From: Andrzej K. Haczewski <ahaczewski@xxxxxxxxx>
This patch implements native to Windows subset of pthreads API used by Git.
It allows to remove Pthreads for Win32 dependency for MSVC, msysgit and
Cygwin.
[J6t: If the MinGW build was built as part of the msysgit build
environment, then threading was already enabled because the
pthreads-win32 package is available in msysgit. With this patch, we can now
enable threaded code unconditionally.]
Signed-off-by: Andrzej K. Haczewski <ahaczewski@xxxxxxxxx>
Signed-off-by: Johannes Sixt <j6t@xxxxxxxx>
---
This version uses Interlocked{Inc,Dec}rement and volatile waiters count.
The change to the MinGW section is mine and was a separate patch.
Makefile | 13 +++---
builtin-pack-objects.c | 31 ++++++++++++--
compat/mingw.c | 2 +-
compat/mingw.h | 5 ++
compat/win32/pthread.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++
compat/win32/pthread.h | 67 +++++++++++++++++++++++++++++
6 files changed, 217 insertions(+), 11 deletions(-)
create mode 100644 compat/win32/pthread.c
create mode 100644 compat/win32/pthread.h
diff --git a/Makefile b/Makefile
index 6933555..7f5814c 100644
--- a/Makefile
+++ b/Makefile
@@ -478,6 +478,7 @@ LIB_H += commit.h
LIB_H += compat/bswap.h
LIB_H += compat/cygwin.h
LIB_H += compat/mingw.h
+LIB_H += compat/win32/pthread.h
LIB_H += csum-file.h
LIB_H += decorate.h
LIB_H += delta.h
@@ -996,15 +997,15 @@ ifeq ($(uname_S),Windows)
NO_REGEX = YesPlease
NO_CURL = YesPlease
NO_PYTHON = YesPlease
- NO_PTHREADS = YesPlease
BLK_SHA1 = YesPlease
+ THREADED_DELTA_SEARCH = YesPlease
CC = compat/vcbuild/scripts/clink.pl
AR = compat/vcbuild/scripts/lib.pl
CFLAGS =
BASIC_CFLAGS = -nologo -I. -I../zlib -Icompat/vcbuild -Icompat/vcbuild/include -DWIN32 -D_CONSOLE -DHAVE_STRING_H -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE
- COMPAT_OBJS = compat/msvc.o compat/fnmatch/fnmatch.o compat/winansi.o
- COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -DHAVE_ALLOCA_H -Icompat -Icompat/fnmatch -Icompat/regex -Icompat/fnmatch -DSTRIP_EXTENSION=\".exe\"
+ COMPAT_OBJS = compat/msvc.o compat/fnmatch/fnmatch.o compat/winansi.o compat/win32/pthread.o
+ COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -DHAVE_ALLOCA_H -Icompat -Icompat/fnmatch -Icompat/regex -Icompat/fnmatch -Icompat/win32 -DSTRIP_EXTENSION=\".exe\"
BASIC_LDFLAGS = -IGNORE:4217 -IGNORE:4049 -NOLOGO -SUBSYSTEM:CONSOLE -NODEFAULTLIB:MSVCRT.lib
EXTLIBS = advapi32.lib shell32.lib wininet.lib ws2_32.lib
lib =
@@ -1048,9 +1049,11 @@ ifneq (,$(findstring MINGW,$(uname_S)))
NO_REGEX = YesPlease
NO_PYTHON = YesPlease
BLK_SHA1 = YesPlease
+ THREADED_DELTA_SEARCH = YesPlease
COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/fnmatch
COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
- COMPAT_OBJS += compat/mingw.o compat/fnmatch/fnmatch.o compat/winansi.o
+ COMPAT_OBJS += compat/mingw.o compat/fnmatch/fnmatch.o compat/winansi.o \
+ compat/win32/pthread.o
EXTLIBS += -lws2_32
X = .exe
ifneq (,$(wildcard ../THIS_IS_MSYSGIT))
@@ -1060,10 +1063,8 @@ ifneq (,$(wildcard ../THIS_IS_MSYSGIT))
EXTLIBS += /mingw/lib/libz.a
NO_R_TO_GCC_LINKER = YesPlease
INTERNAL_QSORT = YesPlease
- THREADED_DELTA_SEARCH = YesPlease
else
NO_CURL = YesPlease
- NO_PTHREADS = YesPlease
endif
endif
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index 4429d53..2fdabaa 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -1256,15 +1256,15 @@ static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
#ifdef THREADED_DELTA_SEARCH
-static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t read_mutex;
#define read_lock() pthread_mutex_lock(&read_mutex)
#define read_unlock() pthread_mutex_unlock(&read_mutex)
-static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t cache_mutex;
#define cache_lock() pthread_mutex_lock(&cache_mutex)
#define cache_unlock() pthread_mutex_unlock(&cache_mutex)
-static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t progress_mutex;
#define progress_lock() pthread_mutex_lock(&progress_mutex)
#define progress_unlock() pthread_mutex_unlock(&progress_mutex)
@@ -1591,7 +1591,26 @@ struct thread_params {
unsigned *processed;
};
-static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
+static pthread_cond_t progress_cond;
+
+/*
+ * Mutex and conditional variable can't be statically-initialized on Windows.
