vulkan/overlay: Add support for a control socket.

Add support for socket from which the overlay layer can receive
commands. This control socket can be useful to allow setting options
once the application is already running. For instance, triggering the
capture of fps data at a certain point.

Reviewed-by: Lionel Landwerlin <[email protected]>

1 files changed, 198 insertions, 0 deletions

diff --git a/src/vulkan/overlay-layer/overlay.cpp b/src/vulkan/overlay-layer/overlay.cpp
index f1cfb172b19..bc4240d8d76 100644
--- a/src/vulkan/overlay-layer/overlay.cpp
+++ b/src/vulkan/overlay-layer/overlay.cpp
@@ -28,6 +28,8 @@
 #include <vulkan/vulkan.h>
 #include <vulkan/vk_layer.h>
 
+#include "git_sha1.h"
+
 #include "imgui.h"
 
 #include "overlay_params.h"
@@ -52,6 +54,8 @@ struct instance_data {
    bool pipeline_statistics_enabled;
 
    bool first_line_printed;
+
+   int control_client;
 };
 
 struct frame_stat {
@@ -313,6 +317,7 @@ static struct instance_data *new_instance_data(VkInstance instance)
 {
    struct instance_data *data = rzalloc(NULL, struct instance_data);
    data->instance = instance;
+   data->control_client = -1;
    map_object(HKEY(data->instance), data);
    return data;
 }
@@ -553,6 +558,194 @@ static const char *param_unit(enum overlay_param_enabled param)
    }
 }
 
