Fix 64 bit variants. Note undefined behavior

Remove unnneded align_up. last_alloc could point to the middle
of a merged block. Fix by resetting the last_alloc on free

.vscode/settings.json

@@ -7,5 +7,5 @@
         "$(workspaceFolder)/include/",
 
     ],
-    "C_Cpp.default.cStandard": "gnu99"
+    "C_Cpp.default.cStandard": "gnu17"
 }

CMakeLists.txt

@@ -10,7 +10,7 @@ set(libucore_VERSION ${libucore_VERSION_MAJOR}.${libucore_VERSION_MINOR}.${libuc
 
 set(CMAKE_VERBOSE_MAKEFILE ON)
 
-set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD 17)
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wundef -Wcast-qual -Wshadow -Wcast-align -pipe -Wno-unused-parameter -Werror=implicit-function-declaration -Winit-self")
 add_definitions(-D_FILE_OFFSET_BITS=64)
 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -O2")
@@ -30,13 +30,14 @@ if (CODE_COVERAGE)
   set(build_type "${build_type}-coverage")
 endif()
 
+add_compile_definitions($<$<CONFIG:Debug>:DEBUG>)
 option(BUILD_SANITIZE "build with address sanitizer" OFF)
 if (BUILD_SANITIZE)
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=address")
   set(build_type "${build_type}-sanitize")
 endif()
-
+find_package(PkgConfig REQUIRED)
-
+pkg_check_modules(CHECK REQUIRED IMPORTED_TARGET check)
 include_directories(include)
 
 add_subdirectory(src)