+ */
+static void init_threaded_search()
+{
+ pthread_mutex_init(&read_mutex, NULL);
+ pthread_mutex_init(&cache_mutex, NULL);
+ pthread_mutex_init(&progress_mutex, NULL);
+ pthread_cond_init(&progress_cond, NULL);
+}
+
+static void cleanup_threaded_search()
+{
+ pthread_cond_destroy(&progress_cond);
+ pthread_mutex_destroy(&read_mutex);
+ pthread_mutex_destroy(&cache_mutex);
+ pthread_mutex_destroy(&progress_mutex);
+}
static void *threaded_find_deltas(void *arg)
{
@@ -1630,10 +1649,13 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
struct thread_params *p;
int i, ret, active_threads = 0;
+ init_threaded_search();
+
if (!delta_search_threads) /* --threads=0 means autodetect */
delta_search_threads = online_cpus();
if (delta_search_threads <= 1) {
find_deltas(list, &list_size, window, depth, processed);
+ cleanup_threaded_search();
return;
}
if (progress > pack_to_stdout)
@@ -1748,6 +1770,7 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
active_threads--;
}
}
+ cleanup_threaded_search();
free(p);
}
diff --git a/compat/mingw.c b/compat/mingw.c
index 7376247..74ffc18 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -3,7 +3,7 @@
#include <conio.h>
#include "../strbuf.h"
-static int err_win_to_posix(DWORD winerr)
+int err_win_to_posix(DWORD winerr)
{
int error = ENOSYS;
switch(winerr) {
diff --git a/compat/mingw.h b/compat/mingw.h
index afe12ea..e254fb4 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -310,3 +310,8 @@ struct mingw_dirent
#define readdir(x) mingw_readdir(x)
struct dirent *mingw_readdir(DIR *dir);
#endif // !NO_MINGW_REPLACE_READDIR
+
+/*
+ * Used by Pthread API implementation for Windows
+ */
+extern int err_win_to_posix(DWORD winerr);
diff --git a/compat/win32/pthread.c b/compat/win32/pthread.c
new file mode 100644
index 0000000..631c0a4
--- /dev/null
+++ b/compat/win32/pthread.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2009 Andrzej K. Haczewski <ahaczewski@xxxxxxxxx>
+ *
+ * DISCLAMER: The implementation is Git-specific, it is subset of original
+ * Pthreads API, without lots of other features that Git doesn't use.
+ * Git also makes sure that the passed arguments are valid, so there's
+ * no need for double-checking.
+ */
+
+#include "../../git-compat-util.h"
+#include "pthread.h"
+
+#include <errno.h>
+#include <limits.h>
+
+static unsigned __stdcall win32_start_routine(void *arg)
+{
+ pthread_t *thread = arg;
+ thread->arg = thread->start_routine(thread->arg);
+ return 0;
+}
+
+int pthread_create(pthread_t *thread, const void *unused,
+ void *(*start_routine)(void*), void *arg)
+{
+ thread->arg = arg;
+ thread->start_routine = start_routine;
+ thread->handle = (HANDLE)
+ _beginthreadex(NULL, 0, win32_start_routine, thread, 0, NULL);
+
+ if (!thread->handle)
+ return errno;
+ else
+ return 0;
+}
+
+int win32_pthread_join(pthread_t *thread, void **value_ptr)
+{
+ DWORD result = WaitForSingleObject(thread->handle, INFINITE);
+ switch (result) {
+ case WAIT_OBJECT_0:
+ if (value_ptr)
+ *value_ptr = thread->arg;
+ return 0;
+ case WAIT_ABANDONED:
+ return EINVAL;
+ default:
+ return err_win_to_posix(GetLastError());
+ }
+}
+
+int pthread_cond_init(pthread_cond_t *cond, const void *unused)
+{
+ cond->waiters = 0;
+
+ cond->sema = CreateSemaphore(NULL, 0, LONG_MAX, NULL);
+ if (!cond->sema)
+ die("CreateSemaphore() failed");
+ return 0;
+}
+
+int pthread_cond_destroy(pthread_cond_t *cond)
+{
+ CloseHandle(cond->sema);
+ cond->sema = NULL;
+
+ return 0;
+}
+
+int pthread_cond_wait(pthread_cond_t *cond, CRITICAL_SECTION *mutex)
+{
+ InterlockedIncrement(&cond->waiters);
+
+ /*
+ * Unlock external mutex and wait for signal.
