From fbf71645d12d30219e88598c4867ef7c2fe48cee Mon Sep 17 00:00:00 2001 From: Jonathan Nieder Date: Tue, 15 Dec 2015 16:04:06 -0800 Subject: submodule.c: write "Fetching submodule " to stderr The "Pushing submodule " progress output correctly goes to stderr, but "Fetching submodule " is going to stdout by mistake. Fix it to write to stderr. Noticed while trying to implement a parallel submodule fetch. When this particular output line went to a different file descriptor, it was buffered separately, resulting in wrongly interleaved output if we copied it to the terminal naively. Signed-off-by: Jonathan Nieder Signed-off-by: Stefan Beller Signed-off-by: Junio C Hamano --- submodule.c | 2 +- t/t5526-fetch-submodules.sh | 51 +++++++++++++++++++++++---------------------- 2 files changed, 27 insertions(+), 26 deletions(-) diff --git a/submodule.c b/submodule.c index 14e76247bf..8386477d62 100644 --- a/submodule.c +++ b/submodule.c @@ -689,7 +689,7 @@ int fetch_populated_submodules(const struct argv_array *options, git_dir = submodule_git_dir.buf; if (is_directory(git_dir)) { if (!quiet) - printf("Fetching submodule %s%s\n", prefix, ce->name); + fprintf(stderr, "Fetching submodule %s%s\n", prefix, ce->name); cp.dir = submodule_path.buf; argv_array_push(&argv, default_argv); argv_array_push(&argv, "--submodule-prefix"); diff --git a/t/t5526-fetch-submodules.sh b/t/t5526-fetch-submodules.sh index a4532b00d6..17759b145f 100755 --- a/t/t5526-fetch-submodules.sh +++ b/t/t5526-fetch-submodules.sh @@ -16,7 +16,8 @@ add_upstream_commit() { git add subfile && git commit -m new subfile && head2=$(git rev-parse --short HEAD) && - echo "From $pwd/submodule" > ../expect.err && + echo "Fetching submodule submodule" > ../expect.err && + echo "From $pwd/submodule" >> ../expect.err && echo " $head1..$head2 master -> origin/master" >> ../expect.err ) && ( @@ -27,6 +28,7 @@ add_upstream_commit() { git add deepsubfile && git commit -m new deepsubfile && head2=$(git rev-parse --short HEAD) && + echo "Fetching submodule submodule/subdir/deepsubmodule" >> ../expect.err echo "From $pwd/deepsubmodule" >> ../expect.err && echo " $head1..$head2 master -> origin/master" >> ../expect.err ) @@ -56,9 +58,7 @@ test_expect_success setup ' ( cd downstream && git submodule update --init --recursive - ) && - echo "Fetching submodule submodule" > expect.out && - echo "Fetching submodule submodule/subdir/deepsubmodule" >> expect.out + ) ' test_expect_success "fetch --recurse-submodules recurses into submodules" ' @@ -67,7 +67,7 @@ test_expect_success "fetch --recurse-submodules recurses into submodules" ' cd downstream && git fetch --recurse-submodules >../actual.out 2>../actual.err ) && - test_i18ncmp expect.out actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err actual.err ' @@ -96,7 +96,7 @@ test_expect_success "using fetchRecurseSubmodules=true in .gitmodules recurses i git config -f .gitmodules submodule.submodule.fetchRecurseSubmodules true && git fetch >../actual.out 2>../actual.err ) && - test_i18ncmp expect.out actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err actual.err ' @@ -127,7 +127,7 @@ test_expect_success "--recurse-submodules overrides fetchRecurseSubmodules setti git config --unset -f .gitmodules submodule.submodule.fetchRecurseSubmodules && git config --unset submodule.submodule.fetchRecurseSubmodules ) && - test_i18ncmp expect.out actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err actual.err ' @@ -146,7 +146,7 @@ test_expect_success "--dry-run propagates to submodules" ' cd downstream && git fetch --recurse-submodules --dry-run >../actual.out 2>../actual.err ) && - test_i18ncmp expect.out actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err actual.err ' @@ -155,7 +155,7 @@ test_expect_success "Without --dry-run propagates to submodules" ' cd downstream && git fetch --recurse-submodules >../actual.out 2>../actual.err ) && - test_i18ncmp expect.out actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err actual.err ' @@ -166,7 +166,7 @@ test_expect_success "recurseSubmodules=true propagates into submodules" ' git config fetch.recurseSubmodules true git fetch >../actual.out 2>../actual.err ) && - test_i18ncmp expect.out actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err actual.err ' @@ -180,7 +180,7 @@ test_expect_success "--recurse-submodules overrides config in submodule" ' ) && git fetch --recurse-submodules >../actual.out 2>../actual.err ) && - test_i18ncmp expect.out actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err actual.err ' @@ -214,16 +214,15 @@ test_expect_success "Recursion stops when no new submodule commits are fetched" git add submodule && git commit -m "new submodule" && head2=$(git rev-parse --short HEAD) && - echo "Fetching submodule submodule" > expect.out.sub && echo "From $pwd/." > expect.err.sub && echo " $head1..$head2 master -> origin/master" >>expect.err.sub && - head -2 expect.err >> expect.err.sub && + head -3 expect.err >> expect.err.sub && ( cd downstream && git fetch >../actual.out 2>../actual.err ) && test_i18ncmp expect.err.sub actual.err && - test_i18ncmp expect.out.sub actual.out + test_must_be_empty actual.out ' test_expect_success "Recursion doesn't happen when new superproject commits don't change any submodules" ' @@ -269,7 +268,7 @@ test_expect_success "Recursion picks up config in submodule" ' ) ) && test_i18ncmp expect.err.sub actual.err && - test_i18ncmp expect.out actual.out + test_must_be_empty actual.out ' test_expect_success "Recursion picks up all submodules when necessary" ' @@ -285,7 +284,8 @@ test_expect_success "Recursion picks up all submodules when necessary" ' git add subdir/deepsubmodule && git commit -m "new deepsubmodule" head2=$(git rev-parse --short HEAD) && - echo "From $pwd/submodule" > ../expect.err.sub && + echo "Fetching submodule submodule" > ../expect.err.sub && + echo "From $pwd/submodule" >> ../expect.err.sub && echo " $head1..