SConstruct

@@ -1,177 +0,0 @@
-import os
-import platform
-
-#version info of the library, we use 5 chars from the git hash
-revision = os.popen('git describe --abbrev=5 --dirty --always').read()[:-1]
-
-version_info =  {
-    'version_major':  1 ,
-    'version_minor':  0 ,
-    'version_patch':  0 ,
-    'version_revision': revision,
-#version_abi is the abi version of the shared library. Only bump it when
-#backwards compatibility breaks. Strive to not break the ABI.
-    'version_abi':    '1.0.0'
-}
-version_info['version_str'] = "%d.%d.%d.%s" % (
-    version_info['version_major'],
-    version_info['version_minor'],
-    version_info['version_patch'],
-    version_info['version_revision'])
-
-
-AddOption('--build_type',
-            dest = 'build_type',
-            type = 'choice',
-            nargs = 1,
-            action='store',
-            default='debug',
-            metavar='TYPE',
-            choices = ['debug', 'release'],
-            help = 'debug|release - Build a Debug (default) or Release variant'
-)
-AddOption('--prefix',
-            dest='prefix',
-            type='string',
-            nargs=1,
-            action='store',
-            metavar='DIR',
-            default='/usr',
-            help='installation prefix'
-)
-
-AddOption('--test_xml',
-            dest='test_xml',
-            action='store_true',
-            help='Create a result.xml when running the testsuite'
-)
-
-AddOption('--coverage',
-            dest='coverage',
-            action='store_true',
-            help='Build with coverage (gcov) support'
-)
-
-AddOption('--without-assertions',
-            dest='assertions',
-            action='store_false',
-            default=True,
-            help='Build without assertions enabled'
-)
-
-AddOption('--stack-protection',
-            dest = 'stack_protection',
-            action='store_true',
-            default=False,
-            help = 'Build with stack protection support'
-)
-
-AddOption('--sanitizer',
-            dest = 'sanitizer',
-            action='store_true',
-            default=False,
-            help = 'Build with gcc sanitizer'
-)
-
-AddOption('--32',
-            dest='force32bit',
-            action='store_true',
-            default=False,
-            help='Force building for 32 bit architecture'
-)
-
-build_type = GetOption('build_type')
-assertions = GetOption('assertions')
-stack_protection = GetOption('stack_protection')
-test_xml = GetOption('test_xml')
-prefix = GetOption('prefix')
-lib_suffix = ''
-if not (build_type in ['debug', 'release']):
-    print("Error: expected 'debug' or 'release', found: " + build_type)
-    Exit(1)
-
-def InstallPerm(env, dest, files, perm):
-    obj = env.Install(dest, files)
-    for i in obj:
-        env.AddPostAction(i, Chmod(str(i), perm))
-    return obj
-
-
-env = Environment(tools = ['default', 'textfile', 'packaging'])
-
-#allow shell environment to override compiler
-if os.environ.get('CC'):
-    env['CC'] = os.environ['CC']
-
-env.AddMethod(InstallPerm)
-
-env.Append(CFLAGS = ['-std=gnu99','-Wall', '-Wextra', '-Wundef', '-Wcast-qual','-Wshadow' ,'-Wcast-align','-pipe', '-ggdb', '-pthread'])
-env.Append(CFLAGS = ['-Wno-unused-parameter', '-Werror=implicit-function-declaration', '-Winit-self'])
-env.Append(LINKFLAGS = ['-O2', '-pthread'])
-env.Append(CPPDEFINES = ['_FILE_OFFSET_BITS=64'])
-env.Append(CPPPATH = ['#include'])
-env.Append(SHLIBVERSION = version_info['version_abi'])
-
-if GetOption('force32bit'):
-    env.Append(CFLAGS = ['-m32'])
-    env.Append(LINKFLAGS = ['-m32'])
-
-if build_type == 'release':
-    env.Append(CFLAGS = ['-O2'])
-elif build_type == 'debug':
-    lib_suffix = 'D'
-    env.Append(CPPDEFINES = ['DEBUG'])
-
-if stack_protection:
-    env.Append(CFLAGS = ['-fstack-protector', '--param=ssp-buffer-size=4'])
-    env.Append(CPPDEFINES = ['_FORTIFY_SOURCE=2'])
-if not assertions:
-    #this will turn off assert()
-    env.Append(CPPDEFINES = ['NDEBUG'])
-
-if GetOption('coverage'):
-    env.Append(CFLAGS = ['--coverage'])
-    env.Append(LINKFLAGS = ['--coverage'])
-
-if GetOption('sanitizer'):
-    env.Append(CFLAGS = ['-fsanitize=undefined', '-fsanitize=address'])
-    env.Append(LINKFLAGS = ['-fsanitize=undefined', '-fsanitize=address'])
-
-# Generate substitute dictionary
-subst_info = dict(('@' + key + '@', version_info[key]) for key in version_info)
-subst_info['@prefix@'] = prefix
-subst_info['@build_type@'] = build_type
-
-if assertions:
-    subst_info['@build_type@'] += '_A'
-if stack_protection:
-    subst_info['@build_type@'] += '_SP'
-
-subst_info['@build_host@'] = platform.node()
-
-Export('env', 'build_type', 'prefix', 'lib_suffix', 'version_info', 'test_xml', 'subst_info')
-
-#put all .sconsign files in one place
-env.SConsignFile()
-
-subdirs = [
-'src',
-'include',
-'test',
-]
-
-for subdir in subdirs:
-    env.SConscript(subdir + '/SConscript', variant_dir='#build/' + subdir, src_dir='#'+subdir, duplicate=0)
-
-env.Package(target = 'libucore-' + version_info['version_str'] + '.tar.gz',
-            source         = env.FindInstalledFiles(),
-            NAME           = 'libucore',
-            VERSION        = version_info['version_str'],
-            PACKAGEVERSION = 0,
-            PACKAGETYPE    = 'targz',
-            LICENSE        = 'BSD',
-            SUMMARY        = 'libucore is a C library of misc useful stuff including an eventloop, timer support and various data-structures.',
-            DESCRIPTION    = 'libucore is a C library of misc useful stuff including an eventloop, timer support and various data-structures.',
-            X_RPM_GROUP    = 'Development/Libraries'
-)
-

include/SConscript

@@ -1,13 +0,0 @@
-import os
-
-Import('env', 'build_type', 'prefix', 'version_info')
-
-ucore_env = env.Clone()
-
-headers = ucore_env.Glob('ucore/*.h')
-
-#install targets
-
-ucore_env.Alias('install',
-    ucore_env.InstallPerm(os.path.join(prefix, 'include', 'ucore'), headers, 0o0644))
-

include/ucore/math.h

@@ -19,9 +19,40 @@ uc_phi_32(uint32_t N);
 uint64_t 
 uc_phi_64(uint64_t N);
 
