/* Flags for virExecWithHook */
enum {
- VIR_EXEC_NONE = 0,
- VIR_EXEC_NONBLOCK = (1 << 0),
- VIR_EXEC_DAEMON = (1 << 1),
+ VIR_EXEC_NONE = 0,
+ VIR_EXEC_NONBLOCK = (1 << 0),
+ VIR_EXEC_DAEMON = (1 << 1),
VIR_EXEC_CLEAR_CAPS = (1 << 2),
- VIR_EXEC_RUN_SYNC = (1 << 3),
+ VIR_EXEC_RUN_SYNC = (1 << 3),
+ VIR_EXEC_ASYNC_IO = (1 << 4),
};
struct _virCommand {
int *outfdptr;
int *errfdptr;
+ size_t inbufOffset;
+ int inWatch;
+ int outWatch;
+ int errWatch;
+
bool handshake;
int handshakeWait[2];
int handshakeNotify[2];
cmd->handshakeNotify[1] = -1;
cmd->infd = cmd->outfd = cmd->errfd = -1;
+ cmd->inWatch = cmd->outWatch = cmd->errWatch = -1;
cmd->pid = -1;
virCommandAddArgSet(cmd, args);
* @cmd: the command to modify
* @inbuf: string to feed to stdin
*
- * Feed the child's stdin from a string buffer. This requires the use
- * of virCommandRun().
+ * Feed the child's stdin from a string buffer. This requires the
+ * use of virCommandRun() or combination of virCommandDoAsyncIO and
+ * virCommandRunAsync. The buffer is forgotten after each @cmd run.
*/
void
virCommandSetInputBuffer(virCommandPtr cmd, const char *inbuf)
* Capture the child's stdout to a string buffer. *outbuf is
* guaranteed to be allocated after successful virCommandRun or
* virCommandWait, and is best-effort allocated after failed
- * virCommandRun; caller is responsible for freeing *outbuf.
- * This requires the use of virCommandRun.
+ * virCommandRun or virCommandRunAsync; caller is responsible for
+ * freeing *outbuf. This requires the use of virCommandRun() or
+ * combination of virCommandDoAsyncIO and virCommandRunAsync. The
+ * buffer is forgotten after each @cmd run.
*/
void
virCommandSetOutputBuffer(virCommandPtr cmd, char **outbuf)
* Capture the child's stderr to a string buffer. *errbuf is
* guaranteed to be allocated after successful virCommandRun or
* virCommandWait, and is best-effort allocated after failed
- * virCommandRun; caller is responsible for freeing *errbuf.
- * This requires the use of virCommandRun. It is possible to
- * pass the same pointer as for virCommandSetOutputBuffer(), in
- * which case the child process will interleave all output into
- * a single string.
+ * virCommandRun or virCommandRunAsync; caller is responsible for
+ * freeing *errbuf. It is possible to pass the same pointer as
+ * for virCommandSetOutputBuffer(), in which case the child
+ * process will interleave all output into a single string. This
+ * requires the use of virCommandRun() or combination of
+ * virCommandDoAsyncIO and virCommandRunAsync.The buffer is
+ * forgotten after each @cmd run.
*/
void
virCommandSetErrorBuffer(virCommandPtr cmd, char **errbuf)
}
+static void
+virCommandHandleReadWrite(int watch, int fd, int events, void *opaque)
+{
+ virCommandPtr cmd = (virCommandPtr) opaque;
+ char ***bufptr = NULL;
+ char buf[1024];
+ ssize_t nread, nwritten;
+ size_t len = 0;
+ int *watchPtr = NULL;
+ bool eof = false;
+ int *fdptr = NULL, **fdptrptr = NULL;
+
+ VIR_DEBUG("watch=%d fd=%d events=%d", watch, fd, events);
+ errno = 0;
+
+ if (watch == cmd->inWatch) {
+ watchPtr = &cmd->inWatch;
+ fdptr = &cmd->infd;
+
+ if (events & VIR_EVENT_HANDLE_WRITABLE) {
+ len = strlen(cmd->inbuf);
+
+ while (true) {
+ nwritten = write(fd, cmd->inbuf + cmd->inbufOffset,