$head2 master -> origin/master" >> ../expect.err.sub ) && head1=$(git rev-parse --short HEAD) && @@ -295,13 +295,13 @@ test_expect_success "Recursion picks up all submodules when necessary" ' echo "From $pwd/." > expect.err.2 && echo " $head1..$head2 master -> origin/master" >> expect.err.2 && cat expect.err.sub >> expect.err.2 && - tail -2 expect.err >> expect.err.2 && + tail -3 expect.err >> expect.err.2 && ( cd downstream && git fetch >../actual.out 2>../actual.err ) && test_i18ncmp expect.err.2 actual.err && - test_i18ncmp expect.out actual.out + test_must_be_empty actual.out ' test_expect_success "'--recurse-submodules=on-demand' doesn't recurse when no new commits are fetched in the superproject (and ignores config)" ' @@ -317,7 +317,8 @@ test_expect_success "'--recurse-submodules=on-demand' doesn't recurse when no ne git add subdir/deepsubmodule && git commit -m "new deepsubmodule" && head2=$(git rev-parse --short HEAD) && - echo "From $pwd/submodule" > ../expect.err.sub && + echo Fetching submodule submodule > ../expect.err.sub && + echo "From $pwd/submodule" >> ../expect.err.sub && echo " $head1..$head2 master -> origin/master" >> ../expect.err.sub ) && ( @@ -335,7 +336,7 @@ test_expect_success "'--recurse-submodules=on-demand' recurses as deep as necess git add submodule && git commit -m "new submodule" && head2=$(git rev-parse --short HEAD) && - tail -2 expect.err > expect.err.deepsub && + tail -3 expect.err > expect.err.deepsub && echo "From $pwd/." > expect.err && echo " $head1..$head2 master -> origin/master" >>expect.err && cat expect.err.sub >> expect.err && @@ -354,7 +355,7 @@ test_expect_success "'--recurse-submodules=on-demand' recurses as deep as necess git config --unset -f .gitmodules submodule.subdir/deepsubmodule.fetchRecursive ) ) && - test_i18ncmp expect.out actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err actual.err ' @@ -388,7 +389,7 @@ test_expect_success "'fetch.recurseSubmodules=on-demand' overrides global config head2=$(git rev-parse --short HEAD) && echo "From $pwd/." > expect.err.2 && echo " $head1..$head2 master -> origin/master" >>expect.err.2 && - head -2 expect.err >> expect.err.2 && + head -3 expect.err >> expect.err.2 && ( cd downstream && git config fetch.recurseSubmodules on-demand && @@ -399,7 +400,7 @@ test_expect_success "'fetch.recurseSubmodules=on-demand' overrides global config cd downstream && git config --unset fetch.recurseSubmodules ) && - test_i18ncmp expect.out.sub actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err.2 actual.err ' @@ -416,7 +417,7 @@ test_expect_success "'submodule..fetchRecurseSubmodules=on-demand' override head2=$(git rev-parse --short HEAD) && echo "From $pwd/." > expect.err.2 && echo " $head1..$head2 master -> origin/master" >>expect.err.2 && - head -2 expect.err >> expect.err.2 && + head -3 expect.err >> expect.err.2 && ( cd downstream && git config submodule.submodule.fetchRecurseSubmodules on-demand && @@ -427,7 +428,7 @@ test_expect_success "'submodule..fetchRecurseSubmodules=on-demand' override cd downstream && git config --unset submodule.submodule.fetchRecurseSubmodules ) && - test_i18ncmp expect.out.sub actual.out && + test_must_be_empty actual.out && test_i18ncmp expect.err.2 actual.err ' -- cgit v1.2.3 From 1079c4be0b72003668df647f8a520fa137c7e158 Mon Sep 17 00:00:00 2001 From: Stefan Beller Date: Tue, 15 Dec 2015 16:04:07 -0800 Subject: xread: poll on non blocking fds The man page of read(2) says: EAGAIN The file descriptor fd refers to a file other than a socket and has been marked nonblocking (O_NONBLOCK), and the read would block. EAGAIN or EWOULDBLOCK The file descriptor fd refers to a socket and has been marked nonblocking (O_NONBLOCK), and the read would block. POSIX.1-2001 allows either error to be returned for this case, and does not require these constants to have the same value, so a portable application should check for both possibilities. If we get an EAGAIN or EWOULDBLOCK the fd must have set O_NONBLOCK. As the intent of xread is to read as much as possible either until the fd is EOF or an actual error occurs, we can ease the feeder of the fd by not spinning the whole time, but rather wait for it politely by not busy waiting. We should not care if the call to poll failed, as we're in an infinite loop and can only get out with the correct read(). Signed-off-by: Stefan Beller Acked-by: Johannes Sixt Signed-off-by: Junio C Hamano --- wrapper.