+#if defined(__has_builtin)
+#  if __has_builtin(__builtin_clzll)
+#    define HAVE_BUILTIN_CLZ 1
+#  endif
+#endif
+
+
+// Note: the nextpow2 functions have undefined behavior if 
+// x > 2^(n-1) for n of the 32 or 64 bit variants
+
+#if HAVE_BUILTIN_CLZ
+
 static inline uint32_t
 uc_nextpow2(uint32_t x)
 {
+    if (x <= 1) return 1;
+    return 1u << (32 - __builtin_clz(x - 1));
+    return x;
+}
+
+static inline uint64_t
+uc_nextpow2_64(uint64_t x)
+{
+    if (x <= 1) return 1;
+    return (uint64_t)1 << (64 - __builtin_clzll(x - 1));
+    return x;
+}
+#else
+static inline uint32_t
+uc_nextpow2(uint32_t x)
+{
+    if (x == 0) {
+        return 1;
+    }
     x--;
     x |= x >> 1;
     x |= x >> 2;
@@ -33,6 +64,26 @@ uc_nextpow2(uint32_t x)
     return x;
 }
 
+static inline uint64_t
+uc_nextpow2_64(uint64_t x)
+{
+    if (x == 0) {
+        return 1;
+    }
+    x--;
+    x |= x >> 1;
+    x |= x >> 2;
+    x |= x >> 4;
+    x |= x >> 8;
+    x |= x >> 16;
+    x |= x >> 32;
+    x++;
+
+    return x;
+}
+#endif
+
+#undef HAVE_BUILTIN_CLZ
 #ifdef __cplusplus
 }
 #endif

