Use frame callbacks instead of vsync on Wayland

Instead of blocking on vsync, Alacritty now requests a notification from
wayland about when the next frame should be rendered. this helps with
input latency, since it gives alacritty more time to process events
before a redraw. it also prevents alacritty from drawing unless the
compositor tells it to do so.

Fixes #2851.

1 files changed, 62 insertions, 0 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 1904799c..bb7bae20 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -38,6 +38,7 @@ dependencies = [
  "time 0.1.43 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-width 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "urlocator 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-client 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "x11-dl 2.18.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "xdg 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1196,6 +1197,11 @@ dependencies = [
 ]
 
 [[package]]
+name = "once_cell"
+version = "1.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "openssl"
 version = "0.10.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1533,6 +1539,11 @@ dependencies = [
 ]
 
 [[package]]
+name = "scoped-tls"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "scopeguard"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1950,6 +1961,21 @@ dependencies = [
 ]
 
 [[package]]
+name = "wayland-client"
+version = "0.26.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "downcast-rs 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.69 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nix 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "scoped-tls 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-commons 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-scanner 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-sys 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "wayland-commons"
 version = "0.23.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1959,6 +1985,17 @@ dependencies = [
 ]
 
 [[package]]
+name = "wayland-commons"
+version = "0.26.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "nix 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "once_cell 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-sys 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "wayland-protocols"
 version = "0.23.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1980,6 +2017,16 @@ dependencies = [
 ]
 
 [[package]]
+name = "wayland-scanner"
+version = "0.26.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "xml-rs 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "wayland-sys"
 version = "0.23.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1989,6 +2036,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "wayland-sys"
+version = "0.26.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "dlib 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "which"
 version = "3.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2295,6 +2351,7 @@ dependencies = [
 "checksum objc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "915b1b472bc21c53464d6c8461c9d3af805ba1ef837e1cac254428f4a77177b1"
 "checksum objc-foundation 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1add1b659e36c9607c7aab864a76c7a4c2760cd0cd2e120f3fb8b952c7e22bf9"
 "checksum objc_id 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c92d4ddb4bd7b50d730c215ff871754d0da6b2178849f8a2a2ab69712d0c073b"
+"checksum once_cell 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b1c601810575c99596d4afc46f78a678c80105117c379eb3650cf99b8a21ce5b"
 "checksum openssl 0.10.29 (registry+https://github.com/rust-lang/crates.io-index)" = "cee6d85f4cb4c4f59a6a85d5b68a233d280c82e29e822913b9c8b129fbf20bdd"
 "checksum openssl-probe 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "77af24da69f9d9341038eba93a073b1fdaaa1b788221b00a69bce9e762cb32de"
 "checksum openssl-sys 0.9.55 (registry+https://github.com/rust-lang/crates.io-index)" = "7717097d810a0f2e2323f9e5d11e71608355e24828410b55b9d4f18aa5f9a5d8"
@@ -2337,6 +2394,7 @@ dependencies = [
 "checksum ryu 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "ed3d612bc64430efeb3f7ee6ef26d590dce0c43249217bddc62112540c7941e1"
 "checksum same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
 "checksum schannel 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)" = "039c25b130bd8c1321ee2d7de7fde2659fa9c2744e4bb29711cfc852ea53cd19"
+"checksum scoped-tls 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ea6a9290e3c9cf0f18145ef7ffa62d68ee0bf5fcd651017e586dc7fd5da448c2"
 "checksum scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 "checksum security-framework 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "572dfa3a0785509e7a44b5b4bebcf94d41ba34e9ed9eb9df722545c3b3c4144a"
 "checksum security-framework-sys 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "8ddb15a5fec93b7021b8a9e96009c5d8d51c15673569f7c0f6b7204e5b7b404f"
@@ -2389,10 +2447,14 @@ dependencies = [
 "checksum walkdir 2.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "777182bc735b6424e1a57516d35ed72cb8019d85c8c9bf536dccb3445c1a2f7d"
 "checksum wasi 0.9.0+wasi-snapshot-preview1 (registry+https://github.com/rust-lang/crates.io-index)" = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
 "checksum wayland-client 0.23.6 (registry+https://github.com/rust-lang/crates.io-index)" = "af1080ebe0efabcf12aef2132152f616038f2d7dcbbccf7b2d8c5270fe14bcda"
+"checksum wayland-client 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)" = "6eda8c06906f6572f840930588ce28f021485bc9679af0191aeb753ad6c7b46b"
 "checksum wayland-commons 0.23.6 (registry+https://github.com/rust-lang/crates.io-index)" = "bb66b0d1a27c39bbce712b6372131c6e25149f03ffb0cd017cf8f7de8d66dbdb"
+"checksum wayland-commons 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)" = "951aaed76c01185bff7ec68426769c94e88b36113dfe73f8e2356feaa5f09c1f"
 "checksum wayland-protocols 0.23.6 (registry+https://github.com/rust-lang/crates.io-index)" = "6cc286643656742777d55dc8e70d144fa4699e426ca8e9d4ef454f4bf15ffcf9"
 "checksum wayland-scanner 0.23.6 (registry+https://github.com/rust-lang/crates.io-index)" = "93b02247366f395b9258054f964fe293ddd019c3237afba9be2ccbe9e1651c3d"
+"checksum wayland-scanner 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)" = "21ae379761543b2f41ce88010d0f4ee489218c8e8cfa42dd8f070fdb263aa971"
 "checksum wayland-sys 0.23.6 (registry+https://github.com/rust-lang/crates.io-index)" = "d94e89a86e6d6d7c7c9b19ebf48a03afaac4af6bc22ae570e9a24124b75358f4"
+"checksum wayland-sys 0.26.3 (registry+https://github.com/rust-lang/crates.io-index)" = "fab1f1d2ab35838c5fcbbeebee42cf15721c5fdc1add1f13d0e70e219b94e013"
 "checksum which 3.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d011071ae14a2f6671d0b74080ae0cd8ebf3a6f8c9589a2cd45f23126fe29724"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"