(usz*)(old_pointer - DEFAULT_SIZE_PREFIX);
+	if (old_pointer + old_size == &self.data[self.used])
+	{
+		self.used -= old_size;
+		asan::poison_memory_region(&self.data[self.used], old_size);
+	}
+}
+fn void BackedArenaAllocator.reset(&self, usz mark)
+{
+	ExtraPage *last_page = self.last_page;
+	while (last_page && last_page.mark > mark)
+	{
+		self.used = last_page.mark;
+		ExtraPage *to_free = last_page;
+		last_page = last_page.prev_page;
+		self._free_page(to_free)!!;
+	}
+	self.last_page = last_page;
+	$if env::COMPILER_SAFE_MODE || env::ADDRESS_SANITIZER:
+		if (!last_page)
+		{
+			usz cleaned = self.used - mark;
+			if (cleaned > 0)
+			{
+				$if env::COMPILER_SAFE_MODE && !env::ADDRESS_SANITIZER:
+					self.data[mark : cleaned] = 0xAA;
+				$endif
+				asan::poison_memory_region(&self.data[mark], cleaned);
+			}
+		}
+	$endif
+	self.used = mark;
+}
+
+fn void? BackedArenaAllocator._free_page(&self, ExtraPage* page) @inline @local
+{
+	void* mem = page.start;
+	return self.backing_allocator.release(mem, page.is_aligned());
+}
+
+fn void*? BackedArenaAllocator._realloc_page(&self, ExtraPage* page, usz size, usz alignment) @inline @local
+{
+	// Then the actual start pointer:
+	void* real_pointer = page.start;
+
+	// Walk backwards to find the pointer to this page.
+	ExtraPage **pointer_to_prev = &self.last_page;
+	// Remove the page from the list
+	while (*pointer_to_prev != page)
+	{
+		pointer_to_prev = &((*pointer_to_prev).prev_page);
+	}
+	*pointer_to_prev = page.prev_page;
+	usz page_size = page.pagesize();
+	// Clear on size > original size.
+	void* data = self.acquire(size, NO_ZERO, alignment)!;
+	mem::copy(data, &page.data[0], page_size, mem::DEFAULT_MEM_ALIGNMENT, mem::DEFAULT_MEM_ALIGNMENT);
+	self.backing_allocator.release(real_pointer, page.is_aligned());
+	return data;
+}
+
+fn void*? BackedArenaAllocator.resize(&self, void* pointer, usz size, usz alignment) @dynamic
+{
+	AllocChunk *chunk = pointer - AllocChunk.sizeof;
+	if (chunk.size == (usz)-1)
+	{
+		assert(self.last_page, "Realloc of unrelated pointer");
+		// First grab the page
+		ExtraPage *page = pointer - ExtraPage.sizeof;
+		return self._realloc_page(page, size, alignment);
+	}
+
+	AllocChunk* data = self.acquire(size, NO_ZERO, alignment)!;
+	mem::copy(data, pointer, chunk.size, mem::DEFAULT_MEM_ALIGNMENT, mem::DEFAULT_MEM_ALIGNMENT);
+
+	return data;
+}
+
+<*
+ @require size > 0
+ @require !alignment || math::is_power_of_2(alignment)
+ @require alignment <= mem::MAX_MEMORY_ALIGNMENT : `alignment too big`
+*>
+fn void*? BackedArenaAllocator.acquire(&self, usz size, AllocInitType init_type, usz alignment) @dynamic
+{
+	alignment = alignment_for_allocation(alignment);
+	void* start_mem = &self.data;
+	void* starting_ptr = start_mem + self.used;
+	void* aligned_header_start = mem::aligned_pointer(starting_ptr, AllocChunk.alignof);
+	void* mem = aligned_header_start + AllocChunk.sizeof;
+	if (alignment > AllocChunk.alignof)
+	{
+		mem = mem::aligned_pointer(mem, alignment);
+	}
+	usz new_usage = (usz)(mem - start_mem) + size;
+
+	// Arena allocation, simple!
+	if (new_usage <= self.capacity)
+	{
+		asan::unpoison_memory_region(starting_ptr, new_usage - self.used);
+		AllocChunk* chunk_start = mem - AllocChunk.sizeof;
+		chunk_start.size = size;
+		self.used = new_usage;
+		if (init_type == ZERO) mem::clear(mem, size, mem::DEFAULT_MEM_ALIGNMENT);
+		return mem;
+	}
+
+	// Fallback to backing allocator
+	ExtraPage* page;
+
+	// We have something we need to align.
+	if (alignment > mem::DEFAULT_MEM_ALIGNMENT)
+	{
+		// This is actually simpler, since it will create the offset for us.
+		usz total_alloc_size = mem::aligned_offset(ExtraPage.sizeof + size, alignment);
+		if (init_type == ZERO)
+		{
+			mem = allocator::calloc_aligned(self.backing_allocator, total_alloc_size, alignment)!;
+		}
+		else
+		{
+			mem = allocator::malloc_aligned(self.backing_allocator, total_alloc_size, alignment)!;
+		}
+		void* start = mem;
+		mem += mem::aligned_offset(ExtraPage.sizeof, alignment);
+		page = (ExtraPage*)mem - 1;
+		page.start = start;
+		page.size = size | PAGE_IS_ALIGNED;
+	}
+	else
+	{
+		// Here we might need to pad
+		usz padded_header_size = mem::aligned_offset(ExtraPage.sizeof, mem::DEFAULT_MEM_ALIGNMENT);
+		usz total_alloc_size = padded_header_size + size;
+		void* alloc = self.backing_allocator.acquire(total_alloc_size, init_type, 0)!;
+
+		// Find the page.
+		page = alloc + padded_header_size - ExtraPage.sizeof;
+		assert(mem::ptr_is_aligned(page, BackedArenaAllocator.alignof));
+		assert(mem::ptr_is_aligned(&page.data[0], mem::DEFAULT_MEM_ALIGNMENT));
+		page.start = alloc;
+		page.size = size;
+	}
+
+	// Mark it as a page
+	page.ident = ~(usz)0;
+	// Store when it was created
+	page.mark = ++self.used;
+	// Hook up the page.
+	page.prev_page = self.last_page;
+	self.last_page = page;
+	return &page.data[0];
+}
diff --git a/lib/std/core/allocators/dynamic_arena.c3 b/lib/std/core/allocators/dynamic_arena.c3
index 5fd3ec751..cd1520c14 100644
--- a/lib/std/core/allocators/dynamic_arena.c3
+++ b/lib/std/core/allocators/dynamic_arena.c3
@@ -16,7 +16,7 @@ struct DynamicArenaAllocator (Allocator)
  @param [&inout] allocator
  @require page_size >= 128
 *>
-fn void DynamicArenaAllocator.init(&self, usz page_size, Allocator allocator)
+fn void DynamicArenaAllocator.init(&self, Allocator allocator, usz page_size)
 {
 	self.page = null;
 	self.unused_page = null;
@@ -110,9 +110,8 @@ fn void*? DynamicArenaAllocator.resize(&self, void* old_pointer, usz size, usz a
 	return new_mem;
 }
 
-fn void DynamicArenaAllocator.reset(&self, usz mark = 0) @dynamic
+fn void DynamicArenaAllocator.reset(&self)
 {
-	assert(mark == 0, "Unexpectedly reset dynamic arena allocator with mark %d", mark);
 	DynamicArenaPage* page = self.page;
 	DynamicArenaPage** unused_page_ptr = &self.unused_page;
 	while (page)
diff --git a/lib/std/core/allocators/temp_allocator.c3 b/lib/std/core/allocators/temp_allocator.c3
index 48ff2d48c..ecddc22b0 100644
--- a/lib/std/core/allocators/temp_allocator.c3
+++ b/lib/std/core/allocators/temp_allocator.c3
@@ -11,8 +11,11 @@ struct TempAllocator (Allocator)
 {
 	Allocator backing_allocator;
 	TempAllocatorPage* last_page;
+	TempAllocator* derived;
+	bool allocated;
 	usz used;
 	usz capacity;
+	usz original_capacity;
 	char[*] data;
 }
 