+static void parse_command(struct instance_data *instance_data,
+                          const char *cmd, unsigned cmdlen,
+                          const char *param, unsigned paramlen)
+{
+   /* TODO: Parse commands here. */
+}
+
+#define BUFSIZE 4096
+
+/**
+ * This function will process commands through the control file.
+ *
+ * A command starts with a colon, followed by the command, and followed by an
+ * option '=' and a parameter.  It has to end with a semi-colon. A full command
+ * + parameter looks like:
+ *
+ *    :cmd=param;
+ */
+static void process_char(struct instance_data *instance_data, char c)
+{
+   static char cmd[BUFSIZE];
+   static char param[BUFSIZE];
+
+   static unsigned cmdpos = 0;
+   static unsigned parampos = 0;
+   static bool reading_cmd = false;
+   static bool reading_param = false;
+
+   switch (c) {
+   case ':':
+      cmdpos = 0;
+      parampos = 0;
+      reading_cmd = true;
+      reading_param = false;
+      break;
+   case ';':
+      if (!reading_cmd)
+         break;
+      cmd[cmdpos++] = '\0';
+      param[parampos++] = '\0';
+      parse_command(instance_data, cmd, cmdpos, param, parampos);
+      reading_cmd = false;
+      reading_param = false;
+      break;
+   case '=':
+      if (!reading_cmd)
+         break;
+      reading_param = true;
+      break;
+   default:
+      if (!reading_cmd)
+         break;
+
+      if (reading_param) {
+         /* overflow means an invalid parameter */
+         if (parampos >= BUFSIZE - 1) {
+            reading_cmd = false;
+            reading_param = false;
+            break;
+         }
+
+         param[parampos++] = c;
+      } else {
+         /* overflow means an invalid command */
+         if (cmdpos >= BUFSIZE - 1) {
+            reading_cmd = false;
+            break;
+         }
+
+         cmd[cmdpos++] = c;
+      }
+   }
+}
+
+static void control_send(struct instance_data *instance_data,
+                         const char *cmd, unsigned cmdlen,
+                         const char *param, unsigned paramlen)
+{
+   unsigned msglen = 0;
+   char buffer[BUFSIZE];
+
+   assert(cmdlen + paramlen + 3 < BUFSIZE);
+
+   buffer[msglen++] = ':';
+
+   memcpy(&buffer[msglen], cmd, cmdlen);
+   msglen += cmdlen;
+
+   if (paramlen > 0) {
+      buffer[msglen++] = '=';
+      memcpy(&buffer[msglen], param, paramlen);
+      msglen += paramlen;
+      buffer[msglen++] = ';';
+   }
+
+   os_socket_send(instance_data->control_client, buffer, msglen, 0);
+}
+
+static void control_send_connection_string(struct device_data *device_data)
+{
+   struct instance_data *instance_data = device_data->instance;
+
+   const char *controlVersionCmd = "MesaOverlayControlVersion";
+   const char *controlVersionString = "1";
+
+   control_send(instance_data, controlVersionCmd, strlen(controlVersionCmd),
+                controlVersionString, strlen(controlVersionString));
+
+   const char *deviceCmd = "DeviceName";
+   const char *deviceName = device_data->properties.deviceName;
+
+   control_send(instance_data, deviceCmd, strlen(deviceCmd),
+                deviceName, strlen(deviceName));
+
+   const char *mesaVersionCmd = "MesaVersion";
+   const char *mesaVersionString = "Mesa " PACKAGE_VERSION MESA_GIT_SHA1;
+
+   control_send(instance_data, mesaVersionCmd, strlen(mesaVersionCmd),
+                mesaVersionString, strlen(mesaVersionString));
+}
+
+static void control_client_check(struct device_data *device_data)
+{
+   struct instance_data *instance_data = device_data->instance;
+
+   /* Already connected, just return. */
+   if (instance_data->control_client >= 0)
+      return;
+
+   int socket = os_socket_accept(instance_data->params.control);
+   if (socket == -1) {
+      if (errno != EAGAIN && errno != EWOULDBLOCK && errno != ECONNABORTED)
+         fprintf(stderr, "ERROR on socket: %s\n", strerror(errno));
+      return;
+   }
+
+   if (socket >= 0) {
+      os_socket_block(socket, false);
+      instance_data->control_client = socket;
+      control_send_connection_string(device_data);
+   }
+}
+
+static void control_client_disconnected(struct instance_data *instance_data)
+{
+   os_socket_close(instance_data->control_client);
+   instance_data->control_client = -1;
+}
+
+static void process_control_socket(struct instance_data *instance_data)
+{
+   const int client = instance_data->control_client;
+   if (client >= 0) {
+      char buf[BUFSIZE];
+
+      while (true) {
+         ssize_t n = os_socket_recv(client, buf, BUFSIZE, 0);
+
+         if (n == -1) {
+            if (errno == EAGAIN || errno == EWOULDBLOCK) {
+               /* nothing to read, try again later */
+               break;
+            }
+
+            if (errno != ECONNRESET)
+               fprintf(stderr, "ERROR on connection: %s\n", strerror(errno));
+
+            control_client_disconnected(instance_data);
+         } else if (n == 0) {
+            /* recv() returns 0 when the client disconnects */
+            control_client_disconnected(instance_data);
+         }
+
+         for (ssize_t i = 0; i < n; i++) {
+            process_char(instance_data, buf[i]);
+         }
+
+         /* If we try to read BUFSIZE and receive BUFSIZE bytes from the
+          * socket, there's a good chance that there's still more data to be
+          * read, so we will try again. Otherwise, simply be done for this
+          * iteration and try again on the next frame.
+          */
+         if (n < BUFSIZE)
+            break;
+      }
+   }
+}
+
 static void snapshot_swapchain_frame(struct swapchain_data *data)
 {
    struct device_data *device_data = data->device;
@@ -560,6 +753,11 @@ static void snapshot_swapchain_frame(struct swapchain_data *data)
    uint32_t f_idx = data->n_frames % ARRAY_SIZE(data->frames_stats);
    uint64_t now = os_time_get(); /* us */
 
+   if (instance_data->params.control >= 0) {
+      control_client_check(device_data);
+      process_control_socket(instance_data);
+   }
+
    if (data->last_present_time) {
       data->frame_stats.stats[OVERLAY_PARAM_ENABLED_frame_timing] =
          now - data->last_present_time;