From 620d0784290f5d27c7f05b9781173a528c280e77 Mon Sep 17 00:00:00 2001
From: Colin Patrick McCabe <cmccabe@alumni.cmu.edu>
Date: Mon, 20 Jun 2011 15:41:41 -0700
Subject: [PATCH] signal: const cleanup, don't use derr

In signal.cc: const cleanup, don't use derr, add a comment.

Signed-off-by: Colin McCabe <colin.mccabe@dreamhost.com>
---
 src/common/Thread.h       |  4 ++--
 src/common/common_init.cc |  2 +-
 src/common/signal.cc      | 33 ++++++++-------------------------
 src/common/signal.h       |  2 +-
 src/test/signals.cc       |  2 +-
 5 files changed, 13 insertions(+), 30 deletions(-)

diff --git a/src/common/Thread.h b/src/common/Thread.h
index 7bd51b1b7897f..2262568700750 100644
--- a/src/common/Thread.h
+++ b/src/common/Thread.h
@@ -70,11 +70,11 @@ class Thread {
     // another thread or delieverd to this thread later.)
     sigset_t old_sigset;
     if (g_code_env == CODE_ENVIRONMENT_LIBRARY) {
-      block_signals(&old_sigset, NULL);
+      block_signals(NULL, &old_sigset);
     }
     else {
       int to_block[] = { SIGPIPE , 0 };
-      block_signals(&old_sigset, to_block);
+      block_signals(to_block, &old_sigset);
     }
     r = pthread_create(&thread_id, thread_attr, _entry_func, (void*)this);
     restore_sigset(&old_sigset);
diff --git a/src/common/common_init.cc b/src/common/common_init.cc
index ad52a5c976011..ff88c0c035f21 100644
--- a/src/common/common_init.cc
+++ b/src/common/common_init.cc
@@ -130,7 +130,7 @@ void common_init(std::vector < const char* >& args,
 
   // signal stuff
   int siglist[] = { SIGPIPE, 0 };
-  block_signals(NULL, siglist);
+  block_signals(siglist, NULL);
   install_standard_sighandlers();
 
   if (code_env == CODE_ENVIRONMENT_DAEMON) {
diff --git a/src/common/signal.cc b/src/common/signal.cc
index 6bc15ed569839..bac8a18946259 100644
--- a/src/common/signal.cc
+++ b/src/common/signal.cc
@@ -143,7 +143,8 @@ void install_standard_sighandlers(void)
   install_sighandler(SIGINT, handle_shutdown_signal, SA_RESETHAND | SA_NODEFER);
 }
 
-void block_signals(sigset_t *old_sigset, int *siglist)
+/* Block the signals in 'siglist'. If siglist == NULL, block all signals. */
+void block_signals(const int *siglist, sigset_t *old_sigset)
 {
   sigset_t sigset;
   if (!siglist) {
@@ -157,26 +158,14 @@ void block_signals(sigset_t *old_sigset, int *siglist)
       ++i;
     }
   }
-  sigdelset(&sigset, SIGKILL);
-  if (pthread_sigmask(SIG_BLOCK, &sigset, old_sigset)) {
-    derr << "block_all_signals: sigprocmask failed" << dendl;
-    if (old_sigset)
-      sigaddset(old_sigset, SIGKILL);
-    return;
-  }
-  if (old_sigset)
-    sigdelset(old_sigset, SIGKILL);
+  int ret = pthread_sigmask(SIG_BLOCK, &sigset, old_sigset);
+  assert(ret == 0);
 }
 
 void restore_sigset(const sigset_t *old_sigset)
 {
-  if (sigismember(old_sigset, SIGKILL) != 0) {
-    derr << "restore_sigset: not restoring invalid old_sigset" << dendl;
-    return;
-  }
-  if (pthread_sigmask(SIG_SETMASK, old_sigset, NULL)) {
-    derr << "restore_sigset: sigprocmask failed" << dendl;
-  }
+  int ret = pthread_sigmask(SIG_SETMASK, old_sigset, NULL);
+  assert(ret == 0);
 }
 
 void unblock_all_signals(sigset_t *old_sigset)
@@ -184,12 +173,6 @@ void unblock_all_signals(sigset_t *old_sigset)
   sigset_t sigset;
   sigfillset(&sigset);
   sigdelset(&sigset, SIGKILL);
-  if (pthread_sigmask(SIG_UNBLOCK, &sigset, old_sigset)) {
-    derr << "unblock_all_signals: sigprocmask failed" << dendl;
-    if (old_sigset)
-      sigaddset(old_sigset, SIGKILL);
-    return;
-  }
-  if (old_sigset)
-    sigdelset(old_sigset, SIGKILL);
+  int ret = pthread_sigmask(SIG_UNBLOCK, &sigset, old_sigset);
+  assert(ret == 0);
 }
diff --git a/src/common/signal.h b/src/common/signal.h
index ed9ef2891dcf9..cac3c7bb6569e 100644
--- a/src/common/signal.h
+++ b/src/common/signal.h
@@ -38,7 +38,7 @@ std::string signal_mask_to_str();
 // On success, stores the old set of blocked signals in
 // old_sigset. On failure, stores an invalid set of blocked signals in
 // old_sigset.
-void block_signals(sigset_t *old_sigset, int *siglist);
+void block_signals(const int *siglist, sigset_t *old_sigset);
 
 // Restore the set of blocked signals. Will not restore an invalid set of
 // blocked signals.
diff --git a/src/test/signals.cc b/src/test/signals.cc
index 468b27096aae2..344cc59a78772 100644
--- a/src/test/signals.cc
+++ b/src/test/signals.cc
@@ -26,7 +26,7 @@ TEST(SignalApi, SimpleInstallAndTest)
 
   // blocked signal should not be delievered until we call sigsuspend()
   sigset_t old_sigset;
-  block_signals(&old_sigset, NULL);
+  block_signals(NULL, &old_sigset);
 
   int ret = kill(getpid(), SIGUSR1);
   ASSERT_EQ(ret, 0);
-- 
2.39.5