path: root/libemail-engine/mail-mt.c

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include <gtk/gtk.h>

#include <libedataserver/libedataserver.h>

#include "mail-mt.h"

/*#define MALLOC_CHECK*/
#define d(x)

/* XXX This is a dirty hack on a dirty hack.  We really need
 *     to rework or get rid of the functions that use this. */
const gchar *shell_builtin_backend = "mail";

static guint mail_msg_seq; /* sequence number of each message */

/* Table of active messages.  Must hold mail_msg_lock to access. */
static GHashTable *mail_msg_active_table;
static GMutex mail_msg_lock;
static GCond mail_msg_cond;

static MailMsgCreateActivityFunc create_activity = NULL;
static MailMsgSubmitActivityFunc submit_activity = NULL;
static MailMsgFreeActivityFunc free_activity = NULL;
static MailMsgCompleteActivityFunc complete_activity = NULL;
static MailMsgAlertErrorFunc alert_error = NULL;
static MailMsgCancelActivityFunc cancel_activity = NULL;
static MailMsgGetAlertSinkFunc get_alert_sink = NULL;

void
mail_msg_register_activities (MailMsgCreateActivityFunc acreate,
                              MailMsgSubmitActivityFunc asubmit,
                              MailMsgFreeActivityFunc freeact,
                              MailMsgCompleteActivityFunc comp_act,
                              MailMsgCancelActivityFunc cancel_act,
                              MailMsgAlertErrorFunc ealert,
                              MailMsgGetAlertSinkFunc ealertsink)
{
    /* XXX This is an utter hack to keep EActivity out
     *     of EDS and still let Evolution do EActivity. */
    create_activity = acreate;
    submit_activity = asubmit;
    free_activity = freeact;
    complete_activity = comp_act;
    cancel_activity = cancel_act;
    alert_error = ealert;
    get_alert_sink = ealertsink;
}

EAlertSink *
mail_msg_get_alert_sink ()
{
    if (get_alert_sink)
        return get_alert_sink ();

    return NULL;
}

static void
mail_msg_cancelled (CamelOperation *operation,
                    gpointer user_data)
{
    mail_msg_cancel (GPOINTER_TO_UINT (user_data));
}

static gboolean
mail_msg_submit (CamelOperation *cancellable)
{

    if (submit_activity)
        submit_activity ((GCancellable *) cancellable);
    return FALSE;
}

gpointer
mail_msg_new (MailMsgInfo *info)
{
    MailMsg *msg;

    g_mutex_lock (&mail_msg_lock);

    msg = g_slice_alloc0 (info->size);
    msg->info = info;
    msg->ref_count = 1;
    msg->seq = mail_msg_seq++;

    msg->cancellable = camel_operation_new ();

    if (create_activity)
        create_activity (msg->cancellable);

    g_signal_connect (
        msg->cancellable, "cancelled",
        G_CALLBACK (mail_msg_cancelled),
        GINT_TO_POINTER (msg->seq));

    g_hash_table_insert (
        mail_msg_active_table, GINT_TO_POINTER (msg->seq), msg);

    d (printf ("New message %p\n", msg));

    g_mutex_unlock (&mail_msg_lock);

    return msg;
}

#ifdef MALLOC_CHECK
#include <mcheck.h>

static void
checkmem (gpointer p)
{
    if (p) {
        gint status = mprobe (p);

        switch (status) {
        case MCHECK_HEAD:
            printf ("Memory underrun at %p\n", p);
            abort ();
        case MCHECK_TAIL:
            printf ("Memory overrun at %p\n", p);
            abort ();
        case MCHECK_FREE:
            printf ("Double free %p\n", p);
            abort ();
        }
    }
}
#endif

static gboolean
mail_msg_free (MailMsg *mail_msg)
{
    /* This is an idle callback. */

    if (free_activity)
        free_activity (mail_msg->cancellable);

    if (mail_msg->cancellable != NULL)
        g_object_unref (mail_msg->cancellable);

    if (mail_msg->error != NULL)
        g_error_free (mail_msg->error);

    g_slice_free1 (mail_msg->info->size, mail_msg);

    return FALSE;
}

gpointer
mail_msg_ref (gpointer msg)
{
    MailMsg *mail_msg = msg;

    g_return_val_if_fail (mail_msg != NULL, msg);
    g_return_val_if_fail (mail_msg->ref_count > 0, msg);

    g_atomic_int_inc (&mail_msg->ref_count);

