From 337967fb7794b300f1633a413c0db525ab517a3e Mon Sep 17 00:00:00 2001 From: Heiko Voigt Date: Mon, 7 Feb 2011 21:49:33 +0100 Subject: [PATCH 1/5] mingw: move unlink wrapper to mingw.c The next patch implements a workaround in case unlink fails on Windows. Signed-off-by: Heiko Voigt Signed-off-by: Junio C Hamano --- compat/mingw.c | 8 ++++++++ compat/mingw.h | 11 +++-------- 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index bee6054419..a7e1c6b471 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -116,6 +116,14 @@ int err_win_to_posix(DWORD winerr) return error; } +#undef unlink +int mingw_unlink(const char *pathname) +{ + /* read-only files cannot be removed */ + chmod(pathname, 0666); + return unlink(pathname); +} + #undef open int mingw_open (const char *filename, int oflags, ...) { diff --git a/compat/mingw.h b/compat/mingw.h index 2283071109..8316938020 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -125,14 +125,6 @@ static inline int mingw_mkdir(const char *path, int mode) } #define mkdir mingw_mkdir -static inline int mingw_unlink(const char *pathname) -{ - /* read-only files cannot be removed */ - chmod(pathname, 0666); - return unlink(pathname); -} -#define unlink mingw_unlink - #define WNOHANG 1 pid_t waitpid(pid_t pid, int *status, unsigned options); @@ -180,6 +172,9 @@ int link(const char *oldpath, const char *newpath); * replacements of existing functions */ +int mingw_unlink(const char *pathname); +#define unlink mingw_unlink + int mingw_open (const char *filename, int oflags, ...); #define open mingw_open From 19e125498bc417e20f0b8c1014b808654e4acfe4 Mon Sep 17 00:00:00 2001 From: Heiko Voigt Date: Mon, 7 Feb 2011 21:50:26 +0100 Subject: [PATCH 2/5] mingw: work around irregular failures of unlink on windows If a file is opened by another process (e.g. indexing of an IDE) for reading it is not allowed to be deleted. So in case unlink fails retry after waiting for some time. This extends the workaround from 6ac6f878. Signed-off-by: Heiko Voigt Signed-off-by: Junio C Hamano --- compat/mingw.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index a7e1c6b471..9421a37c19 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -3,6 +3,8 @@ #include #include "../strbuf.h" +static const int delay[] = { 0, 1, 10, 20, 40 }; + int err_win_to_posix(DWORD winerr) { int error = ENOSYS; @@ -116,12 +118,38 @@ int err_win_to_posix(DWORD winerr) return error; } +static inline int is_file_in_use_error(DWORD errcode) +{ + switch (errcode) { + case ERROR_SHARING_VIOLATION: + case ERROR_ACCESS_DENIED: + return 1; + } + + return 0; +} + #undef unlink int mingw_unlink(const char *pathname) { + int ret, tries = 0; + /* read-only files cannot be removed */ chmod(pathname, 0666); - return unlink(pathname); + while ((ret = unlink(pathname)) == -1 && tries < ARRAY_SIZE(delay)) { + if (!is_file_in_use_error(GetLastError())) + break; + /* + * We assume that some other process had the source or + * destination file open at the wrong moment and retry. + * In order to give the other process a higher chance to + * complete its operation, we give up our time slice now. + * If we have to retry again, we do sleep a bit. + */ + Sleep(delay[tries]); + tries++; + } + return ret; } #undef open @@ -1257,7 +1285,6 @@ int mingw_rename(const char *pold, const char *pnew) { DWORD attrs, gle; int tries = 0; - static const int delay[] = { 0, 1, 10, 20, 40 }; /* * Try native rename() first to get errno right. From c9b78400802acb3e02249c44286162edd9ed2b35 Mon Sep 17 00:00:00 2001 From: Heiko Voigt Date: Mon, 7 Feb 2011 21:51:21 +0100 Subject: [PATCH 3/5] mingw: make failures to unlink or move raise a question On Windows in case a program is accessing a file unlink or move operations may fail. To give the user a chance to correct