include/ucore/slot_allocator.h

@@ -1,112 +0,0 @@
-#ifndef UC_SLOT_ALLOCATOR_H_
-#define UC_SLOT_ALLOCATOR_H_
-
-#include <stddef.h>
-#include <stdint.h>
-#include "ucore/bitvec.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-/** @file
- * Fixed size slot memory allocator
- *
- * UCSlotAlloc is used to allocate fixed slots of memory from a pre-allocated
- * piece of memory.
- *
- * The main use case is to keep allocated memory in a contiguous block for use
- * maximum number of objects(slots) is known and relatively small. More than 131072 slots
- * is not recommended.
- *
- * Note that this allocator is not thread safe.
- *
- * A bitmap is used to track which slots are allocated.
- */
-
-
-
-typedef struct UCSlotAlloc UCSlotAlloc;
-struct UCSlotAlloc {
-    const uint32_t slot_size;
-    const uint32_t num_slots;
-    struct UCBitVec bitmap;
-    uint8_t *slots;
-};
-
-
-/** Initialize a UCSlotAlloc with an array as the backing memory to allocate slots from.
- * The macro can be used at local scope to allocate memory automatic (stack) storage,
- * or at global scope where the backin array will have static storage duration
- *
- * Use as:
- * @code
- * UC_SLOT_ALLOC_DEF(my_allocator, sizeof foo, 1024)
- * struct foo *foo = uc_slot_alloc(&my_allocator);
- * if (foo == NULL) {
- *     // out of memory
- * } else {
- *     .. use foo
- *     uc_slot_free(&my_allocator, foo);
- * }
- * @endcode
- *
- * @param var_name Variable name for the allocator
- * @param v slot_size Memory size allocated for each slot
- * @param v num_slots Number of slots to reserve memory for
-*/
-#define UC_SLOT_ALLOC_DEF(var_name, slot_size_, num_slots_) \
-struct {\
-    uc_bv_integer bitmap[UC_BV_LEN((num_slots_))]; \
-    uint8_t memory[(num_slots_) * (slot_size_)] __attribute__((aligned)); \
-} var_name ## _memory = { \
-}; \
-UCSlotAlloc var_name = { \
-    .slot_size = (slot_size_), \
-    .num_slots = (num_slots_), \
-    .bitmap = UC_BV_STATIC_INIT(var_name ## _memory.bitmap), \
-    .slots = var_name ## _memory.memory \
-};
-
-/** Similar to UC_SLOT_ALLOC_DEF but allows you to specify the backing memory that must
- * be atleast as large as num_slots * slot_size. Note that an array of num_slots * slot_size
- * bits is also allocated for the bitmap with this definition
- */
-#define UC_SLOT_ALLOC_DEF_EX(var_name, slot_size_, num_slots_, memory) \
-uc_bv_integer var_name ## _bitmap[UC_BV_LEN((num_slots_))] = {}; \
-UCSlotAlloc var_name = { \
-    .slot_size = (slot_size_), \
-    .num_slots = (num_slots_), \
-    .bitmap = UC_BV_STATIC_INIT(var_name ## _bitmap), \
-    .slots = (memory) \
-};
-
-/** Allocate a memory slot
- *
- * @param sa The allocator to allocate from
- * @return A pointer to the memory slot that's sa.slot_size big, or NULL if
- *          all slots are allocated
- */
-void *uc_slot_alloc(UCSlotAlloc *sa);
-
-
-/** Free a memory slot previously returned from uc_slot_alloc()
- *
- * @param sa The allocator to free from.
- * @param slot The memory slot to free. Passing a NULL pointer is undefined behavior
- */
-void uc_slot_free(UCSlotAlloc *restrict sa, void *restrict slot);
-
-/** uc_slot_free() where the slot can be a  NULL pointer */
-#define uc_slot_free_safe(sa, slot) \
-do { \
-    if ((slot) != NULL) { \
-        uc_slot_free((sa), (slot)); \
-    } \
-} while (0)
-
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

src/SConscript

@@ -1,25 +0,0 @@
-import os
-
-Import('env', 'build_type', 'prefix', 'lib_suffix', 'subst_info')
-
-ucore_env = env.Clone()
-
-ucore_env.Substfile('version.c.in', SUBST_DICT = subst_info)
-
-sources = ucore_env.Glob('*.c')
-
-#print 'ucore_env', dir(ucore_env)
-#print ucore_env.Dump()
-#print 'sources:', sources[len(sources)-2]
-
-#Build library
-ucore_staticlib = ucore_env.StaticLibrary(target='ucore' + lib_suffix , source=sources)
-ucore_sharedlib = ucore_env.SharedLibrary(target='ucore' + lib_suffix , source=sources)
-
-#install targets
-ucore_env.Alias('install', 
-    ucore_env.Install(os.path.join(prefix, 'lib'), [ucore_staticlib]))
-ucore_env.Alias('install', 
-    ucore_env.InstallVersionedLib(os.path.join(prefix, 'lib'), [ucore_sharedlib]))
-
-ucore_env.Default([ucore_staticlib, ucore_sharedlib])

