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Posted to commits@nuttx.apache.org by ac...@apache.org on 2020/03/29 14:58:48 UTC
[incubator-nuttx] branch master updated: "Uninterruptible"
semaphore waits must return when canceled.
This is an automated email from the ASF dual-hosted git repository.
acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new 0558aa0 "Uninterruptible" semaphore waits must return when canceled.
0558aa0 is described below
commit 0558aa0a78de7c62181bdf8514716f8f4f384f15
Author: Gregory Nutt <gn...@nuttx.org>
AuthorDate: Sun Mar 29 11:56:18 2020 -0300
"Uninterruptible" semaphore waits must return when canceled.
nxsem_timedwait_uninterruptible() must return -ECANCELED if the thread is canceled:
include/nuttx/semaphore.h: Return if nxsem_wait() returns ECANCELED meaning that the thread waiting for the semaphore has been canceled.
sched/semaphore/sem_timedwait.c: Same change (the inline version is in semaphore.h, the non-inlined version is in sem_tickwait.c).
drivers/sensors/lps25h.c and drivers/wireless/bluetooth/bt_uart_bcm4343x.c: Make sure that the caller deals correctly with the -ECANCELED return value.
Refer to issue 619.
---
drivers/sensors/lps25h.c | 33 ++++++------
drivers/wireless/bluetooth/bt_uart_bcm4343x.c | 22 ++++----
include/nuttx/semaphore.h | 78 +++++++++++++--------------
include/nuttx/sensors/lps25h.h | 4 +-
sched/semaphore/sem_tickwait.c | 50 +++++++----------
sched/semaphore/sem_timedwait.c | 43 ++++++---------
6 files changed, 102 insertions(+), 128 deletions(-)
diff --git a/drivers/sensors/lps25h.c b/drivers/sensors/lps25h.c
index 109443e..34a0bb2 100644
--- a/drivers/sensors/lps25h.c
+++ b/drivers/sensors/lps25h.c
@@ -69,8 +69,8 @@
* for conversion times:
*
* Typical conversion time ≈ 62*(Pavg+Tavg) + 975 μs
- * ex: Tavg = 64; Pavg = 512; Typ. conversation time ≈ 36.7 ms (compatible with
- * ODT=25 Hz)
+ * ex: Tavg = 64; Pavg = 512; Typ. conversation time ≈ 36.7 ms
+ * (compatible with ODT=25 Hz)
* ex: Tavg = 32; Pavg = 128; Typ. conversation time ≈ 10.9 ms
* The formula is accurate within +/- 3% at room temperature
*
@@ -155,10 +155,10 @@ enum LPS25H_RES_CONF_AVG_TEMP
enum LPS25H_CTRL_REG1_ODR
{
CTRL_REG1_ODR_ONE_SHOT = 0,
- CTRL_REG1_ODR_1Hz,
- CTRL_REG1_ODR_7Hz,
- CTRL_REG1_ODR_12_5Hz,
- CTRL_REG1_ODR_25Hz
+ CTRL_REG1_ODR_1HZ,
+ CTRL_REG1_ODR_7HZ,
+ CTRL_REG1_ODR_12_5HZ,
+ CTRL_REG1_ODR_25HZ
};
enum LPS25H_CTRL_REG4_P1
@@ -196,9 +196,9 @@ enum LPS25H_INT_CFG_OP
LIR = 0x4
};
-/************************************************************************************
+/****************************************************************************
* Private Function Prototypes
- ************************************************************************************/
+ ****************************************************************************/
static int lps25h_open(FAR struct file *filep);
static int lps25h_close(FAR struct file *filep);
@@ -413,7 +413,7 @@ static ssize_t lps25h_read(FAR struct file *filep, FAR char *buffer,
{
/* This interface is mainly intended for easy debugging in nsh. */
- length = snprintf(buffer, buflen, "%u\n", data.pressure_Pa);
+ length = snprintf(buffer, buflen, "%u\n", data.pressure_pa);
if (length > buflen)
{
length = buflen;
@@ -486,7 +486,7 @@ static int lps25h_configure_dev(FAR struct lps25h_dev_s *dev)
/* Write CTRL_REG1 to turn device on */
ret = lps25h_write_reg8(dev, LPS25H_CTRL_REG1,
- LPS25H_PD | (CTRL_REG1_ODR_1Hz << 4));
+ LPS25H_PD | (CTRL_REG1_ODR_1HZ << 4));
return ret;
}
@@ -570,7 +570,7 @@ static int lps25h_one_shot(FAR struct lps25h_dev_s *dev)
{
/* Some unknown mystery error */
- DEBUGASSERT(false);
+ DEBUGASSERT(ret == -ECANCELED);
return ret;
}
@@ -635,10 +635,13 @@ static int lps25h_read_pressure(FAR struct lps25h_dev_s *dev,
/* Convert to more usable format. */
- pres->pressure_int_hP = pres_res / LPS25H_PRESSURE_INTERNAL_DIVIDER;
- pres->pressure_Pa = (uint64_t)pres_res * 100000 / LPS25H_PRESSURE_INTERNAL_DIVIDER;
- pres->raw_data = pres_res;
- lps25h_dbg("Pressure: %u Pa\n", pres->pressure_Pa);
+ pres->pressure_int_hp =
+ pres_res / LPS25H_PRESSURE_INTERNAL_DIVIDER;
