From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 12 Jan 2016 23:16:54 +0000 (-0800)
Subject: Merge branch 'sb/submodule-parallel-fetch'
X-Git-Tag: v2.8.0-rc0~127
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/187c0d3d9e63f7d84d7055372f07bedb52849f06?hp=-c

Merge branch 'sb/submodule-parallel-fetch'

Add a framework to spawn a group of processes in parallel, and use
it to run "git fetch --recurse-submodules" in parallel.

Rerolled and this seems to be a lot cleaner.  The merge of the
earlier one to 'next' has been reverted.

* sb/submodule-parallel-fetch:
submodules: allow parallel fetching, add tests and documentation
fetch_populated_submodules: use new parallel job processing
run-command: add an asynchronous parallel child processor
sigchain: add command to pop all common signals
strbuf: add strbuf_read_once to read without blocking
xread: poll on non blocking fds
submodule.c: write "Fetching submodule <foo>" to stderr
---

187c0d3d9e63f7d84d7055372f07bedb52849f06
diff --combined submodule.h
index ddff512109,cbc000304e..e06eaa5ebb
--- a/submodule.h
+++ b/submodule.h
@@@ -5,7 -5,6 +5,7 @@@ struct diff_options
  struct argv_array;
  
  enum {
 +	RECURSE_SUBMODULES_CHECK = -4,
  	RECURSE_SUBMODULES_ERROR = -3,
  	RECURSE_SUBMODULES_NONE = -2,
  	RECURSE_SUBMODULES_ON_DEMAND = -1,
@@@ -32,7 -31,7 +32,7 @@@ void set_config_fetch_recurse_submodule
  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 --combined wrapper.c
index c95e2906b8,1770efac8e..b43d437630
--- a/wrapper.c
+++ b/wrapper.c
@@@ -236,8 -236,24 +236,24 @@@ ssize_t xread(int fd, void *buf, size_
  	    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;
  	}
  }
@@@ -601,6 -617,18 +617,6 @@@ int access_or_die(const char *path, in
  	return ret;
  }
  
 -struct passwd *xgetpwuid_self(void)
 -{
 -	struct passwd *pw;
 -
 -	errno = 0;
 -	pw = getpwuid(getuid());
 -	if (!pw)
 -		die(_("unable to look up current user in the passwd file: %s"),
 -		    errno ? strerror(errno) : _("no such user"));
 -	return pw;
 -}
 -
  char *xgetcwd(void)
  {
  	struct strbuf sb = STRBUF_INIT;