[Qemu-devel] [PATCH 20/26] link the main loop and its dependencies into the tools

[Paolo Bonzini <pbonzini@redhat.com>]

Using the main loop code from QEMU enables tools to operate fully
asynchronously.  Advantages include better Windows portability (for some
definition of portability) over glib's.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Makefile      |    5 +++--
 main-loop.h   |    6 ++++++
 os-posix.c    |   42 ------------------------------------------
 os-win32.c    |    5 -----
 oslib-posix.c |   43 +++++++++++++++++++++++++++++++++++++++++++
 oslib-win32.c |    5 +++++
 qemu-tool.c   |   42 +++++++++++++++++++++++-------------------
 7 files changed, 80 insertions(+), 68 deletions(-)

diff --git a/Makefile b/Makefile
index 2c03055..368eeae 100644
--- a/Makefile
+++ b/Makefile
@@ -147,8 +147,9 @@ endif
 qemu-img.o: qemu-img-cmds.h
 qemu-img.o qemu-tool.o qemu-nbd.o qemu-io.o cmd.o qemu-ga.o: $(GENERATED_HEADERS)
 
-tools-obj-y = qemu-tool.o $(oslib-obj-y) $(trace-obj-y) \
-	qemu-timer-common.o cutils.o
+tools-obj-y = $(oslib-obj-y) $(trace-obj-y) qemu-tool.o qemu-timer.o \
+	qemu-timer-common.o main-loop.o notify.o iohandler.o cutils.o async.o
+tools-obj-$(CONFIG_POSIX) += compatfd.o
 
 qemu-img$(EXESUF): qemu-img.o $(tools-obj-y) $(block-obj-y)
 qemu-nbd$(EXESUF): qemu-nbd.o $(tools-obj-y) $(block-obj-y)
diff --git a/main-loop.h b/main-loop.h
index 876092d..f971013 100644
--- a/main-loop.h
+++ b/main-loop.h
@@ -324,6 +324,9 @@ int qemu_add_child_watch(pid_t pid);
  * by threads other than the main loop thread when calling
  * qemu_bh_new(), qemu_set_fd_handler() and basically all other
  * functions documented in this file.
+ *
+ * NOTE: tools currently are single-threaded and qemu_mutex_lock_iothread
+ * is a no-op there.
  */
 void qemu_mutex_lock_iothread(void);
 
@@ -336,6 +339,9 @@ void qemu_mutex_lock_iothread(void);
  * as soon as possible by threads other than the main loop thread,
  * because it prevents the main loop from processing callbacks,
  * including timers and bottom halves.
+ *
+ * NOTE: tools currently are single-threaded and qemu_mutex_unlock_iothread
+ * is a no-op there.
  */
 void qemu_mutex_unlock_iothread(void);
 
diff --git a/os-posix.c b/os-posix.c
index dc4a6bb..5c437ca 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -42,11 +42,6 @@
 
 #ifdef CONFIG_LINUX
 #include <sys/prctl.h>
-#include <sys/syscall.h>
-#endif
-
-#ifdef CONFIG_EVENTFD
-#include <sys/eventfd.h>
 #endif
 
 static struct passwd *user_pwd;
@@ -333,34 +328,6 @@ void os_set_line_buffering(void)
     setvbuf(stdout, NULL, _IOLBF, 0);
 }
 
-/*
- * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
- */
-int qemu_eventfd(int fds[2])
-{
-#ifdef CONFIG_EVENTFD
-    int ret;
-
-    ret = eventfd(0, 0);
-    if (ret >= 0) {
-        fds[0] = ret;
-        qemu_set_cloexec(ret);
-        if ((fds[1] = dup(ret)) == -1) {
-            close(ret);
-            return -1;
-        }
-        qemu_set_cloexec(fds[1]);
-        return 0;
-    }
-
-    if (errno != ENOSYS) {
-        return -1;
-    }
-#endif
-
-    return qemu_pipe(fds);
-}
-
 int qemu_create_pidfile(const char *filename)
 {
     char buffer[128];
@@ -384,12 +351,3 @@ int qemu_create_pidfile(const char *filename)
     close(fd);
     return 0;
 }
-
-int qemu_get_thread_id(void)
-{
-#if defined (__linux__)
-    return syscall(SYS_gettid);
-#else
-    return getpid();
-#endif
-}
diff --git a/os-win32.c b/os-win32.c
index 8523d8d..ad76370 100644
--- a/os-win32.c
+++ b/os-win32.c
@@ -151,8 +151,3 @@ int qemu_create_pidfile(const char *filename)
     }
     return 0;
 }
-
-int qemu_get_thread_id(void)
-{
-    return GetCurrentThreadId();
-}
diff --git a/oslib-posix.c b/oslib-posix.c
index ce75549..b6a3c7f 100644
--- a/oslib-posix.c
+++ b/oslib-posix.c
@@ -55,6 +55,21 @@ static int running_on_valgrind = -1;
 #else
 #  define running_on_valgrind 0
 #endif
+#ifdef CONFIG_LINUX
+#include <sys/syscall.h>
+#endif
+#ifdef CONFIG_EVENTFD
+#include <sys/eventfd.h>
+#endif
+
+int qemu_get_thread_id(void)
+{
+#if defined(__linux__)
+    return syscall(SYS_gettid);
+#else
+    return getpid();
+#endif
+}
 