@@ -23,7 +26,6 @@ struct TempAllocatorPage
 {
 	TempAllocatorPage* prev_page;
 	void* start;
-	usz mark;
 	usz size;
 	usz ident;
 	char[*] data;
@@ -34,25 +36,92 @@ macro bool TempAllocatorPage.is_aligned(&self) => self.size & PAGE_IS_ALIGNED ==
 
 <*
  @require size >= 16
+ @require allocator.type != TempAllocator.typeid : "You may not create a temp allocator with a TempAllocator as the backing allocator."
 *>
-fn TempAllocator*? new_temp_allocator(usz size, Allocator allocator)
+fn TempAllocator*? new_temp_allocator(Allocator allocator, usz size)
 {
 	TempAllocator* temp = allocator::alloc_with_padding(allocator, TempAllocator, size)!;
 	temp.last_page = null;
 	temp.backing_allocator = allocator;
 	temp.used = 0;
-	temp.capacity = size;
+	temp.allocated = true;
+	temp.derived = null;
+	temp.original_capacity = temp.capacity = size;
 	return temp;
 }
-
-fn void TempAllocator.destroy(&self)
+<*
+ @require !self.derived
+ @require min_size > TempAllocator.sizeof + 64 : "Min size must meaningfully hold the data + some bytes"
+ @require mult > 0 : "The multiple can never be zero"
+*>
+fn TempAllocator*? TempAllocator.derive_allocator(&self, usz min_size, usz buffer, usz mult)
 {
-	self.reset(0);
-	if (self.last_page) (void)self._free_page(self.last_page);
-	allocator::free(self.backing_allocator, self);
+	usz remaining = self.capacity - self.used;
+	void* mem @noinit;
+	usz size @noinit;
+	if (min_size + buffer > remaining)
+	{
+		return self.derived = new_temp_allocator(self.backing_allocator, min_size * mult)!;
+	}
+	usz start = mem::aligned_offset(self.used + buffer, mem::DEFAULT_MEM_ALIGNMENT);
+	void* ptr = &self.data[start];
+	TempAllocator* temp = (TempAllocator*)ptr;
+	temp.last_page = null;
+    temp.backing_allocator = self.backing_allocator;
+    temp.used = 0;
+    temp.allocated = false;
+    temp.derived = null;
+    temp.original_capacity = temp.capacity = self.capacity - start - TempAllocator.sizeof;
+    self.capacity = start;
+	self.derived = temp;
+    return temp;
 }
 
-fn usz TempAllocator.mark(&self) @dynamic => self.used;
+fn void TempAllocator.reset(&self)
+{
+	TempAllocator* child = self.derived;
+	if (!child) return;
+	while (child)
+	{
+		TempAllocator* old = child;
+		old.destroy();
+		child = old.derived;
+	}
+	self.capacity = self.original_capacity;
+	self.derived = null;
+}
+
+<*
+ @require self.allocated : "Only a top level allocator should be freed."
+*>
+fn void TempAllocator.free(&self)
+{
+	self.reset();
+	self.destroy();
+}
+
+fn void TempAllocator.destroy(&self) @local
+{
+	TempAllocatorPage *last_page = self.last_page;
+	while (last_page)
+	{
+		TempAllocatorPage *to_free = last_page;
+		last_page = last_page.prev_page;
+		self._free_page(to_free)!!;
+	}
+	if (self.allocated)
+	{
+		allocator::free(self.backing_allocator, self);
+		return;
+	}
+	$if env::COMPILER_SAFE_MODE || env::ADDRESS_SANITIZER:
+    	$if env::COMPILER_SAFE_MODE && !env::ADDRESS_SANITIZER:
+    		self.data[0 : self.used] = 0xAA;
+		$else
+            asan::poison_memory_region(&self.data[0], self.used);
+    	$endif
+    $endif
+}
 
 fn void TempAllocator.release(&self, void* old_pointer, bool) @dynamic
 {
@@ -63,32 +132,7 @@ fn void TempAllocator.release(&self, void* old_pointer, bool) @dynamic
 		asan::poison_memory_region(&self.data[self.used], old_size);
 	}
 }
-fn void TempAllocator.reset(&self, usz mark) @dynamic
-{
-	TempAllocatorPage *last_page = self.last_page;
-	while (last_page && last_page.mark > mark)
-	{
-		self.used = last_page.mark;
-		TempAllocatorPage *to_free = last_page;
-		last_page = last_page.prev_page;
-		self._free_page(to_free)!!;
-	}
-	self.last_page = last_page;
-	$if env::COMPILER_SAFE_MODE || env::ADDRESS_SANITIZER:
-		if (!last_page)
-		{
-			usz cleaned = self.used - mark;
-			if (cleaned > 0)
-			{
-				$if env::COMPILER_SAFE_MODE && !env::ADDRESS_SANITIZER:
-					self.data[mark : cleaned] = 0xAA;
-				$endif
-				asan::poison_memory_region(&self.data[mark], cleaned);
-			}
-		}
-	$endif
-	self.used = mark;
-}
+
 
 fn void? TempAllocator._free_page(&self, TempAllocatorPage* page) @inline @local
 {
@@ -202,29 +246,9 @@ fn void*? TempAllocator.acquire(&self, usz size, AllocInitType init_type, usz al
 
 	// Mark it as a page
 	page.ident = ~(usz)0;
-	// Store when it was created
-	page.mark = ++self.used;
 	// Hook up the page.
 	page.prev_page = self.last_page;
 	self.last_page = page;
 	return &page.data[0];
 }
 
-fn void? TempAllocator.print_pages(&self, File* f)
-{
-	TempAllocatorPage *last_page = self.last_page;
-	if (!last_page)
-	{
-		io::fprintf(f, "No pages.\n")!;
-		return;
-	}
-	io::fprintf(f, "---Pages----\n")!;
-	uint index = 0;
-	while (last_page)
-	{
-		bool is_not_aligned = !(last_page.size & (1u64 << 63));
-		io::fprintf(f, "%d. Alloc: %d %d at %p%s\n", ++index,
-				last_page.size & ~(1u64 << 63), last_page.mark, &last_page.data[0], is_not_aligned ? "" : " [aligned]")!;
-		last_page = last_page.prev_page;
-	}
-}
diff --git a/lib/std/core/builtin.c3 b/lib/std/core/builtin.c3
index a3cdb3b47..dd19c7698 100644
--- a/lib/std/core/builtin.c3
+++ b/lib/std/core/builtin.c3
@@ -4,6 +4,7 @@
 module std::core::builtin;
 import libc, std::hash, std::io, std::os::backtrace;
 
+
 <*
  EMPTY_MACRO_SLOT is a value used for implementing optional arguments for macros in an efficient
  way. It relies on the fact that distinct types are not implicitly convertable.
@@ -87,8 +88,16 @@ macro anycast(any v, $Type) @builtin
 	return ($Type*)v.ptr;
 }
 
