Initial C++ conversion

event.cpp

@@ -0,0 +1,731 @@
+/** \file event.c
+
+	Functions for handling event triggers
+
+*/
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <wchar.h>
+#include <unistd.h>
+#include <termios.h>
+#include <signal.h>
+#include <string.h>
+
+#include "fallback.h"
+#include "util.h"
+
+#include "wutil.h"
+#include "function.h"
+#include "proc.h"
+#include "parser.h"
+#include "common.h"
+#include "event.h"
+#include "signal.h"
+
+#include "halloc_util.h"
+
+/**
+   Number of signals that can be queued before an overflow occurs
+*/
+#define SIG_UNHANDLED_MAX 64
+
+/**
+   This struct contains a list of generated signals waiting to be
+   dispatched
+*/
+typedef struct
+{
+	/**
+	   Number of delivered signals
+	*/
+	int count;
+	/**
+	   Whether signals have been skipped
+	*/
+	int overflow;
+	/**
+	   Array of signal events
+	*/
+	int signal[SIG_UNHANDLED_MAX];
+}
+	signal_list_t;
+
+/**
+  The signal event list. Actually two separate lists. One which is
+  active, which is the one that new events is written to. The inactive
+  one contains the events that are currently beeing performed.
+*/
+static signal_list_t sig_list[]={{0,0},{0,0}};
+
+/**
+   The index of sig_list that is the list of signals currently written to
+*/
+static int active_list=0;
+
+/**
+   List of event handlers
+*/
+static array_list_t *events;
+/**
+   List of event handlers that should be removed
+*/
+static array_list_t *killme;
+
+/**
+   List of events that have been sent but have not yet been delivered because they are blocked.
+*/
+static array_list_t *blocked;
+
+/**
+   Tests if one event instance matches the definition of a event
+   class. If both the class and the instance name a function,
+   they must name the same function.
+
+*/
+static int event_match( event_t *class, event_t *instance )
+{
+
+	if( class->function_name && instance->function_name )
+	{
+		if( wcscmp( class->function_name, instance->function_name ) != 0 )
+			return 0;
+	}
+
+	if( class->type == EVENT_ANY )
+		return 1;
+
+	if( class->type != instance->type )
+		return 0;
+
+
+	switch( class->type )
+	{
+
+		case EVENT_SIGNAL:
+			if( class->param1.signal == EVENT_ANY_SIGNAL )
+				return 1;
+			return class->param1.signal == instance->param1.signal;
+
+		case EVENT_VARIABLE:
+			return wcscmp( instance->param1.variable,
+				       class->param1.variable )==0;
+
+		case EVENT_EXIT:
+			if( class->param1.pid == EVENT_ANY_PID )
+				return 1;
+			return class->param1.pid == instance->param1.pid;
+
+		case EVENT_JOB_ID:
+			return class->param1.job_id == instance->param1.job_id;
+
+		case EVENT_GENERIC:
+			return wcscmp( instance->param1.param,
+				       class->param1.param )==0;
+
+	}
+
+	/**
+	   This should never be reached
+	*/
+	return 0;
+}
+
+
+/**
+   Create an identical copy of an event. Use deep copying, i.e. make
+   duplicates of any strings used as well.