src/slot_allocator.c

@@ -1,67 +0,0 @@
-
-#include <stdio.h>
-#include <assert.h>
-#include <stdlib.h>
-#include "ucore/bitvec.h"
-#include "ucore/slot_allocator.h"
-
-void *uc_slot_alloc(UCSlotAlloc *sa)
-{
-    int free_slot = uc_bv_find_first_zero(&sa->bitmap);
-    if (free_slot < 0) {
-        return NULL;
-    } else if ((size_t)free_slot >= sa->num_slots) { // bit vector may have more bits than slots
-        return NULL;
-    }
-
-    uc_bv_set_bit(&sa->bitmap, free_slot);
-
-    return sa->slots + free_slot * sa->slot_size;
-}
-
-void uc_slot_free(UCSlotAlloc *restrict sa, void *restrict slot)
-{
-    assert((uint8_t *)slot >= sa->slots);
-    int slot_index = ((uint8_t *)slot - sa->slots) / sa->slot_size;
-    assert((size_t)slot_index < sa->num_slots);
-    uc_bv_clr_bit(&sa->bitmap, slot_index);
-}
-
-int main()
-{
-
-    UC_SLOT_ALLOC_DEF(sa, 24, 1)
-
-    void *p1 = uc_slot_alloc(&sa);
-    printf("%p\n", &sa_memory.memory[0]);
-    printf("%p\n", p1);
-
-    void *p2 = uc_slot_alloc(&sa);
-    printf("%p\n", p2);
-    uc_slot_free(&sa, p1);
-
-    p2 = uc_slot_alloc(&sa);
-    printf("%p\n", p2);
-
-    printf("__malloc__\n");
-    void *v = malloc(24 * (1<<16));
-    UC_SLOT_ALLOC_DEF_EX(sa2, 24, (1<<16), v)
-    char *v2 = NULL;
-    for (int i = 0; i < 1<<16; i++) {
-        char *c = uc_slot_alloc(&sa2);
-        if (c == NULL) {
-            printf("uc_slot_alloc failed at %d\n", i);
-            break;
-        }
-        *c = i;
-        if (i == 0) {
-            v2 = c;
-        }
-    }
-    for (int i = (1<<16) -1 ; i >= 0; i--) {
-        uc_slot_free(&sa2, v2 + 24*i);
-    }
-    free(v);
-    return 0;
-}
-

test/CMakeLists.txt

@@ -1,6 +1,6 @@
 file(GLOB TEST_SOURCE_FILES test_*.c)
 
-link_libraries(check ucore Threads::Threads)
+link_libraries(ucore Threads::Threads PkgConfig::CHECK)
 if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
     include_directories("/opt/homebrew/include")
     link_directories("/opt/homebrew/lib")

test/SConscript

@@ -1,42 +0,0 @@
-import platform
-
-Import('env', 'build_type', 'prefix', 'lib_suffix', 'version_info', 'test_xml')
-
-test_env = env.Clone()
-test_env.Append(LIBPATH = ['#build/src']);
-test_env.Append(LIBS = ['ucore' + lib_suffix, 'check','m'])
-
-system = platform.system()
-
-#NetBSD needs /usr/pkg/...
-if 'netbsd' in system.lower():
-    test_env.Append(LIBPATH = ['/usr/pkg/lib'])
-    test_env.Append(LINKFLAGS = ['-Wl,-rpath,/usr/pkg/lib'])
-    test_env.Append(CPPPATH = ['/usr/pkg/include'])
-
-if 'darwin' in system.lower():
-    test_env.Append(LIBPATH = ['/opt/homebrew/lib'])
-    test_env.Append(LINKFLAGS = ['-Wl,-rpath,/opt/homebrew/lib'])
-    test_env.Append(CPPPATH = ['/opt/homebrew/include'])
-
-if 'darwin' not in system.lower():
-    test_env.Append(LIBS = ['rt'])
-
-
-tests = test_env.Glob('test_*.c')
-
-test_executable = 'test_runner'
-#run test_runner --xml to produce an xml result file
-if test_xml:
-    test_executable += ' -x'
-
-#rpath to shared lib, so test_runner can actually be executed
-test_env.Append(LINKFLAGS = ['-Wl,-rpath,\\$$ORIGIN/../src'])
-
-prog = test_env.Program('test_runner', tests)
-cmd  = test_env.Command(target='test_phony' ,
-                            source = None,
-                            action= test_env.Dir('.').abspath + '/' + test_executable)
-test_env.Depends(cmd, prog)
-test_env.AlwaysBuild(cmd)
-test_env.Default(test_executable)