 int qemu_daemon(int nochdir, int noclose)
 {
@@ -162,6 +177,34 @@ int qemu_pipe(int pipefd[2])
     return ret;
 }
 
+/*
+ * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
+ */
+int qemu_eventfd(int fds[2])
+{
+#ifdef CONFIG_EVENTFD
+    int ret;
+
+    ret = eventfd(0, 0);
+    if (ret >= 0) {
+        fds[0] = ret;
+        fds[1] = dup(ret);
+        if (fds[1] == -1) {
+            close(ret);
+            return -1;
+        }
+        qemu_set_cloexec(ret);
+        qemu_set_cloexec(fds[1]);
+        return 0;
+    }
+    if (errno != ENOSYS) {
+        return -1;
+    }
+#endif
+
+    return qemu_pipe(fds);
+}
+
 int qemu_utimens(const char *path, const struct timespec *times)
 {
     struct timeval tv[2], tv_now;
diff --git a/oslib-win32.c b/oslib-win32.c
index 5e3de7d..ce3021e 100644
--- a/oslib-win32.c
+++ b/oslib-win32.c
@@ -118,3 +118,8 @@ int qemu_gettimeofday(qemu_timeval *tp)
      Do not set errno on error.  */
   return 0;
 }
+
+int qemu_get_thread_id(void)
+{
+    return GetCurrentThreadId();
+}
diff --git a/qemu-tool.c b/qemu-tool.c
index 5df7279..226b6e8 100644
--- a/qemu-tool.c
+++ b/qemu-tool.c
@@ -16,12 +16,12 @@
 #include "qemu-timer.h"
 #include "qemu-log.h"
 #include "migration.h"
+#include "main-loop.h"
+#include "qemu_socket.h"
+#include "slirp/libslirp.h"
 
 #include <sys/time.h>
 
-QEMUClock *rt_clock;
-QEMUClock *vm_clock;
-
 FILE *logfile;
 
 struct QEMUBH
@@ -57,41 +57,45 @@ void monitor_protocol_event(MonitorEvent event, QObject *data)
 {
 }
 
-int qemu_set_fd_handler2(int fd,
-                         IOCanReadHandler *fd_read_poll,
-                         IOHandler *fd_read,
-                         IOHandler *fd_write,
-                         void *opaque)
+int64 cpu_get_clock(void)
 {
-    return 0;
+    abort();
 }
 
-void qemu_notify_event(void)
+int64 cpu_get_icount(void)
 {
+    abort();
 }
 
-QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
-                          QEMUTimerCB *cb, void *opaque)
+void qemu_mutex_lock_iothread(void)
 {
-    return g_malloc(1);
 }
 
-void qemu_free_timer(QEMUTimer *ts)
+void qemu_mutex_unlock_iothread(void)
 {
-    g_free(ts);
 }
 
-void qemu_del_timer(QEMUTimer *ts)
+int use_icount;
+
+void qemu_clock_warp(QEMUClock *clock)
 {
 }
 
-void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
+static void __attribute__((constructor)) init_main_loop(void)
 {
+    init_clocks();
+    init_timer_alarm();
+    qemu_clock_enable(vm_clock, false);
 }
 
-int64_t qemu_get_clock_ns(QEMUClock *clock)
+void slirp_select_fill(int *pnfds, fd_set *readfds,
+                       fd_set *writefds, fd_set *xfds)
+{
+}
+
+void slirp_select_poll(fd_set *readfds, fd_set *writefds,
+                       fd_set *xfds, int select_error)
 {
-    return 0;
 }
 
 void migrate_add_blocker(Error *reason)
-- 
1.7.7.1