Thread safe cache
diff --git a/include/git2/thread-utils.h b/include/git2/thread-utils.h
index ecb09bb..fb8644b 100644
--- a/include/git2/thread-utils.h
+++ b/include/git2/thread-utils.h
@@ -67,6 +67,4 @@
# define GIT_TLS
#endif
-#define GIT_THREADS 1
-
#endif /* INCLUDE_git_thread_utils_h__ */
diff --git a/src/cache.c b/src/cache.c
new file mode 100644
index 0000000..cabd286
--- /dev/null
+++ b/src/cache.c
@@ -0,0 +1,175 @@
+/*
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file. (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "common.h"
+#include "repository.h"
+#include "commit.h"
+#include "thread-utils.h"
+#include "cache.h"
+
+#define GIT_CACHE_OPENADR 3
+
+
+GIT_INLINE(int) cached_obj_compare(git_cached_obj *obj, const git_oid *oid)
+{
+ return git_oid_cmp(&obj->oid, oid);
+}
+
+GIT_INLINE(void) cached_obj_incref(git_cached_obj *obj)
+{
+ obj->refcount++;
+}
+
+GIT_INLINE(void) cached_obj_decref(git_cached_obj *obj, git_cached_obj_freeptr free_obj)
+{
+ if (--obj->refcount == 0)
+ free_obj(obj);
+}
+
+
+void git_cache_init(git_cache *cache, size_t size, git_cached_obj_freeptr free_ptr)
+{
+ size_t i;
+
+ if (size < 8)
+ size = 8;
+
+ /* round up size to closest power of 2 */
+ size--;
+ size |= size >> 1;
+ size |= size >> 2;
+ size |= size >> 4;
+ size |= size >> 8;
+ size |= size >> 16;
+
+ cache->size_mask = size;
+ cache->lru_count = 0;
+ cache->free_obj = free_ptr;
+
+ cache->nodes = git__malloc((size + 1) * sizeof(cache_node));
+
+ for (i = 0; i < (size + 1); ++i) {
+ git_mutex_init(&cache->nodes[i].lock);
+ cache->nodes[i].ptr = NULL;
+ cache->nodes[i].lru = 0;
+ }
+}
+
+void git_cache_free(git_cache *cache)
+{
+ size_t i;
+
+ for (i = 0; i < (cache->size_mask + 1); ++i) {
+ cached_obj_decref(cache->nodes[i].ptr, cache->free_obj);
+ git_mutex_free(&cache->nodes[i].lock);
+ }
+
+ free(cache->nodes);
+}
+
+void *git_cache_get(git_cache *cache, const git_oid *oid)
+{
+ const uint32_t *hash;
+ size_t i, pos, found = 0;
+ cache_node *node;
+
+ hash = (const uint32_t *)oid->id;
+
+ for (i = 0; !found && i < GIT_CACHE_OPENADR; ++i) {
+ pos = hash[i] & cache->size_mask;
+ node = &cache->nodes[pos];
+
+ git_mutex_lock(&node->lock);
+ {
+ if (cached_obj_compare(node->ptr, oid) == 0) {
+ cached_obj_incref(node->ptr);
+ node->lru = ++cache->lru_count;
+ found = 1;
+ }
+ }
+ git_mutex_unlock(&node->lock);
+ }
+
+
+ return found ? node->ptr : NULL;
+}
+
+void *git_cache_try_store(git_cache *cache, void *entry)
+{
+ cache_node *nodes[GIT_CACHE_OPENADR], *lru_node;
+ const uint32_t *hash;
+ const git_oid *oid;
+ size_t i, stored = 0;
+
+ oid = &((git_cached_obj*)entry)->oid;
+ hash = (const uint32_t *)oid->id;
+
+ /* increase the refcount on this object, because
+ * the cache now owns it */
+ cached_obj_incref(entry);
+
+ for (i = 0; i < GIT_CACHE_OPENADR; ++i) {
+ size_t pos = hash[i] & cache->size_mask;
+
+ nodes[i] = &cache->nodes[pos];
+ git_mutex_lock(&nodes[i]->lock);
+ }
+
+ lru_node = nodes[0];
+
+ for (i = 0; !stored && entry && i < GIT_CACHE_OPENADR; ++i) {
+
+ if (nodes[i]->ptr == NULL) {
+ nodes[i]->ptr = entry;
+ nodes[i]->lru = ++cache->lru_count;
+ stored = 1;
+ } else if (cached_obj_compare(nodes[i]->ptr, oid) == 0) {
+ cached_obj_decref(entry, cache->free_obj);
+ entry = nodes[i]->ptr;
+ stored = 1;
+ }
+
+ if (nodes[i]->lru < lru_node->lru)