+*/
+static event_t *event_copy( event_t *event, int copy_arguments )
+{
+	event_t *e = malloc( sizeof( event_t ) );
+
+	if( !e )
+		DIE_MEM();
+
+	memcpy( e, event, sizeof(event_t));
+
+	if( e->function_name )
+		e->function_name = wcsdup( e->function_name );
+
+	if( e->type == EVENT_VARIABLE )
+		e->param1.variable = wcsdup( e->param1.variable );
+	else if( e->type == EVENT_GENERIC )
+		e->param1.param = wcsdup( e->param1.param );
+
+	al_init( &e->arguments );
+	if( copy_arguments )
+	{
+		int i;
+		for( i=0; i<al_get_count( &event->arguments ); i++ )
+		{
+			al_push( &e->arguments, wcsdup( (wchar_t *)al_get( &event->arguments, i ) ) );
+		}
+
+	}
+
+	return e;
+}
+
+/**
+   Test if specified event is blocked
+*/
+static int event_is_blocked( event_t *e )
+{
+	block_t *block;
+	event_block_t *eb;
+
+	for( block = current_block; block; block = block->outer )
+	{
+		for( eb = block->first_event_block; eb; eb=eb->next )
+		{
+			if( eb->type & (1<<EVENT_ANY ) )
+				return 1;
+			if( eb->type & (1<<e->type) )
+				return 1;
+		}
+	}
+	for( eb = global_event_block; eb; eb=eb->next )
+	{
+		if( eb->type & (1<<EVENT_ANY ) )
+			return 1;
+		if( eb->type & (1<<e->type) )
+			return 1;
+		return 1;
+
+	}
+
+	return 0;
+}
+
+const wchar_t *event_get_desc( event_t *e )
+{
+
+	/*
+	  String buffer used for formating event descriptions in event_get_desc()
+	*/
+	static string_buffer_t *get_desc_buff=0;
+
+	CHECK( e, 0 );
+
+	if( !get_desc_buff )
+	{
+		get_desc_buff=sb_halloc( global_context );
+	}
+	else
+	{
+		sb_clear( get_desc_buff );
+	}
+
+	switch( e->type )
+	{
+
+		case EVENT_SIGNAL:
+			sb_printf( get_desc_buff, _(L"signal handler for %ls (%ls)"), sig2wcs(e->param1.signal ), signal_get_desc( e->param1.signal ) );
+			break;
+
+		case EVENT_VARIABLE:
+			sb_printf( get_desc_buff, _(L"handler for variable '%ls'"), e->param1.variable );
+			break;
+
+		case EVENT_EXIT:
+			if( e->param1.pid > 0 )
+			{
+				sb_printf( get_desc_buff, _(L"exit handler for process %d"), e->param1.pid );
+			}
+			else
+			{
+				job_t *j = job_get_from_pid( -e->param1.pid );
+				if( j )
+					sb_printf( get_desc_buff, _(L"exit handler for job %d, '%ls'"), j->job_id, j->command );
+				else
+					sb_printf( get_desc_buff, _(L"exit handler for job with process group %d"), -e->param1.pid );
+			}
+
+			break;
+
+		case EVENT_JOB_ID:
+		{
+			job_t *j = job_get( e->param1.job_id );
+			if( j )
+				sb_printf( get_desc_buff, _(L"exit handler for job %d, '%ls'"), j->job_id, j->command );
+			else
+				sb_printf( get_desc_buff, _(L"exit handler for job with job id %d"), j->job_id );
+
+			break;
+		}
+
+		case EVENT_GENERIC:
+			sb_printf( get_desc_buff, _(L"handler for generic event '%ls'"), e->param1.param );
+			break;
+
+		default:
+			sb_printf( get_desc_buff, _(L"Unknown event type") );
+			break;
+
+	}
+
+	return (const wchar_t *)get_desc_buff->buff;
+}
+
+
+void event_add_handler( event_t *event )
+{
+	event_t *e;
+
+	CHECK( event, );
+
+	e = event_copy( event, 0 );
+
+	if( !events )
+		events = al_new();
+
+	if( e->type == EVENT_SIGNAL )
+	{
+		signal_handle( e->param1.signal, 1 );
+	}
+
+	al_push( events, e );
+}
+
+void event_remove( event_t *criterion )
+{
+	int i;
+	array_list_t *new_list=0;
+	event_t e;
+
+	CHECK( criterion, );
+
+	/*
+	  Because of concurrency issues (env_remove could remove an event
+	  that is currently being executed), env_remove does not actually
+	  free any events - instead it simply moves all events that should
+	  be removed from the event list to the killme list, and the ones
+	  that shouldn't be killed to new_list, and then drops the empty
+	  events-list.
+	*/
+
+	if( !events )
+		return;
+
+	for( i=0; i<al_get_count( events); i++ )
+	{
+		event_t *n = (event_t *)al_get( events, i );
+		if( event_match( criterion, n ) )
+		{
+			if( !killme )
+				killme = al_new();
+
+			al_push( killme, n );
+
+			/*
+			  If this event was a signal handler and no other handler handles
+			  the specified signal type, do not handle that type of signal any
+			  more.