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/wrapper.c b/wrapper.c index 6fcaa4dc62..1770efac8e 100644 --- a/wrapper.c +++ b/wrapper.c @@ -236,8 +236,24 @@ ssize_t xread(int fd, void *buf, size_t len) len = MAX_IO_SIZE; while (1) { nr = read(fd, buf, len); - if ((nr < 0) && (errno == EAGAIN || errno == EINTR)) - continue; + if (nr < 0) { + if (errno == EINTR) + continue; + if (errno == EAGAIN || errno == EWOULDBLOCK) { + struct pollfd pfd; + pfd.events = POLLIN; + pfd.fd = fd; + /* + * it is OK if this poll() failed; we + * want to leave this infinite loop + * only when read() returns with + * success, or an expected failure, + * which would be checked by the next + * call to read(2). + */ + poll(&pfd, 1, -1); + } + } return nr; } } -- cgit v1.2.3 From b4e04fb66e87a027c5f9c96bcbbba50719400169 Mon Sep 17 00:00:00 2001 From: Stefan Beller Date: Tue, 15 Dec 2015 16:04:08 -0800 Subject: strbuf: add strbuf_read_once to read without blocking The new call will read from a file descriptor into a strbuf once. The underlying call xread is just run once. xread only reattempts reading in case of EINTR, which makes it suitable to use for a nonblocking read. Signed-off-by: Stefan Beller Signed-off-by: Junio C Hamano --- strbuf.c | 11 +++++++++++ strbuf.h | 8 ++++++++ 2 files changed, 19 insertions(+) diff --git a/strbuf.c b/strbuf.c index d76f0aed85..38686ffb65 100644 --- a/strbuf.c +++ b/strbuf.c @@ -384,6 +384,17 @@ ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint) return sb->len - oldlen; } +ssize_t strbuf_read_once(struct strbuf *sb, int fd, size_t hint) +{ + ssize_t cnt; + + strbuf_grow(sb, hint ? hint : 8192); + cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1); + if (cnt > 0) + strbuf_setlen(sb, sb->len + cnt); + return cnt; +} + #define STRBUF_MAXLINK (2*PATH_MAX) int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) diff --git a/strbuf.h b/strbuf.h index 7123fca7af..2bf90e70fc 100644 --- a/strbuf.h +++ b/strbuf.h @@ -366,6 +366,14 @@ extern size_t strbuf_fread(struct strbuf *, size_t, FILE *); */ extern ssize_t strbuf_read(struct strbuf *, int fd, size_t hint); +/** + * Read the contents of a given file descriptor partially by using only one + * attempt of xread. The third argument can be used to give a hint about the + * file size, to avoid reallocs. Returns the number of new bytes appended to + * the sb. + */ +extern ssize_t strbuf_read_once(struct strbuf *, int fd, size_t hint); + /** * Read the contents of a file, specified by its path. The third argument * can be used to give a hint about the file size, to avoid reallocs. -- cgit v1.2.3 From bfb6b53c05daedc4084a5f716804a83781826230 Mon Sep 17 00:00:00 2001 From: Stefan Beller Date: Tue, 15 Dec 2015 16:04:09 -0800 Subject: sigchain: add command to pop all common signals The new method removes all common signal handlers that were installed by sigchain_push. CC: Jeff King Signed-off-by: Stefan Beller Signed-off-by: Junio C Hamano --- sigchain.c | 9 +++++++++ sigchain.h | 1 + 2 files changed, 10 insertions(+) diff --git a/sigchain.c b/sigchain.c index faa375d5d8..2ac43bbd28 100644 --- a/sigchain.c +++ b/sigchain.c @@ -50,3 +50,12 @@ void sigchain_push_common(sigchain_fun f) sigchain_push(SIGQUIT, f); sigchain_push(SIGPIPE, f); } + +void sigchain_pop_common(void) +{ + sigchain_pop(SIGPIPE); + sigchain_pop(SIGQUIT); + sigchain_pop(SIGTERM); + sigchain_pop(SIGHUP); + sigchain_pop(SIGINT); +} diff --git a/sigchain.h b/sigchain.h index 618083bce0..138b20f54b 100644 --- a/sigchain.h +++ b/sigchain.h @@ -7,5 +7,6 @@ int sigchain_push(int sig, sigchain_fun f); int sigchain_pop(int sig); void sigchain_push_common(sigchain_fun f); +void sigchain_pop_common(void); #endif /* SIGCHAIN_H */ -- cgit v1.2.3 From c553c72eed64b5f7316ce227f6d5d783eae6f2ed Mon Sep 17 00:00:00 2001 From: Stefan Beller Date: Tue, 15 Dec 2015 16:04:10 -0800 Subject: run-command: add an asynchronous parallel child processor This allows to run external commands in parallel with ordered output on stderr. If we run external commands in parallel we cannot pipe the output directly to the our stdout/err as it would mix up. So each process's output will flow through a pipe, which we buffer. One subprocess can be directly piped to out stdout/err for a low latency feedback to the user. Example: Let's assume we have 5 submodules A,B,C,D,E and each fetch takes a different amount of time as the different submodules vary in size, then the output of fetches in sequential order might look like this: time --> output: |---A---| |-B-| |-------C-------| |-D-| |-E-| When we schedule these submodules into maximal two parallel processes, a schedule and sample output over time may look like this: process 1: |---A---| |-D-| |-E-| process 2: |-B-| |-------C-------| output: |---A---|B|---C-------|DE So A will be perceived as it would run normally in the single child version. As B has finished by the time A is done, we can dump its whole progress buffer on stderr, such that it looks like it finished in no time. Once that is done, C is determined to be the visible child and its progress will be reported in real time. So this way of output is really good for human consumption, as it only changes the timing, not the actual output. For machine consumption the output needs to be prepared in the tasks, by either having a prefix per line or per block to indicate whose tasks output is displayed, because the output order may not follow the original sequential ordering: |----A----| |--B--| |-C-| will be scheduled to be all parallel: process 1: |----A----| process 2: |--B--| process 3: |-C-| output: |----A----|CB This happens because C finished before B did, so it will be queued for output before B. To detect when a child has finished executing, we check interleaved with other actions (such as checking the liveliness of children or starting new processes) whether the stderr pipe still exists. Once a child closed its stderr stream, we assume it is terminating very soon, and use `finish_command()` from the single external process execution interface to collect the exit status. By maintaining the strong assumption