+ len - cmd->inbufOffset);
+ if (nwritten < 0) {
+ if (errno != EAGAIN && errno != EINTR) {
+ virReportSystemError(errno,
+ _("Unable to write command's "
+ "input to FD %d"),
+ fd);
+ eof = true;
+ }
+ break;
+ }
+
+ if (nwritten == 0) {
+ eof = true;
+ break;
+ }
+
+ cmd->inbufOffset += nwritten;
+ if (cmd->inbufOffset == len) {
+ VIR_FORCE_CLOSE(cmd->infd);
+ eof = true;
+ break;
+ }
+ }
+
+ }
+ } else {
+ if (watch == cmd->outWatch) {
+ watchPtr = &cmd->outWatch;
+ bufptr = &cmd->outbuf;
+ fdptr = &cmd->outfd;
+ fdptrptr = &cmd->outfdptr;
+ } else {
+ watchPtr = &cmd->errWatch;
+ bufptr = &cmd->errbuf;
+ fdptr = &cmd->errfd;
+ fdptrptr = &cmd->errfdptr;
+ }
+
+ if (events & VIR_EVENT_HANDLE_READABLE) {
+ if (**bufptr)
+ len = strlen(**bufptr);
+
+ while (true) {
+ nread = read(fd, buf, sizeof(buf));
+ if (nread < 0) {
+ if (errno != EAGAIN && errno != EINTR) {
+ virReportSystemError(errno,
+ _("unable to read command's "
+ "output from FD %d"),
+ fd);
+ eof = true;
+ }
+ break;
+ }
+
+ if (nread == 0) {
+ eof = true;
+ break;
+ }
+
+ if (VIR_REALLOC_N(**bufptr, len + nread + 1) < 0) {
+ virReportOOMError();
+ break;
+ }
+
+ memcpy(**bufptr + len, buf, nread);
+ (**bufptr)[len + nread] = '\0';
+ }
+
+ }
+ }
+
+ if (eof || (events & VIR_EVENT_HANDLE_HANGUP) ||
+ (events & VIR_EVENT_HANDLE_ERROR)) {
+ virEventRemoveHandle(watch);
+
+ *watchPtr = -1;
+ VIR_FORCE_CLOSE(*fdptr);
+ if (bufptr)
+ *bufptr = NULL;
+ if (fdptrptr)
+ *fdptrptr = NULL;
+ }
+}
+
+
+static int
+virCommandRegisterEventLoop(virCommandPtr cmd)
+{
+ int ret = -1;
+
+ if (cmd->inbuf &&
+ (cmd->inWatch = virEventAddHandle(cmd->infd,
+ VIR_EVENT_HANDLE_WRITABLE |
+ VIR_EVENT_HANDLE_HANGUP |
+ VIR_EVENT_HANDLE_ERROR,
+ virCommandHandleReadWrite,
+ cmd, NULL)) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Unable to register infd %d in the event loop"),
+ cmd->infd);
+ goto cleanup;
+ }
+
+ if (cmd->outbuf && cmd->outfdptr == &cmd->outfd &&
+ (cmd->outWatch = virEventAddHandle(cmd->outfd,
+ VIR_EVENT_HANDLE_READABLE |
+ VIR_EVENT_HANDLE_HANGUP |
+ VIR_EVENT_HANDLE_ERROR,
+ virCommandHandleReadWrite,
+ cmd, NULL)) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Unable to register outfd %d in the event loop"),
+ cmd->outfd);
+
+ if (cmd->inWatch != -1) {
+ virEventRemoveHandle(cmd->inWatch);
+ cmd->inWatch = -1;
+ }
+ goto cleanup;
+ }
+
+ if (cmd->errbuf && cmd->errfdptr == &cmd->errfd &&
+ (cmd->errWatch = virEventAddHandle(cmd->errfd,
+ VIR_EVENT_HANDLE_READABLE |
+ VIR_EVENT_HANDLE_HANGUP |
+ VIR_EVENT_HANDLE_ERROR,
+ virCommandHandleReadWrite,
+ cmd, NULL)) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Unable to register errfd %d in the event loop"),
+ cmd->errfd);
+ if (cmd->inWatch != -1) {
+ virEventRemoveHandle(cmd->inWatch);
+ cmd->inWatch = -1;
+ }
+ if (cmd->outWatch != -1) {
+ virEventRemoveHandle(cmd->outWatch);
+ cmd->outWatch = -1;
+ }
+ goto cleanup;
+ }
+
+ ret = 0;
+
+cleanup:
+ return ret;
+}
+
+
/**
* virCommandRunAsync:
* @cmd: command to start
char *str;
int i;
bool synchronous = false;
+ int infd[2] = {-1, -1};
if (!cmd || cmd->has_error == ENOMEM) {
virReportOOMError();
synchronous = cmd->flags & VIR_EXEC_RUN_SYNC;
cmd->flags &= ~VIR_EXEC_RUN_SYNC;
- /* Buffer management can only be requested via virCommandRun. */
