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Implemented new API function burn_set_signal_handling(), libburner uses it

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This commit is contained in:
Thomas Schmitt
2006-10-03 16:37:08 +00:00
parent b3bea43074
commit 3b16ef699f
11 changed files with 349 additions and 35 deletions
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5
Makefile.am
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@@ -12,6 +12,8 @@ libburn_libburn_la_SOURCES = \
libburn/async.c \
libburn/async.h \
libburn/back_hacks.h \
libburn/cleanup.c \
libburn/cleanup.h \
libburn/crc.c \
libburn/crc.h \
libburn/debug.c \
@@ -119,7 +121,8 @@ test_iso_SOURCES = test/iso.c
cdrskin_cdrskin_CPPFLAGS = -Ilibburn
cdrskin_cdrskin_CFLAGS = -DCdrskin_libburn_0_2_3
cdrskin_cdrskin_LDADD = $(libburn_libburn_la_OBJECTS) $(THREAD_LIBS)
cdrskin_cdrskin_SOURCES = cdrskin/cdrskin.c cdrskin/cdrfifo.c cdrskin/cdrfifo.h cdrskin/cleanup.c cdrskin/cleanup.h cdrskin/cdrskin_timestamp.h
cdrskin_cdrskin_SOURCES = cdrskin/cdrskin.c cdrskin/cdrfifo.c cdrskin/cdrfifo.h cdrskin/cdrskin_timestamp.h
## cdrskin_cdrskin_SOURCES = cdrskin/cdrskin.c cdrskin/cdrfifo.c cdrskin/cdrfifo.h cdrskin/cleanup.c cdrskin/cleanup.h cdrskin/cdrskin_timestamp.h
##
## Open questions: how to compute $timestamp and express -DX="$timestamp"
##

13
cdrskin/cdrskin.c
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@@ -186,6 +186,7 @@ or
#ifdef Cdrskin_new_api_tesT
/* put macros under test caveat here */
#define Cdrskin_libburn_has_cleanup_handleR 1
#endif
@@ -273,7 +274,12 @@ or
#include <libburn/libburn.h>
#ifdef Cdrskin_libburn_has_cleanup_handleR
#define Cleanup_set_handlers burn_set_signal_handling
#define Cleanup_app_handler_T burn_abort_handler_t
#else
#include "cleanup.h"
#endif
/** The size of a string buffer for pathnames and similar texts */
@@ -2652,11 +2658,10 @@ int Cdrskin_abort_handler(struct CdrskiN *skin, int signum, int flag)
if(getpid()!=skin->control_pid) {
if(skin->verbosity>=Cdrskin_verbose_debuG)
ClN(fprintf(stderr,
"cdrskin_debug: ABORT : Thread rejected: pid=%d, signum=%d\n",
getpid(),signum));
return(2); /* do only process the control thread */
"\ncdrskin_debug: ABORT : [%d] Thread rejected: pid=%d, signum=%d\n",
skin->control_pid,getpid(),signum));
return(-2); /* do only process the control thread */
}
if(skin->preskin->abort_handler==3)
Cleanup_set_handlers(NULL,NULL,2); /* ignore all signals */
else if(skin->preskin->abort_handler==4)

2
cdrskin/cdrskin_timestamp.h
View File

@@ -1 +1 @@
#define Cdrskin_timestamP "2006.10.02.103418"
#define Cdrskin_timestamP "2006.10.03.162719"

17
cdrskin/cleanup.c
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@@ -3,7 +3,7 @@
A signal handler which cleans up an application and exits.
Provided under GPL license within cdrskin and under BSD license elsewise.
Provided under GPL license within GPL projects, BSD license elsewise.
*/
/*
@@ -65,7 +65,7 @@ static int Cleanup_handler_exit(int exit_value, int signum, int flag)
if(cleanup_perform_app_handler_first)
if(cleanup_app_handler!=NULL) {
ret= (*cleanup_app_handler)(cleanup_app_handle,signum,0);
if(ret==2)
if(ret==2 || ret==-2)
return(2);
}
if(cleanup_exiting) {
@@ -77,11 +77,14 @@ static int Cleanup_handler_exit(int exit_value, int signum, int flag)
}
cleanup_exiting= 1;
if(cleanup_msg[0]!=0)
fprintf(stderr,"%s\n",cleanup_msg);
fprintf(stderr,"\n%s\n",cleanup_msg);
alarm(0);
if(!cleanup_perform_app_handler_first)
if(cleanup_app_handler!=NULL)
(*cleanup_app_handler)(cleanup_app_handle,signum,0);
if(cleanup_app_handler!=NULL) {
ret= (*cleanup_app_handler)(cleanup_app_handle,signum,0);
if(ret==2 || ret==-2)
return(2);
}
exit(exit_value);
}
@@ -115,8 +118,12 @@ int Cleanup_set_handlers(void *handle, Cleanup_app_handler_T handler, int flag)
cleanup_msg[0]= 0;
cleanup_app_handle= handle;
cleanup_app_handler= handler;
/* <<< make cleanup_exiting thread safe to get rid of this */
if(flag&4)
cleanup_perform_app_handler_first= 1;
if(flag&1)
sig_handler= SIG_DFL;
else if(flag&2)