+ lru_node = nodes[i];
+ }
+
+ if (!stored) {
+ void *old_entry = lru_node->ptr;
+ assert(old_entry);
+
+ cached_obj_decref(old_entry, cache->free_obj);
+ lru_node->ptr = entry;
+ lru_node->lru = ++cache->lru_count;
+ }
+
+ /* increase the refcount again, because we are
+ * returning it to the user */
+ cached_obj_incref(entry);
+
+ for (i = 0; i < GIT_CACHE_OPENADR; ++i)
+ git_mutex_unlock(&nodes[i]->lock);
+
+ return entry;
+}
diff --git a/src/cache.h b/src/cache.h
new file mode 100644
index 0000000..a84267b
--- /dev/null
+++ b/src/cache.h
@@ -0,0 +1,38 @@
+#ifndef INCLUDE_cache_h__
+#define INCLUDE_cache_h__
+
+#include "git2/common.h"
+#include "git2/oid.h"
+#include "git2/odb.h"
+
+#include "thread-utils.h"
+
+typedef void (*git_cached_obj_freeptr)(void *);
+
+typedef struct {
+ git_oid oid;
+ unsigned int refcount;
+} git_cached_obj;
+
+typedef struct {
+ git_cached_obj *ptr;
+ git_mutex lock;
+ unsigned int lru;
+} cache_node;
+
+typedef struct {
+ cache_node *nodes;
+
+ unsigned int lru_count;
+ size_t size_mask;
+ git_cached_obj_freeptr free_obj;
+} git_cache;
+
+
+void git_cache_init(git_cache *cache, size_t size, git_cached_obj_freeptr free_ptr);
+void git_cache_free(git_cache *cache);
+
+void *git_cache_try_store(git_cache *cache, void *entry);
+void *git_cache_get(git_cache *cache, const git_oid *oid);
+
+#endif
diff --git a/src/common.h b/src/common.h
index 723085a..5ad878e 100644
--- a/src/common.h
+++ b/src/common.h
@@ -31,18 +31,21 @@
# include <windows.h>
# include "msvc-compat.h"
# include "mingw-compat.h"
-# include "win32/pthread.h"
+# ifdef GIT_THREADS
+# include "win32/pthread.h"
+#endif
# define snprintf _snprintf
typedef SSIZE_T ssize_t;
#else
-
# include <unistd.h>
# include <arpa/inet.h>
-# include <pthread.h>
+# ifdef GIT_THREADS
+# include <pthread.h>
+# endif
#endif
#include "git2/common.h"
diff --git a/src/thread-utils.h b/src/thread-utils.h
index e8372e7..ee26ad2 100644
--- a/src/thread-utils.h
+++ b/src/thread-utils.h
@@ -1,6 +1,7 @@
#ifndef INCLUDE_thread_utils_h__
#define INCLUDE_thread_utils_h__
+#ifdef GIT_THREADS
#define git_thread pthread_t
#define git_thread_create(thread, attr, start_routine, arg) pthread_create(thread, attr, start_routine, arg)
@@ -23,6 +24,31 @@
#define git_cond_signal(c) pthread_cond_signal(c)
#define git_cond_broadcast(c) pthread_cond_broadcast(c)
+#else
+
+#define git_thread unsigned int
+#define git_thread_create(thread, attr, start_routine, arg) (void)0
+#define git_thread_kill(thread) (void)0
+#define git_thread_exit(status) (void)0
+#define git_thread_join(id, status) (void)0
+
+/* Pthreads Mutex */
+#define git_mutex unsigned int
+#define git_mutex_init(a) (void)0
+#define git_mutex_lock(a) (void)0
+#define git_mutex_unlock(a) (void)0
+#define git_mutex_free(a) (void)0
+
+/* Pthreads condition vars */
+#define git_cond unsigned int
+#define git_cond_init(c, a) (void)0
+#define git_cond_free(c) (void)0
+#define git_cond_wait(c, l) (void)0
+#define git_cond_signal(c) (void)0
+#define git_cond_broadcast(c) (void)0
+
+#endif
+
extern int git_online_cpus(void);
#endif /* INCLUDE_thread_utils_h__ */
diff --git a/tests/t11-sqlite.c b/tests/t11-sqlite.c
index 9e9d1b7..ba9065e 100644
--- a/tests/t11-sqlite.c
+++ b/tests/t11-sqlite.c
@@ -23,11 +23,14 @@
* Boston, MA 02110-1301, USA.