+			*/
+			if( n->type == EVENT_SIGNAL )
+			{
+				e.type = EVENT_SIGNAL;
+				e.param1.signal = n->param1.signal;
+				e.function_name = 0;
+
+				if( event_get( &e, 0 ) == 1 )
+				{
+					signal_handle( e.param1.signal, 0 );
+				}
+			}
+		}
+		else
+		{
+			if( !new_list )
+				new_list = al_new();
+			al_push( new_list, n );
+		}
+	}
+	al_destroy( events );
+	free( events );
+	events = new_list;
+}
+
+int event_get( event_t *criterion, array_list_t *out )
+{
+	int i;
+	int found = 0;
+
+	if( !events )
+		return 0;
+
+	CHECK( criterion, 0 );
+
+	for( i=0; i<al_get_count( events); i++ )
+	{
+		event_t *n = (event_t *)al_get( events, i );
+		if( event_match(criterion, n ) )
+		{
+			found++;
+			if( out )
+				al_push( out, n );
+		}
+	}
+	return found;
+}
+
+/**
+   Free all events in the kill list
+*/
+static void event_free_kills()
+{
+	int i;
+	if( !killme )
+		return;
+
+	for( i=0; i<al_get_count( killme ); i++ )
+	{
+		event_t *roadkill = (event_t *)al_get( killme, i );
+		event_free( roadkill );
+	}
+	al_truncate( killme, 0 );
+}
+
+/**
+   Test if the specified event is waiting to be killed
+*/
+static int event_is_killed( event_t *e )
+{
+	int i;
+	if( !killme )
+		return 0;
+
+	for( i=0; i<al_get_count( killme ); i++ )
+	{
+		event_t *roadkill = (event_t *)al_get( events, i );
+		if( roadkill ==e )
+			return 1;
+
+	}
+	return 0;
+}
+
+/**
+   Perform the specified event. Since almost all event firings will
+   not be matched by even a single event handler, we make sure to
+   optimize the 'no matches' path. This means that nothing is
+   allocated/initialized unless needed.
+*/
+static void event_fire_internal( event_t *event )
+{
+	int i, j;
+	string_buffer_t *b=0;
+	array_list_t *fire=0;
+
+	/*
+	  First we free all events that have been removed
+	*/
+	event_free_kills();
+
+	if( !events )
+		return;
+
+	/*
+	  Then we iterate over all events, adding events that should be
+	  fired to a second list. We need to do this in a separate step
+	  since an event handler might call event_remove or
+	  event_add_handler, which will change the contents of the \c
+	  events list.
+	*/
+	for( i=0; i<al_get_count( events ); i++ )
+	{
+		event_t *criterion = (event_t *)al_get( events, i );
+
+		/*
+		  Check if this event is a match
+		*/
+		if(event_match( criterion, event ) )
+		{
+			if( !fire )
+				fire = al_new();
+			al_push( fire, criterion );
+		}
+	}
+
+	/*
+	  No matches. Time to return.
+	*/
+	if( !fire )
+		return;
+
+	/*
+	  Iterate over our list of matching events
+	*/
+
+	for( i=0; i<al_get_count( fire ); i++ )
+	{
+		event_t *criterion = (event_t *)al_get( fire, i );
+		int prev_status;
+
+		/*
+		  Check if this event has been removed, if so, dont fire it
+		*/
+		if( event_is_killed( criterion ) )
+			continue;
+
+		/*
+		  Fire event
+		*/
+		if( !b )
+			b = sb_new();
+		else
+			sb_clear( b );
+
+		sb_append( b, criterion->function_name );
+
+		for( j=0; j<al_get_count(&event->arguments); j++ )
+		{
+			wchar_t *arg_esc = escape( (wchar_t *)al_get( &event->arguments, j), 1 );
+			sb_append( b, L" " );
+			sb_append( b, arg_esc );
+			free( arg_esc );
+		}
+
+//		debug( 1, L"Event handler fires command '%ls'", (wchar_t *)b->buff );
+
+		/*
+		  Event handlers are not part of the main flow of code, so
+		  they are marked as non-interactive
+		*/
+		proc_push_interactive(0);
+		prev_status = proc_get_last_status();
+		parser_push_block( EVENT );
+		current_block->param1.event = event;
+		eval( (wchar_t *)b->buff, 0, TOP );
+		parser_pop_block();
+		proc_pop_interactive();
+		proc_set_last_status( prev_status );
+	}
+
+	if( b )
+	{
+		sb_destroy( b );
+		free( b );
+	}
+
+	if( fire )
+	{
+		al_destroy( fire );
+		free( fire );
+	}
+
+	/*
+	  Free killed events
+	*/
+	event_free_kills();
+
+}
+
+/**
+   Handle all pending signal events
+*/
+static void event_fire_delayed()
+{
+
+	int i;
+
+	/*
+	  If is_event is one, we are running the event-handler non-recursively.
+
+	  When the event handler has called a piece of code that triggers
+	  another event, we do not want to fire delayed events because of
+	  concurrency problems.
