vulkan/overlay: Add basic overlay control script.

This can be used to start/stop statistics capturing from the command
line.

v3:
 - Install script (Lionel)

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>

2 files changed, 210 insertions, 0 deletions

diff --git a/src/vulkan/overlay-layer/mesa-overlay-control.py b/src/vulkan/overlay-layer/mesa-overlay-control.py
new file mode 100755
index 00000000000..6947250cff8
--- /dev/null
+++ b/src/vulkan/overlay-layer/mesa-overlay-control.py
@@ -0,0 +1,203 @@
+#!/usr/bin/env python3
+import os
+import socket
+import sys
+import select
+from select import EPOLLIN, EPOLLPRI, EPOLLERR
+import time
+from collections import namedtuple
+import argparse
+
+TIMEOUT = 1.0 # seconds
+
+VERSION_HEADER = bytearray('MesaOverlayControlVersion', 'utf-8')
+DEVICE_NAME_HEADER = bytearray('DeviceName', 'utf-8')
+MESA_VERSION_HEADER = bytearray('MesaVersion', 'utf-8')
+
+DEFAULT_SERVER_ADDRESS = "\0mesa_overlay"
+
+class Connection:
+    def __init__(self, path):
+        # Create a Unix Domain socket and connect
+        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        try:
+            sock.connect(path)
+        except socket.error as msg:
+            print(msg)
+            sys.exit(1)
+
+        self.sock = sock
+
+        # initialize poll interface and register socket
+        epoll = select.epoll()
+        epoll.register(sock, EPOLLIN | EPOLLPRI | EPOLLERR)
+        self.epoll = epoll
+
+    def recv(self, timeout):
+        '''
+        timeout as float in seconds
+        returns:
+            - None on error or disconnection
+            - bytes() (empty) on timeout
+        '''
+
+        events = self.epoll.poll(timeout)
+        for ev in events:
+            (fd, event) = ev
+            if fd != self.sock.fileno():
+                continue
+
+            # check for socket error
+            if event & EPOLLERR:
+                return None
+
+            # EPOLLIN or EPOLLPRI, just read the message
+            msg = self.sock.recv(4096)
+
+            # socket disconnected
+            if len(msg) == 0:
+                return None
+
+            return msg
+
+        return bytes()
+
+    def send(self, msg):
+        self.sock.send(msg)
+
+class MsgParser:
+    MSGBEGIN = bytes(':', 'utf-8')[0]
+    MSGEND = bytes(';', 'utf-8')[0]
+    MSGSEP = bytes('=', 'utf-8')[0]
+
+    def __init__(self, conn):
+        self.cmdpos = 0
+        self.parampos = 0
+        self.bufferpos = 0
+        self.reading_cmd = False
+        self.reading_param = False
+        self.buffer = None
+        self.cmd = bytearray(4096)
+        self.param = bytearray(4096)
+
+        self.conn = conn
+
+    def readCmd(self, ncmds, timeout=TIMEOUT):
+        '''
+        returns:
+            - None on error or disconnection
+            - bytes() (empty) on timeout
+        '''
+
+        parsed = []
+
+        remaining = timeout
+
+        while remaining > 0 and ncmds > 0:
+            now = time.monotonic()
+
+            if self.buffer == None:
+                self.buffer = self.conn.recv(remaining)
+                self.bufferpos = 0
+
+            # disconnected or error
+            if self.buffer == None:
+                return None
+
+            for i in range(self.bufferpos, len(self.buffer)):
+                c = self.buffer[i]
+                self.bufferpos += 1
+                if c == self.MSGBEGIN:
+                    self.cmdpos = 0
+                    self.parampos = 0
+                    self.reading_cmd = True
+                    self.reading_param = False
+                elif c == self.MSGEND:
+                    if not self.reading_cmd:
+                        continue
+                    self.reading_cmd = False
+                    self.reading_param = False
+
+                    cmd = self.cmd[0:self.cmdpos]
+                    param = self.param[0:self.parampos]
+                    self.reading_cmd = False
+                    self.reading_param = False
+
+                    parsed.append((cmd, param))
+                    ncmds -= 1
+                    if ncmds == 0:
+                        break
+                elif c == self.MSGSEP:
+                    if self.reading_cmd:
+                        self.reading_param = True
+                else:
+                    if self.reading_param:
+                        self.param[self.parampos] = c
+                        self.parampos += 1
+                    elif self.reading_cmd:
+                        self.cmd[self.cmdpos] = c
+                        self.cmdpos += 1
+
+            # if we read the entire buffer and didn't finish the command,
+            # throw it away
+            self.buffer = None
+
+            # check if we have time for another iteration
+            elapsed = time.monotonic() - now
+            remaining = max(0, remaining - elapsed)
+
+        # timeout
+        return parsed
+
+def control(args):
+    if args.socket:
+        address = '\0' + args.socket
+    else:
+        address = DEFAULT_SERVER_ADDRESS
+
+    conn = Connection(address)
+    msgparser = MsgParser(conn)
+
+    version = None
+    name = None
+    mesa_version = None
+
+    msgs = msgparser.readCmd(3)
+
+    for m in msgs:
+        cmd, param = m
+        if cmd == VERSION_HEADER:
+            version = int(param)
+        elif cmd == DEVICE_NAME_HEADER:
+            name = param.decode('utf-8')
+        elif cmd == MESA_VERSION_HEADER:
+            mesa_version = param.decode('utf-8')
+
+    if version != 1 or name == None or mesa_version == None:
+        print('ERROR: invalid protocol')
+        sys.exit(1)
+
+
+    if args.info:
+        info = "Protocol Version: {}\n"
+        info += "Device Name: {}\n"
+        info += "Mesa Version: {}"
+        print(info.format(version, name, mesa_version))
+
+    if args.cmd == 'start-capture':
+        conn.send(bytearray(':capture=1;', 'utf-8'))
+    elif args.cmd == 'stop-capture':
+        conn.send(bytearray(':capture=0;', 'utf-8'))
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description='MESA_overlay control client')
+    parser.add_argument('--info', action='store_true', help='Print info from socket')
+    parser.add_argument('--socket', '-s', type=str, help='Path to socket')
+
+    commands = parser.add_subparsers(help='commands to run', dest='cmd')
+    commands.add_parser('start-capture')
+    commands.add_parser('stop-capture')
+
+    args = parser.parse_args()
+
+    control(args)
diff --git a/src/vulkan/overlay-layer/meson.build b/src/vulkan/overlay-layer/meson.build
index 96134d356ff..5b553d0b51e 100644
--- a/src/vulkan/overlay-layer/meson.build
+++ b/src/vulkan/overlay-layer/meson.build
@@ -51,3 +51,10 @@ install_data(
   files('VkLayer_MESA_overlay.json'),
   install_dir : join_paths(get_option('datadir'), 'vulkan', 'explicit_layer.d'),
 )
+
+configure_file(
+  input : files('mesa-overlay-control.py'),
+  output : '@PLAINNAME@',
+  configuration : configuration_data(), # only copy the file
+  install_dir: get_option('bindir'),
+)