    return msg;
}

void
mail_msg_unref (gpointer msg)
{
    MailMsg *mail_msg = msg;

    g_return_if_fail (mail_msg != NULL);
    g_return_if_fail (mail_msg->ref_count > 0);

    if (g_atomic_int_dec_and_test (&mail_msg->ref_count)) {

#ifdef MALLOC_CHECK
        checkmem (mail_msg);
        checkmem (mail_msg->cancel);
        checkmem (mail_msg->priv);
#endif
        d (printf ("Free message %p\n", msg));

        if (mail_msg->info->free)
            mail_msg->info->free (mail_msg);

        g_mutex_lock (&mail_msg_lock);

        g_hash_table_remove (
            mail_msg_active_table,
            GINT_TO_POINTER (mail_msg->seq));
        g_cond_broadcast (&mail_msg_cond);

        g_mutex_unlock (&mail_msg_lock);

        /* Destroy the message from an idle callback
         * so we know we're in the main loop thread. */
        g_idle_add ((GSourceFunc) mail_msg_free, mail_msg);
    }
}

void
mail_msg_check_error (gpointer msg)
{
    MailMsg *m = msg;

#ifdef MALLOC_CHECK
    checkmem (m);
    checkmem (m->cancel);
    checkmem (m->priv);
#endif

    if (m->error == NULL)
        return;

    if (complete_activity)
        complete_activity (m->cancellable);

    if (g_error_matches (m->error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
        if (cancel_activity)
            cancel_activity (m->cancellable);
        return;
    }

    /* XXX Hmm, no explanation of why this is needed.  It looks like
     *     a lame hack and will be removed at some point, if only to
     *     reintroduce whatever issue made this necessary so we can
     *     document it in the source code this time. */
    if (g_error_matches (
        m->error, CAMEL_FOLDER_ERROR,
        CAMEL_FOLDER_ERROR_INVALID_UID))
        return;

    /* FIXME: Submit an error on the dbus */
    if (alert_error) {
        gchar *what;

        if (m->info->desc && (what = m->info->desc (m))) {
            alert_error (m->cancellable, what, m->error->message);
            g_free (what);
        } else
            alert_error (m->cancellable, NULL, m->error->message);
    }
}

void
mail_msg_cancel (guint msgid)
{
    MailMsg *msg;
    GCancellable *cancellable = NULL;

    g_mutex_lock (&mail_msg_lock);

    msg = g_hash_table_lookup (
        mail_msg_active_table, GINT_TO_POINTER (msgid));

    /* Hold a reference to the GCancellable so it doesn't finalize
     * itself on us between unlocking the mutex and cancelling. */
    if (msg != NULL) {
        cancellable = msg->cancellable;
        if (g_cancellable_is_cancelled (cancellable))
            cancellable = NULL;
        else
            g_object_ref (cancellable);
    }

    g_mutex_unlock (&mail_msg_lock);

    if (cancellable != NULL) {
        g_cancellable_cancel (cancellable);
        g_object_unref (cancellable);
    }
}

gboolean
mail_msg_active (void)
{
    gboolean active;

    g_mutex_lock (&mail_msg_lock);
    active = g_hash_table_size (mail_msg_active_table) > 0;
    g_mutex_unlock (&mail_msg_lock);

    return active;
}

/* **************************************** */

static GHookList cancel_hook_list;

GHook *
mail_cancel_hook_add (GHookFunc func,
                      gpointer data)
{
    GHook *hook;

    g_mutex_lock (&mail_msg_lock);

    if (!cancel_hook_list.is_setup)
        g_hook_list_init (&cancel_hook_list, sizeof (GHook));

    hook = g_hook_alloc (&cancel_hook_list);
    hook->func = func;
    hook->data = data;

    g_hook_append (&cancel_hook_list, hook);

    g_mutex_unlock (&mail_msg_lock);

    return hook;
}

void
mail_cancel_hook_remove (GHook *hook)
{
    g_mutex_lock (&mail_msg_lock);

    g_return_if_fail (cancel_hook_list.is_setup);
    g_hook_destroy_link (&cancel_hook_list, hook);

    g_mutex_unlock (&mail_msg_lock);
}

void
mail_cancel_all (void)
{
    camel_operation_cancel_all ();

    g_mutex_lock (&mail_msg_lock);

    if (cancel_hook_list.is_setup)
        g_hook_list_invoke (&cancel_hook_list, FALSE);

    g_mutex_unlock (&mail_msg_lock);
}

static guint idle_source_id = 0;
G_LOCK_DEFINE_STATIC (idle_source_id);
static GAsyncQueue *main_loop_queue = NULL;
static GAsyncQueue *msg_reply_queue = NULL;
static GThread *main_thread = NULL;

static gboolean
mail_msg_idle_cb (void)
{
    MailMsg *msg;

    g_return_val_if_fail (main_loop_queue != NULL, FALSE);
    g_return_val_if_fail (msg_reply_queue != NULL, FALSE);