of stderr being open until the very end of a child process, we can avoid other hassle such as an implementation using `waitpid(-1)`, which is not implemented in Windows. Signed-off-by: Stefan Beller Signed-off-by: Junio C Hamano --- run-command.c | 335 +++++++++++++++++++++++++++++++++++++++++++++++++ run-command.h | 80 ++++++++++++ t/t0061-run-command.sh | 53 ++++++++ test-run-command.c | 55 +++++++- 4 files changed, 522 insertions(+), 1 deletion(-) diff --git a/run-command.c b/run-command.c index 13fa452e8c..51fd72c427 100644 --- a/run-command.c +++ b/run-command.c @@ -3,6 +3,8 @@ #include "exec_cmd.h" #include "sigchain.h" #include "argv-array.h" +#include "thread-utils.h" +#include "strbuf.h" void child_process_init(struct child_process *child) { @@ -865,3 +867,336 @@ int capture_command(struct child_process *cmd, struct strbuf *buf, size_t hint) close(cmd->out); return finish_command(cmd); } + +enum child_state { + GIT_CP_FREE, + GIT_CP_WORKING, + GIT_CP_WAIT_CLEANUP, +}; + +struct parallel_processes { + void *data; + + int max_processes; + int nr_processes; + + get_next_task_fn get_next_task; + start_failure_fn start_failure; + task_finished_fn task_finished; + + struct { + enum child_state state; + struct child_process process; + struct strbuf err; + void *data; + } *children; + /* + * The struct pollfd is logically part of *children, + * but the system call expects it as its own array. + */ + struct pollfd *pfd; + + unsigned shutdown : 1; + + int output_owner; + struct strbuf buffered_output; /* of finished children */ +}; + +static int default_start_failure(struct child_process *cp, + struct strbuf *err, + void *pp_cb, + void *pp_task_cb) +{ + int i; + + strbuf_addstr(err, "Starting a child failed:"); + for (i = 0; cp->argv[i]; i++) + strbuf_addf(err, " %s", cp->argv[i]); + + return 0; +} + +static int default_task_finished(int result, + struct child_process *cp, + struct strbuf *err, + void *pp_cb, + void *pp_task_cb) +{ + int i; + + if (!result) + return 0; + + strbuf_addf(err, "A child failed with return code %d:", result); + for (i = 0; cp->argv[i]; i++) + strbuf_addf(err, " %s", cp->argv[i]); + + return 0; +} + +static void kill_children(struct parallel_processes *pp, int signo) +{ + int i, n = pp->max_processes; + + for (i = 0; i < n; i++) + if (pp->children[i].state == GIT_CP_WORKING) + kill(pp->children[i].process.pid, signo); +} + +static struct parallel_processes *pp_for_signal; + +static void handle_children_on_signal(int signo) +{ + kill_children(pp_for_signal, signo); + sigchain_pop(signo); + raise(signo); +} + +static void pp_init(struct parallel_processes *pp, + int n, + get_next_task_fn get_next_task, + start_failure_fn start_failure, + task_finished_fn task_finished, + void *data) +{ + int i; + + if (n < 1) + n = online_cpus(); + + pp->max_processes = n; + + trace_printf("run_processes_parallel: preparing to run up to %d tasks", n); + + pp->data = data; + if (!get_next_task) + die("BUG: you need to specify a get_next_task function"); + pp->get_next_task = get_next_task; + + pp->start_failure = start_failure ? start_failure : default_start_failure; + pp->task_finished = task_finished ? task_finished : default_task_finished; + + pp->nr_processes = 0; + pp->output_owner = 0; + pp->shutdown = 0; + pp->children = xcalloc(n, sizeof(*pp->children)); + pp->pfd = xcalloc(n, sizeof(*pp->pfd)); + strbuf_init(&pp->buffered_output, 0); + + for (i = 0; i < n; i++) { + strbuf_init(&pp->children[i].err, 0); + child_process_init(&pp->children[i].process); + pp->pfd[i].events = POLLIN | POLLHUP; + pp->pfd[i].fd = -1; + } + + pp_for_signal = pp; + sigchain_push_common(handle_children_on_signal); +} + +static void pp_cleanup(struct parallel_processes *pp) +{ + int i; + + trace_printf("run_processes_parallel: done"); + for (i = 0; i < pp->max_processes; i++) { + strbuf_release(&pp->children[i].err); + child_process_clear(&pp->children[i].process); + } + + free(pp->children); + free(pp->pfd); + + /* + * When get_next_task added messages to the buffer in its last + * iteration, the buffered output is non empty. + */ + fputs(pp->buffered_output.buf, stderr); + strbuf_release(&pp->buffered_output); + + sigchain_pop_common(); +} + +/* returns + * 0 if a new task was started. + * 1 if no new jobs was started (get_next_task ran out of work, non critical + * problem with starting a new command) + * <0 no new job was started, user wishes to shutdown early. Use negative code + * to signal the children. + */ +static int pp_start_one(struct parallel_processes *pp) +{ + int i, code; + + for (i = 0; i < pp->max_processes; i++) + if (pp->children[i].state == GIT_CP_FREE) + break; + if (i == pp->max_processes) + die("BUG: bookkeeping is hard"); + + code = pp->get_next_task(&pp->children[i].process, + &pp->children[i].err, + pp->data, + &pp->children[i].data); + if (!code) { + strbuf_addbuf(&pp->buffered_output, &pp->children[i].err); + strbuf_reset(&pp->children[i].err); + return 1; + } + pp->children[i].process.err = -1; + pp->children[i].process.stdout_to_stderr = 1; + pp->children[i].process.no_stdin = 1; + + if (start_command(&pp->children[i].process)) { + code = pp->start_failure(&pp->children[i].process, + &pp->children[i].err, + pp->data, + &pp->children[i].data); + strbuf_addbuf(&pp->buffered_output, &pp->children[i].err); + strbuf_reset(&pp->children[i].err); + if (code) + pp->shutdown = 1; + return code; + } + + pp->nr_processes++; + pp->children[i].state = GIT_CP_WORKING; + pp->pfd[i].fd = pp->children[i].process.err; + return 0; +} + +static void pp_buffer_stderr(struct parallel_processes *pp, int output_timeout) +{ + int i; + + while ((i = poll(pp->pfd, pp->max_processes, output_timeout)) < 0) { + if (errno == EINTR) + continue; + pp_cleanup(pp); + die_errno("poll"); + } + + /* Buffer output from all pipes. */ + for (i = 0; i < pp->max_processes; i++) { + if (pp->children[i].state == GIT_CP_WORKING && + pp->pfd[i].revents & (POLLIN | POLLHUP)) { + int n = strbuf_read_once(&pp->children[i].err, + pp->children[i].process.err, 0); + if (n == 0) { + close(pp->children[i].process.err); + pp->children[i].state = GIT_CP_WAIT_CLEANUP; + } else if (n < 0) + if (errno != EAGAIN) + die_errno("read"); + } + } +} + +static void pp_output(struct parallel_processes *pp) +{ + int i = pp->output_owner; + if (pp->children[i].state == GIT_CP_WORKING && + pp->children[i].err.len) { + fputs(pp->children[i].err.buf, stderr); + strbuf_reset(&pp->children[i].err); + } +} + +static int pp_collect_finished(struct parallel_processes *pp) +{ + int i, code; + int n = pp->max_processes; + int result = 0; + + while (pp->nr_processes > 0) { + for (i = 0; i < pp->max_processes; i++) + if (pp->children[i].state == GIT_CP_WAIT_CLEANUP) + break; + if (i == pp->max_processes) + break; + + code = finish_command(&pp->children[i].process); + + code = pp->task_finished(code, &pp->children[i].process, + &pp->children[i].err, pp->data, + &pp->children[i].data); + + if (code) + result = code; + if (code < 0) + break; + + pp->nr_processes--; + pp->children[i].state = GIT_CP_FREE; + pp->pfd[i].fd = -1; + child_process_init(&pp->children[i].process); + + if (i != pp->output_owner) { + strbuf_addbuf(&pp->buffered_output, &pp->children[i].err); + strbuf_reset(&pp->children[i].err); + } else { + fputs(pp->children[i].err.buf, stderr); + strbuf_reset(&pp->children[i].err); + + /* Output all other finished child processes */ + fputs(pp->buffered_output.buf, stderr); + strbuf_reset(&pp->buffered_output); + + /* + * Pick next process to output live. + * NEEDSWORK: + * For now we pick it randomly by doing a round + * robin. Later we may want to pick the one with + * the most output or the longest or shortest + * running process time. + */ + for (i = 0; i < n; i++) + if (pp->children[(pp->output_owner + i) % n].state == GIT_CP_WORKING) + break; + pp->output_owner = (pp->output_owner + i) % n; + } + } + return result; +} + +int run_processes_parallel(int n, + get_next_task_fn get_next_task, + start_failure_fn start_failure, + task_finished_fn task_finished, + void *pp_cb) +{ + int i, code; + int output_timeout = 100; + int spawn_cap = 4; + struct parallel_processes pp; + + pp_init(&pp, n, get_next_task, start_failure, task_finished, pp_cb); + while (1) { + for (i = 0; + i < spawn_cap && !pp.shutdown && + pp.nr_processes < pp.max_processes; + i++) { + code = pp_start_one(&pp); + if (!code) + continue; + if (code < 0) { + pp.shutdown = 1; + kill_children(&pp, -code); + } + break; + } + if (!pp.nr_processes) + break; + pp_buffer_stderr(&pp, output_timeout); + pp_output(&pp); + code = pp_collect_finished(&pp); + if (code) { + pp.shutdown = 1; + if (code < 0) + kill_children(&pp, -code); + } + } + + pp_cleanup(&pp); + return 0; +} diff --git a/run-command.h b/run-command.h index 12bb26c2a6..d5a57f9227 100644 --- a/run-command.h +++ b/run-command.h @@ -122,4 +122,84 @@ int start_async(struct async *async); int finish_async(struct async *async); int in_async(void); +/** + * This callback should initialize the child process and preload the + * error channel if desired. The preloading of is useful if you want to + * have a message printed directly before the output of the child process. + * pp_cb is the callback cookie as passed to run_processes_parallel. + * You can store a child process specific callback cookie in pp_task_cb. + * + * Even after returning 0 to indicate that there are no more processes, + * this function will be called again until there are no more running + * child processes. + * + * Return 1 if the next child is ready to run. + * Return 0 if there are currently no more tasks to be processed. + * To send a signal to other child processes for abortion, + * return the negative signal number. + */ +typedef int (*get_next_task_fn)(struct child_process *cp, + struct strbuf *err, + void *pp_cb, + void **pp_task_cb); + +/** + * This callback is called whenever there are problems starting + * a new process. + * + * You must not write to stdout or stderr in this function. Add your + * message to the strbuf err instead, which will be printed without + * messing up the output of the other parallel processes. + * + * pp_cb is the callback cookie as passed into run_processes_parallel, + * pp_task_cb is the callback cookie as passed into get_next_task_fn. + * + * Return 0 to continue the parallel processing. To abort return non zero. + * To send a signal to other child processes for abortion, return + * the negative signal number. + */ +typedef int (*start_failure_fn)(struct child_process *cp, + struct strbuf *err, + void *pp_cb, + void *pp_task_cb); + +/** + * This callback is called on every child process that finished processing. + * + * You must not write to stdout or stderr in this function. Add your + * message to the strbuf err instead, which will be printed without + * messing up the output of the other parallel processes. + * + * pp_cb is the callback cookie as passed into run_processes_parallel, + * pp_task_cb is the callback