-fn bool print_backtrace(String message, int backtraces_to_ignore) @if(env::NATIVE_STACKTRACE) => @pool()
+fn bool print_backtrace(String message, int backtraces_to_ignore) @if(env::NATIVE_STACKTRACE) => @stack_mem(0x1100; Allocator smem)
 {
+	TempAllocator* t = allocator::current_temp;
+	TempAllocator* new_t = allocator::new_temp_allocator(smem, 0x1000)!!;
+	allocator::current_temp = new_t;
+	defer
+	{
+		allocator::current_temp = t;
+		new_t.free();
+	}
 	void*[256] buffer;
 	void*[] backtraces = backtrace::capture_current(&buffer);
 	backtraces_to_ignore++;
diff --git a/lib/std/core/dstring.c3 b/lib/std/core/dstring.c3
index 3ef63db93..712b051fd 100644
--- a/lib/std/core/dstring.c3
+++ b/lib/std/core/dstring.c3
@@ -69,7 +69,8 @@ fn void DString.replace(&self, String needle, String replacement)
 		self.replace_char(needle[0], replacement[0]);
 		return;
 	}
-	@pool(data.allocator) {
+	@pool()
+	{
 		String str = self.tcopy_str();
 		self.clear();
 		usz len = str.len;
@@ -538,7 +539,7 @@ macro void DString.insert_at(&self, usz index, value)
 fn usz? DString.appendf(&self, String format, args...) @maydiscard
 {
 	if (!self.data()) self.tinit(format.len + 20);
-	@pool(self.data().allocator)
+	@pool()
 	{
 		Formatter formatter;
 		formatter.init(&out_string_append_fn, self);
@@ -549,7 +550,7 @@ fn usz? DString.appendf(&self, String format, args...) @maydiscard
 fn usz? DString.appendfn(&self, String format, args...) @maydiscard
 {
 	if (!self.data()) self.tinit(format.len + 20);
-	@pool(self.data().allocator)
+	@pool()
 	{
 		Formatter formatter;
 		formatter.init(&out_string_append_fn, self);
diff --git a/lib/std/core/mem.c3 b/lib/std/core/mem.c3
index 3c1ac07f5..e9c2063f4 100644
--- a/lib/std/core/mem.c3
+++ b/lib/std/core/mem.c3
@@ -555,61 +555,32 @@ macro void @stack_pool(usz $size; @body) @builtin
 	};
 }
 
-struct TempState
-{
-	TempAllocator* old;
-	TempAllocator* current;
-	usz mark;
-}
 <*
  Push the current temp allocator. A push must always be balanced with a pop using the current state.
 *>
-fn TempState temp_push(TempAllocator* other = null)
+fn PoolState temp_push()
 {
-	TempAllocator* current = allocator::temp();
-	TempAllocator* old = current;
-	if (other == current)
-	{
-		current = allocator::temp_allocator_next();
-	}
-	return { old, current, current.used };
+	return allocator::push_pool() @inline;
 }
 
 <*
  Pop the current temp allocator. A pop must always be balanced with a push.
 *>
-fn void temp_pop(TempState old_state)
+fn void temp_pop(PoolState old_state)
 {
-	assert(allocator::thread_temp_allocator == old_state.current, "Tried to pop temp allocators out of order.");
-	assert(old_state.current.used >= old_state.mark, "Tried to pop temp allocators out of order.");
-	old_state.current.reset(old_state.mark);
-	allocator::thread_temp_allocator = old_state.old;
+	allocator::pop_pool(old_state) @inline;
 }
 
-<*
- @require @is_empty_macro_slot(#other_temp) ||| $assignable(#other_temp, Allocator) : "Must be an allocator"
- *>
-macro void @pool(#other_temp = EMPTY_MACRO_SLOT; @body) @builtin
+macro void @pool(;@body) @builtin
 {
-	TempAllocator* current = allocator::temp();
-	$if @is_valid_macro_slot(#other_temp):
-		TempAllocator* original = current;
-		if (current == #other_temp.ptr) current = allocator::temp_allocator_next();
-	$endif
-	usz mark = current.used;
+	PoolState state = allocator::push_pool() @inline;
 	defer
 	{
-		current.reset(mark);
-		$if @is_valid_macro_slot(#other_temp):
-			allocator::thread_temp_allocator = original;
-		$endif;
+		allocator::pop_pool(state) @inline;
 	}
 	@body();
 }
 
-import libc;
-
-
 module std::core::mem @if(WASM_NOLIBC);
 import std::core::mem::allocator @public;
 SimpleHeapAllocator wasm_allocator @private;
@@ -624,7 +595,6 @@ fn void initialize_wasm_mem() @init(1024) @private
 	wasm_allocator.init(fn (x) => allocator::wasm_memory.allocate_block(x));
 	allocator::thread_allocator = &wasm_allocator;
 	allocator::temp_base_allocator = &wasm_allocator;
-	allocator::init_default_temp_allocators();
 }
 
 module std::core::mem;
diff --git a/lib/std/core/mem_allocator.c3 b/lib/std/core/mem_allocator.c3
index 228491377..93fee8087 100644
--- a/lib/std/core/mem_allocator.c3
+++ b/lib/std/core/mem_allocator.c3
@@ -1,5 +1,6 @@
 module std::core::mem::allocator;
 
+
 const DEFAULT_SIZE_PREFIX = usz.sizeof;
 const DEFAULT_SIZE_PREFIX_ALIGNMENT = usz.alignof;
 
@@ -18,8 +19,6 @@ enum AllocInitType
 
 interface Allocator
 {
-	fn void reset(usz mark) @optional;
-	fn usz mark() @optional;
 	<*
 	 @require !alignment || math::is_power_of_2(alignment)
 	 @require alignment <= mem::MAX_MEMORY_ALIGNMENT : `alignment too big`
@@ -356,14 +355,32 @@ macro void*? @aligned_realloc(#calloc_fn, #free_fn, void* old_pointer, usz bytes
 
 
 // All allocators
-
-
 alias mem @builtin = thread_allocator ;
 tlocal Allocator thread_allocator @private = base_allocator();
 Allocator temp_base_allocator @private = base_allocator();
 
-tlocal TempAllocator* thread_temp_allocator @private = null;
-tlocal TempAllocator*[2] temp_allocator_pair @private;
+typedef PoolState = void*;
+
+tlocal TempAllocator* current_temp;
+tlocal TempAllocator* top_temp;
+
+usz temp_allocator_min_size = temp_allocator_default_min_size();
+usz temp_allocator_buffer_size = temp_allocator_default_buffer_size();
+usz temp_allocator_new_mult = 4;
+
+fn PoolState push_pool()
+{
+	TempAllocator* old = current_temp ?: create_temp_allocator();
+	current_temp = current_temp.derive_allocator(temp_allocator_min_size, temp_allocator_buffer_size, temp_allocator_new_mult)!!;
+	return (PoolState)old;
+}
+
+fn void pop_pool(PoolState old)
+{
+	current_temp = (TempAllocator*)old;
+	current_temp.reset();
+
+}
 
 macro Allocator base_allocator() @private
 {
@@ -374,46 +391,51 @@ macro Allocator base_allocator() @private
 	$endif
 }
 
-macro TempAllocator* create_default_sized_temp_allocator(Allocator allocator) @local
+macro usz temp_allocator_size() @local
 {
 	$switch env::MEMORY_ENV:
-	$case NORMAL:
-		return new_temp_allocator(1024 * 256, allocator)!!;
-	$case SMALL:
-		return new_temp_allocator(1024 * 16, allocator)!!;
-	$case TINY:
-		return new_temp_allocator(1024 * 2, allocator)!!;
-	$case NONE:
-		unreachable("Temp allocator must explicitly created when memory-env is set to 'none'.");
+		$case NORMAL: return 256 * 1024;
+		$case SMALL: return 1024 * 32;
+		$case TINY: return 1024 * 4;
+		$case NONE: return 0;
+	$endswitch
+}
+
+macro usz temp_allocator_default_min_size() @local
+{
+	$switch env::MEMORY_ENV:
+		$case NORMAL: return 16 * 1024;
+		$case SMALL: return 1024 * 2;
+		$case TINY: return 256;
+		$case NONE: return 256;
+	$endswitch
+}
+
+macro usz temp_allocator_default_buffer_size() @local
+{
+	$switch env::MEMORY_ENV:
+		$case NORMAL: return 1024;
+		$case SMALL: return 128;
+		$case TINY: return 64;
+		$case NONE: return 64;
 	$endswitch
 }
 
 macro Allocator heap() => thread_allocator;
 
