daemon: Client settings no longer override daemon settings.

Fixes <http://bugs.gnu.org/20217>.

* nix/libstore/worker-protocol.hh (PROTOCOL_VERSION): Bump to 0x161.
* nix/nix-daemon/nix-daemon.cc (performOp): "build-max-jobs",
"build-max-silent-time", and "build-cores" are no longer read upfront;
instead, read them from the key/value list at the end.
* nix/nix-daemon/guix-daemon.cc (main): Explicitly set
'settings.maxBuildJobs'.
* guix/store.scm (%protocol-version): Bump to #x161.
(set-build-options): #:max-build-jobs, #:max-silent-time, and
 #:build-cores now default to #f.  Adjust handshake to new protocol.
* tests/store.scm ("build-cores"): New test.
* tests/guix-daemon.sh: Add test for default "build-cores" value.

3 files changed, 16 insertions, 7 deletions

diff --git a/nix/libstore/worker-protocol.hh b/nix/libstore/worker-protocol.hh
index bdeaca2e3a..efe9eadf23 100644
--- a/nix/libstore/worker-protocol.hh
+++ b/nix/libstore/worker-protocol.hh
@@ -6,7 +6,7 @@ namespace nix {
 #define WORKER_MAGIC_1 0x6e697863
 #define WORKER_MAGIC_2 0x6478696f
 
-#define PROTOCOL_VERSION 0x160
+#define PROTOCOL_VERSION 0x161
 #define GET_PROTOCOL_MAJOR(x) ((x) & 0xff00)
 #define GET_PROTOCOL_MINOR(x) ((x) & 0x00ff)
 
diff --git a/nix/nix-daemon/guix-daemon.cc b/nix/nix-daemon/guix-daemon.cc
index d5d33a587a..aa47a290d2 100644
--- a/nix/nix-daemon/guix-daemon.cc
+++ b/nix/nix-daemon/guix-daemon.cc
@@ -1,5 +1,5 @@
 /* GNU Guix --- Functional package management for GNU
-   Copyright (C) 2012, 2013, 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org>
+   Copyright (C) 2012, 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
 
    This file is part of GNU Guix.
 
@@ -301,8 +301,9 @@ main (int argc, char *argv[])
   /* Turn automatic deduplication on by default.  */
   settings.autoOptimiseStore = true;
 
-  /* Default to using as many cores as possible.  */
+  /* Default to using as many cores as possible and one job at a time.  */
   settings.buildCores = 0;
+  settings.maxBuildJobs = 1;
 
   argvSaved = argv;
 
diff --git a/nix/nix-daemon/nix-daemon.cc b/nix/nix-daemon/nix-daemon.cc
index 47b67d5863..79580ffb48 100644
--- a/nix/nix-daemon/nix-daemon.cc
+++ b/nix/nix-daemon/nix-daemon.cc
@@ -549,8 +549,12 @@ static void performOp(bool trusted, unsigned int clientVersion,
         settings.keepGoing = readInt(from) != 0;
         settings.set("build-fallback", readInt(from) ? "true" : "false");
         verbosity = (Verbosity) readInt(from);
-        settings.set("build-max-jobs", std::to_string(readInt(from)));
-        settings.set("build-max-silent-time", std::to_string(readInt(from)));
+
+        if (GET_PROTOCOL_MINOR(clientVersion) < 0x61) {
+            settings.set("build-max-jobs", std::to_string(readInt(from)));
+            settings.set("build-max-silent-time", std::to_string(readInt(from)));
+        }
+
         if (GET_PROTOCOL_MINOR(clientVersion) >= 2)
             settings.useBuildHook = readInt(from) != 0;
         if (GET_PROTOCOL_MINOR(clientVersion) >= 4) {
@@ -558,7 +562,8 @@ static void performOp(bool trusted, unsigned int clientVersion,
             logType = (LogType) readInt(from);
             settings.printBuildTrace = readInt(from) != 0;
         }
-        if (GET_PROTOCOL_MINOR(clientVersion) >= 6)
+        if (GET_PROTOCOL_MINOR(clientVersion) >= 6
+            && GET_PROTOCOL_MINOR(clientVersion) < 0x61)
             settings.set("build-cores", std::to_string(readInt(from)));
         if (GET_PROTOCOL_MINOR(clientVersion) >= 10)
             settings.set("build-use-substitutes", readInt(from) ? "true" : "false");
@@ -567,7 +572,10 @@ static void performOp(bool trusted, unsigned int clientVersion,
             for (unsigned int i = 0; i < n; i++) {
                 string name = readString(from);
                 string value = readString(from);
-                if (name == "build-timeout" || name == "build-repeat" || name == "use-ssh-substituter")
+                if (name == "build-timeout" || name == "build-max-silent-time"
+                    || name == "build-max-jobs" || name == "build-cores"
+                    || name == "build-repeat"
+                    || name == "use-ssh-substituter")
                     settings.set(name, value);
                 else
                     settings.set(trusted ? name : "untrusted-" + name, value);