| |
|`KC_NONUS_HASH` |`KC_NUHS` |Non-US `#` and `~` |
|`KC_SCOLON` |`KC_SCLN` |`;` and `:` |
|`KC_QUOTE` |`KC_QUOT` |`'` and `"` |
|`KC_GRAVE` |`KC_GRV`, `KC_ZKHK` |` and `~`, JIS Zenkaku/Hankaku|
|`KC_COMMA` |`KC_COMM` |`,` and `<` |
|`KC_DOT` | |`.` and `>` |
|`KC_SLASH` |`KC_SLSH` |`/` and `?` |
|`KC_CAPSLOCK` |`KC_CLCK`, `KC_CAPS` |Caps Lock |
|`KC_F1` | |F1 |
|`KC_F2` | |F2 |
|`KC_F3` | |F3 |
|`KC_F4` | |F4 |
|`KC_F5` | |F5 |
|`KC_F6` | |F6 |
|`KC_F7` | |F7 |
|`KC_F8` | |F8 |
|`KC_F9` | |F9 |
|`KC_F10` | |F10 |
|`KC_F11` | |F11 |
|`KC_F12` | |F12 |
|`KC_PSCREEN` |`KC_PSCR` |Print Screen |
|`KC_SCROLLLOCK` |`KC_SLCK`, `KC_BRMD` |Scroll Lock, Brightness Down (macOS) |
|`KC_PAUSE` |`KC_PAUS`, `KC_BRK`, `KC_BRMU`|Pause, Brightness Up (macOS) |
|`KC_INSERT` |`KC_INS` |Insert |
|`KC_HOME` | |Home |
|`KC_PGUP` | |Page Up |
|`KC_DELETE` |`KC_DEL` |Forward Delete |
|`KC_END` | |End |
|`KC_PGDOWN` |`KC_PGDN` |Page Down |
|`KC_RIGHT` |`KC_RGHT` |Right Arrow |
|`KC_LEFT` | |Left Arrow |
|`KC_DOWN` | |Down Arrow |
|`KC_UP` | |Up Arrow |
|`KC_NUMLOCK` |`KC_NLCK` |Keypad Num Lock and Clear |
|`KC_KP_SLASH` |`KC_PSLS` |Keypad `/` |
|`KC_KP_ASTERISK` |`KC_PAST` |Keypad `*` |
|`KC_KP_MINUS` |`KC_PMNS` |Keypad `-` |
|`KC_KP_PLUS` |`KC_PPLS` |Keypad `+` |
|`KC_KP_ENTER` |`KC_PENT` |Keypad Enter |
|`KC_KP_1` |`KC_P1` |Keypad `1` and End |
|`KC_KP_2` |`KC_P2` |Keypad `2` and Down Arrow |
|`KC_KP_3` |`KC_P3` |Keypad `3` and Page Down |
|`KC_KP_4` |`KC_P4` |Keypad `4` and Left Arrow |
|`KC_KP_5` |`KC_P5` |Keypad `5` |
|`KC_KP_6` |`KC_P6` |Keypad `6` and Right Arrow |
|`KC_KP_7` |`KC_P7` |Keypad `7` and Home |
|`KC_KP_8` |`KC_P8` |Keypad `8` and Up Arrow |
|`KC_KP_9` |`KC_P9` |Keypad `9` and Page Up |
|`KC_KP_0` |`KC_P0` |Keypad `0` and Insert |
|`KC_KP_DOT` |`KC_PDOT` |Keypad `.` and Delete |
|`KC_NONUS_BSLASH` |`KC_NUBS` |Non-US `\` and | |
|`KC_APPLICATION` |`KC_APP` |Application (Windows Menu Key) |
|`KC_POWER` | |System Power (macOS) |
|`KC_KP_EQUAL` |`KC_PEQL` |Keypad `=` |
|`KC_F13` | |F13 |
|`KC_F14` | |F14 |
|`KC_F15` | |F15 |
|`KC_F16` | |F16 |
|`KC_F17` | |F17 |
|`KC_F18` | |F18 |
|`KC_F19` | |F19 |
|`KC_F20` | |F20 |
|`KC_F21` | |F21 |
|`KC_F22` | |F22 |
|`KC_F23` | |F23 |
|`KC_F24` | |F24 |
|`KC_EXECUTE` |`KC_EXEC` |Execute |
|`KC_HELP` | |Help |
|`KC_MENU` | |Menu |
|`KC_SELECT` |`KC_SLCT` |Select |
|`KC_STOP` | |Stop |
|`KC_AGAIN` |`KC_AGIN` |Again |
|`KC_UNDO` | |Undo |
|`KC_CUT` | |Cut |
|`KC_COPY` | |Copy |
|`KC_PASTE` |`KC_PSTE` |Paste |
|`KC_FIND` | |Find |
|`KC__MUTE` | |Mute (macOS) |
|`KC__VOLUP` | |Volume Up (macOS) |
|`KC__VOLDOWN` | |Volume Down (macOS) |
|`KC_LOCKING_CAPS` |`KC_LCAP` |Locking Caps Lock |
|`KC_LOCKING_NUM` |`KC_LNUM` |Locking Num Lock |
|`KC_LOCKING_SCROLL` |`KC_LSCR` |Locking Scroll Lock |