-macro TempAllocator* temp()
+<*
+ @require !current_temp : "This should never be called when temp already exists"
+*>
+fn TempAllocator* create_temp_allocator() @private
 {
-	if (!thread_temp_allocator)
-	{
-		init_default_temp_allocators();
-	}
-	return thread_temp_allocator;
+	return top_temp = current_temp = allocator::new_temp_allocator(base_allocator(), temp_allocator_size())!!;
+}
+macro Allocator temp()
+{
+	return current_temp ?: create_temp_allocator();
 }
 
-macro TempAllocator* tmem() @builtin
-{
-	if (!thread_temp_allocator)
-	{
-		init_default_temp_allocators();
-	}
-	return thread_temp_allocator;
-}
-
-fn void init_default_temp_allocators() @private
-{
-	temp_allocator_pair[0] = create_default_sized_temp_allocator(temp_base_allocator);
-	temp_allocator_pair[1] = create_default_sized_temp_allocator(temp_base_allocator);
-	thread_temp_allocator = temp_allocator_pair[0];
-}
+alias tmem @builtin = temp;
 
 fn void destroy_temp_allocators_after_exit() @finalizer(65535) @local @if(env::LIBC)
 {
@@ -425,22 +447,8 @@ fn void destroy_temp_allocators_after_exit() @finalizer(65535) @local @if(env::L
 *>
 fn void destroy_temp_allocators()
 {
-	if (!thread_temp_allocator) return;
-	temp_allocator_pair[0].destroy();
-	temp_allocator_pair[1].destroy();
-	temp_allocator_pair[..] = null;
-	thread_temp_allocator = null;
-}
-
-fn TempAllocator* temp_allocator_next() @private
-{
-	if (!thread_temp_allocator)
-	{
-		init_default_temp_allocators();
-		return thread_temp_allocator;
-	}
-	usz index = thread_temp_allocator == temp_allocator_pair[0] ? 1 : 0;
-	return thread_temp_allocator = temp_allocator_pair[index];
+	if (!top_temp) return;
+	top_temp.free();
 }
 
 const NullAllocator NULL_ALLOCATOR = {};
diff --git a/lib/std/core/runtime_test.c3 b/lib/std/core/runtime_test.c3
index 950a87d89..17b26fa46 100644
--- a/lib/std/core/runtime_test.c3
+++ b/lib/std/core/runtime_test.c3
@@ -244,7 +244,7 @@ fn bool run_tests(String[] args, TestUnit[] tests) @private
 	name.append_repeat('-', len - len / 2);
 	if (!context.is_quiet_mode) io::printn(name);
 	name.clear();
-	TempState temp_state = mem::temp_push();
+	PoolState temp_state = mem::temp_push();
 	defer mem::temp_pop(temp_state);
 	foreach(unit : tests)
 	{
diff --git a/lib/std/core/string.c3 b/lib/std/core/string.c3
index ac05d8b3f..938cb284e 100644
--- a/lib/std/core/string.c3
+++ b/lib/std/core/string.c3
@@ -59,7 +59,7 @@ fn ZString tformat_zstr(String fmt, args...)
  @param [inout] allocator : `The allocator to use`
  @param [in] fmt : `The formatting string`
 *>
-fn String format(Allocator allocator, String fmt, args...) => @pool(allocator)
+fn String format(Allocator allocator, String fmt, args...) => @pool()
 {
 	DString str = dstring::temp_with_capacity(fmt.len + args.len * 8);
 	str.appendf(fmt, ...args);
@@ -104,7 +104,7 @@ fn String join(Allocator allocator, String[] s, String joiner)
 	{
 		total_size += str.len;
 	}
-	@pool(allocator)
+	@pool()
 	{
 		DString res = dstring::temp_with_capacity(total_size);
 		res.append(s[0]);
diff --git a/lib/std/encoding/json.c3 b/lib/std/encoding/json.c3
index 99cfa7e98..65f9676db 100644
--- a/lib/std/encoding/json.c3
+++ b/lib/std/encoding/json.c3
@@ -23,7 +23,7 @@ fn Object*? parse(Allocator allocator, InStream s)
 	@stack_mem(512; Allocator smem)
 	{
 		JsonContext context = { .last_string = dstring::new_with_capacity(smem, 64), .stream = s, .allocator = allocator };
-		@pool(allocator)
+		@pool()
 		{
 			return parse_any(&context);
 		};
diff --git a/lib/std/io/io.c3 b/lib/std/io/io.c3
index cf1edda21..9f24434f5 100644
--- a/lib/std/io/io.c3
+++ b/lib/std/io/io.c3
@@ -64,7 +64,7 @@ macro String? readline(Allocator allocator, stream = io::stdin())
 	$endif
 
 	if (val == '\n') return "";
-	@pool(allocator)
+	@pool()
 	{
 		DString str = dstring::temp_with_capacity(256);
 		if (val != '\r') str.append(val);
diff --git a/lib/std/io/os/ls.c3 b/lib/std/io/os/ls.c3
index 9b290bd15..c1569d3f7 100644
--- a/lib/std/io/os/ls.c3
+++ b/lib/std/io/os/ls.c3
@@ -29,7 +29,7 @@ fn PathList? native_ls(Path dir, bool no_dirs, bool no_symlinks, String mask, Al
 	PathList list;
 	list.init(allocator);
 
-	@pool(allocator)
+	@pool()
 	{
 		WString result = dir.str_view().tconcat(`\*`).to_temp_wstring()!!;
 		Win32_WIN32_FIND_DATAW find_data;
@@ -39,7 +39,7 @@ fn PathList? native_ls(Path dir, bool no_dirs, bool no_symlinks, String mask, Al
 		do
 		{
 			if (no_dirs && (find_data.dwFileAttributes & win32::FILE_ATTRIBUTE_DIRECTORY)) continue;
-			@pool(allocator)
+			@pool()
 			{
 				String filename = string::tfrom_wstring((WString)&find_data.cFileName)!;
 				if (filename == ".." || filename == ".") continue;
diff --git a/lib/std/io/os/temp_directory.c3 b/lib/std/io/os/temp_directory.c3
index da53da537..9e81e25e9 100644
--- a/lib/std/io/os/temp_directory.c3
+++ b/lib/std/io/os/temp_directory.c3
@@ -11,7 +11,7 @@ fn Path? native_temp_directory(Allocator allocator) @if(!env::WIN32)
 	return path::new(allocator, "/tmp");
 }
 
-fn Path? native_temp_directory(Allocator allocator) @if(env::WIN32) => @pool(allocator)
+fn Path? native_temp_directory(Allocator allocator) @if(env::WIN32) => @pool()
 {
 	Win32_DWORD len = win32::getTempPathW(0, null);
 	if (!len) return io::GENERAL_ERROR?;
diff --git a/lib/std/io/path.c3 b/lib/std/io/path.c3
index 43908e9cc..09ca26ea2 100644
--- a/lib/std/io/path.c3
+++ b/lib/std/io/path.c3
@@ -28,7 +28,7 @@ enum PathEnv
 
 fn Path? cwd(Allocator allocator)
 {
-	@pool(allocator)
+	@pool()
 	{
 		return new(allocator, os::getcwd(tmem()));
 	};
@@ -153,7 +153,7 @@ fn Path? temp(String path, PathEnv path_env = DEFAULT_ENV)
 	return new(tmem(), path, path_env);
 }
 
-fn Path? from_win32_wstring(Allocator allocator, WString path) => @pool(allocator)
+fn Path? from_win32_wstring(Allocator allocator, WString path) => @pool()
 {
 	return path::new(allocator, string::tfrom_wstring(path)!);
 }
@@ -183,7 +183,7 @@ fn Path? Path.append(self, Allocator allocator, String filename)
 	if (!self.path_string.len) return new(allocator, filename, self.env)!;
 	assert(!is_separator(self.path_string[^1], self.env));
 
-	@pool(allocator)
+	@pool()
 	{
 		DString dstr = dstring::temp_with_capacity(self.path_string.len + 1 + filename.len);
 		dstr.append(self.path_string);
@@ -232,7 +232,7 @@ fn bool? Path.is_absolute(self)
 }
 
