ide: convert ide_sector_read() to asynchronous I/O

[qemu.git] / qemu-ga.c

diff --git a/qemu-ga.c b/qemu-ga.c
index ba355d878355dae9b44e249e42545e5b4cc4e9af..d6f786e50d7e2b4bec864feebbd63a20514ea650 100644 (file)
--- a/qemu-ga.c
+++ b/qemu-ga.c
@@ -17,6 +17,7 @@
 #include <getopt.h>
 #ifndef _WIN32
 #include <syslog.h>
+#include <sys/wait.h>
 #endif
 #include "json-streamer.h"
 #include "json-parser.h"
@@ -40,6 +41,7 @@
 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
 #endif
 #define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
+#define QGA_SENTINEL_BYTE 0xFF
 
 struct GAState {
     JSONMessageParser parser;
@@ -53,9 +55,10 @@ struct GAState {
 #ifdef _WIN32
     GAService service;
 #endif
+    bool delimit_response;
 };
 
-static struct GAState *ga_state;
+struct GAState *ga_state;
 
 #ifdef _WIN32
 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
@@ -73,9 +76,16 @@ static void quit_handler(int sig)
 }
 
 #ifndef _WIN32
+/* reap _all_ terminated children */
+static void child_handler(int sig)
+{
+    int status;
+    while (waitpid(-1, &status, WNOHANG) > 0) /* NOTHING */;
+}
+
 static gboolean register_signal_handlers(void)
 {
-    struct sigaction sigact;
+    struct sigaction sigact, sigact_chld;
     int ret;
 
     memset(&sigact, 0, sizeof(struct sigaction));
@@ -91,6 +101,15 @@ static gboolean register_signal_handlers(void)
         g_error("error configuring signal handler: %s", strerror(errno));
         return false;
     }
+
+    memset(&sigact_chld, 0, sizeof(struct sigaction));
+    sigact_chld.sa_handler = child_handler;
+    sigact_chld.sa_flags = SA_NOCLDSTOP;
+    ret = sigaction(SIGCHLD, &sigact_chld, NULL);
+    if (ret == -1) {
+        g_error("error configuring signal handler: %s", strerror(errno));
+    }
+
     return true;
 }
 #endif
@@ -181,6 +200,11 @@ static void ga_log(const gchar *domain, GLogLevelFlags level,
     }
 }
 
+void ga_set_response_delimited(GAState *s)
+{
+    s->delimit_response = true;
+}
+
 #ifndef _WIN32
 static void become_daemon(const char *pidfile)
 {
@@ -237,7 +261,7 @@ fail:
 static int send_response(GAState *s, QObject *payload)
 {
     const char *buf;
-    QString *payload_qstr;
+    QString *payload_qstr, *response_qstr;
     GIOStatus status;
 
     g_assert(payload && s->channel);
@@ -247,10 +271,20 @@ static int send_response(GAState *s, QObject *payload)
         return -EINVAL;
     }
 
-    qstring_append_chr(payload_qstr, '\n');
-    buf = qstring_get_str(payload_qstr);
+    if (s->delimit_response) {
+        s->delimit_response = false;
+        response_qstr = qstring_new();
+        qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
+        qstring_append(response_qstr, qstring_get_str(payload_qstr));
+        QDECREF(payload_qstr);
+    } else {
+        response_qstr = payload_qstr;
+    }
+
+    qstring_append_chr(response_qstr, '\n');
+    buf = qstring_get_str(response_qstr);
     status = ga_channel_write_all(s->channel, buf, strlen(buf));
-    QDECREF(payload_qstr);
+    QDECREF(response_qstr);
     if (status != G_IO_STATUS_NORMAL) {
         return -EIO;
     }