4
cdrskin/cleanup.h
View File

@@ -3,7 +3,7 @@
A signal handler which cleans up an application and exits.
Provided under GPL license within cdrskin and under BSD license elsewise.
Provided under GPL license within GPL projects, BSD license elsewise.
*/
#ifndef Cleanup_includeD
@@ -13,7 +13,7 @@
/** Layout of an application provided cleanup function using an application
provided handle as first argument and the signal number as second
argument. The third argument is a flag bit field with no defined bits yet.
If the handler returns 2 then it has delegated exit() to some other
If the handler returns 2 or -2 then it has delegated exit() to some other
instance and the Cleanup handler shall return rather than exit.
*/
typedef int (*Cleanup_app_handler_T)(void *, int, int);

10
cdrskin/compile_cdrskin.sh
View File

@@ -7,6 +7,7 @@
debug_opts=
def_opts=
libvers="-DCdrskin_libburn_0_2_3"
cleanup_src_or_obj="cdrskin/cleanup.c"
libdax_msgs_o="libburn/libdax_msgs.o"
do_strip=0
static_opts=
@@ -24,10 +25,12 @@ do
then
libvers="-DCdrskin_libburn_cvs_A60220_tS"
libdax_msgs_o="libburn/message.o"
cleanup_src_or_obj="cdrskin/cleanup.c"
elif test "$i" = "-libburn_0_2_2"
then
libvers="-DCdrskin_libburn_0_2_2"
libdax_msgs_o="libburn/message.o"
cleanup_src_or_obj="cdrskin/cleanup.c"
elif test "$i" = "-libburn_0_2_3"
then
libvers="-DCdrskin_libburn_0_2_3"
@@ -35,9 +38,11 @@ do
elif test "$i" = "-newapi" -o "$i" = "-experimental"
then
def_opts="$def_opts -DCdrskin_new_api_tesT"
cleanup_src_or_obj="libburn/cleanup.o"
elif test "$i" = "-oldfashioned"
then
def_opts="$def_opts -DCdrskin_oldfashioned_api_usE"
cleanup_src_or_obj="cdrskin/cleanup.c"
elif test "$i" = "-do_not_compile_cdrskin"
then
compile_cdrskin=0
@@ -85,7 +90,7 @@ echo "Build timestamp : $timestamp"
if test "$compile_cdrskin"
then
echo "compiling program cdrskin/cdrskin.c $static_opts $debug_opts $libvers $def_opts"
echo "compiling program cdrskin/cdrskin.c $static_opts $debug_opts $libvers $def_opts $cleanup_src_or_obj"
cc $warn_opts -I. $static_opts $debug_opts $libvers $def_opts \
-DCdrskin_build_timestamP='"'"$timestamp"'"' \
\
@@ -93,7 +98,8 @@ then
\
cdrskin/cdrskin.c \
$fifo_source \
cdrskin/cleanup.c \
\
$cleanup_src_or_obj \
\
libburn/async.o \
libburn/debug.o \

