I think it's safe to drop this patch now. It's mostly to prove that it
could work on Windows. But I don't think it's tested a lot (even I
only occasionally test it under wine).
On Thu, Mar 10, 2016 at 1:36 AM, David Turner <dturner@xxxxxxxxxxxxxxxx> wrote:
> From: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
>
> Windows supports shared memory, but the semantics is a bit different
> than POSIX shm. The most noticeable thing is there's no way to get the
> shared memory's size by the reader, and wrapping fstat to do that
> would be hell. So the shm size is added near the end, hidden away from
> shm users (storing it in headers would cause more problems with munmap,
> storing it as a separate shm is even worse).
>
> PostMessage is used instead of UNIX signals for
> notification. Lightweight (at least code-wise) on the client side.
>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
> ---
> config.mak.uname | 2 ++
> index-helper.c | 48 ++++++++++++++++++++++++++++
> read-cache.c | 13 ++++++++
> shm.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 159 insertions(+)
>
> diff --git a/config.mak.uname b/config.mak.uname
> index b5108e1..49320c7 100644
> --- a/config.mak.uname
> +++ b/config.mak.uname
> @@ -394,6 +394,7 @@ ifndef DEBUG
> else
> BASIC_CFLAGS += -Zi -MDd
> endif
> + PROGRAM_OBJS += index-helper.o
> X = .exe
> endif
> ifeq ($(uname_S),Interix)
> @@ -574,6 +575,7 @@ else
> NO_CURL = YesPlease
> endif
> endif
> + PROGRAM_OBJS += index-helper.o
> endif
> ifeq ($(uname_S),QNX)
> COMPAT_CFLAGS += -DSA_RESTART=0
> diff --git a/index-helper.c b/index-helper.c
> index 4dd9656..cf26da7 100644
> --- a/index-helper.c
> +++ b/index-helper.c
> @@ -155,6 +155,51 @@ static void loop(const char *pid_file, int idle_in_seconds)
> ; /* do nothing, all is handled by signal handlers already */
> }
>
> +#elif defined(GIT_WINDOWS_NATIVE)
> +
> +static void loop(const char *pid_file, int idle_in_seconds)
> +{
> + HWND hwnd;
> + UINT_PTR timer = 0;
> + MSG msg;
> + HINSTANCE hinst = GetModuleHandle(NULL);
> + WNDCLASS wc;
> +
> + /*
> + * Emulate UNIX signals by sending WM_USER+x to a
> + * window. Register window class and create a new window to
> + * catch these messages.
> + */
> + memset(&wc, 0, sizeof(wc));
> + wc.lpfnWndProc = DefWindowProc;
> + wc.hInstance = hinst;
> + wc.lpszClassName = "git-index-helper";
> + if (!RegisterClass(&wc))
> + die_errno(_("could not register new window class"));
> +
> + hwnd = CreateWindow("git-index-helper", pid_file,
> + 0, 0, 0, 1, 1, NULL, NULL, hinst, NULL);
> + if (!hwnd)
> + die_errno(_("could not register new window"));
> +
> + refresh(0);
> + while (1) {
> + timer = SetTimer(hwnd, timer, idle_in_seconds * 1000, NULL);
> + if (!timer)
> + die(_("no timer!"));
> + if (!GetMessage(&msg, hwnd, 0, 0) || msg.message == WM_TIMER)
> + break;
> + switch (msg.message) {
> + case WM_USER:
> + refresh(0);
> + break;
> + default:
> + /* just reset the timer */
> + break;
> + }
> + }
> +}
> +
> #else
>
> static void loop(const char *pid_file, int idle_in_seconds)
> @@ -198,6 +243,9 @@ int main(int argc, char **argv)
> fd = hold_lock_file_for_update(&lock,
> git_path("index-helper.pid"),
> LOCK_DIE_ON_ERROR);
> +#ifdef GIT_WINDOWS_NATIVE
> + strbuf_addstr(&sb, "HWND");
> +#endif
> strbuf_addf(&sb, "%" PRIuMAX, (uintmax_t) getpid());
> write_in_full(fd, sb.buf, sb.len);
> commit_lock_file(&lock);
> diff --git a/read-cache.c b/read-cache.c
> index 1a0ab0c..16fbdf6 100644
> --- a/read-cache.c
> +++ b/read-cache.c
> @@ -1546,6 +1546,18 @@ static void post_read_index_from(struct index_state *istate)
> tweak_untracked_cache(istate);
> }
>
> +#if defined(GIT_WINDOWS_NATIVE)
> +static void do_poke(struct strbuf *sb, int refresh_cache)
> +{
> + HWND hwnd;
> + if (!starts_with(sb->buf, "HWND"))
> + return;
> + hwnd = FindWindow("git-index-helper", sb->buf);
> + if (!hwnd)
> + return;
> + PostMessage(hwnd, refresh_cache ? WM_USER : WM_USER + 1, 0, 0);
> +}
> +#else
> static void do_poke(struct strbuf *sb, int refresh_cache)
> {
> char *start = sb->buf;
> @@ -1555,6 +1567,7 @@ static void do_poke(struct strbuf *sb, int refresh_cache)
> return;
> kill(pid, refresh_cache ? SIGHUP : SIGUSR1);
> }
> +#endif
>
> static void poke_daemon(struct index_state *istate,
> const struct stat *st, int refresh_cache)
> diff --git a/shm.c b/shm.c
> index 4ec1a00..04d8a35 100644
> --- a/shm.c
> +++ b/shm.c
> @@ -52,6 +52,102 @@ void git_shm_unlink(const char *fmt, ...)