|`KC_KP_COMMA` |`KC_PCMM` |Keypad `,` |
|`KC_KP_EQUAL_AS400` | |Keypad `=` on AS/400 keyboards |
|`KC_INT1` |`KC_RO` |JIS `\` and `_` |
|`KC_INT2` |`KC_KANA` |JIS Katakana/Hiragana |
|`KC_INT3` |`KC_JYEN` |JIS `¥` and | |
|`KC_INT4` |`KC_HENK` |JIS Henkan |
|`KC_INT5` |`KC_MHEN` |JIS Muhenkan |
|`KC_INT6` | |JIS Numpad `,` |
|`KC_INT7` | |International 7 |
|`KC_INT8` | |International 8 |
|`KC_INT9` | |International 9 |
|`KC_LANG1` |`KC_HAEN` |Hangul/English |
|`KC_LANG2` |`KC_HANJ` |Hanja |
|`KC_LANG3` | |JIS Katakana |
|`KC_LANG4` | |JIS Hiragana |
|`KC_LANG5` | |JIS Zenkaku/Hankaku |
|`KC_LANG6` | |Language 6 |
|`KC_LANG7` | |Language 7 |
|`KC_LANG8` | |Language 8 |
|`KC_LANG9` | |Language 9 |
|`KC_ALT_ERASE` |`KC_ERAS` |Alternate Erase |
|`KC_SYSREQ` | |SysReq/Attention |
|`KC_CANCEL` | |Cancel |
|`KC_CLEAR` |`KC_CLR` |Clear |
|`KC_PRIOR` | |Prior |
|`KC_RETURN` | |Return |
|`KC_SEPARATOR` | |Separator |
|`KC_OUT` | |Out |
|`KC_OPER` | |Oper |
|`KC_CLEAR_AGAIN` | |Clear/Again |
|`KC_CRSEL` | |CrSel/Props |
|`KC_EXSEL` | |ExSel |
|`KC_LCTRL` |`KC_LCTL` |Left Control |
|`KC_LSHIFT` |`KC_LSFT` |Left Shift |
|`KC_LALT` | |Left Alt |
|`KC_LGUI` |`KC_LCMD`, `KC_LWIN` |Left GUI (Windows/Command/Meta key) |
|`KC_RCTRL` |`KC_RCTL` |Right Control |
|`KC_RSHIFT` |`KC_RSFT` |Right Shift |
|`KC_RALT` |`KC_ALGR` |Right Alt (AltGr) |
|`KC_RGUI` |`KC_RCMD`, `KC_RWIN` |Right GUI (Windows/Command/Meta key) |
|`KC_SYSTEM_POWER` |`KC_PWR` |System Power Down |
|`KC_SYSTEM_SLEEP` |`KC_SLEP` |System Sleep |
|`KC_SYSTEM_WAKE` |`KC_WAKE` |System Wake |
|`KC_AUDIO_MUTE` |`KC_MUTE` |Mute |
|`KC_AUDIO_VOL_UP` |`KC_VOLU` |Volume Up |
|`KC_AUDIO_VOL_DOWN` |`KC_VOLD` |Volume Down |
|`KC_MEDIA_NEXT_TRACK` |`KC_MNXT` |Next Track (Windows) |
|`KC_MEDIA_PREV_TRACK` |`KC_MPRV` |Previous Track (Windows) |
|`KC_MEDIA_STOP` |`KC_MSTP` |Stop Track (Windows) |
|`KC_MEDIA_PLAY_PAUSE` |`KC_MPLY` |Play/Pause Track |
|`KC_MEDIA_SELECT` |`KC_MSEL` |Launch Media Player (Windows) |
|`KC_MEDIA_EJECT` |`KC_EJCT` |Eject (macOS) |
|`KC_MAIL` | |Launch Mail (Windows) |
|`KC_CALCULATOR` |`KC_CALC` |Launch Calculator (Windows) |
|`KC_MY_COMPUTER` |`KC_MYCM` |Launch My Computer (Windows) |
|`KC_WWW_SEARCH` |`KC_WSCH` |Browser Search (Windows) |
|`KC_WWW_HOME` |`KC_WHOM` |Browser Home (Windows) |
|`KC_WWW_BACK` |`KC_WBAK` |Browser Back (Windows) |
|`KC_WWW_FORWARD` |`KC_WFWD` |Browser Forward (Windows) |
|`KC_WWW_STOP` |`KC_WSTP` |Browser Stop (Windows) |
|`KC_WWW_REFRESH` |`KC_WREF` |Browser Refresh (Windows) |
|`KC_WWW_FAVORITES` |`KC_WFAV` |Browser Favorites (Windows) |
|`KC_MEDIA_FAST_FORWARD`|`KC_MFFD` |Next Track (macOS) /*
ChibiOS - Copyright (C) 2006..2016 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chmboxes.c
