Re: [Maria-developers] [Commits] 6811945e: MDEV-6756: map a linux pid (child pid) to a connection id shown in the output of SHOW PROCESSLIST
Hi, Sanja! On Aug 12, sanja@mariadb.com wrote:
revision-id: 6811945eaf6a6e979d92739399b084bf4e00ae2d (mariadb-10.1.6-12-g6811945e) parent(s): 86a3613d4e981c341e38291c9eeec5dc9f836fae committer: Oleksandr Byelkin timestamp: 2015-08-12 23:09:48 +0200 message:
MDEV-6756: map a linux pid (child pid) to a connection id shown in the output of SHOW PROCESSLIST
Added tid & pid for Linux.
diff --git a/mysql-test/r/information_schema.result b/mysql-test/r/information_schema.result index 2a918ad..5b3370b 100644 --- a/mysql-test/r/information_schema.result +++ b/mysql-test/r/information_schema.result @@ -2066,3 +2066,18 @@ Variable_name Value Opened_tables 3 drop database mysqltest; drop database db1; +SHOW PROCESSLIST; +Id User Host db Command Time State Info Progress +# root # NULL Query # # SHOW PROCESSLIST 0.000 +set @@old_mode=""; +SHOW PROCESSLIST;
Eh, no, please, don't change SHOW PROCESSLIST. Only add new columns to I_S.PROCESSLIST. And without OLD_MODE.
diff --git a/sql/CMakeLists.txt b/sql/CMakeLists.txt index 033a0e0..d1fbaa3 100644 --- a/sql/CMakeLists.txt +++ b/sql/CMakeLists.txt @@ -143,6 +143,10 @@ SET (SQL_SOURCE ${MYSYS_LIBWRAP_SOURCE} )
+IF (CMAKE_SYSTEM_NAME MATCHES "Linux") + ADD_DEFINITIONS(-DHAVE_TID_SYSCALL) +ENDIF()
Don't match OS name please, better use #ifdef HAVE_SYS_SYSCALL_H #include <sys/syscall.h> #endif ... #ifdef __NR_gettid ... #endif
+ IF (CMAKE_SYSTEM_NAME MATCHES "Linux" OR CMAKE_SYSTEM_NAME MATCHES "Windows" OR CMAKE_SYSTEM_NAME MATCHES "SunOS" OR diff --git a/sql/sql_class.cc b/sql/sql_class.cc index bf161b2..20c03fe 100644 --- a/sql/sql_class.cc +++ b/sql/sql_class.cc @@ -2062,6 +2068,13 @@ bool THD::store_globals() This allows us to move THD to different threads if needed. */ mysys_var->id= thread_id; +#ifdef HAVE_TID_SYSCALL + os_pid= getpid();
why would you want to have pid there? isn't it the same for all threads?
+ os_thread_id= syscall(__NR_gettid); +#else + os_pid= 0; + os_thread_id= 0; +#endif real_id= pthread_self(); // For debugging mysys_var->stack_ends_here= thread_stack + // for consistency, see libevent_thread_proc STACK_DIRECTION * (long)my_thread_stack_size;
I didn't review the rest of the patch as without old_mode and SHOW PROCESSLIST changes most of it will disappear. Regards, Sergei
Hi, Sanja!
On Aug 12, sanja@mariadb.com wrote:
revision-id: 6811945eaf6a6e979d92739399b084bf4e00ae2d (mariadb-10.1.6-12-g6811945e) parent(s): 86a3613d4e981c341e38291c9eeec5dc9f836fae committer: Oleksandr Byelkin timestamp: 2015-08-12 23:09:48 +0200 message:
MDEV-6756: map a linux pid (child pid) to a connection id shown in the output of SHOW PROCESSLIST
Added tid & pid for Linux.
diff --git a/mysql-test/r/information_schema.result b/mysql-test/r/information_schema.result index 2a918ad..5b3370b 100644 --- a/mysql-test/r/information_schema.result +++ b/mysql-test/r/information_schema.result @@ -2066,3 +2066,18 @@ Variable_name Value Opened_tables 3 drop database mysqltest; drop database db1; +SHOW PROCESSLIST; +Id User Host db Command Time State Info Progress +# root # NULL Query # # SHOW PROCESSLIST 0.000 +set @@old_mode=""; +SHOW PROCESSLIST; Eh, no, please, don't change SHOW PROCESSLIST. Only add new columns to I_S.PROCESSLIST. And without OLD_MODE.
