Re: git archive, cygwin, and --git-dir vs --remote
From: René Scharfe <hidden>
Date: 2016-06-15 22:46:48
Subsystem:
the rest · Maintainer:
Linus Torvalds
Bob Kagy schrieb:
I'm using git on cygwin, and am confused by behavior from git archive. git --version git version 1.6.1.2 This command works as expected: git --git-dir=/cygdrive/w archive --format=tar --verbose --prefix=tmp/ HEAD | tar -xpf - The latest copy is retrieved and dumped to the tmp subdirectory. However, I first went down the path of using the --remote option, as described in the git-archive man page: git archive --format=tar --verbose --prefix=tmp/ --remote=/cygdrive/w HEAD | tar -xpf - When I use the --remote branch it seems to create the same files. But then rather than exiting it hangs out until I kill the process, using about the same CPU % as it did when creating files.
That's strange. It seems that poll() reports that there is data to read from the child (which is running git-upload-archive), even though it already called exit(). The following patch works around this issue by terminating the otherwise endless loop after read() returned nothing for the thousandth time in a row. I'm not sure that there's really no way to get a thousand empty reads without the child being done, though. builtin-upload-archive.c | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/builtin-upload-archive.c b/builtin-upload-archive.c
index 0206b41..3d7b11b 100644
--- a/builtin-upload-archive.c
+++ b/builtin-upload-archive.c@@ -17,6 +17,7 @@ static const char lostchild[] = "git upload-archive: archiver process was lost"; #define MAX_ARGS (64) +#define MAX_EMPTY_READS (1000) static int run_upload_archive(int argc, const char **argv, const char *prefix) {
@@ -80,10 +81,11 @@ static void error_clnt(const char *fmt, ...) die("sent error to the client: %s", buf); } -static void process_input(int child_fd, int band) +static void process_input(int child_fd, int band, int *empty_reads) { char buf[16384]; ssize_t sz = read(child_fd, buf, sizeof(buf)); + *empty_reads = sz ? 0 : *empty_reads + 1; if (sz < 0) { if (errno != EAGAIN && errno != EINTR) error_clnt("read error: %s\n", strerror(errno));
@@ -96,6 +98,8 @@ int cmd_upload_archive(int argc, const char **argv, const char *prefix) { pid_t writer; int fd1[2], fd2[2]; + int empty_reads_1 = 0; + int empty_reads_2 = 0; /* * Set up sideband subprocess. *
@@ -147,12 +151,14 @@ int cmd_upload_archive(int argc, const char **argv, const char *prefix) } if (pfd[0].revents & POLLIN) /* Data stream ready */ - process_input(pfd[0].fd, 1); + process_input(pfd[0].fd, 1, &empty_reads_1); if (pfd[1].revents & POLLIN) /* Status stream ready */ - process_input(pfd[1].fd, 2); + process_input(pfd[1].fd, 2, &empty_reads_2); /* Always finish to read data when available */ - if ((pfd[0].revents | pfd[1].revents) & POLLIN) + if (((pfd[0].revents | pfd[1].revents) & POLLIN) && + empty_reads_1 <= MAX_EMPTY_READS && + empty_reads_2 <= MAX_EMPTY_READS) continue; if (waitpid(writer, &status, 0) < 0)