* @brief Mailboxes code.
*
* @addtogroup mailboxes
* @details Asynchronous messages.
* <h2>Operation mode</h2>
* A mailbox is an asynchronous communication mechanism.<br>
* Operations defined for mailboxes:
* - <b>Post</b>: Posts a message on the mailbox in FIFO order.
* - <b>Post Ahead</b>: Posts a message on the mailbox with urgent
* priority.
* - <b>Fetch</b>: A message is fetched from the mailbox and removed
* from the queue.
* - <b>Reset</b>: The mailbox is emptied and all the stored messages
* are lost.
* .
* A message is a variable of type msg_t that is guaranteed to have
* the same size of and be compatible with (data) pointers (anyway an
* explicit cast is needed).
* If larger messages need to be exchanged then a pointer to a
* structure can be posted in the mailbox but the posting side has
* no predefined way to know when the message has been processed. A
* possible approach is to allocate memory (from a memory pool for
* example) from the posting side and free it on the fetching side.
* Another approach is to set a "done" flag into the structure pointed
* by the message.
* @pre In order to use the mailboxes APIs the @p CH_CFG_USE_MAILBOXES
* option must be enabled in @p chconf.h.
* @note Compatible with RT and NIL.
* @{
*/
#include "ch.h"
#if (CH_CFG_USE_MAILBOXES == TRUE) || defined(__DOXYGEN__)
/*===========================================================================*/
/* Module exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local types. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Module exported functions. */
/*===========================================================================*/
/**
* @brief Initializes a @p mailbox_t object.
*
* @param[out] mbp the pointer to the @p mailbox_t structure to be
* initialized
* @param[in] buf pointer to the messages buffer as an array of @p msg_t
* @param[in] n number of elements in the buffer array
*
* @init
*/
void chMBObjectInit(mailbox_t *mbp, msg_t *buf, size_t n) {
chDbgCheck((mbp != NULL) && (buf != NULL) && (n > (size_t)0));
mbp->buffer = buf;
mbp->rdptr = buf;
mbp->wrptr = buf;
mbp->top = &buf[n];
mbp->cnt = (size_t)0;
mbp->reset = false;
chThdQueueObjectInit(&mbp->qw);
chThdQueueObjectInit(&mbp->qr);
}
/**
* @brief Resets a @p mailbox_t object.
* @details All the waiting threads are resumed with status @p MSG_RESET and
* the queued messages are lost.
* @post The mailbox is in reset state, all operations will fail and
* return @p MSG reset until the mailbox is enabled again using
* @p chMBResumeX().
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
*
* @api
*/
void chMBReset(mailbox_t *mbp) {
chSysLock();
chMBResetI(mbp);
chSchRescheduleS();
chSysUnlock();
}
/**
* @brief Resets a @p mailbox_t object.
