Add memory manager tests

src/modules/kutil/assert.h

@@ -3,8 +3,7 @@
 namespace kutil {
 
 using assert_callback =
-	[[noreturn]] void (*)
+	void (*) (const char *file, unsigned line, const char *message);
-	(const char *file, unsigned line, const char *message);
 
 /// Set the global kernel assert callback
 /// \args f   The new callback

src/modules/kutil/memory.cpp

@@ -1,6 +1,6 @@
 #include "memory.h"
 
-void * operator new (size_t, void *p) { return p; }
+void * operator new (size_t, void *p) noexcept { return p; }
 
 namespace kutil {
 

src/modules/kutil/memory.h

@@ -5,7 +5,8 @@
 
 
 using addr_t = uint64_t;
-void * operator new (size_t, void *p);
+
+void * operator new (size_t, void *p) noexcept;
 
 
 namespace kutil {

src/modules/kutil/memory_manager.h

@@ -31,8 +31,13 @@ public:
 	/// \arg p  A pointer previously retuned by allocate()
 	void free(void *p);
 
+	/// Minimum block size is (2^min_size). Must be at least 6.
+	static const unsigned min_size = 6;
 
-private:
+	/// Maximum block size is (2^max_size). Must be less than 64.
+	static const unsigned max_size = 16;
+
+protected:
 	class mem_header;
 
 	/// Expand the size of memory
@@ -43,17 +48,15 @@ private:
 	void ensure_block(unsigned size);
 
 	/// Helper accessor for the list of blocks of a given size
+	/// \arg size   Size category of the block we want
+	/// \returns    A mutable reference to the head of the list
 	mem_header *& get_free(unsigned size)  { return m_free[size - min_size]; }
 
 	/// Helper to get a block of the given size, growing if necessary
+	/// \arg size   Size category of the block we want
+	/// \returns    A detached block of the given size
 	mem_header * pop_free(unsigned size);
 
-	/// Minimum block size is (2^min_size). Must be at least 6.
-	static const unsigned min_size = 6;
-
-	/// Maximum block size is (2^max_size). Must be less than 64.
-	static const unsigned max_size = 16;
-
 	mem_header *m_free[max_size - min_size];
 	void *m_start;
 	size_t m_length;

src/tests/main.cpp

@@ -0,0 +1,2 @@
+#define CATCH_CONFIG_MAIN
+#include "catch.hpp"

src/tests/memory_manager.cpp

@@ -0,0 +1,114 @@
+#include <chrono>
+#include <random>
+#include <vector>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "kutil/memory.h"
+#include "kutil/memory_manager.h"
+#include "catch.hpp"
+
+using namespace kutil;
+
+
+void *memory = nullptr;
+size_t total_alloc_size = 0;
+size_t total_alloc_calls = 0;
+
+const size_t hs = 0x10; // header size
+const size_t max_block = 1 << 16;
+
+
+void grow_callback(void *start, size_t length)
+{
+	total_alloc_size += length;
+	total_alloc_calls += 1;
+}
+
+
+TEST_CASE( "Buddy blocks tests", "[memory buddy]" )
+{
+	using clock = std::chrono::system_clock;
+	unsigned seed = clock::now().time_since_epoch().count();
+	std::default_random_engine rng(seed);
+
+	memory = aligned_alloc(max_block, 4 * max_block);
+
+	memory_manager mm(memory, grow_callback);
+
+	// The ctor should have allocated an initial block
+	CHECK( total_alloc_size == max_block );
+	CHECK( total_alloc_calls == 1 );
+
+	// Blocks should be:
+	// 16: 0-64K
+
+	std::vector<void *> allocs(6);
+	for (int i = 0; i < 6; ++i)
+		allocs[i] = mm.allocate(150); // size 8
+
+	// Should not have grown
+	CHECK( total_alloc_size == max_block );
+	CHECK( total_alloc_calls == 1 );
+
+	// Blocks should be:
+	// 16: [0-64K]
+	// 15: [0-32K], 32K-64K
+	// 14: [0-16K], 16K-32K
+	// 13: [0-8K], 8K-16K
+	// 12: [0-4K], 4K-8K
+	// 11: [0-2K], 2K-4K
+	// 10: [0-1K, 1-2K]
+	//  9: [0, 512, 1024], 1536
+	//  8: [0, 256, 512, 768, 1024, 1280]
+
+	// We have free memory at 1526 and 2K, but we should get 4K
+	void *big = mm.allocate(4000); // size 12
+	REQUIRE( big == offset_pointer(memory, 4096 + hs) );
+	mm.free(big);
+
+	// free up 512
+	mm.free(allocs[3]);
+	mm.free(allocs[4]);
+
+	// Blocks should be:
+	// ...
+	//  9: [0, 512, 1024], 1536
+	//  8: [0, 256, 512], 768, 1024, [1280]
+
+	// A request for a 512-block should not cross the buddy divide
+	big = mm.allocate(500); // size 9
+	REQUIRE( big >= offset_pointer(memory, 1536 + hs) );
+	mm.free(big);
+
+	mm.free(allocs[0]);
+	mm.free(allocs[1]);
+	mm.free(allocs[2]);
+	mm.free(allocs[5]);
+	allocs.clear();
+
+	std::vector<size_t> sizes = {
+		16000, 8000, 4000, 4000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 150,
+		150, 150, 150, 150, 150, 150, 150, 150, 150, 150, 150, 48, 48, 48, 13 };
+
+	std::shuffle(sizes.begin(), sizes.end(), rng);
+
+	allocs.reserve(sizes.size());
+	for (size_t size : sizes)
+		allocs.push_back(mm.allocate(size));
+
+	std::shuffle(allocs.begin(), allocs.end(), rng);
+	for (void *p: allocs)
+		mm.free(p);
+	allocs.clear();
+
+	big = mm.allocate(64000);
+
+	// If everything was freed / joined correctly, that should not have allocated
+	CHECK( total_alloc_size == max_block );
+	CHECK( total_alloc_calls == 1 );
+
+	// And we should have gotten back the start of memory
+	CHECK( big == offset_pointer(memory, hs) );
+}

