Add -no-snapshot-load option to permit reboot.

This is a workaround for the emulator not being able to detect the guest's
power-down situation, and simply lingering like a zombie: on exit it's saved
as a zombie, and is restored as a zombie which isn't useful. Denying autoload
forces a reboot.

Change-Id: I48f32600f5ce18cd5c71aa01d1b71b382102f227

4 files changed, 32 insertions, 12 deletions

diff --git a/android/cmdline-options.h b/android/cmdline-options.h
index 3aaa478..fc30ebc 100644
--- a/android/cmdline-options.h
+++ b/android/cmdline-options.h
@@ -79,9 +79,10 @@ OPT_PARAM( sdcard, "<file>", "SD card image (default <system>/sdcard.img")
 #if CONFIG_ANDROID_SNAPSHOTS
 OPT_PARAM( snapstorage,    "<file>", "file that contains all state snapshots (default <datadir>/snapshots.img)")
 OPT_FLAG ( no_snapstorage, "do not mount a snapshot storage file (this disables all snapshot functionality)" )
-OPT_PARAM( snapshot,       "<name>", "immediately load state snapshot rather than doing a full boot (default 'default-boot')" )
-OPT_FLAG ( no_snapshot,    "do not start from snapshot, but perform a full boot sequence" )
-OPT_FLAG ( no_snapshot_save, "do not preserve snapshot, if restore was attempted" )
+OPT_PARAM( snapshot,       "<name>", "name of snapshot within storage file for auto-start and auto-save (default 'default-boot')" )
+OPT_FLAG ( no_snapshot,    "perform a full boot and do not do not auto-save, but qemu vmload and vmsave operate on snapstorage" )
+OPT_FLAG ( no_snapshot_save, "do not auto-save to snapshot on exit: abandon changed state" )
+OPT_FLAG ( no_snapshot_load, "do not auto-start from snapshot: perform a full boot" )
 OPT_FLAG ( snapshot_list,  "show a list of available snapshots" )
 #endif
 OPT_FLAG ( wipe_data, "reset the use data image (copy it from initdata)" )
diff --git a/android/help.c b/android/help.c
index 348e2e6..f49e3fa 100644
--- a/android/help.c
+++ b/android/help.c
@@ -670,18 +670,19 @@ help_snapshot(stralloc_t*  out)
     "  Rather than executing a full boot sequence, the Android emulator can\n"
     "  resume execution from an earlier state snapshot (which is usually\n"
     "  significantly faster). When the parameter '-snapshot <name>' is given,\n"
-    "  the emulator loads the snapshot of that name from the snapshot image.\n\n"
+    "  the emulator loads the snapshot of that name from the snapshot image,\n"
+    "  and saves it back under the same name on exit.\n\n"
 
     "  If the option is not specified, it defaults to 'default-boot'. If the\n"
     "  specified snapshot does not exist, the emulator will perform a full boot\n"
-    "  sequence instead.\n\n"
+    "  sequence instead, but will still save.\n\n"
 
     "  WARNING: In the process of loading, all contents of the system, userdata\n"
     "           and SD card images will be OVERWRITTEN with the contents they\n"
     "           held when the snapshot was made. Unless saved in a different\n"
     "           snapshot, any changes since will be lost!\n\n"
 
-    "  If you want to create a snapshot, connect to the emulator console:\n\n"
+    "  If you want to create a snapshot manually, connect to the emulator console:\n\n"
 
     "      telnet localhost <port>\n\n"
 
@@ -694,13 +695,23 @@ static void
 help_no_snapshot(stralloc_t*  out)
 {
     PRINTF(
-    "  This forces the emulator to perform a full boot sequence, rather than\n"
-    "  loading the default snapshot. It overrides the '-snapshot' parameter.\n"
+    "  This inhibits both the autoload and autosave operations, forcing\n"
+    "  emulator to perform a full boot sequence and losing state on close.\n"
+    "  It overrides the '-snapshot' parameter.\n"
     "  If '-snapshot' was specified anyway, a warning is raised.\n\n"
     );
 }
 
 static void
+help_no_snapshot_load(stralloc_t*  out)
+{
+    PRINTF(
+    "  Prevents the emulator from loading the AVD's state from the snapshot\n"
+    "  storage on start.\n\n"
+    );
+}
+
+static void
 help_no_snapshot_save(stralloc_t*  out)
 {
     PRINTF(
diff --git a/android/main-ui.c b/android/main-ui.c
index 9366efd..16762a5 100644
--- a/android/main-ui.c
+++ b/android/main-ui.c
@@ -1520,14 +1520,18 @@ int main(int argc, char **argv)
         if (!opts->no_snapshot) {
             char* snapshot_name =
                 opts->snapshot ? opts->snapshot : "default-boot";
-            args[n++] = "-loadvm";
-            args[n++] = snapshot_name;
+            if (!opts->no_snapshot_load) {
+              args[n++] = "-loadvm";
+              args[n++] = snapshot_name;
+            }
             if (!opts->no_snapshot_save) {
               args[n++] = "-savevm-on-exit";
               args[n++] = snapshot_name;
             }
         } else if (opts->snapshot) {
             dwarning("option '-no-snapshot' overrides '-snapshot', continuing with boot sequence");
+        } else if (opts->no_snapshot_load || opts->no_snapshot_save) {
+            D("ignoring redundant option(s) '-no-snapshot-load' and/or '-no-snapshot-save' implied by '-no-snapshot'");
         }
     } else if (opts->snapshot || opts->snapstorage) {
         dwarning("option '-no-snapstorage' overrides '-snapshot' and '-snapstorage', "
diff --git a/android/main.c b/android/main.c
index 677980b..03bd472 100644
--- a/android/main.c
+++ b/android/main.c
@@ -1412,14 +1412,18 @@ int main(int argc, char **argv)
         if (!opts->no_snapshot) {
             char* snapshot_name =
                 opts->snapshot ? opts->snapshot : "default-boot";
-            args[n++] = "-loadvm";
-            args[n++] = snapshot_name;
+            if (!opts->no_snapshot_load) {
+              args[n++] = "-loadvm";
+              args[n++] = snapshot_name;
+            }
             if (!opts->no_snapshot_save) {
               args[n++] = "-savevm-on-exit";
               args[n++] = snapshot_name;
             }
         } else if (opts->snapshot) {
             dwarning("option '-no-snapshot' overrides '-snapshot', continuing with boot sequence");
+        } else if (opts->no_snapshot_load || opts->no_snapshot_save) {
+            D("ignoring redundant option(s) '-no-snapshot-load' and/or '-no-snapshot-save' implied by '-no-snapshot'");
         }
     } else if (opts->snapshot || opts->snapstorage) {
         dwarning("option '-no-snapstorage' overrides '-snapshot' and '-snapstorage', "