 
-fn Path? String.to_absolute_path(self, Allocator allocator) => @pool(allocator)
+fn Path? String.to_absolute_path(self, Allocator allocator) => @pool()
 {
 	return temp(self).absolute(allocator);
 }
@@ -247,14 +247,14 @@ fn Path? Path.absolute(self, Allocator allocator)
 	if (self.is_absolute()!) return new(allocator, path_str, self.env);
 	if (path_str == ".")
 	{
-		@pool(allocator)
+		@pool()
 		{
 			String cwd = os::getcwd(tmem())!;
 			return new(allocator, cwd, self.env);
 		};
 	}
 	$if DEFAULT_ENV == WIN32:
-		@pool(allocator)
+		@pool()
 		{
 			const usz BUFFER_LEN = 4096;
 			WString buffer = (WString)mem::talloc_array(Char16, BUFFER_LEN);
@@ -268,7 +268,7 @@ fn Path? Path.absolute(self, Allocator allocator)
 	$endif
 }
 
-fn String? String.file_basename(self, Allocator allocator) => @pool(allocator)
+fn String? String.file_basename(self, Allocator allocator) => @pool()
 {
 	return temp(self).basename().copy(allocator);
 }
@@ -285,7 +285,7 @@ fn String Path.basename(self)
 
 fn String? String.path_tdirname(self) => self.path_dirname(tmem());
 
-fn String? String.path_dirname(self, Allocator allocator) => @pool(allocator)
+fn String? String.path_dirname(self, Allocator allocator) => @pool()
 {
 	return temp(self).dirname().copy(allocator);
 }
diff --git a/lib/std/net/url.c3 b/lib/std/net/url.c3
index 26ee1238b..a3419df5e 100644
--- a/lib/std/net/url.c3
+++ b/lib/std/net/url.c3
@@ -89,7 +89,7 @@ fn Url? parse(Allocator allocator, String url_string)
 			String userinfo = authority[:user_info_end];
 			String username @noinit;
 			String password;
-			@pool(allocator)
+			@pool()
 			{
 				String[] userpass = userinfo.tsplit(":", 2);
 				username = userpass[0];
@@ -115,7 +115,7 @@ fn Url? parse(Allocator allocator, String url_string)
 		}
 		else
 		{
-			@pool(allocator)
+			@pool()
 			{
 				String[] host_port = authority.tsplit(":", 2);
 				if (host_port.len > 1)
@@ -270,7 +270,7 @@ fn UrlQueryValues parse_query(Allocator allocator, String query)
 	Splitter raw_vals = query.tokenize("&");
 	while (try String rv = raw_vals.next())
 	{
-		@pool(allocator)
+		@pool()
 		{
 			String[] parts = rv.tsplit("=", 2);
 			String key = tdecode(parts[0], QUERY) ?? parts[0];
diff --git a/lib/std/net/url_encoding.c3 b/lib/std/net/url_encoding.c3
index 0976a40b3..90c6156fa 100644
--- a/lib/std/net/url_encoding.c3
+++ b/lib/std/net/url_encoding.c3
@@ -64,7 +64,7 @@ fn usz encode_len(String s, UrlEncodingMode mode) @inline
  @param [inout] allocator
  @return "Percent-encoded String"
 *>
-fn String encode(Allocator allocator, String s, UrlEncodingMode mode) => @pool(allocator)
+fn String encode(Allocator allocator, String s, UrlEncodingMode mode) => @pool()
 {
 	usz n = encode_len(s, mode);
 	DString builder = dstring::temp_with_capacity(n);
@@ -131,7 +131,7 @@ fn usz? decode_len(String s, UrlEncodingMode mode) @inline
  @param [inout] allocator
  @return "Percent-decoded String"
 *>
-fn String? decode(Allocator allocator, String s, UrlEncodingMode  mode) => @pool(allocator)
+fn String? decode(Allocator allocator, String s, UrlEncodingMode  mode) => @pool()
 {
 	usz n = decode_len(s, mode)!;
 	DString builder = dstring::temp_with_capacity(n);
diff --git a/lib/std/os/env.c3 b/lib/std/os/env.c3
index 2f0cf02ba..1304aa09e 100644
--- a/lib/std/os/env.c3
+++ b/lib/std/os/env.c3
@@ -9,7 +9,7 @@ import std::io::path, libc, std::os;
  @require name.len > 0
  @return? NOT_FOUND
 *>
-fn String? get_var(Allocator allocator, String name) => @pool(allocator)
+fn String? get_var(Allocator allocator, String name) => @pool()
 {
 
 	$switch:
@@ -81,7 +81,7 @@ fn String? get_home_dir(Allocator using = allocator::heap())
 <*
 Returns the current user's config directory.
 *>
-fn Path? get_config_dir(Allocator allocator) => @pool(allocator)
+fn Path? get_config_dir(Allocator allocator) => @pool()
 {
 	$if env::WIN32:
 		return path::new(allocator, tget_var("AppData"));
diff --git a/lib/std/os/linux/linux.c3 b/lib/std/os/linux/linux.c3
index 1e73461e0..b16aa8286 100644
--- a/lib/std/os/linux/linux.c3
+++ b/lib/std/os/linux/linux.c3
@@ -204,7 +204,7 @@ fn void? backtrace_add_element(Allocator allocator, BacktraceList *list, void* a
 		return;
 	}
 
-	@pool(allocator)
+	@pool()
 	{
 		Linux_Dl_info info;
 		if (dladdr(addr, &info) == 0)
@@ -227,7 +227,7 @@ fn BacktraceList? symbolize_backtrace(Allocator allocator, void*[] backtrace)
 		}
 		list.free();
 	}
-	@pool(allocator)
+	@pool()
 	{
 		foreach (addr : backtrace)
 		{
diff --git a/lib/std/os/macos/darwin.c3 b/lib/std/os/macos/darwin.c3
index 8d1b1b383..d666e1418 100644
--- a/lib/std/os/macos/darwin.c3
+++ b/lib/std/os/macos/darwin.c3
@@ -95,7 +95,7 @@ fn uptr? load_address() @local
 
 fn Backtrace? backtrace_load_element(String execpath, void* buffer, void* load_address, Allocator allocator = allocator::heap()) @local
 {
-	@pool(allocator)
+	@pool()
 	{
 		if (buffer)
 		{
@@ -145,9 +145,9 @@ fn BacktraceList? symbolize_backtrace(Allocator allocator, void*[] backtrace)
 		}
 		list.free();
 	}
-	@pool(allocator)
+	@pool()
 	{
-		String execpath = executable_path(allocator::temp())!;
+		String execpath = executable_path(tmem())!;
 		foreach (addr : backtrace)
 		{
 			list.push(backtrace_load_element(execpath, addr, load_addr, allocator) ?? backtrace::BACKTRACE_UNKNOWN);
diff --git a/releasenotes.md b/releasenotes.md
index 6b94a393c..94a5c45d4 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -37,6 +37,8 @@
 - Added `LANGUAGE_DEV_VERSION` env constant.
 - Rename `anyfault` -> `fault`.
 - `!!foo` now works same as as `! ! foo`.
+- Temp allocator now supports more than 2 in-flight stacks.
+- Printing stacktrace uses its own temp allocator.
 
 ### Fixes
 - Fix address sanitizer to work on MachO targets (e.g. MacOS).
@@ -65,6 +67,10 @@
 - `@wstring`, `@wstring32`, `@char32` and `@char16` compile time macros added.
 - Updates to `Atomic` to handle distinct types and booleans.
 - Added `math::iota`.
+- `@pool` no longer takes an argument.
+- `Allocator` interface removes `mark` and `reset`.
+- DynamicArenaAllocator has changed init function.
+- Added `BackedArenaAllocator` which is allocated to a fixed size, then allocates on the backing allocator and supports mark/reset.
 