+ * NOTE: we've held mutex locked long enough to increment
+ * waiters count above, so there's no problem with
+ * leaving mutex unlocked before we wait on semaphore.
+ */
+ LeaveCriticalSection(mutex);
+
+ /* let's wait - ignore return value */
+ WaitForSingleObject(cond->sema, INFINITE);
+
+ /* we're done waiting, so make sure we decrease waiters count */
+ InterlockedDecrement(&cond->waiters);
+
+ /* lock external mutex again */
+ EnterCriticalSection(mutex);
+
+ return 0;
+}
+
+int pthread_cond_signal(pthread_cond_t *cond)
+{
+ /*
+ * Access to waiters count is atomic; see "Interlocked Variable Access"
+ * http://msdn.microsoft.com/en-us/library/ms684122(VS.85).aspx
+ */
+ int have_waiters = cond->waiters > 0;
+
+ /*
+ * Signal only when there are waiters
+ */
+ if (have_waiters)
+ return ReleaseSemaphore(cond->sema, 1, NULL) ?
+ 0 : err_win_to_posix(GetLastError());
+ else
+ return 0;
+}
diff --git a/compat/win32/pthread.h b/compat/win32/pthread.h
new file mode 100644
index 0000000..b8e1bcb
--- /dev/null
+++ b/compat/win32/pthread.h
@@ -0,0 +1,67 @@
+/*
+ * Header used to adapt pthread-based POSIX code to Windows API threads.
+ *
+ * Copyright (C) 2009 Andrzej K. Haczewski <ahaczewski@xxxxxxxxx>
+ */
+
+#ifndef PTHREAD_H
+#define PTHREAD_H
+
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+
+#include <windows.h>
+
+/*
+ * Defines that adapt Windows API threads to pthreads API
+ */
+#define pthread_mutex_t CRITICAL_SECTION
+
+#define pthread_mutex_init(a,b) InitializeCriticalSection((a))
+#define pthread_mutex_destroy(a) DeleteCriticalSection((a))
+#define pthread_mutex_lock EnterCriticalSection
+#define pthread_mutex_unlock LeaveCriticalSection
+
+/*
+ * Implement simple condition variable for Windows threads, based on ACE
+ * implementation.
+ *
+ * See original implementation: http://bit.ly/1vkDjo
+ * ACE homepage: http://www.cse.wustl.edu/~schmidt/ACE.html
+ * See also: http://www.cse.wustl.edu/~schmidt/win32-cv-1.html
+ */
+typedef struct {
+ volatile LONG waiters;
+ HANDLE sema;
+} pthread_cond_t;
+
+extern int pthread_cond_init(pthread_cond_t *cond, const void *unused);
+
+extern int pthread_cond_destroy(pthread_cond_t *cond);
+
+extern int pthread_cond_wait(pthread_cond_t *cond, CRITICAL_SECTION *mutex);
+
+extern int pthread_cond_signal(pthread_cond_t *cond);
+
+/*
+ * Simple thread creation implementation using pthread API
+ */
+typedef struct {
+ HANDLE handle;
+ void *(*start_routine)(void*);
+ void *arg;
+} pthread_t;
+
+extern int pthread_create(pthread_t *thread, const void *unused,
+ void *(*start_routine)(void*), void *arg);
+
+/*
+ * To avoid the need of copying a struct, we use small macro wrapper to pass
+ * pointer to win32_pthread_join instead.
+ */
+#define pthread_join(a, b) win32_pthread_join(&(a), (b))
+
+extern int win32_pthread_join(pthread_t *thread, void **value_ptr);
+
+#endif /* PTHREAD_H */
--
1.6.6.218.g3e6eb
--
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