mpv/input/pipe.c

134 lines
3.3 KiB
C

#include <pthread.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#ifndef __MINGW32__
#include <poll.h>
#endif
#include "common/msg.h"
#include "misc/bstr.h"
#include "osdep/io.h"
#include "input.h"
#include "cmd_parse.h"
static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
struct priv {
struct mp_log *log;
char *filename;
struct mp_input_src *src;
int wakeup_pipe[2];
};
static void *reader_thread(void *ctx)
{
struct priv *p = ctx;
pthread_detach(pthread_self());
int mode = O_RDONLY;
#ifndef __MINGW32__
// Use RDWR for FIFOs to ensure they stay open over multiple accesses.
// Note that on Windows due to how the API works, using RDONLY should
// be ok.
struct stat st;
if (stat(p->filename, &st) == 0 && S_ISFIFO(st.st_mode))
mode = O_RDWR;
#endif
int fd = -1;
bool close_fd = true;
if (strcmp(p->filename, "/dev/stdin") == 0) { // mainly for win32
fd = STDIN_FILENO;
close_fd = false;
}
if (fd < 0)
fd = open(p->filename, mode);
if (fd < 0) {
MP_ERR(p, "Can't open %s.\n", p->filename);
goto done;
}
while (1) {
#ifndef __MINGW32__
struct pollfd fds[2] = {
{ .fd = fd, .events = POLLIN },
{ .fd = p->wakeup_pipe[0], .events = POLLIN },
};
poll(fds, 2, -1);
if (!(fds[0].revents & POLLIN))
break;
#endif
char buffer[128];
int r = read(fd, buffer, sizeof(buffer));
if (r <= 0)
break;
pthread_mutex_lock(&lock);
if (!p->src) {
pthread_mutex_unlock(&lock);
break;
}
mp_input_src_feed_cmd_text(p->src, buffer, r);
pthread_mutex_unlock(&lock);
}
if (close_fd)
close(fd);
done:
pthread_mutex_lock(&lock);
if (p->src)
p->src->priv = NULL;
pthread_mutex_unlock(&lock);
close(p->wakeup_pipe[0]);
close(p->wakeup_pipe[1]);
talloc_free(p);
return NULL;
}
static void close_pipe(struct mp_input_src *src)
{
pthread_mutex_lock(&lock);
struct priv *p = src->priv;
// Windows pipe have a severe problem: they can't be made non-blocking (not
// after creation), and you can't wait on them. The only things that work
// are cancellation (Vista+, broken in wine) or forceful thread termination.
// So don't bother with "correct" termination, and just abandon the reader
// thread.
// On Unix, we interrupt it using the wakeup pipe.
if (p) {
#ifndef __MINGW32__
write(p->wakeup_pipe[1], &(char){0}, 1);
#endif
p->src = NULL;
}
pthread_mutex_unlock(&lock);
}
void mp_input_add_pipe(struct input_ctx *ictx, const char *filename)
{
struct mp_input_src *src = mp_input_add_src(ictx);
if (!src)
return;
struct priv *p = talloc_zero(NULL, struct priv);
src->priv = p;
p->filename = talloc_strdup(p, filename);
p->src = src;
p->log = mp_log_new(p, src->log, NULL);
mp_make_wakeup_pipe(p->wakeup_pipe);
pthread_t thread;
if (pthread_create(&thread, NULL, reader_thread, p)) {
close(p->wakeup_pipe[0]);
close(p->wakeup_pipe[1]);
talloc_free(p);
mp_input_src_kill(src);
} else {
src->close = close_pipe;
}
}