cookie as passed into get_next_task_fn. + * + * Return 0 to continue the parallel processing. To abort return non zero. + * To send a signal to other child processes for abortion, return + * the negative signal number. + */ +typedef int (*task_finished_fn)(int result, + struct child_process *cp, + struct strbuf *err, + void *pp_cb, + void *pp_task_cb); + +/** + * Runs up to n processes at the same time. Whenever a process can be + * started, the callback get_next_task_fn is called to obtain the data + * required to start another child process. + * + * The children started via this function run in parallel. Their output + * (both stdout and stderr) is routed to stderr in a manner that output + * from different tasks does not interleave. + * + * If start_failure_fn or task_finished_fn are NULL, default handlers + * will be used. The default handlers will print an error message on + * error without issuing an emergency stop. + */ +int run_processes_parallel(int n, + get_next_task_fn, + start_failure_fn, + task_finished_fn, + void *pp_cb); + #endif diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh index 9acf628726..12228b4aa6 100755 --- a/t/t0061-run-command.sh +++ b/t/t0061-run-command.sh @@ -47,4 +47,57 @@ test_expect_success POSIXPERM,SANITY 'unreadable directory in PATH' ' test_cmp expect actual ' +cat >expect <<-EOF +preloaded output of a child +Hello +World +preloaded output of a child +Hello +World +preloaded output of a child +Hello +World +preloaded output of a child +Hello +World +EOF + +test_expect_success 'run_command runs in parallel with more jobs available than tasks' ' + test-run-command run-command-parallel 5 sh -c "printf \"%s\n%s\n\" Hello World" 2>actual && + test_cmp expect actual +' + +test_expect_success 'run_command runs in parallel with as many jobs as tasks' ' + test-run-command run-command-parallel 4 sh -c "printf \"%s\n%s\n\" Hello World" 2>actual && + test_cmp expect actual +' + +test_expect_success 'run_command runs in parallel with more tasks than jobs available' ' + test-run-command run-command-parallel 3 sh -c "printf \"%s\n%s\n\" Hello World" 2>actual && + test_cmp expect actual +' + +cat >expect <<-EOF +preloaded output of a child +asking for a quick stop +preloaded output of a child +asking for a quick stop +preloaded output of a child +asking for a quick stop +EOF + +test_expect_success 'run_command is asked to abort gracefully' ' + test-run-command run-command-abort 3 false 2>actual && + test_cmp expect actual +' + +cat >expect <<-EOF +no further jobs available +EOF + +test_expect_success 'run_command outputs ' ' + test-run-command run-command-no-jobs 3 sh -c "printf \"%s\n%s\n\" Hello World" 2>actual && + test_cmp expect actual +' + test_done diff --git a/test-run-command.c b/test-run-command.c index 89c7de2c60..fbe0a27ef3 100644 --- a/test-run-command.c +++ b/test-run-command.c @@ -10,16 +10,54 @@ #include "git-compat-util.h" #include "run-command.h" +#include "argv-array.h" +#include "strbuf.h" #include #include +static int number_callbacks; +static int parallel_next(struct child_process *cp, + struct strbuf *err, + void *cb, + void **task_cb) +{ + struct child_process *d = cb; + if (number_callbacks >= 4) + return 0; + + argv_array_pushv(&cp->args, d->argv); + strbuf_addf(err, "preloaded output of a child\n"); + number_callbacks++; + return 1; +} + +static int no_job(struct child_process *cp, + struct strbuf *err, + void *cb, + void **task_cb) +{ + strbuf_addf(err, "no further jobs available\n"); + return 0; +} + +static int task_finished(int result, + struct child_process *cp, + struct strbuf *err, + void *pp_cb, + void *pp_task_cb) +{ + strbuf_addf(err, "asking for a quick stop\n"); + return 1; +} + int main(int argc, char **argv) { struct child_process proc = CHILD_PROCESS_INIT; + int jobs; if (argc < 3) return 1; - proc.argv = (const char **)argv+2; + proc.argv = (const char **)argv + 2; if (!strcmp(argv[1], "start-command-ENOENT")) { if (start_command(&proc) < 0 && errno == ENOENT) @@ -30,6 +68,21 @@ int main(int argc, char **argv) if (!strcmp(argv[1], "run-command")) exit(run_command(&proc)); + jobs = atoi(argv[2]); + proc.argv = (const char **)argv + 3; + + if (!strcmp(argv[1], "run-command-parallel")) + exit(run_processes_parallel(jobs, parallel_next, + NULL, NULL, &proc)); + + if (!strcmp(argv[1], "run-command-abort")) + exit(run_processes_parallel(jobs, parallel_next, + NULL, task_finished, &proc)); + + if (!strcmp(argv[1], "run-command-no-jobs")) + exit(run_processes_parallel(jobs, no_job, + NULL, task_finished, &proc)); + fprintf(stderr, "check usage\n"); return 1; } -- cgit v1.2.3 From fe85ee6e23e642985004d37e63b4c0d0e5f30587 Mon Sep 17 00:00:00 2001 From: Stefan Beller Date: Tue, 15 Dec 2015 16:04:11 -0800 Subject: fetch_populated_submodules: use new parallel job processing In a later patch we enable parallel processing of submodules, this only adds the possibility for it. So this change should not change any user facing behavior. Signed-off-by: Stefan Beller Signed-off-by: Junio C Hamano --- submodule.c | 142 +++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 98 insertions(+), 44 deletions(-) diff --git a/submodule.c b/submodule.c index 8386477d62..4bc7a45393 100644 --- a/submodule.c +++ b/submodule.c @@ -12,6 +12,7 @@ #include "sha1-array.h" #include "argv-array.h" #include "blob.h" +#include "thread-utils.h" static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND; static struct string_list changed_submodule_paths; @@ -610,37 +611,28 @@ static void calculate_changed_submodule_paths(void) initialized_fetch_ref_tips = 0; } -int fetch_populated_submodules(const struct argv_array *options, - const char *prefix, int command_line_option, - int quiet) +struct submodule_parallel_fetch { + int count; + struct argv_array args; + const char *work_tree; + const char *prefix; + int command_line_option; + int quiet; + int result; +}; +#define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0} + +static int get_next_submodule(struct child_process *cp, + struct strbuf *err, void *data, void **task_cb) { - int i, result = 0; - struct child_process cp = CHILD_PROCESS_INIT; - struct argv_array argv = ARGV_ARRAY_INIT; - const char *work_tree = get_git_work_tree(); - if (!work_tree) - goto out; - - if (read_cache() < 0) - die("index file corrupt"); - - argv_array_push(&argv, "fetch"); - for (i = 0; i < options->argc; i++) - argv_array_push(&argv, options->argv[i]); - argv_array_push(&argv, "--recurse-submodules-default"); - /* default value, "--submodule-prefix" and its value are added later */ - - cp.env = local_repo_env; - cp.git_cmd = 1; - cp.no_stdin = 1; - - calculate_changed_submodule_paths(); + int ret = 0; + struct submodule_parallel_fetch *spf = data; - for (i = 0; i < active_nr; i++) { + for (; spf->count < active_nr; spf->count++) { struct strbuf submodule_path = STRBUF_INIT; struct strbuf submodule_git_dir = STRBUF_INIT; struct strbuf submodule_prefix = STRBUF_INIT; - const struct cache_entry *ce = active_cache[i]; + const struct cache_entry *ce = active_cache[spf->count]; const char *git_dir, *default_argv; const struct submodule *submodule; @@ -652,7 +644,7 @@ int fetch_populated_submodules(const struct argv_array *options, submodule = submodule_from_name(null_sha1, ce->name); default_argv = "yes"; - if (command_line_option == RECURSE_SUBMODULES_DEFAULT) { + if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) { if (submodule && submodule->fetch_recurse != RECURSE_SUBMODULES_NONE) { @@ -675,40 +667,102 @@ int fetch_populated_submodules(const struct argv_array *options, default_argv = "on-demand"; } } - } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) { + } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) { if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name)) continue; default_argv = "on-demand"; } - strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name); + strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name); strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf); - strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name); + strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name); git_dir = read_gitfile(submodule_git_dir.buf); if (!git_dir) git_dir = submodule_git_dir.buf; if (is_directory(git_dir)) { - if (!quiet) - fprintf(stderr, "Fetching submodule %s%s\n", prefix, ce->name); - cp.dir = submodule_path.buf; - argv_array_push(&argv, default_argv); - argv_array_push(&argv, "--submodule-prefix"); - argv_array_push(&argv, submodule_prefix.buf); - cp.argv = argv.argv; - if (run_command(&cp)) - result = 1; - argv_array_pop(&argv); - argv_array_pop(&argv); - argv_array_pop(&argv); + child_process_init(cp); + cp->dir = strbuf_detach(&submodule_path, NULL); + cp->env = local_repo_env; + cp->git_cmd = 1; + if (!spf->quiet) + strbuf_addf(err, "Fetching submodule %s%s\n", + spf->prefix, ce->name); + argv_array_init(&cp->args); + argv_array_pushv(&cp->args, spf->args.argv); + argv_array_push(&cp->args, default_argv); + argv_array_push(&cp->args, "--submodule-prefix"); + argv_array_push(&cp->args, submodule_prefix.buf); + ret = 1; } strbuf_release(&submodule_path); strbuf_release(&submodule_git_dir); strbuf_release(&submodule_prefix); + if (ret) { + spf->count++; + return 1; + } } - argv_array_clear(&argv); + return 0; +} + +static int fetch_start_failure(struct child_process *cp, + struct strbuf *err, + void *cb, void *task_cb) +{ + struct submodule_parallel_fetch *spf = cb; + + spf->result = 1; + + return 0; +} + +static int fetch_finish(int retvalue, struct child_process *cp, + struct strbuf *err, void *cb, void *task_cb) +{ + struct submodule_parallel_fetch *spf = cb; + + if (retvalue) + spf->result = 1; + + return 0; +} + +int fetch_populated_submodules(const struct argv_array *options, + const char *prefix, int command_line_option, + int quiet) +{ + int i; + int max_parallel_jobs = 1; + struct submodule_parallel_fetch spf = SPF_INIT; + + spf.work_tree = get_git_work_tree(); + spf.command_line_option = command_line_option; + spf.quiet = quiet; + spf.prefix = prefix; + + if (!spf.work_tree) + goto out; + + if (read_cache() < 0) + die("index file corrupt"); + + argv_array_push(&spf.args, "fetch"); + for (i = 0; i < options->argc; i++) + argv_array_push(&spf.args, options->argv[i]); + argv_array_push(&spf.args, "--recurse-submodules-default"); + /* default value, "--submodule-prefix" and its value are added later */ + + calculate_changed_submodule_paths(); + run_processes_parallel(max_parallel_jobs, + get_next_submodule, + fetch_start_failure, + fetch_finish, + &spf); + + argv_array_clear(&spf.args); out: string_list_clear(&changed_submodule_paths, 1); - return result; + return spf.result; } unsigned is_submodule_modified(const char *path, int ignore_untracked) -- cgit v1.2.3 From 62104ba14af4845c6c1ba1dab05fad4a289d806f Mon Sep 17 00:00:00 2001 From: Stefan Beller Date: Tue, 15 Dec 2015 16:04:12 -0800 Subject: submodules: allow parallel fetching, add tests and