191
libburn/cleanup.c Normal file
View File

@@ -0,0 +1,191 @@
/*
cleanup.c , Copyright 2006 Thomas Schmitt <scdbackup@gmx.net>
A signal handler which cleans up an application and exits.
Provided under GPL license within GPL projects, BSD license elsewise.
*/
/*
cc -g -o cleanup -DCleanup_standalonE cleanup.c
*/
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
typedef void (*sighandler_t)(int);
#include "cleanup.h"
/* Signals to be caught */
static int signal_list[]= {
SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGABRT,
SIGFPE, SIGSEGV, SIGPIPE, SIGALRM, SIGTERM,
SIGUSR1, SIGUSR2, SIGXCPU, SIGTSTP, SIGTTIN,
SIGTTOU,
SIGBUS, SIGPOLL, SIGPROF, SIGSYS, SIGTRAP,
SIGVTALRM, SIGXCPU, SIGXFSZ, -1
};
static char *signal_name_list[]= {
"SIGHUP", "SIGINT", "SIGQUIT", "SIGILL", "SIGABRT",
"SIGFPE", "SIGSEGV", "SIGPIPE", "SIGALRM", "SIGTERM",
"SIGUSR1", "SIGUSR2", "SIGXCPU", "SIGTSTP", "SIGTTIN",
"SIGTTOU",
"SIGBUS", "SIGPOLL", "SIGPROF", "SIGSYS", "SIGTRAP",
"SIGVTALRM", "SIGXCPU", "SIGXFSZ", "@"
};
static int signal_list_count= 24;
/* Signals not to be caught */
static int non_signal_list[]= {
SIGKILL, SIGCHLD, SIGSTOP, SIGURG, -1
};
static int non_signal_list_count= 4;
/* run time dynamic part */
static char cleanup_msg[4096]= {""};
static int cleanup_exiting= 0;
static void *cleanup_app_handle= NULL;
static Cleanup_app_handler_T cleanup_app_handler= NULL;
static int cleanup_perform_app_handler_first= 0;
static int Cleanup_handler_exit(int exit_value, int signum, int flag)
{
int ret;
if(cleanup_perform_app_handler_first)
if(cleanup_app_handler!=NULL) {
ret= (*cleanup_app_handler)(cleanup_app_handle,signum,0);
if(ret==2 || ret==-2)
return(2);
}
if(cleanup_exiting) {
if(cleanup_msg[0]!=0)
fprintf(stderr,"%s\n",cleanup_msg);
fprintf(stderr,"cleanup: ABORT : repeat by pid=%d, signum=%d\n",
getpid(),signum);
return(0);
}
cleanup_exiting= 1;
if(cleanup_msg[0]!=0)
fprintf(stderr,"\n%s\n",cleanup_msg);
alarm(0);
if(!cleanup_perform_app_handler_first)
if(cleanup_app_handler!=NULL) {
ret= (*cleanup_app_handler)(cleanup_app_handle,signum,0);
if(ret==2 || ret==-2)
return(2);
}
exit(exit_value);
}
static void Cleanup_handler_generic(int signum)
{
int i;
sprintf(cleanup_msg,"UNIX-SIGNAL caught: %d errno= %d",signum,errno);
for(i= 0; i<signal_list_count; i++)
if(signum==signal_list[i]) {
sprintf(cleanup_msg,"UNIX-SIGNAL: %s errno= %d",
signal_name_list[i],errno);
break;
}
Cleanup_handler_exit(1,signum,0);
}
int Cleanup_set_handlers(void *handle, Cleanup_app_handler_T handler, int flag)
/*
bit0= set to default handlers
bit1= set to ignore
bit2= set cleanup_perform_app_handler_first
bit3= set SIGABRT to handler (makes sense with bits 0 or 1)
*/
{
int i,j,max_sig= -1,min_sig= 0x7fffffff;
sighandler_t sig_handler;
cleanup_msg[0]= 0;
cleanup_app_handle= handle;
cleanup_app_handler= handler;
/* <<< make cleanup_exiting thread safe to get rid of this */
if(flag&4)
cleanup_perform_app_handler_first= 1;
if(flag&1)
sig_handler= SIG_DFL;
else if(flag&2)
sig_handler= SIG_IGN;
else
sig_handler= Cleanup_handler_generic;
/* set all signal numbers between the lowest and highest in the list
except those in the non-signal list */
for(i= 0; i<signal_list_count; i++) {
if(signal_list[i]>max_sig)
max_sig= signal_list[i];
if(signal_list[i]<min_sig)
min_sig= signal_list[i];
}
for(i= min_sig; i<=max_sig; i++) {
for(j= 0; j<non_signal_list_count; j++)
if(i==non_signal_list[j])
break;
if(j>=non_signal_list_count) {
if(i==SIGABRT && (flag&8))
signal(i,Cleanup_handler_generic);
else
signal(i,sig_handler);
}
}
return(1);
}
#ifdef Cleanup_standalonE
struct Demo_apP {
char *msg;
};
int Demo_app_handler(struct Demo_apP *demoapp, int signum, int flag)
{
printf("Handling exit of demo application on signal %d. msg=\"%s\"\n",
signum,demoapp->msg);
return(1);
}
main()
{
struct Demo_apP demoapp;
demoapp.msg= "Good Bye";
Cleanup_set_handlers(&demoapp,(Cleanup_app_handler_T) Demo_app_handler,0);
if(1) { /* change to 0 in order to wait for external signals */
char *cpt= NULL,c;
printf("Intentionally provoking SIGSEGV ...\n");
c= *cpt;
} else {
printf("killme: %d\n",getpid());
sleep(3600);
}
Cleanup_set_handlers(NULL,NULL,1);
exit(0);
}
#endif /* Cleanup_standalonE */