*/
#include "test_lib.h"
-#include "t03-data.h"
+
+#ifdef GIT2_SQLITE_BACKEND
+#include "t03-data.h"
#include "fileops.h"
#include "git2/odb_backend.h"
+
static int cmp_objects(git_rawobj *o1, git_rawobj *o2)
{
if (o1->type != o2->type)
@@ -41,7 +44,6 @@
static git_odb *open_sqlite_odb(void)
{
-#ifdef GIT2_SQLITE_BACKEND
git_odb *odb;
git_odb_backend *sqlite;
@@ -55,9 +57,6 @@
return NULL;
return odb;
-#else
- return NULL;
-#endif
}
#define TEST_WRITE(PTR) {\
@@ -105,7 +104,6 @@
BEGIN_SUITE(sqlite)
-#ifdef GIT2_SQLITE_BACKEND
ADD_TEST(sqlite0);
ADD_TEST(sqlite1);
ADD_TEST(sqlite2);
@@ -113,5 +111,13 @@
ADD_TEST(sqlite4);
ADD_TEST(sqlite5);
ADD_TEST(sqlite6);
-#endif
END_SUITE
+
+#else /* no sqlite builtin */
+BEGIN_SUITE(sqlite)
+ /* empty */
+END_SUITE
+#endif
+
+
+
diff --git a/tests/t13-threads.c b/tests/t13-threads.c
new file mode 100644
index 0000000..7da1076
--- /dev/null
+++ b/tests/t13-threads.c
@@ -0,0 +1,50 @@
+/*
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file. (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+#include "test_lib.h"
+#include "test_helpers.h"
+#include "cache.h"
+
+
+typedef struct {
+ git_cached_obj cached;
+ unsigned int __dummy;
+} ttest_obj;
+
+void *cache0_thread(void *data)
+{
+ git_cache *cache = (git_cache*)data;
+ unsigned int num;
+
+
+
+}
+
+BEGIN_TEST(cache0, "run several threads polling the cache at the same time")
+
+END_TEST
+
+BEGIN_SUITE(threads)
+ ADD_TEST(cache0);
+END_SUITE
diff --git a/tests/test_main.c b/tests/test_main.c
index 9308b8d..f2a623a 100644
--- a/tests/test_main.c
+++ b/tests/test_main.c
@@ -42,6 +42,7 @@
DECLARE_SUITE(refs);
DECLARE_SUITE(sqlite);
DECLARE_SUITE(repository);
+DECLARE_SUITE(threads);
static libgit2_suite suite_methods[]= {
SUITE_NAME(core),
@@ -57,6 +58,7 @@
SUITE_NAME(refs),
SUITE_NAME(sqlite),
SUITE_NAME(repository),
+ SUITE_NAME(threads),
};
#define GIT_SUITE_COUNT (ARRAY_SIZE(suite_methods))
diff --git a/wscript b/wscript
index 4e8294c..b990e14 100644
--- a/wscript
+++ b/wscript
@@ -29,8 +29,10 @@
help='Force a specific MSVC++ version (7.1, 8.0, 9.0, 10.0), if more than one is installed')
opt.add_option('--arch', action='store', default='x86',
help='Select target architecture (ia64, x64, x86, x86_amd64, x86_ia64)')
- opt.add_option('--without-sqlite', action='store_false', default=True,
+ opt.add_option('--with-sqlite', action='store_true', default=False,
dest='use_sqlite', help='Disable sqlite support')
+ opt.add_option('--threadsafe', action='store_true', default=False,
+ help='Make libgit2 thread-safe (requires pthreads)')
def configure(conf):
@@ -59,7 +61,11 @@
else:
conf.env.PLATFORM = 'unix'
- conf.check_cc(lib='pthread', uselib_store='pthread')
+
+ if conf.options.threadsafe:
+ if conf.env.PLATFORM == 'unix':
+ conf.check_cc(lib='pthread', uselib_store='pthread')
+ conf.env.DEFINES += ['GIT_THREADS']
# check for sqlite3
if conf.options.use_sqlite and conf.check_cc(