this we simply wait until the user asks us to retry or fail. This is useful because of the following use case which seem to happen rarely but when it does it is a mess: After making some changes the user realizes that he was on the incorrect branch. When trying to change the branch some file is still in use by some other process and git stops in the middle of changing branches. Now the user has lots of files with changes mixed with his own. This is especially confusing on repositories that contain lots of files. Although the recent implementation of automatic retry makes this scenario much more unlikely lets provide a fallback as a last resort. Thanks to Albert Dvornik for disabling the question if users can't see it. If the stdout of the command is connected to a terminal but the stderr has been redirected, the odds are good that the user can't see any question we print out to stderr. This will result in a "mysterious hang" while the app is waiting for user input. It seems better to be conservative, and avoid asking for input whenever the stderr is not a terminal, just like we do for stdin. Signed-off-by: Heiko Voigt Signed-off-by: Albert Dvornik Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- compat/mingw.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index 9421a37c19..e8e20282df 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2,6 +2,7 @@ #include "win32.h" #include #include "../strbuf.h" +#include "../run-command.h" static const int delay[] = { 0, 1, 10, 20, 40 }; @@ -129,6 +130,74 @@ static inline int is_file_in_use_error(DWORD errcode) return 0; } +static int read_yes_no_answer(void) +{ + char answer[1024]; + + if (fgets(answer, sizeof(answer), stdin)) { + size_t answer_len = strlen(answer); + int got_full_line = 0, c; + + /* remove the newline */ + if (answer_len >= 2 && answer[answer_len-2] == '\r') { + answer[answer_len-2] = '\0'; + got_full_line = 1; + } else if (answer_len >= 1 && answer[answer_len-1] == '\n') { + answer[answer_len-1] = '\0'; + got_full_line = 1; + } + /* flush the buffer in case we did not get the full line */ + if (!got_full_line) + while ((c = getchar()) != EOF && c != '\n') + ; + } else + /* we could not read, return the + * default answer which is no */ + return 0; + + if (tolower(answer[0]) == 'y' && !answer[1]) + return 1; + if (!strncasecmp(answer, "yes", sizeof(answer))) + return 1; + if (tolower(answer[0]) == 'n' && !answer[1]) + return 0; + if (!strncasecmp(answer, "no", sizeof(answer))) + return 0; + + /* did not find an answer we understand */ + return -1; +} + +static int ask_yes_no_if_possible(const char *format, ...) +{ + char question[4096]; + const char *retry_hook[] = { NULL, NULL, NULL }; + va_list args; + + va_start(args, format); + vsnprintf(question, sizeof(question), format, args); + va_end(args); + + if ((retry_hook[0] = getenv("GIT_ASK_YESNO"))) { + retry_hook[1] = question; + return !run_command_v_opt(retry_hook, 0); + } + + if (!isatty(_fileno(stdin)) || !isatty(_fileno(stderr))) + return 0; + + while (1) { + int answer; + fprintf(stderr, "%s (y/n) ", question); + + if ((answer = read_yes_no_answer()) >= 0) + return answer; + + fprintf(stderr, "Sorry, I did not understand your answer. " + "Please type 'y' or 'n'\n"); + } +} + #undef unlink int mingw_unlink(const char *pathname) { @@ -149,6 +218,10 @@ int mingw_unlink(const char *pathname) Sleep(delay[tries]); tries++; } + while (ret == -1 && is_file_in_use_error(GetLastError()) && + ask_yes_no_if_possible("Unlink of file '%s' failed. " + "Should I try again?", pathname)) + ret = unlink(pathname); return ret; } @@ -1326,6 +1399,11 @@ repeat: tries++; goto repeat; } + if (gle == ERROR_ACCESS_DENIED && + ask_yes_no_if_possible("Rename from '%s' to '%s' failed. " + "Should I try again?", pold, pnew)) + goto