* @details All the waiting threads are resumed with status @p MSG_RESET and
* the queued messages are lost.
* @post The mailbox is in reset state, all operations will fail and
* return @p MSG reset until the mailbox is enabled again using
* @p chMBResumeX().
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
*
* @api
*/
void chMBResetI(mailbox_t *mbp) {
chDbgCheckClassI();
chDbgCheck(mbp != NULL);
mbp->wrptr = mbp->buffer;
mbp->rdptr = mbp->buffer;
mbp->cnt = (size_t)0;
mbp->reset = true;
chThdDequeueAllI(&mbp->qw, MSG_RESET);
chThdDequeueAllI(&mbp->qr, MSG_RESET);
}
/**
* @brief Posts a message into a mailbox.
* @details The invoking thread waits until a empty slot in the mailbox becomes
* available or the specified time runs out.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[in] msg the message to be posted on the mailbox
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval MSG_OK if a message has been correctly posted.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @api
*/
msg_t chMBPostTimeout(mailbox_t *mbp, msg_t msg, sysinterval_t timeout) {
msg_t rdymsg;
chSysLock();
rdymsg = chMBPostTimeoutS(mbp, msg, timeout);
chSysUnlock();
return rdymsg;
}
/**
* @brief Posts a message into a mailbox.
* @details The invoking thread waits until a empty slot in the mailbox becomes
* available or the specified time runs out.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[in] msg the message to be posted on the mailbox
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval MSG_OK if a message has been correctly posted.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @sclass
*/
msg_t chMBPostTimeoutS(mailbox_t *mbp, msg_t msg, sysinterval_t timeout) {
msg_t rdymsg;
chDbgCheckClassS();
chDbgCheck(mbp != NULL);
do {
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a free message slot in queue? if so then post.*/
if (chMBGetFreeCountI(mbp) > (size_t)0) {
*mbp->wrptr++ = msg;
if (mbp->wrptr >= mbp->top) {
mbp->wrptr = mbp->buffer;
}
mbp->cnt++;
/* If there is a reader waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qr, MSG_OK);
chSchRescheduleS();
return MSG_OK;
}
/* No space in the queue, waiting for a slot to become available.*/
rdymsg = chThdEnqueueTimeoutS(&mbp->qw, timeout);
} while (rdymsg == MSG_OK);
return rdymsg;
}
/**
* @brief Posts a message into a mailbox.
* @details This variant is non-blocking, the function returns a timeout
* condition if the queue is full.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[in] msg the message to be posted on the mailbox
* @return The operation status.
* @retval MSG_OK if a message has been correctly posted.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the mailbox is full and the message cannot be
* posted.
*
* @iclass
*/
msg_t chMBPostI(mailbox_t *mbp, msg_t msg) {
chDbgCheckClassI();
chDbgCheck(mbp != NULL);
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a free message slot in queue? if so then post.*/
if (chMBGetFreeCountI(mbp) > (size_t)0) {
*mbp->wrptr++ = msg;
if (mbp->wrptr >= mbp->top) {
mbp->wrptr = mbp->buffer;
}
mbp->cnt++;
/* If there is a reader waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qr, MSG_OK);
return MSG_OK;
}
/* No space, immediate timeout.*/
return MSG_TIMEOUT;
}
/**
* @brief Posts an high priority message into a mailbox.
* @details The invoking thread waits until a empty slot in the mailbox becomes
* available or the specified time runs out.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[in] msg the message to be posted on the mailbox
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval MSG_OK if a message has been correctly posted.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @api
*/
msg_t chMBPostAheadTimeout(mailbox_t *mbp, msg_t msg, sysinterval_t timeout) {
msg_t rdymsg;
chSysLock();
rdymsg = chMBPostAheadTimeoutS(mbp, msg, timeout);
chSysUnlock();
return rdymsg;
}
/**
* @brief Posts an high priority message into a mailbox.