34
libburn/cleanup.h Normal file
View File

@@ -0,0 +1,34 @@
/*
cleanup.c , Copyright 2006 Thomas Schmitt <scdbackup@gmx.net>
A signal handler which cleans up an application and exits.
Provided under GPL license within GPL projects, BSD license elsewise.
*/
#ifndef Cleanup_includeD
#define Cleanup_includeD 1
/** Layout of an application provided cleanup function using an application
provided handle as first argument and the signal number as second
argument. The third argument is a flag bit field with no defined bits yet.
If the handler returns 2 or -2 then it has delegated exit() to some other
instance and the Cleanup handler shall return rather than exit.
*/
typedef int (*Cleanup_app_handler_T)(void *, int, int);
/** Establish exiting signal handlers on (hopefully) all signals that are
not ignored by default or non-catchable.
@param handle Opaque object which knows how to cleanup application
@param handler Function which uses handle to perform application cleanup
@param flag Control Bitfield
bit0= reset to default signal handling
*/
int Cleanup_set_handlers(void *handle, Cleanup_app_handler_T handler,
int flag);
#endif /* ! Cleanup_includeD */

46
libburn/init.c
View File

@@ -38,6 +38,15 @@ int burn_sg_open_o_nonblock = 1;
int burn_sg_open_abort_busy = 0;
/* ts A61002 */
#include "cleanup.h"
/* Parameters for builtin abort handler */
static char abort_message_prefix[81] = {"libburn : "};
static pid_t abort_control_pid= 0;
/* ts A60925 : ticket 74 */
/** Create the messenger object for libburn. */
int burn_msgs_initialize(void)
@@ -197,3 +206,40 @@ ex:
return ret;
}
int burn_builtin_abort_handler(void *handle, int signum, int flag)
{
if(getpid() != abort_control_pid)
return -2;
Cleanup_set_handlers(NULL, NULL, 2);
fprintf(stderr,"%sABORT : Trying to shut down drive and library\n",
abort_message_prefix);
fprintf(stderr,
"%sABORT : Wait the normal burning time before any kill -9\n",
abort_message_prefix);
close(0); /* somehow stdin as input blocks abort until EOF */
burn_abort(4440, burn_abort_pacifier, abort_message_prefix);
fprintf(stderr,
"\n%sABORT : Program done. Even if you do not see a shell prompt.\n\n",
abort_message_prefix);
return(1);
}
void burn_set_signal_handling(void *handle, burn_abort_handler_t handler,
int mode)
{
if(handler == NULL && mode == 0) {
handler = burn_builtin_abort_handler;
/*
fprintf(stderr, "libburn_experimental: activated burn_builtin_abort_handler() with handle '%s'\n",(handle==NULL ? "libburn : " : (char *) handle));
*/
}
strcpy(abort_message_prefix, "libburn : ");
if(handle != NULL)
strncpy(abort_message_prefix, (char *) handle,
sizeof(abort_message_prefix)-1);
abort_message_prefix[sizeof(abort_message_prefix)-1] = 0;
abort_control_pid= getpid();
Cleanup_set_handlers(handle, (Cleanup_app_handler_T) handler, mode|4);
}

