Use signals for postmaster death on FreeBSD.

Use FreeBSD 11.2's new support for detecting parent process death to
make PostmasterIsAlive() very cheap, as was done for Linux in an
earlier commit.

Author: Thomas Munro
Discussion: https://postgr.es/m/7261eb39-0369-f2f4-1bb5-62f3b6083b5e@iki.fi

diff --git a/configure b/configure
index 41e0e1cf34ab73c94c04fae218db49f94bf33c84..f891914ed9963e1d3a14fe98176a2b29943070a6 100755 (executable)
--- a/configure
+++ b/configure
@@ -12494,7 +12494,7 @@ $as_echo "#define HAVE_STDBOOL_H 1" >>confdefs.h
 fi
 
 
-for ac_header in atomic.h crypt.h dld.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h mbarrier.h poll.h sys/epoll.h sys/ipc.h sys/prctl.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/sockio.h sys/tas.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h
+for ac_header in atomic.h crypt.h dld.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h mbarrier.h poll.h sys/epoll.h sys/ipc.h sys/prctl.h sys/procctl.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/sockio.h sys/tas.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"

diff --git a/configure.in b/configure.in
index 1e76c9ee46b5ca849ffccf5671cdd192e6a4a5b8..5712419a2749a79dc1c2e9f9ce183009ef0cf5a4 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -1260,7 +1260,7 @@ AC_SUBST(UUID_LIBS)
 
 AC_HEADER_STDBOOL
 
-AC_CHECK_HEADERS([atomic.h crypt.h dld.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h mbarrier.h poll.h sys/epoll.h sys/ipc.h sys/prctl.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/sockio.h sys/tas.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h])
+AC_CHECK_HEADERS([atomic.h crypt.h dld.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h mbarrier.h poll.h sys/epoll.h sys/ipc.h sys/prctl.h sys/procctl.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/sockio.h sys/tas.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h])
 
 # On BSD, test for net/if.h will fail unless sys/socket.h
 # is included first.

diff --git a/src/backend/storage/ipc/pmsignal.c b/src/backend/storage/ipc/pmsignal.c
index ebf027306f7754b55320938d667d2bd943e388b5..f658588c272f8e810fcb0472feebc66a5721d856 100644 (file)
--- a/src/backend/storage/ipc/pmsignal.c
+++ b/src/backend/storage/ipc/pmsignal.c
@@ -379,6 +379,9 @@ PostmasterDeathSignalInit(void)
 #if defined(PR_SET_PDEATHSIG)
    if (prctl(PR_SET_PDEATHSIG, signum) < 0)
        elog(ERROR, "could not request parent death signal: %m");
+#elif defined(PROC_PDEATHSIG_CTL)
+   if (procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum) < 0)
+       elog(ERROR, "could not request parent death signal: %m");
 #else
 #error "USE_POSTMASTER_DEATH_SIGNAL set, but there is no mechanism to request the signal"
 #endif

diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 4ef53416785062119f007b11d352478934fb8497..f9fb92f31c125aeeaf3ff1c7d8d313d11f8327e7 100644 (file)
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -603,6 +603,9 @@
 /* Define to 1 if you have the <sys/prctl.h> header file. */
 #undef HAVE_SYS_PRCTL_H
 
+/* Define to 1 if you have the <sys/procctl.h> header file. */
+#undef HAVE_SYS_PROCCTL_H
+
 /* Define to 1 if you have the <sys/pstat.h> header file. */
 #undef HAVE_SYS_PSTAT_H
 

diff --git a/src/include/storage/pmsignal.h b/src/include/storage/pmsignal.h
index 54e7108ac0b316176cdaf2631f7e276092ad9195..5ecc1b757c8b72a95d4e1873925b98a9f5b810d3 100644 (file)
--- a/src/include/storage/pmsignal.h
+++ b/src/include/storage/pmsignal.h
@@ -18,6 +18,10 @@
 #include "sys/prctl.h"
 #endif
 
+#ifdef HAVE_SYS_PROCCTL_H
+#include "sys/procctl.h"
+#endif
+
 /*
  * Reasons for signaling the postmaster.  We can cope with simultaneous
  * signals for different reasons.  If the same reason is signaled multiple
@@ -66,7 +70,8 @@ extern void PostmasterDeathSignalInit(void);
  * the parent dies.  Checking the flag first makes PostmasterIsAlive() a lot
  * cheaper in usual case that the postmaster is alive.
  */
-#if defined(HAVE_SYS_PRCTL_H) && defined(PR_SET_PDEATHSIG)
+#if (defined(HAVE_SYS_PRCTL_H) && defined(PR_SET_PDEATHSIG)) || \
+   (defined(HAVE_SYS_PROCCTL_H) && defined(PROC_PDEATHSIG_CTL))
 #define USE_POSTMASTER_DEATH_SIGNAL
 #endif