On Wed, Mar 19, 2014 at 7:46 AM, <sza...@chromium.org> wrote: > This adds a Windows implementation of pread. Note that it is NOT > safe to intersperse calls to read() and pread() on a file > descriptor. According to the ReadFile spec, using the 'overlapped' > argument should not affect the implicit position pointer of the > descriptor. Experiments have shown that this is, in fact, a lie.
If I understand it correctly, new pread() is added because compat/pread.c does not work because of some other read() in between? Where are those read() (I can only see one in index-pack.c, but there could be some hidden read()..) > > To accomodate that fact, this change also incorporates: > > http://article.gmane.org/gmane.comp.version-control.git/196042 > > ... which gives each index-pack thread its own file descriptor. > --- > builtin/index-pack.c | 21 ++++++++++++++++----- > compat/mingw.c | 31 ++++++++++++++++++++++++++++++- > compat/mingw.h | 3 +++ > config.mak.uname | 1 - > 4 files changed, 49 insertions(+), 7 deletions(-) > > diff --git a/builtin/index-pack.c b/builtin/index-pack.c > index 2f37a38..c02dd4c 100644 > --- a/builtin/index-pack.c > +++ b/builtin/index-pack.c > @@ -51,6 +51,7 @@ struct thread_local { > #endif > struct base_data *base_cache; > size_t base_cache_used; > + int pack_fd; > }; > > /* > @@ -91,7 +92,8 @@ static off_t consumed_bytes; > static unsigned deepest_delta; > static git_SHA_CTX input_ctx; > static uint32_t input_crc32; > -static int input_fd, output_fd, pack_fd; > +static const char *curr_pack; > +static int input_fd, output_fd; > > #ifndef NO_PTHREADS > > @@ -134,6 +136,7 @@ static inline void unlock_mutex(pthread_mutex_t *mutex) > */ > static void init_thread(void) > { > + int i; > init_recursive_mutex(&read_mutex); > pthread_mutex_init(&counter_mutex, NULL); > pthread_mutex_init(&work_mutex, NULL); > @@ -141,11 +144,17 @@ static void init_thread(void) > pthread_mutex_init(&deepest_delta_mutex, NULL); > pthread_key_create(&key, NULL); > thread_data = xcalloc(nr_threads, sizeof(*thread_data)); > + for (i = 0; i < nr_threads; i++) { > + thread_data[i].pack_fd = open(curr_pack, O_RDONLY); > + if (thread_data[i].pack_fd == -1) > + die_errno("unable to open %s", curr_pack); > + } > threads_active = 1; > } > > static void cleanup_thread(void) > { > + int i; > if (!threads_active) > return; > threads_active = 0; > @@ -155,6 +164,8 @@ static void cleanup_thread(void) > if (show_stat) > pthread_mutex_destroy(&deepest_delta_mutex); > pthread_key_delete(key); > + for (i = 0; i < nr_threads; i++) > + close(thread_data[i].pack_fd); > free(thread_data); > } > > @@ -288,13 +299,13 @@ static const char *open_pack_file(const char *pack_name) > output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, > 0600); > if (output_fd < 0) > die_errno(_("unable to create '%s'"), pack_name); > - pack_fd = output_fd; > + nothread_data.pack_fd = output_fd; > } else { > input_fd = open(pack_name, O_RDONLY); > if (input_fd < 0) > die_errno(_("cannot open packfile '%s'"), pack_name); > output_fd = -1; > - pack_fd = input_fd; > + nothread_data.pack_fd = input_fd; > } > git_SHA1_Init(&input_ctx); > return pack_name; > @@ -542,7 +553,7 @@ static void *unpack_data(struct object_entry *obj, > > do { > ssize_t n = (len < 64*1024) ? len : 64*1024; > - n = pread(pack_fd, inbuf, n, from); > + n = pread(get_thread_data()->pack_fd, inbuf, n, from); > if (n < 0) > die_errno(_("cannot pread pack file")); > if (!n) > @@ -1490,7 +1501,7 @@ static void show_pack_info(int stat_only) > int cmd_index_pack(int argc, const char **argv, const char *prefix) > { > int i, fix_thin_pack = 0, verify = 0, stat_only = 0; > - const char *curr_pack, *curr_index; > + const char *curr_index; > const char *index_name = NULL, *pack_name = NULL; > const char *keep_name = NULL, *keep_msg = NULL; > char *index_name_buf = NULL, *keep_name_buf = NULL; > diff --git a/compat/mingw.c b/compat/mingw.c > index 383cafe..6cc85d6 100644 > --- a/compat/mingw.c > +++ b/compat/mingw.c > @@ -329,7 +329,36 @@ int mingw_mkdir(const char *path, int mode) > return ret; > } > > -int mingw_open (const char *filename, int oflags, ...) > + > +ssize_t mingw_pread(int fd, void *buf, size_t count, off64_t offset) > +{ > + HANDLE hand = (HANDLE)_get_osfhandle(fd); > + if (hand == INVALID_HANDLE_VALUE) { > + errno = EBADF; > + return -1; > + } > + > + LARGE_INTEGER offset_value; > + offset_value.QuadPart = offset; > + > + DWORD bytes_read = 0; > + OVERLAPPED overlapped = {0}; > + overlapped.Offset = offset_value.LowPart; > + overlapped.OffsetHigh = offset_value.HighPart; > + BOOL result = ReadFile(hand, buf, count, &bytes_read, &overlapped); > + > + ssize_t ret = bytes_read; > + > + if (!result && GetLastError() != ERROR_HANDLE_EOF) > + { > + errno = err_win_to_posix(GetLastError()); > + ret = -1; > + } > + > + return ret; > +} > + > +int mingw_open(const char *filename, int oflags, ...) > { > va_list args; > unsigned mode; > diff --git a/compat/mingw.h b/compat/mingw.h > index 08b83fe..377ba50 100644 > --- a/compat/mingw.h > +++ b/compat/mingw.h > @@ -174,6 +174,9 @@ int mingw_unlink(const char *pathname); > int mingw_rmdir(const char *path); > #define rmdir mingw_rmdir > > +ssize_t mingw_pread(int fd, void *buf, size_t count, off64_t offset); > +#define pread mingw_pread > + > int mingw_open (const char *filename, int oflags, ...); > #define open mingw_open > > diff --git a/config.mak.uname b/config.mak.uname > index e8acc39..b405524 100644 > --- a/config.mak.uname > +++ b/config.mak.uname > @@ -474,7 +474,6 @@ ifeq ($(uname_S),NONSTOP_KERNEL) > endif > ifneq (,$(findstring MINGW,$(uname_S))) > pathsep = ; > - NO_PREAD = YesPlease > NEEDS_CRYPTO_WITH_SSL = YesPlease > NO_LIBGEN_H = YesPlease > NO_POLL = YesPlease > -- > 1.9.0.279.gdc9e3eb > > -- > To unsubscribe from this list: send the line "unsubscribe git" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Duy -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
