MSVC: Windows-native implementation for subset of Pthreads API

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@gmail.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Andrzej K. Haczewski 2010-01-15 21:12:20 +01:00 коммит произвёл Junio C Hamano
Родитель b6f714f89a
Коммит 44626dc7d5
6 изменённых файлов: 217 добавлений и 11 удалений

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@ -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

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@ -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(void)
{
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(void)
{
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);
}

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@ -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) {

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@ -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);

110
compat/win32/pthread.c Normal file
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@ -0,0 +1,110 @@
/*
* Copyright (C) 2009 Andrzej K. Haczewski <ahaczewski@gmail.com>
*
* 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;
}

67
compat/win32/pthread.h Normal file
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@ -0,0 +1,67 @@
/*
* Header used to adapt pthread-based POSIX code to Windows API threads.
*
* Copyright (C) 2009 Andrzej K. Haczewski <ahaczewski@gmail.com>
*/
#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 */