 ## 0.6.8 Change list
 
diff --git a/test/test_suite/generic/generic_lambda_complex.c3t b/test/test_suite/generic/generic_lambda_complex.c3t
index 0a514dbdb..a08951b7d 100644
--- a/test/test_suite/generic/generic_lambda_complex.c3t
+++ b/test/test_suite/generic/generic_lambda_complex.c3t
@@ -179,17 +179,20 @@ entry:
   %indirectarg10 = alloca %"any[]", align 8
   store %"char[]" { ptr @.str, i64 21 }, ptr %foo_tmpl, align 8
   call void @llvm.memset.p0.i64(ptr align 8 %ft, i8 0, i64 72, i1 false)
-  %0 = load ptr, ptr @std.core.mem.allocator.thread_temp_allocator, align 8
-  %i2nb = icmp eq ptr %0, null
-  br i1 %i2nb, label %if.then, label %if.exit
+  %0 = load ptr, ptr @std.core.mem.allocator.current_temp, align 8
+  %i2b = icmp ne ptr %0, null
+  br i1 %i2b, label %cond.lhs, label %cond.rhs
 
-if.then:                                          ; preds = %entry
-  call void @std.core.mem.allocator.init_default_temp_allocators()
-  br label %if.exit
+cond.lhs:                                         ; preds = %entry
+  br label %cond.phi
 
-if.exit:                                          ; preds = %if.then, %entry
-  %1 = load ptr, ptr @std.core.mem.allocator.thread_temp_allocator, align 8
-  %2 = insertvalue %any undef, ptr %1, 0
+cond.rhs:                                         ; preds = %entry
+  %1 = call ptr @std.core.mem.allocator.create_temp_allocator()
+  br label %cond.phi
+
+cond.phi:                                         ; preds = %cond.rhs, %cond.lhs
+  %val = phi ptr [ %0, %cond.lhs ], [ %1, %cond.rhs ]
+  %2 = insertvalue %any undef, ptr %val, 0
   %3 = insertvalue %any %2, i64 ptrtoint (ptr @"$ct.std.core.mem.allocator.TempAllocator" to i64), 1
   %lo = load ptr, ptr %foo_tmpl, align 8
   %ptradd = getelementptr inbounds i8, ptr %foo_tmpl, i64 8
@@ -201,11 +204,11 @@ if.exit:                                          ; preds = %if.then, %entry
   %5 = call i1 @llvm.expect.i1(i1 %not_err, i1 true)
   br i1 %5, label %after_check, label %assign_optional
 
-assign_optional:                                  ; preds = %if.exit
+assign_optional:                                  ; preds = %cond.phi
   store i64 %4, ptr %error_var, align 8
   br label %panic_block
 
-after_check:                                      ; preds = %if.exit
+after_check:                                      ; preds = %cond.phi
   br label %noerr_block
 
 panic_block:                                      ; preds = %assign_optional
diff --git a/test/test_suite/macros/short_trailing_body.c3t b/test/test_suite/macros/short_trailing_body.c3t
index 88e69c7b8..53b3409ec 100644
--- a/test/test_suite/macros/short_trailing_body.c3t
+++ b/test/test_suite/macros/short_trailing_body.c3t
@@ -17,8 +17,7 @@ fn void main()
 /* #expect: test.ll
 
 entry:
-  %current = alloca ptr, align 8
-  %mark = alloca i64, align 8
+  %state = alloca ptr, align 8
   %s = alloca %"char[]", align 8
   %varargslots = alloca [1 x %any], align 16
   %taddr = alloca i32, align 4
@@ -29,94 +28,80 @@ entry:
   %error_var = alloca i64, align 8
   %x2 = alloca %"char[]", align 8
   %retparam = alloca i64, align 8
-  %error_var5 = alloca i64, align 8
-  %error_var11 = alloca i64, align 8
-  %1 = load ptr, ptr @std.core.mem.allocator.thread_temp_allocator, align 8
-  %i2nb = icmp eq ptr %1, null
-  br i1 %i2nb, label %if.then, label %if.exit
-
-if.then:                                          ; preds = %entry
-  call void @std.core.mem.allocator.init_default_temp_allocators()
-  br label %if.exit
-
-if.exit:                                          ; preds = %if.then, %entry
-  %2 = load ptr, ptr @std.core.mem.allocator.thread_temp_allocator, align 8
-  store ptr %2, ptr %current, align 8
-  %3 = load ptr, ptr %current, align 8
-  %ptradd = getelementptr inbounds i8, ptr %3, i64 24
-  %4 = load i64, ptr %ptradd, align 8
-  store i64 %4, ptr %mark, align 8
+  %error_var4 = alloca i64, align 8
+  %error_var10 = alloca i64, align 8
+  %1 = call ptr @std.core.mem.allocator.push_pool() #3
+  store ptr %1, ptr %state, align 8
   store i32 %0, ptr %taddr, align 4
-  %5 = insertvalue %any undef, ptr %taddr, 0
-  %6 = insertvalue %any %5, i64 ptrtoint (ptr @"$ct.int" to i64), 1
-  store %any %6, ptr %varargslots, align 16
-  %7 = call { ptr, i64 } @std.core.string.tformat(ptr @.str, i64 2, ptr %varargslots, i64 1)
-  store { ptr, i64 } %7, ptr %result, align 8
+  %2 = insertvalue %any undef, ptr %taddr, 0
+  %3 = insertvalue %any %2, i64 ptrtoint (ptr @"$ct.int" to i64), 1
+  store %any %3, ptr %varargslots, align 16
+  %4 = call { ptr, i64 } @std.core.string.tformat(ptr @.str, i64 2, ptr %varargslots, i64 1)
+  store { ptr, i64 } %4, ptr %result, align 8
   call void @llvm.memcpy.p0.p0.i32(ptr align 8 %s, ptr align 8 %result, i32 16, i1 false)
   call void @llvm.memcpy.p0.p0.i32(ptr align 8 %x, ptr align 8 %s, i32 16, i1 false)
-  %8 = call ptr @std.io.stdout()
+  %5 = call ptr @std.io.stdout()
   call void @llvm.memcpy.p0.p0.i32(ptr align 8 %x1, ptr align 8 %x, i32 16, i1 false)
   call void @llvm.memcpy.p0.p0.i32(ptr align 8 %x2, ptr align 8 %x1, i32 16, i1 false)
   %lo = load ptr, ptr %x2, align 8
-  %ptradd4 = getelementptr inbounds i8, ptr %x2, i64 8
-  %hi = load i64, ptr %ptradd4, align 8
-  %9 = call i64 @std.io.File.write(ptr %retparam, ptr %8, ptr %lo, i64 %hi)
-  %not_err = icmp eq i64 %9, 0
-  %10 = call i1 @llvm.expect.i1(i1 %not_err, i1 true)
-  br i1 %10, label %after_check, label %assign_optional
+  %ptradd = getelementptr inbounds i8, ptr %x2, i64 8
+  %hi = load i64, ptr %ptradd, align 8
+  %6 = call i64 @std.io.File.write(ptr %retparam, ptr %5, ptr %lo, i64 %hi)
+  %not_err = icmp eq i64 %6, 0
+  %7 = call i1 @llvm.expect.i1(i1 %not_err, i1 true)
+  br i1 %7, label %after_check, label %assign_optional
 
-assign_optional:                                  ; preds = %if.exit
-  store i64 %9, ptr %error_var, align 8
+assign_optional:                                  ; preds = %entry
+  store i64 %6, ptr %error_var, align 8
   br label %guard_block
 