    G_LOCK (idle_source_id);
    idle_source_id = 0;
    G_UNLOCK (idle_source_id);
    /* check the main loop queue */
    while ((msg = g_async_queue_try_pop (main_loop_queue)) != NULL) {
        GCancellable *cancellable;

        cancellable = msg->cancellable;

        g_idle_add_full (
            G_PRIORITY_DEFAULT,
            (GSourceFunc) mail_msg_submit,
            g_object_ref (msg->cancellable),
            (GDestroyNotify) g_object_unref);
        if (msg->info->exec != NULL)
            msg->info->exec (msg, cancellable, &msg->error);
        if (msg->info->done != NULL)
            msg->info->done (msg);
        mail_msg_unref (msg);
    }

    /* check the reply queue */
    while ((msg = g_async_queue_try_pop (msg_reply_queue)) != NULL) {
        if (msg->info->done != NULL)
            msg->info->done (msg);
        mail_msg_check_error (msg);
        mail_msg_unref (msg);
    }
    return FALSE;
}

static void
mail_msg_proxy (MailMsg *msg)
{
    GCancellable *cancellable;

    cancellable = msg->cancellable;

    if (msg->info->desc != NULL) {
        gchar *text = msg->info->desc (msg);
        camel_operation_push_message (cancellable, "%s", text);
        g_free (text);
    }

    g_idle_add_full (
        G_PRIORITY_DEFAULT,
        (GSourceFunc) mail_msg_submit,
        g_object_ref (msg->cancellable),
        (GDestroyNotify) g_object_unref);

    if (msg->info->exec != NULL)
        msg->info->exec (msg, cancellable, &msg->error);

    if (msg->info->desc != NULL)
        camel_operation_pop_message (cancellable);

    g_async_queue_push (msg_reply_queue, msg);

    G_LOCK (idle_source_id);
    if (idle_source_id == 0)
        idle_source_id = g_idle_add (
            (GSourceFunc) mail_msg_idle_cb, NULL);
    G_UNLOCK (idle_source_id);
}

void
mail_msg_init (void)
{
    g_mutex_init (&mail_msg_lock);
    g_cond_init (&mail_msg_cond);

    main_loop_queue = g_async_queue_new ();
    msg_reply_queue = g_async_queue_new ();

    mail_msg_active_table = g_hash_table_new (NULL, NULL);
    main_thread = g_thread_self ();
}

static gint
mail_msg_compare (const MailMsg *msg1,
                  const MailMsg *msg2)
{
    gint priority1 = msg1->priority;
    gint priority2 = msg2->priority;

    if (priority1 == priority2)
        return 0;

    return (priority1 < priority2) ? 1 : -1;
}

static gpointer
create_thread_pool (gpointer data)
{
    GThreadPool *thread_pool;
    gint max_threads = GPOINTER_TO_INT (data);

    /* once created, run forever */
    thread_pool = g_thread_pool_new (
        (GFunc) mail_msg_proxy, NULL, max_threads, FALSE, NULL);
    g_thread_pool_set_sort_function (
        thread_pool, (GCompareDataFunc) mail_msg_compare, NULL);

    return thread_pool;
}

void
mail_msg_main_loop_push (gpointer msg)
{
    g_async_queue_push_sorted (
        main_loop_queue, msg,
        (GCompareDataFunc) mail_msg_compare, NULL);