- if ((cmd->inbuf && cmd->infd == -1) ||
- (cmd->outbuf && cmd->outfdptr != &cmd->outfd) ||
- (cmd->errbuf && cmd->errfdptr != &cmd->errfd)) {
+ /* Buffer management can only be requested via virCommandRun, unless help
+ * from the event loop has been requested via virCommandDoAsyncIO. */
+ if (cmd->flags & VIR_EXEC_ASYNC_IO) {
+ /* If we have an input buffer, we need
+ * a pipe to feed the data to the child */
+ if (cmd->inbuf && cmd->infd == -1) {
+ if (pipe2(infd, O_CLOEXEC) < 0) {
+ virReportSystemError(errno, "%s",
+ _("unable to open pipe"));
+ cmd->has_error = -1;
+ return -1;
+ }
+ cmd->infd = infd[0];
+ }
+ } else if ((cmd->inbuf && cmd->infd == -1) ||
+ (cmd->outbuf && cmd->outfdptr != &cmd->outfd) ||
+ (cmd->errbuf && cmd->errfdptr != &cmd->errfd)) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("cannot mix string I/O with asynchronous command"));
return -1;
else
cmd->reap = true;
+ if (ret == 0 && cmd->flags & VIR_EXEC_ASYNC_IO) {
+ cmd->flags &= ~VIR_EXEC_ASYNC_IO;
+ if (cmd->inbuf && cmd->infd != -1) {
+ /* close the read end of infd and replace it with the write end */
+ VIR_FORCE_CLOSE(cmd->infd);
+ cmd->infd = infd[1];
+ }
+ ret = virCommandRegisterEventLoop(cmd);
+ }
+
return ret;
}
{
int ret;
int status = 0;
+ const int events = VIR_EVENT_HANDLE_READABLE | VIR_EVENT_HANDLE_HANGUP;
if (!cmd ||cmd->has_error == ENOMEM) {
virReportOOMError();
* guarantee that virProcessWait only fails due to failure to wait,
* and repeat the exitstatus check code ourselves. */
ret = virProcessWait(cmd->pid, exitstatus ? exitstatus : &status);
+
+ if (cmd->inWatch != -1) {
+ virEventRemoveHandle(cmd->inWatch);
+ cmd->inWatch = -1;
+ }
+
+ if (cmd->outWatch != -1) {
+ virEventRemoveHandle(cmd->outWatch);
+ virCommandHandleReadWrite(cmd->outWatch, cmd->outfd, events, cmd);
+ cmd->outWatch = -1;
+ }
+
+ if (cmd->errWatch != -1) {
+ virEventRemoveHandle(cmd->errWatch);
+ virCommandHandleReadWrite(cmd->errWatch, cmd->errfd, events, cmd);
+ cmd->errWatch = -1;
+ }
+
if (ret == 0) {
cmd->pid = -1;
cmd->reap = false;
VIR_FREE(cmd);
}
+
+/**
+ * virCommandDoAsyncIO:
+ * @cmd: command to do async IO on
+ *
+ * This requests asynchronous string IO on @cmd. It is useful in
+ * combination with virCommandRunAsync():
+ *
+ * virCommandPtr cmd = virCommandNew*(...);
+ * char *buf = NULL;
+ *
+ * ...
+ *
+ * virCommandSetOutputBuffer(cmd, &buf);
+ * virCommandDoAsyncIO(cmd);
+ *
+ * if (virCommandRunAsync(cmd, NULL) < 0)
+ * goto cleanup;
+ *
+ * ...
+ *
+ * if (virCommandWait(cmd, NULL) < 0)
+ * goto cleanup;
+ *
+ * // @buf now contains @cmd's stdout
+ * VIR_DEBUG("STDOUT: %s", NULLSTR(buf));
+ *
+ * ...
+ *
+ * cleanup:
+ * VIR_FREE(buf);
+ * virCommandFree(cmd);
+ *
+ * The libvirt's event loop is used for handling stdios of @cmd.
+ * Since current implementation uses strlen to determine length
+ * of data to be written to @cmd's stdin, don't pass any binary
+ * data. If you want to re-run command, you need to call this and
+ * buffer setting functions (virCommandSet.*Buffer) prior each run.
+ */
+void
+virCommandDoAsyncIO(virCommandPtr cmd)
+{
+ if (!cmd || cmd->has_error)
+ return;
+
+ cmd->flags |= VIR_EXEC_ASYNC_IO | VIR_EXEC_NONBLOCK;
+}
projects / thirdparty / libvirt.git / commitdiff