repeat; + errno = EACCES; return -1; } From 4f288100ceed14c65a1e964b2db4aaee4f4199fc Mon Sep 17 00:00:00 2001 From: Heiko Voigt Date: Mon, 7 Feb 2011 21:52:34 +0100 Subject: [PATCH 4/5] mingw: add fallback for rmdir in case directory is in use The same logic as for unlink and rename also applies to rmdir. For example in case you have a shell open in a git controlled folder. This will easily fail. So lets be nice for such cases as well. Signed-off-by: Heiko Voigt Signed-off-by: Junio C Hamano --- compat/mingw.c | 25 +++++++++++++++++++++++++ compat/mingw.h | 3 +++ 2 files changed, 28 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index e8e20282df..e55c3cac77 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -225,6 +225,31 @@ int mingw_unlink(const char *pathname) return ret; } +#undef rmdir +int mingw_rmdir(const char *pathname) +{ + int ret, tries = 0; + + while ((ret = rmdir(pathname)) == -1 && tries < ARRAY_SIZE(delay)) { + if (!is_file_in_use_error(GetLastError())) + break; + /* + * We assume that some other process had the source or + * destination file open at the wrong moment and retry. + * In order to give the other process a higher chance to + * complete its operation, we give up our time slice now. + * If we have to retry again, we do sleep a bit. + */ + Sleep(delay[tries]); + tries++; + } + while (ret == -1 && is_file_in_use_error(GetLastError()) && + ask_yes_no_if_possible("Deletion of directory '%s' failed. " + "Should I try again?", pathname)) + ret = rmdir(pathname); + return ret; +} + #undef open int mingw_open (const char *filename, int oflags, ...) { diff --git a/compat/mingw.h b/compat/mingw.h index 8316938020..8b159c4447 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -175,6 +175,9 @@ int link(const char *oldpath, const char *newpath); int mingw_unlink(const char *pathname); #define unlink mingw_unlink +int mingw_rmdir(const char *path); +#define rmdir mingw_rmdir + int mingw_open (const char *filename, int oflags, ...); #define open mingw_open From ab1a11be7858e1f92ee2e4ee1d70fabe7d5fe0ee Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Mon, 7 Feb 2011 21:54:01 +0100 Subject: [PATCH 5/5] mingw_rmdir: set errno=ENOTEMPTY when appropriate On Windows, EACCES overrules ENOTEMPTY when calling rmdir(). But if the directory is busy, we only want to retry deleting the directory if it is empty, so test specifically for that case and set ENOTEMPTY rather than EACCES. Noticed by Greg Hazel. Signed-off-by: Johannes Schindelin Signed-off-by: Heiko Voigt Signed-off-by: Junio C Hamano --- compat/mingw.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index e55c3cac77..878b1de97c 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -225,6 +225,30 @@ int mingw_unlink(const char *pathname) return ret; } +static int is_dir_empty(const char *path) +{ + struct strbuf buf = STRBUF_INIT; + WIN32_FIND_DATAA findbuf; + HANDLE handle; + + strbuf_addf(&buf, "%s\\*", path); + handle = FindFirstFileA(buf.buf, &findbuf); + if (handle == INVALID_HANDLE_VALUE) { + strbuf_release(&buf); + return GetLastError() == ERROR_NO_MORE_FILES; + } + + while (!strcmp(findbuf.cFileName, ".") || + !strcmp(findbuf.cFileName, "..")) + if (!FindNextFile(handle, &findbuf)) { + strbuf_release(&buf); + return GetLastError() == ERROR_NO_MORE_FILES; + } + FindClose(handle); + strbuf_release(&buf); + return 0; +} + #undef rmdir int mingw_rmdir(const char *pathname) { @@ -233,6 +257,10 @@ int mingw_rmdir(const char *pathname) while ((ret = rmdir(pathname)) == -1 && tries < ARRAY_SIZE(delay)) { if (!is_file_in_use_error(GetLastError())) break; + if (!is_dir_empty(pathname)) { + errno = ENOTEMPTY; + break; + } /* * We assume that some other process had the source or * destination file open at the wrong moment and retry.