    G_LOCK (idle_source_id);
    if (idle_source_id == 0)
        idle_source_id = g_idle_add (
            (GSourceFunc) mail_msg_idle_cb, NULL);
    G_UNLOCK (idle_source_id);
}

void
mail_msg_unordered_push (gpointer msg)
{
    static GOnce once = G_ONCE_INIT;

    g_once (&once, (GThreadFunc) create_thread_pool, GINT_TO_POINTER (10));

    g_thread_pool_push ((GThreadPool *) once.retval, msg, NULL);
}

void
mail_msg_fast_ordered_push (gpointer msg)
{
    static GOnce once = G_ONCE_INIT;

    g_once (&once, (GThreadFunc) create_thread_pool, GINT_TO_POINTER (1));

    g_thread_pool_push ((GThreadPool *) once.retval, msg, NULL);
}

void
mail_msg_slow_ordered_push (gpointer msg)
{
    static GOnce once = G_ONCE_INIT;

    g_once (&once, (GThreadFunc) create_thread_pool, GINT_TO_POINTER (1));

    g_thread_pool_push ((GThreadPool *) once.retval, msg, NULL);
}

gboolean
mail_in_main_thread (void)
{
    return (g_thread_self () == main_thread);
}

/* ********************************************************************** */

struct _call_msg {
    MailMsg base;

    mail_call_t type;
    MailMainFunc func;
    gpointer ret;
    va_list ap;
    EFlag *done;
};

static void
do_call (struct _call_msg *m,
         GCancellable *cancellable,
         GError **error)
{
    gpointer p1, *p2, *p3, *p4, *p5;
    gint i1;
    va_list ap;

    G_VA_COPY (ap, m->ap);

    switch (m->type) {
    case MAIL_CALL_p_p:
        p1 = va_arg (ap, gpointer);
        m->ret = m->func (p1);
        break;
    case MAIL_CALL_p_pp:
        p1 = va_arg (ap, gpointer);
        p2 = va_arg (ap, gpointer);
        m->ret = m->func (p1, p2);
        break;
    case MAIL_CALL_p_ppp:
        p1 = va_arg (ap, gpointer);
        p2 = va_arg (ap, gpointer);
        p3 = va_arg (ap, gpointer);
        m->ret = m->func (p1, p2, p3);
        break;
    case MAIL_CALL_p_pppp:
        p1 = va_arg (ap, gpointer);
        p2 = va_arg (ap, gpointer);
        p3 = va_arg (ap, gpointer);
        p4 = va_arg (ap, gpointer);
        m->ret = m->func (p1, p2, p3, p4);
        break;
    case MAIL_CALL_p_ppppp:
        p1 = va_arg (ap, gpointer);
        p2 = va_arg (ap, gpointer);
        p3 = va_arg (ap, gpointer);
        p4 = va_arg (ap, gpointer);
        p5 = va_arg (ap, gpointer);
        m->ret = m->func (p1, p2, p3, p4, p5);
        break;
    case MAIL_CALL_p_ppippp:
        p1 = va_arg (ap, gpointer);
        p2 = va_arg (ap, gpointer);
        i1 = va_arg (ap, gint);
        p3 = va_arg (ap, gpointer);
        p4 = va_arg (ap, gpointer);
        p5 = va_arg (ap, gpointer);
        m->ret = m->func (p1, p2, i1, p3, p4, p5);
        break;
    }

    va_end (ap);

    if (g_cancellable_is_cancelled (cancellable)) {
        if (cancel_activity)
            cancel_activity (cancellable);
    } else {
        if (complete_activity)
            complete_activity (cancellable);
    }

    if (m->done != NULL)
        e_flag_set (m->done);
}

static void
do_free (struct _call_msg *msg)
{
    va_end (msg->ap);
}

static MailMsgInfo mail_call_info = {
    sizeof (struct _call_msg),
    (MailMsgDescFunc) NULL,
    (MailMsgExecFunc) do_call,
    (MailMsgDoneFunc) NULL,
    (MailMsgFreeFunc) do_free
};

gpointer
mail_call_main (mail_call_t type,
                MailMainFunc func,
                ...)
{
    GCancellable *cancellable;
    struct _call_msg *m;
    gpointer ret;
    va_list ap;

    va_start (ap, func);

    m = mail_msg_new (&mail_call_info);
    m->type = type;
    m->func = func;
    G_VA_COPY (m->ap, ap);

    cancellable = m->base.cancellable;

    if (mail_in_main_thread ())
        do_call (m, cancellable, &m->base.error);
    else {
        mail_msg_ref (m);
        m->done = e_flag_new ();
        mail_msg_main_loop_push (m);
        e_flag_wait (m->done);
        e_flag_free (m->done);
    }

    va_end (ap);

    ret = m->ret;
    mail_msg_unref (m);

    return ret;
}

void
mail_mt_set_backend (gchar *backend)
{
    shell_builtin_backend = backend;
}