src/tests/wscript

@@ -0,0 +1,39 @@
+
+def configure(ctx):
+    pass
+
+def build(bld):
+    sources = bld.path.ant_glob("**/*.cpp")
+
+    from waflib import Task
+    @Task.deep_inputs
+    class utest(Task.Task):
+        color = 'PINK'
+        quiet = False
+        def run(self):
+            import sys
+            import subprocess
+
+            args = [self.inputs[0].abspath()]
+            output = None
+
+            try:
+                output = subprocess.check_output(args)
+            except subprocess.CalledProcessError, e:
+                sys.stdout.write(e.output)
+                return "Failed"
+
+            sys.stdout.write(output)
+
+    bld.program(
+        source = sources,
+        name = 'test',
+        target = 'test',
+        use = 'kutil',
+    )
+
+    run_tests = utest(env = bld.env)
+    run_tests.set_inputs(bld.path.get_bld().make_node('test'))
+    bld.add_to_group(run_tests)
+
+# vim: ft=python et

wscript

@@ -2,6 +2,12 @@ top = '.'
 out = 'build'
 
 
+from waflib.Build import BuildContext
+class TestContext(BuildContext):
+    cmd = 'test'
+    variant = 'tests'
+
+
 def options(opt):
     opt.load("nasm gcc g++")
 
@@ -43,6 +49,7 @@ def configure(ctx):
     version = subprocess.check_output("git describe --always", shell=True).strip()
     git_sha = subprocess.check_output("git rev-parse --short HEAD", shell=True).strip()
 
+    env = ctx.env
     major, minor, patch_dirty = version.split(".")
     dirty = 'dirty' in patch_dirty
     patch = patch_dirty.split('-')[0]
@@ -51,7 +58,21 @@ def configure(ctx):
     ctx.env.KERNEL_FILENAME = ctx.options.kernel_filename
     ctx.env.FONT_NAME = ctx.options.font
 
-    ctx.env.EXTERNAL = join(ctx.path.abspath(), "external")
+    ctx.env.ARCH_D = join(str(ctx.path), "src", "arch",
+            ctx.env.POPCORN_ARCH)
+
+    ctx.env.append_value('INCLUDES', [
+        join(ctx.path.abspath(), "src", "include"),
+        join(ctx.path.abspath(), "src", "include", ctx.env.POPCORN_ARCH),
+        join(ctx.path.abspath(), "src", "modules"),
+    ])
+
+    modules = []
+    mod_root = join("src", "modules")
+    for module in os.listdir(mod_root):
+        mod_path = join(mod_root, module)
+        if exists(join(mod_path, "wscript")):
+            modules.append(mod_path)
 
     baseflags = [
         '-nostdlib',
@@ -111,12 +132,6 @@ def configure(ctx):
 
     ctx.env.append_value('ASFLAGS', ['-felf64'])
 
-    ctx.env.append_value('INCLUDES', [
-        join(ctx.path.abspath(), "src", "include"),
-        join(ctx.path.abspath(), "src", "include", ctx.env.POPCORN_ARCH),
-        join(ctx.path.abspath(), "src", "modules"),
-    ])
-
     ctx.env.append_value('LINKFLAGS', [
         '-g',
         '-nostdlib',
@@ -125,9 +140,6 @@ def configure(ctx):
         '-nostartfiles',
     ])
 
-    ctx.env.ARCH_D = join(str(ctx.path), "src", "arch",
-            ctx.env.POPCORN_ARCH)
-
     env = ctx.env
     ctx.setenv('boot', env=env)
     ctx.recurse(join("src", "boot"))
@@ -136,19 +148,36 @@ def configure(ctx):
     ctx.env.append_value('CFLAGS', ['-mcmodel=large'])
     ctx.env.append_value('CXXFLAGS', ['-mcmodel=large'])
 
-    mod_root = join("src", "modules")
+    ctx.env.MODULES = modules
-    for module in os.listdir(mod_root):
+    for mod_path in ctx.env.MODULES:
-        mod_path = join(mod_root, module)
-        if exists(join(mod_path, "wscript")):
-            ctx.env.append_value('MODULES', mod_path)
         ctx.recurse(mod_path)
 
     ctx.recurse(join("src", "kernel"))
 
+    ## Testing configuration
+    ##
+    from waflib.ConfigSet import ConfigSet
+    ctx.setenv('tests', env=ConfigSet())
+    ctx.load("g++")
+
+    ctx.env.append_value('INCLUDES', [
+        join(ctx.path.abspath(), "src", "include"),
+        join(ctx.path.abspath(), "src", "modules"),
+    ])
+
+    ctx.env.CXXFLAGS = ['-g', '-std=c++14', '-fno-rtti']
+    ctx.env.LINKFLAGS = ['-g']
+
+    ctx.env.MODULES = modules
+    for mod_path in ctx.env.MODULES:
+        ctx.recurse(mod_path)
+    ctx.recurse(join("src", "tests"))
+
 
 def build(bld):
     from os.path import join
 
+    if not bld.variant:
         bld.env = bld.all_envs['boot']
         bld.recurse(join("src", "boot"))
 
@@ -187,6 +216,12 @@ def build(bld):
             ]),
         )
 
+    elif bld.variant == 'tests':
+        for mod_path in bld.env.MODULES:
+            bld.recurse(mod_path)
+
+        bld.recurse(join("src", "tests"))
+
 
 def qemu(ctx):
     import subprocess