diff --git a/sql/CMakeLists.txt b/sql/CMakeLists.txt index 033a0e0..d1fbaa3 100644 --- a/sql/CMakeLists.txt +++ b/sql/CMakeLists.txt @@ -143,6 +143,10 @@ SET (SQL_SOURCE ${MYSYS_LIBWRAP_SOURCE} )
+IF (CMAKE_SYSTEM_NAME MATCHES "Linux") + ADD_DEFINITIONS(-DHAVE_TID_SYSCALL) +ENDIF() Don't match OS name please, better use
#ifdef HAVE_SYS_SYSCALL_H #include <sys/syscall.h> #endif ... #ifdef __NR_gettid ... #endif Are there way to check that it has thread ID syscall particulary (I am afraid that most OSes has syscall)?
+ IF (CMAKE_SYSTEM_NAME MATCHES "Linux" OR CMAKE_SYSTEM_NAME MATCHES "Windows" OR CMAKE_SYSTEM_NAME MATCHES "SunOS" OR diff --git a/sql/sql_class.cc b/sql/sql_class.cc index bf161b2..20c03fe 100644 --- a/sql/sql_class.cc +++ b/sql/sql_class.cc @@ -2062,6 +2068,13 @@ bool THD::store_globals() This allows us to move THD to different threads if needed. */ mysys_var->id= thread_id; +#ifdef HAVE_TID_SYSCALL + os_pid= getpid(); why would you want to have pid there? isn't it the same for all threads? No, it (PID) differs from thread on 1 and it is what actually shown in
Hi! On 12.09.15 21:35, Sergei Golubchik wrote: the process list. My understanding is that each thread group has own PID, and now we have threads each in its own group, so they have both PID and thread ID different and unique. Thread IDs are really unique ID for thread, but I was not able to make ps show it. It shows PID in TID column at least on my computer, so I decided to have them both is the best variant.
+ os_thread_id= syscall(__NR_gettid); +#else + os_pid= 0; + os_thread_id= 0; +#endif real_id= pthread_self(); // For debugging mysys_var->stack_ends_here= thread_stack + // for consistency, see libevent_thread_proc STACK_DIRECTION * (long)my_thread_stack_size; I didn't review the rest of the patch as without old_mode and SHOW PROCESSLIST changes most of it will disappear.
Regards, Sergei
Hi, Oleksandr! On Sep 14, Oleksandr Byelkin wrote:
Don't match OS name please, better use
#ifdef HAVE_SYS_SYSCALL_H #include <sys/syscall.h> #endif ... #ifdef __NR_gettid ... #endif Are there way to check that it has thread ID syscall particulary (I am afraid that most OSes has syscall)?
That's why you put the code inside #ifdef __NR_gettid ... #endif
diff --git a/sql/sql_class.cc b/sql/sql_class.cc index bf161b2..20c03fe 100644 --- a/sql/sql_class.cc +++ b/sql/sql_class.cc @@ -2062,6 +2068,13 @@ bool THD::store_globals() This allows us to move THD to different threads if needed. */ mysys_var->id= thread_id; +#ifdef HAVE_TID_SYSCALL + os_pid= getpid(); why would you want to have pid there? isn't it the same for all threads? No, it (PID) differs from thread on 1 and it is what actually shown in the process list.
'man gettid' says In a multithreaded process, all threads have the same PID, but each one has a unique TID. I've just tried: ==================================================== #define _GNU_SOURCE #include <pthread.h> #include <sys/types.h> #include <sys/syscall.h> #include <unistd.h> #include <stdio.h> void *print(void *a) { printf("%u %ld %lu\n", getpid(), syscall(__NR_gettid), pthread_self()); sleep(10); } main() { int i; pthread_t t; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM); for (i=0; i < 20; i++) pthread_create(&t, &attr, print, 0); print(0); } ==================================================== for me all threads do have the same PID (I tried with and without attr).
My understanding is that each thread group has own PID, and now we have threads each in its own group, so they have both PID and thread ID different and unique.
That's not what I see.
Thread IDs are really unique ID for thread, but I was not able to make ps show it. It shows PID in TID column at least on my computer, so I decided to have them both is the best variant.
From 'man ps': ==================================================== THREAD DISPLAY H Show threads as if they were processes.
-L Show threads, possibly with LWP and NLWP columns. m Show threads after processes. -m Show threads after processes. -T Show threads, possibly with SPID column. ==================================================== all these switches worked for me, showing threads and either showing tid automatically (-L, -T) or when I requested it with -o tid. Regards, Sergei
participants (2)
-
Oleksandr Byelkin -
Sergei Golubchik