+	*/
+	if( blocked && is_event==1)
+	{
+		array_list_t *new_blocked = 0;
+
+		for( i=0; i<al_get_count( blocked ); i++ )
+		{
+			event_t *e = (event_t *)al_get( blocked, i );
+			if( event_is_blocked( e ) )
+			{
+				if( !new_blocked )
+					new_blocked = al_new();
+				al_push( new_blocked, e );
+			}
+			else
+			{
+				event_fire_internal( e );
+				event_free( e );
+			}
+		}
+		al_destroy( blocked );
+		free( blocked );
+		blocked = new_blocked;
+	}
+
+	while( sig_list[active_list].count > 0 )
+	{
+		signal_list_t *lst;
+		event_t e;
+		al_init( &e.arguments );
+
+		/*
+		  Switch signal lists
+		*/
+		sig_list[1-active_list].count=0;
+		sig_list[1-active_list].overflow=0;
+		active_list=1-active_list;
+
+		/*
+		  Set up
+		*/
+		e.type=EVENT_SIGNAL;
+		e.function_name=0;
+
+		lst = &sig_list[1-active_list];
+
+		if( lst->overflow )
+		{
+			debug( 0, _( L"Signal list overflow. Signals have been ignored." ) );
+		}
+
+		/*
+		  Send all signals in our private list
+		*/
+		for( i=0; i<lst->count; i++ )
+		{
+			e.param1.signal = lst->signal[i];
+			al_set( &e.arguments, 0, sig2wcs( e.param1.signal ) );
+			if( event_is_blocked( &e ) )
+			{
+				if( !blocked )
+					blocked = al_new();
+				al_push( blocked, event_copy(&e, 1) );
+			}
+			else
+			{
+				event_fire_internal( &e );
+			}
+		}
+
+		al_destroy( &e.arguments );
+
+	}
+}
+
+
+void event_fire( event_t *event )
+{
+	is_event++;
+
+	if( event && (event->type == EVENT_SIGNAL) )
+	{
+		/*
+		  This means we are in a signal handler. We must be very
+		  careful not do do anything that could cause a memory
+		  allocation or something else that might be bad when in a
+		  signal handler.
+		*/
+		if( sig_list[active_list].count < SIG_UNHANDLED_MAX )
+			sig_list[active_list].signal[sig_list[active_list].count++]=event->param1.signal;
+		else
+			sig_list[active_list].overflow=1;
+	}
+	else
+	{
+		/*
+		  Fire events triggered by signals
+		*/
+		event_fire_delayed();
+
+		if( event )
+		{
+			if( event_is_blocked( event ) )
+			{
+				if( !blocked )
+					blocked = al_new();
+
+				al_push( blocked, event_copy(event, 1) );
+			}
+			else
+			{
+				event_fire_internal( event );
+			}
+		}
+
+	}
+	is_event--;
+}
+
+
+void event_init()
+{
+}
+
+void event_destroy()
+{
+
+	if( events )
+	{
+		al_foreach( events, (void (*)(void *))&event_free );
+		al_destroy( events );
+		free( events );
+		events=0;
+	}
+
+	if( killme )
+	{
+		al_foreach( killme, (void (*)(void *))&event_free );
+		al_destroy( killme );
+		free( killme );
+		killme=0;
+	}
+}
+
+void event_free( event_t *e )
+{
+	CHECK( e, );
+
+	/*
+	  When apropriate, we clear the argument vector
+	*/
+	al_foreach( &e->arguments, &free );
+	al_destroy( &e->arguments );
+
+	free( (void *)e->function_name );
+	if( e->type == EVENT_VARIABLE )
+	{
+		free( (void *)e->param1.variable );
+	}
+	else if( e->type == EVENT_GENERIC )
+	{
+		free( (void *)e->param1.param );
+	}
+	free( e );
+}
+
+
+void event_fire_generic_internal(const wchar_t *name, ...)
+{
+	event_t ev;
+	va_list va;
+	wchar_t *arg;
+
+	CHECK( name, );
+
+	ev.type = EVENT_GENERIC;
+	ev.param1.param = name;
+	ev.function_name=0;
+
+	al_init( &ev.arguments );
+	va_start( va, name );
+	while( (arg=va_arg(va, wchar_t *) )!= 0 )
+	{
+		al_push( &ev.arguments, arg );
+	}
+	va_end( va );
+
+	event_fire( &ev );
+}
+
+
+