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authorwm4 <wm4@nowhere>2020-08-16 02:54:44 +0200
committerwm4 <wm4@nowhere>2020-08-16 02:54:44 +0200
commite27c523a10708b7265c33a4bae631663df4bb297 (patch)
tree34bdcd1bc48a5311ec24181dec913768180ad851 /osdep
parentd6bf3880d74459103a39426275837ec0a1d48e54 (diff)
downloadmpv-e27c523a10708b7265c33a4bae631663df4bb297.tar.bz2
mpv-e27c523a10708b7265c33a4bae631663df4bb297.tar.xz
command: extend subprocess command stdin, change behavior
Make it possible to feed a string to stdin of a subprocess. Out of laziness, it can't be an arbitrary byte string. (Would require adding an option type that takes in a Lua byte string.) Do not set stdin of a subprocess to fd 0 (i.e. mpv's stdin) anymore, because it makes things more consistent. Enabling stdin didn't make too much sense in the first place, so this behavior change seems justifiable. win32 support missing. Fixes: #8003
Diffstat (limited to 'osdep')
-rw-r--r--osdep/subprocess-posix.c41
-rw-r--r--osdep/subprocess.h12
2 files changed, 49 insertions, 4 deletions
diff --git a/osdep/subprocess-posix.c b/osdep/subprocess-posix.c
index e7af4663ea..bae0ca2c78 100644
--- a/osdep/subprocess-posix.c
+++ b/osdep/subprocess-posix.c
@@ -165,8 +165,21 @@ void mp_subprocess2(struct mp_subprocess_opts *opts,
}
for (int n = 0; n < opts->num_fds; n++) {
+ assert(!(opts->fds[n].on_read && opts->fds[n].on_write));
+
if (opts->fds[n].on_read && mp_make_cloexec_pipe(comm_pipe[n]) < 0)
goto done;
+
+ if (opts->fds[n].on_write || opts->fds[n].write_buf) {
+ assert(opts->fds[n].on_write && opts->fds[n].write_buf);
+ if (mp_make_cloexec_pipe(comm_pipe[n]) < 0)
+ goto done;
+ MPSWAP(int, comm_pipe[n][0], comm_pipe[n][1]);
+
+ struct sigaction sa = {.sa_handler = SIG_IGN, .sa_flags = SA_RESTART};
+ sigfillset(&sa.sa_mask);
+ sigaction(SIGPIPE, &sa, NULL);
+ }
}
devnull = open("/dev/null", O_RDONLY | O_CLOEXEC);
@@ -225,7 +238,7 @@ void mp_subprocess2(struct mp_subprocess_opts *opts,
if (comm_pipe[n][0] >= 0) {
map_fds[num_fds] = n;
fds[num_fds++] = (struct pollfd){
- .events = POLLIN,
+ .events = opts->fds[n].on_read ? POLLIN : POLLOUT,
.fd = comm_pipe[n][0],
};
}
@@ -249,15 +262,35 @@ void mp_subprocess2(struct mp_subprocess_opts *opts,
kill(pid, SIGKILL);
killed_by_us = true;
break;
- } else {
+ }
+ struct mp_subprocess_fd *fd = &opts->fds[n];
+ if (fd->on_read) {
char buf[4096];
ssize_t r = read(comm_pipe[n][0], buf, sizeof(buf));
if (r < 0 && errno == EINTR)
continue;
- if (r > 0 && opts->fds[n].on_read)
- opts->fds[n].on_read(opts->fds[n].on_read_ctx, buf, r);
+ fd->on_read(fd->on_read_ctx, buf, MPMAX(r, 0));
if (r <= 0)
SAFE_CLOSE(comm_pipe[n][0]);
+ } else if (fd->on_write) {
+ if (!fd->write_buf->len) {
+ fd->on_write(fd->on_write_ctx);
+ if (!fd->write_buf->len) {
+ SAFE_CLOSE(comm_pipe[n][0]);
+ continue;
+ }
+ }
+ ssize_t r = write(comm_pipe[n][0], fd->write_buf->start,
+ fd->write_buf->len);
+ if (r < 0 && errno == EINTR)
+ continue;
+ if (r < 0) {
+ // Let's not signal an error for now - caller can check
+ // whether all buffer was written.
+ SAFE_CLOSE(comm_pipe[n][0]);
+ continue;
+ }
+ *fd->write_buf = bstr_cut(*fd->write_buf, r);
}
}
}
diff --git a/osdep/subprocess.h b/osdep/subprocess.h
index 14d4896c58..4bf2dc32dd 100644
--- a/osdep/subprocess.h
+++ b/osdep/subprocess.h
@@ -22,9 +22,18 @@
#include <stddef.h>
#include <stdint.h>
+#include "misc/bstr.h"
+
struct mp_cancel;
+// Incrementally called with data that was read. Buffer valid only during call.
+// size==0 means EOF.
typedef void (*subprocess_read_cb)(void *ctx, char *data, size_t size);
+// Incrementally called to refill *mp_subprocess_fd.write_buf, whenever write_buf
+// has length 0 and the pipe is writable. While writing, *write_buf is adjusted
+// to contain only the not yet written data.
+// Not filling the buffer means EOF.
+typedef void (*subprocess_write_cb)(void *ctx);
void mp_devnull(void *ctx, char *data, size_t size);
@@ -37,6 +46,9 @@ struct mp_subprocess_fd {
// Note: "neutral" initialization requires setting src_fd=-1.
subprocess_read_cb on_read; // if not NULL, serve reads
void *on_read_ctx; // for on_read(on_read_ctx, ...)
+ subprocess_write_cb on_write; // if not NULL, serve writes
+ void *on_write_ctx; // for on_write(on_write_ctx, ...)
+ bstr *write_buf; // must be !=NULL if on_write is set
int src_fd; // if >=0, dup this FD to target FD
};