documentation This enables the work of the previous patches. Signed-off-by: Stefan Beller Signed-off-by: Junio C Hamano --- Documentation/fetch-options.txt | 7 +++++++ builtin/fetch.c | 6 +++++- builtin/pull.c | 6 ++++++ submodule.c | 3 +-- submodule.h | 2 +- t/t5526-fetch-submodules.sh | 20 ++++++++++++++++++++ 6 files changed, 40 insertions(+), 4 deletions(-) diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt index 45583d8454..6b109f687a 100644 --- a/Documentation/fetch-options.txt +++ b/Documentation/fetch-options.txt @@ -100,6 +100,13 @@ ifndef::git-pull[] reference to a commit that isn't already in the local submodule clone. +-j:: +--jobs=:: + Number of parallel children to be used for fetching submodules. + Each will fetch from different submodules, such that fetching many + submodules will be faster. By default submodules will be fetched + one at a time. + --no-recurse-submodules:: Disable recursive fetching of submodules (this has the same effect as using the '--recurse-submodules=no' option). diff --git a/builtin/fetch.c b/builtin/fetch.c index c85f3471d4..586840d761 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -37,6 +37,7 @@ static int prune = -1; /* unspecified */ static int all, append, dry_run, force, keep, multiple, update_head_ok, verbosity; static int progress = -1, recurse_submodules = RECURSE_SUBMODULES_DEFAULT; static int tags = TAGS_DEFAULT, unshallow, update_shallow; +static int max_children = 1; static const char *depth; static const char *upload_pack; static struct strbuf default_rla = STRBUF_INIT; @@ -99,6 +100,8 @@ static struct option builtin_fetch_options[] = { N_("fetch all tags and associated objects"), TAGS_SET), OPT_SET_INT('n', NULL, &tags, N_("do not fetch all tags (--no-tags)"), TAGS_UNSET), + OPT_INTEGER('j', "jobs", &max_children, + N_("number of submodules fetched in parallel")), OPT_BOOL('p', "prune", &prune, N_("prune remote-tracking branches no longer on remote")), { OPTION_CALLBACK, 0, "recurse-submodules", NULL, N_("on-demand"), @@ -1213,7 +1216,8 @@ int cmd_fetch(int argc, const char **argv, const char *prefix) result = fetch_populated_submodules(&options, submodule_prefix, recurse_submodules, - verbosity < 0); + verbosity < 0, + max_children); argv_array_clear(&options); } diff --git a/builtin/pull.c b/builtin/pull.c index 5145fc60a0..9e3c73809f 100644 --- a/builtin/pull.c +++ b/builtin/pull.c @@ -95,6 +95,7 @@ static int opt_force; static char *opt_tags; static char *opt_prune; static char *opt_recurse_submodules; +static char *max_children; static int opt_dry_run; static char *opt_keep; static char *opt_depth; @@ -178,6 +179,9 @@ static struct option pull_options[] = { N_("on-demand"), N_("control recursive fetching of submodules"), PARSE_OPT_OPTARG), + OPT_PASSTHRU('j', "jobs", &max_children, N_("n"), + N_("number of submodules pulled in parallel"), + PARSE_OPT_OPTARG), OPT_BOOL(0, "dry-run", &opt_dry_run, N_("dry run")), OPT_PASSTHRU('k', "keep", &opt_keep, NULL, @@ -525,6 +529,8 @@ static int run_fetch(const char *repo, const char **refspecs) argv_array_push(&args, opt_prune); if (opt_recurse_submodules) argv_array_push(&args, opt_recurse_submodules); + if (max_children) + argv_array_push(&args, max_children); if (opt_dry_run) argv_array_push(&args, "--dry-run"); if (opt_keep) diff --git a/submodule.c b/submodule.c index 4bc7a45393..b83939c294 100644 --- a/submodule.c +++ b/submodule.c @@ -729,10 +729,9 @@ static int fetch_finish(int retvalue, struct child_process *cp, int fetch_populated_submodules(const struct argv_array *options, const char *prefix, int command_line_option, - int quiet) + int quiet, int max_parallel_jobs) { int i; - int max_parallel_jobs = 1; struct submodule_parallel_fetch spf = SPF_INIT; spf.work_tree = get_git_work_tree(); diff --git a/submodule.h b/submodule.h index 5507c3d9a0..cbc000304e 100644 --- a/submodule.h +++ b/submodule.h @@ -31,7 +31,7 @@ void set_config_fetch_recurse_submodules(int value); void check_for_new_submodule_commits(unsigned char new_sha1[20]); int fetch_populated_submodules(const struct argv_array *options, const char *prefix, int command_line_option, - int quiet); + int quiet, int max_parallel_jobs); unsigned is_submodule_modified(const char *path, int ignore_untracked); int submodule_uses_gitfile(const char *path); int ok_to_remove_submodule(const char *path); diff --git a/t/t5526-fetch-submodules.sh b/t/t5526-fetch-submodules.sh index 17759b145f..1241146227 100755 --- a/t/t5526-fetch-submodules.sh +++ b/t/t5526-fetch-submodules.sh @@ -71,6 +71,17 @@ test_expect_success "fetch --recurse-submodules recurses into submodules" ' test_i18ncmp expect.err actual.err ' +test_expect_success "fetch --recurse-submodules -j2 has the same output behaviour" ' + add_upstream_commit && + ( + cd downstream && + GIT_TRACE=$(pwd)/../trace.out git fetch --recurse-submodules -j2 2>../actual.err + ) && + test_must_be_empty actual.out && + test_i18ncmp expect.err actual.err && + grep "2 tasks" trace.out +' + test_expect_success "fetch alone only fetches superproject" ' add_upstream_commit && ( @@ -140,6 +151,15 @@ test_expect_success "--quiet propagates to submodules" ' ! test -s actual.err ' +test_expect_success "--quiet propagates to parallel submodules" ' + ( + cd downstream && + git fetch --recurse-submodules -j 2 --quiet >../actual.out 2>../actual.err + ) && + ! test -s actual.out && + ! test -s actual.err +' + test_expect_success "--dry-run propagates to submodules" ' add_upstream_commit && ( -- cgit v1.2.3