-after_check:                                      ; preds = %if.exit
+after_check:                                      ; preds = %entry
   br label %noerr_block
 
 guard_block:                                      ; preds = %assign_optional
   br label %voiderr
 
 noerr_block:                                      ; preds = %after_check
-  %11 = load i64, ptr %retparam, align 8
-  store i64 %11, ptr %len, align 8
-  %12 = call i64 @std.io.File.write_byte(ptr %8, i8 zeroext 10)
-  %not_err6 = icmp eq i64 %12, 0
-  %13 = call i1 @llvm.expect.i1(i1 %not_err6, i1 true)
-  br i1 %13, label %after_check8, label %assign_optional7
+  %8 = load i64, ptr %retparam, align 8
+  store i64 %8, ptr %len, align 8
+  %9 = call i64 @std.io.File.write_byte(ptr %5, i8 zeroext 10)
+  %not_err5 = icmp eq i64 %9, 0
+  %10 = call i1 @llvm.expect.i1(i1 %not_err5, i1 true)
+  br i1 %10, label %after_check7, label %assign_optional6
 
-assign_optional7:                                 ; preds = %noerr_block
-  store i64 %12, ptr %error_var5, align 8
-  br label %guard_block9
+assign_optional6:                                 ; preds = %noerr_block
+  store i64 %9, ptr %error_var4, align 8
+  br label %guard_block8
 
-after_check8:                                     ; preds = %noerr_block
-  br label %noerr_block10
+after_check7:                                     ; preds = %noerr_block
+  br label %noerr_block9
 
-guard_block9:                                     ; preds = %assign_optional7
+guard_block8:                                     ; preds = %assign_optional6
   br label %voiderr
 
-noerr_block10:                                    ; preds = %after_check8
-  %14 = call i64 @std.io.File.flush(ptr %8)
-  %not_err12 = icmp eq i64 %14, 0
-  %15 = call i1 @llvm.expect.i1(i1 %not_err12, i1 true)
-  br i1 %15, label %after_check14, label %assign_optional13
+noerr_block9:                                     ; preds = %after_check7
+  %11 = call i64 @std.io.File.flush(ptr %5)
+  %not_err11 = icmp eq i64 %11, 0
+  %12 = call i1 @llvm.expect.i1(i1 %not_err11, i1 true)
+  br i1 %12, label %after_check13, label %assign_optional12
 
-assign_optional13:                                ; preds = %noerr_block10
-  store i64 %14, ptr %error_var11, align 8
-  br label %guard_block15
+assign_optional12:                                ; preds = %noerr_block9
+  store i64 %11, ptr %error_var10, align 8
+  br label %guard_block14
 
-after_check14:                                    ; preds = %noerr_block10
-  br label %noerr_block16
+after_check13:                                    ; preds = %noerr_block9
+  br label %noerr_block15
 
-guard_block15:                                    ; preds = %assign_optional13
+guard_block14:                                    ; preds = %assign_optional12
   br label %voiderr
 
-noerr_block16:                                    ; preds = %after_check14
-  %16 = load i64, ptr %len, align 8
-  %add = add i64 %16, 1
+noerr_block15:                                    ; preds = %after_check13
+  %13 = load i64, ptr %len, align 8
+  %add = add i64 %13, 1
   br label %voiderr
 
-voiderr:                                          ; preds = %noerr_block16, %guard_block15, %guard_block9, %guard_block
-  %17 = load ptr, ptr %current, align 8
-  %18 = load i64, ptr %mark, align 8
-  call void @std.core.mem.allocator.TempAllocator.reset(ptr %17, i64 %18)
+voiderr:                                          ; preds = %noerr_block15, %guard_block14, %guard_block8, %guard_block
+  %14 = load ptr, ptr %state, align 8
+  call void @std.core.mem.allocator.pop_pool(ptr %14) #3
   ret i32 2
 }
diff --git a/test/test_suite/stdlib/map_linux.c3t b/test/test_suite/stdlib/map_linux.c3t
index f9d7c0b89..a46e8a7b5 100644
--- a/test/test_suite/stdlib/map_linux.c3t
+++ b/test/test_suite/stdlib/map_linux.c3t
@@ -123,12 +123,11 @@ entry:
   %varargslots57 = alloca [1 x %any], align 16
   %result60 = alloca %"double[]", align 8
   %retparam61 = alloca i64, align 8
-  %current = alloca ptr, align 8
-  %mark = alloca i64, align 8
+  %state = alloca ptr, align 8
   %map3 = alloca %HashMap.0, align 8
-  %varargslots67 = alloca [1 x %any], align 16
-  %result70 = alloca %"int[]", align 8
-  %retparam71 = alloca i64, align 8
+  %varargslots66 = alloca [1 x %any], align 16
+  %result69 = alloca %"int[]", align 8
+  %retparam70 = alloca i64, align 8
   call void @llvm.memset.p0.i64(ptr align 8 %map, i8 0, i64 48, i1 false)
   %lo = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
   %hi = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
@@ -232,38 +231,24 @@ after_check18:                                    ; preds = %entry, %after_check
   %48 = insertvalue %any %47, i64 ptrtoint (ptr @"$ct.sa$double" to i64), 1
   store %any %48, ptr %varargslots57, align 16
   %49 = call i64 @std.io.printfn(ptr %retparam61, ptr @.str.12, i64 2, ptr %varargslots57, i64 1)
-  %50 = load ptr, ptr @std.core.mem.allocator.thread_temp_allocator, align 8
-  %i2nb = icmp eq ptr %50, null
-  br i1 %i2nb, label %if.then, label %if.exit
-
-if.then:                                          ; preds = %after_check18
-  call void @std.core.mem.allocator.init_default_temp_allocators()
-  br label %if.exit
-
-if.exit:                                          ; preds = %if.then, %after_check18
-  %51 = load ptr, ptr @std.core.mem.allocator.thread_temp_allocator, align 8
-  store ptr %51, ptr %current, align 8
-  %52 = load ptr, ptr %current, align 8
-  %ptradd64 = getelementptr inbounds i8, ptr %52, i64 24
-  %53 = load i64, ptr %ptradd64, align 8
-  store i64 %53, ptr %mark, align 8
+  %50 = call ptr @std.core.mem.allocator.push_pool() #4
+  store ptr %50, ptr %state, align 8
   call void @llvm.memset.p0.i64(ptr align 8 %map3, i8 0, i64 48, i1 false)
-  %lo65 = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
-  %hi66 = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
-  %54 = call ptr @"std_collections_map$int$double$.HashMap.init"(ptr %map3, i64 %lo65, ptr %hi66, i32 16, float 7.500000e-01)
-  %55 = call i8 @"std_collections_map$int$double$.HashMap.set"(ptr %map3, i32 5, double 3.200000e+00)
-  %56 = call i8 @"std_collections_map$int$double$.HashMap.set"(ptr %map3, i32 7, double 5.200000e+00)
-  %lo68 = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
-  %hi69 = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
-  %57 = call { ptr, i64 } @"std_collections_map$int$double$.HashMap.keys"(ptr %map3, i64 %lo68, ptr %hi69)
-  store { ptr, i64 } %57, ptr %result70, align 8
-  %58 = insertvalue %any undef, ptr %result70, 0
-  %59 = insertvalue %any %58, i64 ptrtoint (ptr @"$ct.sa$int" to i64), 1
-  store %any %59, ptr %varargslots67, align 16
-  %60 = call i64 @std.io.printfn(ptr %retparam71, ptr @.str.13, i64 2, ptr %varargslots67, i64 1)
-  %61 = load ptr, ptr %current, align 8
-  %62 = load i64, ptr %mark, align 8
-  call void @std.core.mem.allocator.TempAllocator.reset(ptr %61, i64 %62)
+  %lo64 = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
+  %hi65 = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
+  %51 = call ptr @"std_collections_map$int$double$.HashMap.init"(ptr %map3, i64 %lo64, ptr %hi65, i32 16, float 7.500000e-01)
+  %52 = call i8 @"std_collections_map$int$double$.HashMap.set"(ptr %map3, i32 5, double 3.200000e+00)
+  %53 = call i8 @"std_collections_map$int$double$.HashMap.set"(ptr %map3, i32 7, double 5.200000e+00)
+  %lo67 = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
+  %hi68 = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
+  %54 = call { ptr, i64 } @"std_collections_map$int$double$.HashMap.keys"(ptr %map3, i64 %lo67, ptr %hi68)
+  store { ptr, i64 } %54, ptr %result69, align 8
+  %55 = insertvalue %any undef, ptr %result69, 0
+  %56 = insertvalue %any %55, i64 ptrtoint (ptr @"$ct.sa$int" to i64), 1
+  store %any %56, ptr %varargslots66, align 16
+  %57 = call i64 @std.io.printfn(ptr %retparam70, ptr @.str.13, i64 2, ptr %varargslots66, i64 1)
+  %58 = load ptr, ptr %state, align 8
+  call void @std.core.mem.allocator.pop_pool(ptr %58) #4
   ret void
 }
 