32
libburn/libburn.h
View File

@@ -392,7 +392,14 @@ int burn_initialize(void);
void burn_finish(void);
/* ts A61002 */
/** Abort any running drive operation and finally call burn_finish().
You MUST calm down the busy drive if an aborting event occurs during a
burn run. For that you may call this function either from your own signal
handling code or indirectly by activating the builtin signal handling:
burn_set_signal_handling("my_app_name : ", NULL, 0);
Else you may eventually call burn_drive_cancel() on the active drive and
wait for it to assume state BURN_DRIVE_IDLE.
@param patience Maximum number of seconds to wait for drives to finish
@param pacifier_func If not NULL: a function to produce appeasing messages.
See burn_abort_pacifier() for an example.
@@ -406,6 +413,8 @@ int burn_abort(int patience,
/** A pacifier function suitable for burn_abort.
@param handle If not NULL, a pointer to a text suitable for printf("%s")
@param patience Maximum number of seconds to wait
@param elapsed Elapsed number of seconds
*/
int burn_abort_pacifier(void *handle, int patience, int elapsed);
@@ -1071,6 +1080,29 @@ int burn_msgs_obtain(char *minimum_severity,
char severity[]);
/* ts A61002 */
/* The prototype of a handler function suitable for burn_set_abort_handling().
Such a function has to return -2 if it does not want the process to
exit with value 1.
*/
typedef int (*burn_abort_handler_t)(void *handle, int signum, int flag);
/** Control builtin signal handling. See also burn_abort().
@param handle Opaque handle eventually pointing to an application
provided memory object
@param handler A function to be called on signals. It will get handle as
argument. It should finally call burn_abort(). See there.
@param mode : 0 call handler(handle, signum, 0) on nearly all signals
1 enable system default reaction on all signals
2 try to ignore nearly all signals
10 like mode 2 but handle SIGABRT like with mode 0
Arguments (text, NULL, 0) activate the builtin abort handler. It will
eventually call burn_abort() and then perform exit(1). If text is not NULL
then it is used as prefix for pacifier messages of burn_abort_pacifier().
*/
void burn_set_signal_handling(void *handle, burn_abort_handler_t handler,
int mode);
#ifndef DOXYGEN
BURN_END_DECLS

30
test/libburner.c
View File

@@ -16,6 +16,8 @@
Before you can do anything, you have to initialize libburn by
burn_initialize()
and provide some signal and abort handling, e.g. by the builtin handler, by
burn_set_signal_handling()
as it is done in main() at the end of this file. Then you aquire a
drive in an appropriate way conforming to the API. The two main
approaches are shown here in application functions:
@@ -248,10 +250,8 @@ int libburner_aquire_by_driveno(int *driveno)
To our knowledge it is hardly possible to abort an ongoing blank operation
because after start it is entirely handled by the drive.
So expect a blank run to survive the end of the blanking process and be
patient for the usual timespan of a normal blank run. Only after that
time has surely elapsed, only then you should start any rescue attempts
with the drive. If necessary at all.
So expect signal handling to wait the normal blanking timespan until it
can allow the process to end. External kill -9 will not help the drive.
*/
int libburner_blank_disc(struct burn_drive *drive, int blank_fast)
{
@@ -322,25 +322,11 @@ int libburner_regrab(struct burn_drive *drive) {
/** Brings the preformatted image (ISO 9660, afio, ext2, whatever) onto media.
To make sure your image is fully readable on any Linux machine, this
function adds 300 kB of padding to the track.
Without a signal handler it is quite dangerous to abort the process
while this function is active. See cdrskin/cdrskin.c and its usage
of cdrskin/cleanup.[ch] for an example of application provided
abort handling. It must cope with 2 of 3 threads reporting for
being handled.
Without signal handler have ready a command line
cdrecord dev=... -reset
with a dev= previously inquired by cdrecord [dev=ATA] -scanbus
in order to get your drive out of shock state after raw abort.
Thanks to Joerg Schilling for helping out unquestioned. :)
In general, libburn is less prone to system problems than cdrecord,
i believe. But cdrecord had long years of time to complete itself.
We are still practicing. Help us with that. :))
In case of external signals expect abort handling of an ongoing burn to
last up to a minute. Wait the normal burning timespan before any kill -9.
*/
int libburner_payload(struct burn_drive *drive, const char *source_adr,
off_t size)
@@ -590,6 +576,10 @@ int main(int argc, char **argv)
exit(33);
}
/* Activate the default signal handler which eventually will try to
properly shutdown drive and library on aborting events. */
burn_set_signal_handling("libburner : ", NULL, 0);
/** Note: driveno might change its value in this call */
ret = libburner_aquire_drive(drive_adr, &driveno);
if (ret<=0) {