> shm_unlink(path);
> }
>
> +#elif defined(GIT_WINDOWS_NATIVE)
> +
> +#define SHM_PATH_LEN 82 /* a little bit longer than POSIX because of "Local\\" */
> +
> +static ssize_t create_shm_map(int oflag, int perm, ssize_t length,
> + void **mmap, int prot, int flags,
> + const char *path, unsigned long page_size)
> +{
> + size_t real_length;
> + void *last_page;
> + HANDLE h;
> +
> + assert(perm == 0700);
> + assert(oflag == (O_CREAT | O_EXCL | O_RDWR));
> + assert(prot == (PROT_READ | PROT_WRITE));
> + assert(flags == MAP_SHARED);
> + assert(length >= 0);
> +
> + real_length = length;
> + if (real_length % page_size)
> + real_length += page_size - (real_length % page_size);
> + real_length += page_size;
> + h = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0,
> + real_length, path);
> + if (!h)
> + return -1;
> + *mmap = MapViewOfFile(h, FILE_MAP_ALL_ACCESS, 0, 0, real_length);
> + CloseHandle(h);
> + if (!*mmap)
> + return -1;
> + last_page = (unsigned char *)*mmap + real_length - page_size;
> + *(unsigned long *)last_page = length;
> + return length;
> +}
> +
> +static ssize_t open_shm_map(int oflag, int perm, ssize_t length, void **mmap,
> + int prot, int flags, const char *path,
> + unsigned long page_size)
> +{
> + void *last_page;
> + HANDLE h;
> +
> + assert(perm == 0700);
> + assert(oflag == O_RDONLY);
> + assert(prot == PROT_READ);
> + assert(flags == MAP_SHARED);
> + assert(length <= 0);
> +
> + h = OpenFileMapping(FILE_MAP_READ, FALSE, path);
> + if (!h)
> + return -1;
> + *mmap = MapViewOfFile(h, FILE_MAP_READ, 0, 0, 0);
> + CloseHandle(h);
> + if (!*mmap)
> + return -1;
> + if (length < 0) {
> + MEMORY_BASIC_INFORMATION mbi;
> + if (!VirtualQuery(*mmap, &mbi, sizeof(mbi))) {
> + UnmapViewOfFile(*mmap);
> + return -1;
> + }
> + if (mbi.RegionSize % page_size)
> + die("expected size %lu to be %lu aligned",
> + mbi.RegionSize, page_size);
> + last_page = (unsigned char *)*mmap + mbi.RegionSize - page_size;
> + length = *(unsigned long *)last_page;
> + }
> + return length;
> +}
> +
> +ssize_t git_shm_map(int oflag, int perm, ssize_t length, void **mmap,
> + int prot, int flags, const char *fmt, ...)
> +{
> + SYSTEM_INFO si;
> + va_list ap;
> + char path[SHM_PATH_LEN];
> +
> + GetSystemInfo(&si);
> +
> + strcpy(path, "Local\\");
> + va_start(ap, fmt);
> + vsprintf(path + strlen(path), fmt, ap);
> + va_end(ap);
> +
> + if (oflag & O_CREAT)
> + return create_shm_map(oflag, perm, length, mmap, prot,
> + flags, path, si.dwPageSize);
> + else
> + return open_shm_map(oflag, perm, length, mmap, prot,
> + flags, path, si.dwPageSize);
> +}
> +
> +void git_shm_unlink(const char *fmt, ...)
> +{
> +}
> +
> #else
>
> ssize_t git_shm_map(int oflag, int perm, ssize_t length, void **mmap,
> --
> 2.4.2.767.g62658d5-twtrsrc
>
--
Duy
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