19/118: Report daemon OOM better

[Ludovic Court�s]

civodul pushed a commit to branch nix
in repository guix.

commit b1beed97a0670befbfd5e105a81132e87e58ac37
Author: Eelco Dolstra <eelco.dols...@logicblox.com>
Date:   Tue Jun 10 13:45:50 2014 +0200

    Report daemon OOM better
    
    When copying a large path causes the daemon to run out of memory, you
    now get:
    
      error: Nix daemon out of memory
    
    instead of:
    
      error: writing to file: Broken pipe
---
 src/libstore/remote-store.cc |   22 +++++++++++++++++-----
 src/nix-daemon/nix-daemon.cc |    6 ++----
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index 177b8e7..3b021bb 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -402,11 +402,23 @@ Path RemoteStore::addToStore(const Path & _srcPath,
     writeInt((hashAlgo == htSHA256 && recursive) ? 0 : 1, to);
     writeInt(recursive ? 1 : 0, to);
     writeString(printHashType(hashAlgo), to);
-    to.written = 0;
-    to.warn = true;
-    dumpPath(srcPath, to, filter);
-    to.warn = false;
-    processStderr();
+
+    try {
+        to.written = 0;
+        to.warn = true;
+        dumpPath(srcPath, to, filter);
+        to.warn = false;
+        processStderr();
+    } catch (SysError & e) {
+        /* Daemon closed while we were sending the path. Probably OOM
+           or I/O error. */
+        if (e.errNo == EPIPE)
+            try {
+                processStderr();
+            } catch (EndOfFile & e) { }
+        throw;
+    }
+
     return readStorePath(from);
 }
 
diff --git a/src/nix-daemon/nix-daemon.cc b/src/nix-daemon/nix-daemon.cc
index 8814fe3..0464ac9 100644
--- a/src/nix-daemon/nix-daemon.cc
+++ b/src/nix-daemon/nix-daemon.cc
@@ -735,12 +735,10 @@ static void processConnection(bool trusted)
                during addTextToStore() / importPath().  If that
                happens, just send the error message and exit. */
             bool errorAllowed = canSendStderr;
-            if (!errorAllowed) printMsg(lvlError, format("error processing 
client input: %1%") % e.msg());
             stopWork(false, e.msg(), GET_PROTOCOL_MINOR(clientVersion) >= 8 ? 
e.status : 0);
-            if (!errorAllowed) break;
+            if (!errorAllowed) throw;
         } catch (std::bad_alloc & e) {
-            if (canSendStderr)
-                stopWork(false, "Nix daemon out of memory", 
GET_PROTOCOL_MINOR(clientVersion) >= 8 ? 1 : 0);
+            stopWork(false, "Nix daemon out of memory", 
GET_PROTOCOL_MINOR(clientVersion) >= 8 ? 1 : 0);
             throw;
         }