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A bunch of changes working towards eliminating all memory allocation after fork()

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This commit is contained in:
ridiculousfish
2012-03-08 23:21:07 -08:00
parent ce859c9e92
commit d173bb6e0a
15 changed files with 251 additions and 129 deletions
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97
postfork.cpp
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@@ -20,17 +20,27 @@
#define OPEN_MASK 0666
/** fork error message */
#define FORK_ERROR _( L"Could not create child process - exiting" )
#define FORK_ERROR "Could not create child process - exiting"
/** file redirection clobbering error message */
#define NOCLOB_ERROR _( L"The file '%ls' already exists" )
#define NOCLOB_ERROR "The file '%s' already exists"
/** file redirection error message */
#define FILE_ERROR _( L"An error occurred while redirecting file '%ls'" )
#define FILE_ERROR "An error occurred while redirecting file '%s'"
/** file descriptor redirection error message */
#define FD_ERROR _( L"An error occurred while redirecting file descriptor %d" )
#define FD_ERROR "An error occurred while redirecting file descriptor %s"
/** pipe error */
#define LOCAL_PIPE_ERROR "An error occurred while setting up pipe"
/* Cover for debug_safe that can take an int. The format string should expect a %s */
static void debug_safe_int(int level, const char *format, int val)
{
char buff[128];
format_long_safe(buff, val);
debug_safe(level, format, buff);
}
// PCA These calls to debug are rather sketchy because they may allocate memory. Fortunately they only occur if an error occurs.
int set_child_group( job_t *j, process_t *p, int print_errors )
@@ -48,15 +58,25 @@ int set_child_group( job_t *j, process_t *p, int print_errors )
{
if( getpgid( p->pid) != j->pgid && print_errors )
{
char pid_buff[128];
char job_id_buff[128];
char getpgid_buff[128];
char job_pgid_buff[128];
format_long_safe(pid_buff, p->pid);
format_long_safe(job_id_buff, j->job_id);
format_long_safe(getpgid_buff, getpgid( p->pid));
format_long_safe(job_pgid_buff, j->pgid);
// PCA FIXME This is sketchy to do in a forked child because it may allocate memory. This needs to call only safe functions.
debug( 1,
_( L"Could not send process %d, '%ls' in job %d, '%ls' from group %d to group %d" ),
p->pid,
p->argv0(),
j->job_id,
debug_safe( 1,
"Could not send process %s, '%s' in job %s, '%s' from group %s to group %s",
pid_buff,
p->argv0_cstr(),
job_id_buff,
j->command_cstr(),
getpgid( p->pid),
j->pgid );
getpgid_buff,
job_pgid_buff );
wperror( L"setpgid" );
res = -1;
@@ -72,9 +92,9 @@ int set_child_group( job_t *j, process_t *p, int print_errors )
{
if( tcsetpgrp (0, j->pgid) && print_errors )
{
debug( 1, _( L"Could not send job %d ('%ls') to foreground" ),
j->job_id,
j->command_cstr() );
char job_id_buff[128];
format_long_safe(job_id_buff, j->job_id);
debug_safe( 1, "Could not send job %s ('%s') to foreground", job_id_buff, j->command_cstr() );
wperror( L"tcsetpgrp" );
res = -1;
}
@@ -102,9 +122,7 @@ static void free_fd( io_data_t *io, int fd )
{
if( errno != EINTR )
{
debug( 1,
FD_ERROR,
fd );
debug_safe_int( 1, FD_ERROR, fd );
wperror( L"dup" );
FATAL_EXIT();
}
@@ -161,7 +179,7 @@ static int handle_child_io( io_data_t *io )
{
if( close(io->fd) )
{
debug( 0, _(L"Failed to close file descriptor %d"), io->fd );
debug_safe_int( 0, "Failed to close file descriptor %s", io->fd );
wperror( L"close" );
}
break;
@@ -170,23 +188,18 @@ static int handle_child_io( io_data_t *io )
case IO_FILE:
{
// Here we definitely do not want to set CLO_EXEC because our child needs access
if( (tmp=wopen( io->filename,
if( (tmp=open( io->filename_cstr,
io->param2.flags, OPEN_MASK ) )==-1 )
{
if( ( io->param2.flags & O_EXCL ) &&
( errno ==EEXIST ) )
{
debug( 1,
NOCLOB_ERROR,
io->filename.c_str() );
debug_safe( 1, NOCLOB_ERROR, io->filename_cstr );
}
else
{
debug( 1,
FILE_ERROR,
io->filename.c_str() );
wperror( L"open" );
debug_safe( 1, FILE_ERROR, io->filename_cstr );
perror( "open" );
}
return -1;
@@ -201,10 +214,8 @@ static int handle_child_io( io_data_t *io )
if(dup2( tmp, io->fd ) == -1 )
{
debug( 1,
FD_ERROR,
io->fd );
wperror( L"dup2" );
debug_safe_int( 1, FD_ERROR, io->fd );
perror( "dup2" );
return -1;
}
exec_close( tmp );
@@ -222,9 +233,7 @@ static int handle_child_io( io_data_t *io )
if( dup2( io->param1.old_fd, io->fd ) == -1 )
{
debug( 1,
FD_ERROR,
io->fd );
debug_safe_int( 1, FD_ERROR, io->fd );
wperror( L"dup2" );
return -1;
}
@@ -248,8 +257,8 @@ static int handle_child_io( io_data_t *io )
*/
if( dup2( io->param1.pipe_fd[write_pipe], io->fd ) != io->fd )
{
debug( 1, PIPE_ERROR );
wperror( L"dup2" );
debug_safe( 1, LOCAL_PIPE_ERROR );
perror( "dup2" );
return -1;
}
@@ -275,24 +284,24 @@ static int handle_child_io( io_data_t *io )
int setup_child_process( job_t *j, process_t *p )
{
int res=0;
bool ok=true;
if( p )
{
res = set_child_group( j, p, 1 );
ok = (0 == set_child_group( j, p, 1 ));
}
if( !res )
if( ok )
{
res = handle_child_io( j->io );
if( p != 0 && res )
ok = (0 == handle_child_io( j->io ));
if( p != 0 && ! ok )
{
exit_without_destructors( 1 );
}
}
/* Set the handling for job control signals back to the default. */
if( !res )
if( ok )
{
signal_reset_handlers();
}
@@ -300,7 +309,7 @@ int setup_child_process( job_t *j, process_t *p )
/* Remove all signal blocks */
signal_unblock();
return res;
return ok ? 0 : -1;
}
@@ -353,7 +362,7 @@ pid_t execute_fork(bool wait_for_threads_to_die)
}
}
debug( 0, FORK_ERROR );
debug_safe( 0, FORK_ERROR );
wperror (L"fork");
FATAL_EXIT();
return 0;