* @details The invoking thread waits until a empty slot in the mailbox becomes
* available or the specified time runs out.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[in] msg the message to be posted on the mailbox
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval MSG_OK if a message has been correctly posted.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @sclass
*/
msg_t chMBPostAheadTimeoutS(mailbox_t *mbp, msg_t msg, sysinterval_t timeout) {
msg_t rdymsg;
chDbgCheckClassS();
chDbgCheck(mbp != NULL);
do {
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a free message slot in queue? if so then post.*/
if (chMBGetFreeCountI(mbp) > (size_t)0) {
if (--mbp->rdptr < mbp->buffer) {
mbp->rdptr = mbp->top - 1;
}
*mbp->rdptr = msg;
mbp->cnt++;
/* If there is a reader waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qr, MSG_OK);
chSchRescheduleS();
return MSG_OK;
}
/* No space in the queue, waiting for a slot to become available.*/
rdymsg = chThdEnqueueTimeoutS(&mbp->qw, timeout);
} while (rdymsg == MSG_OK);
return rdymsg;
}
/**
* @brief Posts an high priority message into a mailbox.
* @details This variant is non-blocking, the function returns a timeout
* condition if the queue is full.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[in] msg the message to be posted on the mailbox
* @return The operation status.
* @retval MSG_OK if a message has been correctly posted.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the mailbox is full and the message cannot be
* posted.
*
* @iclass
*/
msg_t chMBPostAheadI(mailbox_t *mbp, msg_t msg) {
chDbgCheckClassI();
chDbgCheck(mbp != NULL);
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a free message slot in queue? if so then post.*/
if (chMBGetFreeCountI(mbp) > (size_t)0) {
if (--mbp->rdptr < mbp->buffer) {
mbp->rdptr = mbp->top - 1;
}
*mbp->rdptr = msg;
mbp->cnt++;
/* If there is a reader waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qr, MSG_OK);
return MSG_OK;
}
/* No space, immediate timeout.*/
return MSG_TIMEOUT;
}
/**
* @brief Retrieves a message from a mailbox.
* @details The invoking thread waits until a message is posted in the mailbox
* or the specified time runs out.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[out] msgp pointer to a message variable for the received message
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval MSG_OK if a message has been correctly fetched.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @api
*/
msg_t chMBFetchTimeout(mailbox_t *mbp, msg_t *msgp, sysinterval_t timeout) {
msg_t rdymsg;
chSysLock();
rdymsg = chMBFetchTimeoutS(mbp, msgp, timeout);
chSysUnlock();
return rdymsg;
}
/**
* @brief Retrieves a message from a mailbox.
* @details The invoking thread waits until a message is posted in the mailbox
* or the specified time runs out.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[out] msgp pointer to a message variable for the received message
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval MSG_OK if a message has been correctly fetched.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @sclass
*/
msg_t chMBFetchTimeoutS(mailbox_t *mbp, msg_t *msgp, sysinterval_t timeout) {
msg_t rdymsg;
chDbgCheckClassS();
chDbgCheck((mbp != NULL) && (msgp != NULL));
do {
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a message in queue? if so then fetch.*/
if (chMBGetUsedCountI(mbp) > (size_t)0) {
*msgp = *mbp->rdptr++;
if (mbp->rdptr >= mbp->top) {
mbp->rdptr = mbp->buffer;
}
mbp->cnt--;
/* If there is a writer waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qw, MSG_OK);
chSchRescheduleS();
return MSG_OK;
}
/* No message in the queue, waiting for a message to become available.*/
rdymsg = chThdEnqueueTimeoutS(&mbp->qr, timeout);
} while (rdymsg == MSG_OK);
return rdymsg;
}
/**
* @brief Retrieves a message from a mailbox.
* @details This variant is non-blocking, the function returns a timeout
* condition if the queue is empty.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[out] msgp pointer to a message variable for the received message
* @return The operation status.
* @retval MSG_OK if a message has been correctly fetched.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the mailbox is empty and a message cannot be
* fetched.
*
* @iclass
*/
msg_t chMBFetchI(mailbox_t *mbp, msg_t *msgp) {
chDbgCheckClassI();
chDbgCheck((mbp != NULL) && (msgp != NULL));
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a message in queue? if so then fetch.*/
if (chMBGetUsedCountI(mbp) > (size_t)0) {
*msgp = *mbp->rdptr++;
if (mbp->rdptr >= mbp->top) {
mbp->rdptr = mbp->buffer;
}
mbp->cnt--;
/* If there is a writer waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qw, MSG_OK);
return MSG_OK;
}
/* No message, immediate timeout.*/
return MSG_TIMEOUT;
}
#endif /* CH_CFG_USE_MAILBOXES == TRUE */
/** @} */