Mirrors/fish-shell
2
0
Fork 0
mirror of https://github.com/fish-shell/fish-shell synced 2024-12-25 12:23:09 +00:00
Code Issues Projects Releases Packages Wiki Activity

Hopeful fix to avoid forking for certain builtins like echo when they have an input redirection only

Browse source
This commit is contained in:
ridiculousfish 2013-02-22 13:20:27 -08:00
parent 3c8c8a7559
commit 9f8fe3d5e3
3 changed files with 26 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
exec.cpp
View file

@ -1159,23 +1159,25 @@ void exec(parser_t &parser, job_t *j)
performance quite a bit in complex completion code.
*/
const shared_ptr<io_data_t> &io = io_chain_get(j->io, 1);
bool buffer_stdout = io && io->io_mode == IO_BUFFER;
const shared_ptr<io_data_t> &stdout_io = io_chain_get(j->io, STDOUT_FILENO);
const shared_ptr<io_data_t> &stderr_io = io_chain_get(j->io, STDERR_FILENO);
const bool buffer_stdout = stdout_io && stdout_io->io_mode == IO_BUFFER;
if ((get_stderr_buffer().empty()) &&
(!p->next) &&
(! get_stdout_buffer().empty()) &&
(buffer_stdout))
{
CAST_INIT(io_buffer_t *, io_buffer, io.get());
CAST_INIT(io_buffer_t *, io_buffer, stdout_io.get());
const std::string res = wcs2string(get_stdout_buffer());
io_buffer->out_buffer_append(res.c_str(), res.size());
skip_fork = true;
}
if (! skip_fork && j->io.empty())
/* PCA for some reason, fish forks a lot, even for basic builtins like echo just to write out their buffers. I'm certain a lot of this is unnecessary, but I am not sure exactly when. If j->io is NULL, then it means there's no pipes or anything, so we can certainly just write out our data. Beyond that, we may be able to do the same if io_get returns 0 for STDOUT_FILENO and STDERR_FILENO.
*/
if (! skip_fork && stdout_io.get() == NULL && stderr_io.get() == NULL)
{
/* PCA for some reason, fish forks a lot, even for basic builtins like echo just to write out their buffers. I'm certain a lot of this is unnecessary, but I am not sure exactly when. If j->io is NULL, then it means there's no pipes or anything, so we can certainly just write out our data. Beyond that, we may be able to do the same if io_get returns 0 for STDOUT_FILENO and STDERR_FILENO. */
if (g_log_forks)
{
printf("fork #-: Skipping fork for internal builtin for '%ls'\n", p->argv0());
@ -1194,12 +1196,16 @@ void exec(parser_t &parser, job_t *j)
for (io_chain_t::iterator iter = j->io.begin(); iter != j->io.end(); ++iter)
{
const shared_ptr<io_data_t> &tmp_io = *iter;
if (tmp_io->io_mode == IO_FILE && strcmp(static_cast<const io_file_t *>(tmp_io.get())->filename_cstr, "/dev/null") != 0)
if (tmp_io->io_mode == IO_FILE)
{
const io_file_t *tmp_file_io = static_cast<const io_file_t *>(tmp_io.get());
if (strcmp(tmp_file_io->filename_cstr, "/dev/null"))
{
skip_fork = false;
break;
}
}
}
if (skip_fork)
@ -1235,7 +1241,7 @@ void exec(parser_t &parser, job_t *j)
if (g_log_forks)
{
printf("fork #%d: Executing fork for internal builtin for '%ls'\n", g_fork_count, p->argv0());
io_print(io_chain_t(io));
io_print(j->io);
}
pid = execute_fork(false);
if (pid == 0)

9
io.cpp
View file

@ -209,7 +209,7 @@ void io_chain_t::push_back(const shared_ptr<io_data_t> &element)
{
// Ensure we never push back NULL
assert(element.get() != NULL);
std::vector<shared_ptr<io_data_t> >:: push_back(element);
std::vector<shared_ptr<io_data_t> >::push_back(element);
}
void io_remove(io_chain_t &list, const shared_ptr<const io_data_t> &element)
@ -229,9 +229,16 @@ void io_print(const io_chain_t &chain)
for (size_t i=0; i < chain.size(); i++)
{
const shared_ptr<const io_data_t> &io = chain.at(i);
if (io.get() == NULL)
{
fprintf(stderr, "\t(null)\n");
}
else
{
fprintf(stderr, "\t%lu: fd:%d, ", (unsigned long)i, io->fd);
io->print();
}
}
}
/* Return the last IO for the given fd */

1
io.h
View file

@ -184,7 +184,6 @@ public:
shared_ptr<const io_data_t> get_io_for_fd(int fd) const;
shared_ptr<io_data_t> get_io_for_fd(int fd);
};
/**