Signal library

Manage signal handlers. More...

Collaboration diagram for Signal library:

Typedefs
typedef void(*	GNUNET_SIGNAL_Handler) (void)
	A signal handler. More...

Functions
struct GNUNET_SIGNAL_Context *	GNUNET_SIGNAL_handler_install (int signal, GNUNET_SIGNAL_Handler handler)
	Install a signal handler that will be run if the given signal is received. More...
void	GNUNET_SIGNAL_handler_uninstall (struct GNUNET_SIGNAL_Context *ctx)
	Uninstall a previously installed signal handler. More...
void	GNUNET_SIGNAL_raise (const int sig)
	Raise the given signal by calling the installed signal handlers. More...

Detailed Description

Manage signal handlers.

Typedef Documentation

GNUNET_SIGNAL_Handler

typedef void(* GNUNET_SIGNAL_Handler) (void)

A signal handler.

Since different OSes have different signatures for their handlers, the API only gives the most restrictive signature – no arguments, no return value. Note that this will work even if the OS expects a function with arguments. However, the implementation must guarantee that this handler is not called for signals other than the one that it has been registered for.

Definition at line 66 of file gnunet_signal_lib.h.

Function Documentation

GNUNET_SIGNAL_handler_install()

struct GNUNET_SIGNAL_Context * GNUNET_SIGNAL_handler_install	(	int	signal,
		GNUNET_SIGNAL_Handler	handler
	)

Install a signal handler that will be run if the given signal is received.

Parameters

signal	the number of the signal
handler	the function to call

Returns

context that can be used to restore, NULL on error

Definition at line 52 of file signal.c.

{
  struct GNUNET_SIGNAL_Context *ret;
 
  struct sigaction sig;
 
  ret = GNUNET_new (struct GNUNET_SIGNAL_Context);
  ret->sig = signum;
  ret->method = handler;
 
  memset (&sig, 0, sizeof(sig));
  sig.sa_handler = (void *) handler;
  sigemptyset (&sig.sa_mask);
#ifdef SA_INTERRUPT
  sig.sa_flags = SA_INTERRUPT;  /* SunOS */
#else
  sig.sa_flags = SA_RESTART;
#endif
  sigaction (signum, &sig, &ret->oldsig);
 
  GNUNET_CONTAINER_DLL_insert_tail (sc_head, sc_tail, ret);
  return ret;
}

References GNUNET_CONTAINER_DLL_insert_tail, GNUNET_new, ret, sc_head, and sc_tail.

Referenced by child_management_start(), GNUNET_SCHEDULER_driver_init(), and main().

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GNUNET_SIGNAL_handler_uninstall()

void GNUNET_SIGNAL_handler_uninstall

(

struct GNUNET_SIGNAL_Context *

ctx

)

Uninstall a previously installed signal handler.

Parameters

ctx	context that was returned when the signal handler was installed

Definition at line 78 of file signal.c.

{
  struct sigaction sig;
 
  sigemptyset (&sig.sa_mask);
  sigaction (ctx->sig, &ctx->oldsig, &sig);
 
  GNUNET_CONTAINER_DLL_remove (sc_head, sc_tail, ctx);
  GNUNET_free (ctx);
}

References ctx, GNUNET_CONTAINER_DLL_remove, GNUNET_free, sc_head, and sc_tail.

Referenced by child_management_done(), GNUNET_SCHEDULER_driver_done(), and main().

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GNUNET_SIGNAL_raise()

void GNUNET_SIGNAL_raise

(

const int

sig

)

Raise the given signal by calling the installed signal handlers.

This will not use the raise() system call but only calls the handlers registered through GNUNET_SIGNAL_handler_install().

Parameters

sig	the signal to raise

Definition at line 98 of file signal.c.

{
  struct GNUNET_SIGNAL_Context *ctx;
 
  for (ctx = sc_head; NULL != ctx; ctx = ctx->next)
  {
    if (sig != ctx->sig)
      continue;
    if (NULL == ctx->method)
      continue;
    ctx->method ();
  }
}

References ctx, sc_head, and GNUNET_SIGNAL_Context::sig.

Referenced by parent_control_handler().

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