diff --git a/test/test_suite/stdlib/map_macos.c3t b/test/test_suite/stdlib/map_macos.c3t
index dd37a39f0..5d613dd84 100644
--- a/test/test_suite/stdlib/map_macos.c3t
+++ b/test/test_suite/stdlib/map_macos.c3t
@@ -123,12 +123,11 @@ entry:
   %varargslots57 = alloca [1 x %any], align 16
   %result60 = alloca %"double[]", align 8
   %retparam61 = alloca i64, align 8
-  %current = alloca ptr, align 8
-  %mark = alloca i64, align 8
+  %state = alloca ptr, align 8
   %map3 = alloca %HashMap.0, align 8
-  %varargslots67 = alloca [1 x %any], align 16
-  %result70 = alloca %"int[]", align 8
-  %retparam71 = alloca i64, align 8
+  %varargslots66 = alloca [1 x %any], align 16
+  %result69 = alloca %"int[]", align 8
+  %retparam70 = alloca i64, align 8
   call void @llvm.memset.p0.i64(ptr align 8 %map, i8 0, i64 48, i1 false)
   %lo = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
   %hi = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
@@ -232,37 +231,23 @@ after_check18:                                    ; preds = %entry, %after_check
   %48 = insertvalue %any %47, i64 ptrtoint (ptr @"$ct.sa$double" to i64), 1
   store %any %48, ptr %varargslots57, align 16
   %49 = call i64 @std.io.printfn(ptr %retparam61, ptr @.str.12, i64 2, ptr %varargslots57, i64 1)
-  %50 = load ptr, ptr @std.core.mem.allocator.thread_temp_allocator, align 8
-  %i2nb = icmp eq ptr %50, null
-  br i1 %i2nb, label %if.then, label %if.exit
-
-if.then:                                          ; preds = %after_check18
-  call void @std.core.mem.allocator.init_default_temp_allocators()
-  br label %if.exit
-
-if.exit:                                          ; preds = %if.then, %after_check18
-  %51 = load ptr, ptr @std.core.mem.allocator.thread_temp_allocator, align 8
-  store ptr %51, ptr %current, align 8
-  %52 = load ptr, ptr %current, align 8
-  %ptradd64 = getelementptr inbounds i8, ptr %52, i64 24
-  %53 = load i64, ptr %ptradd64, align 8
-  store i64 %53, ptr %mark, align 8
+  %50 = call ptr @std.core.mem.allocator.push_pool() #4
+  store ptr %50, ptr %state, align 8
   call void @llvm.memset.p0.i64(ptr align 8 %map3, i8 0, i64 48, i1 false)
-  %lo65 = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
-  %hi66 = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
-  %54 = call ptr @"std_collections_map$int$double$.HashMap.init"(ptr %map3, i64 %lo65, ptr %hi66, i32 16, float 7.500000e-01)
-  %55 = call i8 @"std_collections_map$int$double$.HashMap.set"(ptr %map3, i32 5, double 3.200000e+00)
-  %56 = call i8 @"std_collections_map$int$double$.HashMap.set"(ptr %map3, i32 7, double 5.200000e+00)
-  %lo68 = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
-  %hi69 = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
-  %57 = call { ptr, i64 } @"std_collections_map$int$double$.HashMap.keys"(ptr %map3, i64 %lo68, ptr %hi69)
-  store { ptr, i64 } %57, ptr %result70, align 8
-  %58 = insertvalue %any undef, ptr %result70, 0
-  %59 = insertvalue %any %58, i64 ptrtoint (ptr @"$ct.sa$int" to i64), 1
-  store %any %59, ptr %varargslots67, align 16
-  %60 = call i64 @std.io.printfn(ptr %retparam71, ptr @.str.13, i64 2, ptr %varargslots67, i64 1)
-  %61 = load ptr, ptr %current, align 8
-  %62 = load i64, ptr %mark, align 8
-  call void @std.core.mem.allocator.TempAllocator.reset(ptr %61, i64 %62)
+  %lo64 = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
+  %hi65 = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
+  %51 = call ptr @"std_collections_map$int$double$.HashMap.init"(ptr %map3, i64 %lo64, ptr %hi65, i32 16, float 7.500000e-01)
+  %52 = call i8 @"std_collections_map$int$double$.HashMap.set"(ptr %map3, i32 5, double 3.200000e+00)
+  %53 = call i8 @"std_collections_map$int$double$.HashMap.set"(ptr %map3, i32 7, double 5.200000e+00)
+  %lo67 = load i64, ptr @std.core.mem.allocator.thread_allocator, align 8
+  %hi68 = load ptr, ptr getelementptr inbounds (i8, ptr @std.core.mem.allocator.thread_allocator, i64 8), align 8
+  %54 = call { ptr, i64 } @"std_collections_map$int$double$.HashMap.keys"(ptr %map3, i64 %lo67, ptr %hi68)
+  store { ptr, i64 } %54, ptr %result69, align 8
+  %55 = insertvalue %any undef, ptr %result69, 0
+  %56 = insertvalue %any %55, i64 ptrtoint (ptr @"$ct.sa$int" to i64), 1
+  store %any %56, ptr %varargslots66, align 16
+  %57 = call i64 @std.io.printfn(ptr %retparam70, ptr @.str.13, i64 2, ptr %varargslots66, i64 1)
+  %58 = load ptr, ptr %state, align 8
+  call void @std.core.mem.allocator.pop_pool(ptr %58) #4
   ret void
 }
\ No newline at end of file
diff --git a/test/unit/stdlib/mem/temp_mem.c3 b/test/unit/stdlib/mem/temp_mem.c3
index 2b67564f6..69d58a211 100644
--- a/test/unit/stdlib/mem/temp_mem.c3
+++ b/test/unit/stdlib/mem/temp_mem.c3
@@ -4,7 +4,7 @@ fn String add(String s, Allocator a, int x)
 {
     if (x < 0) return s.copy(a);
     String tmp;
-    @pool(a)
+    @pool()
     {
         tmp = "foo".tconcat(s);
         tmp = add(tmp, a, x - 1);
@@ -16,7 +16,7 @@ fn String add(String s, Allocator a, int x)
 
 fn String breakit(String s, Allocator a)
 {
-    @pool(a)
+    @pool()
     {
         return inner2("foo".concat(tmem(), s), a);
     };
@@ -24,7 +24,7 @@ fn String breakit(String s, Allocator a)
 
 fn String inner2(String s, Allocator a)
 {
-    @pool(a)
+    @pool()
     {
         ulong* z1 = mem::talloc(ulong);
         *z1 = 0xAAAA_AAAA_AAAA_AAAA;
@@ -37,7 +37,7 @@ fn String inner2(String s, Allocator a)
 
 fn String inner3(String s, Allocator a)
 {
-    @pool(a)
+    @pool()
     {
         ulong* z1 = mem::talloc(ulong);
         *z1 = 0xAAAA_AAAA_AAAA_AAAA;
@@ -50,7 +50,7 @@ fn String inner3(String s, Allocator a)
 
 fn String inner4(String s, Allocator a)
 {
-    @pool(a)
+    @pool()
     {
         String y = s.concat(tmem(), "xy**********").copy(a);
         return y;