path: root/mail/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)
 */

#include <config.h>

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

#include <glib.h>
#include <gtk/gtk.h>

#include <libedataserver/e-flag.h>

#include <shell/e-shell-view.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 void
mail_msg_cancelled (CamelOperation *operation,
                    gpointer user_data)
{
    mail_msg_cancel (GPOINTER_TO_UINT (user_data));
}

static gboolean
mail_msg_submit (EActivity *activity)
{
    EShell *shell;
    EShellBackend *shell_backend;

    shell = e_shell_get_default ();
    shell_backend = e_shell_get_backend_by_name (
        shell, shell_builtin_backend);

    e_shell_backend_add_activity (shell_backend, activity);

    return FALSE;
}

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

    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->activity = e_activity_new ();

    cancellable = camel_operation_new ();

    e_activity_set_percent (msg->activity, 0.0);
    e_activity_set_cancellable (msg->activity, cancellable);

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

    g_object_unref (cancellable);

    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)
{
    EShell *shell;
    EShellBackend *shell_backend;

    /* This is an idle callback. */

    shell = e_shell_get_default ();
    shell_backend = e_shell_get_backend_by_name (
        shell, shell_builtin_backend);

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

    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_add (&mail_msg->ref_count, 1);
    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_exchange_and_add (&mail_msg->ref_count, -1) > 1)
        return;

#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)
{
    EShell *shell;
    EShellView *shell_view;
    EShellWindow *shell_window = NULL;
    EShellContent *shell_content;
    MailMsg *m = msg;
    gchar *what;
    GList *list, *iter;

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

    if (g_error_matches (m->error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
        e_activity_set_state (m->activity, E_ACTIVITY_CANCELLED);
        return;
    }

    e_activity_set_state (m->activity, E_ACTIVITY_COMPLETED);

    if (m->error == NULL)
        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 the source code this time. */
    if (g_error_matches (m->error, CAMEL_FOLDER_ERROR, CAMEL_FOLDER_ERROR_INVALID_UID))
        return;

    shell = e_shell_get_default ();

    /* Find the most recently used EShellWindow. */
    list =  e_shell_get_watched_windows (shell);
    for (iter = list; iter != NULL; iter = g_list_next (iter)) {
        if (E_IS_SHELL_WINDOW (iter->data)) {
            shell_window = E_SHELL_WINDOW (iter->data);
            break;
        }
    }

    /* If we can't find an EShellWindow then... well, screw it. */
    if (shell_window == NULL)
        return;

    shell_view = e_shell_window_get_shell_view (
        shell_window, shell_builtin_backend);
    shell_content = e_shell_view_get_shell_content (shell_view);

    if (m->info->desc && (what = m->info->desc (m))) {
        e_alert_submit (
            GTK_WIDGET (shell_content),
            "mail:async-error", what,
            m->error->message, NULL);
        g_free (what);
    } else
        e_alert_submit (
            GTK_WIDGET (shell_content),
            "mail:async-error-nodescribe",
            m->error->message, NULL);
}

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 = e_activity_get_cancellable (msg->activity);
        if (g_cancellable_is_cancelled (cancellable))
            cancellable = NULL;
        else
            g_object_ref (cancellable);
    }

    g_mutex_unlock (mail_msg_lock);

    if (cancellable != NULL) {
        camel_operation_cancel (CAMEL_OPERATION (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 (NULL);

    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 = e_activity_get_cancellable (msg->activity);

        g_idle_add_full (
            G_PRIORITY_DEFAULT,
            (GSourceFunc) mail_msg_submit,
            g_object_ref (msg->activity),
            (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 = e_activity_get_cancellable (msg->activity);

    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->activity),
        (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)
{
    mail_msg_lock = g_mutex_new ();
    mail_msg_cond = g_cond_new ();

    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;
    }

    e_activity_set_state (
        m->base.activity,
        g_cancellable_is_cancelled (cancellable) ?
        E_ACTIVITY_CANCELLED : E_ACTIVITY_COMPLETED);

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

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

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 = e_activity_get_cancellable (m->base.activity);

    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;
}