+ pres->pressure_pa = (uint64_t)
+ pres_res * 100000 / LPS25H_PRESSURE_INTERNAL_DIVIDER;
+ pres->raw_data = pres_res;
+
+ lps25h_dbg("Pressure: %u Pa\n", pres->pressure_pa);
return ret;
}
diff --git a/drivers/wireless/bluetooth/bt_uart_bcm4343x.c b/drivers/wireless/bluetooth/bt_uart_bcm4343x.c
index 9378769..609298f 100644
--- a/drivers/wireless/bluetooth/bt_uart_bcm4343x.c
+++ b/drivers/wireless/bluetooth/bt_uart_bcm4343x.c
@@ -107,7 +107,6 @@ extern const uint8_t g_bt_firmware_hcd[];
static void hciuart_cb(FAR const struct btuart_lowerhalf_s *lower,
FAR void *param)
-
{
FAR sem_t *rxsem = (FAR sem_t *)param;
@@ -138,7 +137,6 @@ static int uartwriteconf(FAR const struct btuart_lowerhalf_s *lower,
FAR sem_t *rxsem,
FAR const uint8_t *dout, uint32_t doutl,
FAR const uint8_t *cmp, uint32_t maxl)
-
{
int ret;
int gotlen = 0;
@@ -183,18 +181,18 @@ static int uartwriteconf(FAR const struct btuart_lowerhalf_s *lower,
}
ret = nxsem_timedwait_uninterruptible(rxsem, &abstime);
- if (ret == -ETIMEDOUT)
+ if (ret < 0)
{
/* We didn't receive enough message, so fall out */
- wlerr("Response timed out\n");
+ wlerr("Response timed out: %d\n", ret);
goto exit_uartwriteconf;
}
ret = lower->read(lower, &din[gotlen], maxl - gotlen);
if (ret < 0)
{
- wlerr("Couldn't read\n");
+ wlerr("Couldn't read: %d\n", ret);
ret = -ECOMM;
goto exit_uartwriteconf;
}
@@ -228,7 +226,6 @@ exit_uartwriteconf_nofree:
static int set_baudrate(FAR const struct btuart_lowerhalf_s *lower,
FAR sem_t *rxsem, int targetspeed)
-
{
int ret;
uint8_t baudrate_cmd[] =
@@ -268,7 +265,6 @@ static int set_baudrate(FAR const struct btuart_lowerhalf_s *lower,
****************************************************************************/
static int load_bcm4343x_firmware(FAR const struct btuart_lowerhalf_s *lower)
-
{
FAR uint8_t *rp = (FAR uint8_t *)g_bt_firmware_hcd;
int ret = OK;
@@ -282,24 +278,28 @@ static int load_bcm4343x_firmware(FAR const struct btuart_lowerhalf_s *lower)
const uint8_t command_resp[] =
{
- 0x04, 0x0e, 0x04, 0x01, g_hcd_write_command, g_hcd_command_byte2, 0x00
+ 0x04, 0x0e, 0x04, 0x01, g_hcd_write_command, g_hcd_command_byte2,
+ 0x00
};
const uint8_t launch_resp[] =
{
- 0x04, 0x0e, 0x04, 0x01, g_hcd_launch_command, g_hcd_command_byte2, 0x00
+ 0x04, 0x0e, 0x04, 0x01, g_hcd_launch_command, g_hcd_command_byte2,
+ 0x00
};
const uint8_t download_resp[] =
{
- 0x04, 0x0e, 0x04, 0x01, g_hcd_patchram_command, g_hcd_command_byte2, 0x00
+ 0x04, 0x0e, 0x04, 0x01, g_hcd_patchram_command, g_hcd_command_byte2,
+ 0x00
};
/* Command to switch the chip into download mode */
const uint8_t enter_download_mode[] =
{
- 0x01, g_hcd_patchram_command, g_hcd_command_byte2, 0x00
+ 0x01, g_hcd_patchram_command, g_hcd_command_byte2,
+ 0x00
};
/* Let's temporarily connect to the hci uart rx callback so we can get data */
diff --git a/include/nuttx/semaphore.h b/include/nuttx/semaphore.h
index a976b4e..925bc39 100644
--- a/include/nuttx/semaphore.h
+++ b/include/nuttx/semaphore.h
@@ -1,35 +1,20 @@
/****************************************************************************
* include/nuttx/semaphore.h
*
- * Copyright (C) 2014-2017, 2020 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gn...@nuttx.org>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
*
****************************************************************************/
@@ -174,10 +159,10 @@ int nxsem_init(FAR sem_t *sem, int pshared, unsigned int value);
* Description:
* This function is used to destroy the un-named semaphore indicated by
* 'sem'. Only a semaphore that was created using nxsem_init() may be
- * destroyed using nxsem_destroy(); the effect of calling nxsem_destroy() with
- * a named semaphore is undefined. The effect of subsequent use of the
- * semaphore sem is undefined until sem is re-initialized by another call
- * to nxsem_init().
+ * destroyed using nxsem_destroy(); the effect of calling nxsem_destroy()
+ * with a named semaphore is undefined. The effect of subsequent use of
+ * the semaphore sem is undefined until sem is re-initialized by another
+ * call to nxsem_init().
*
* The effect of destroying a semaphore upon which other processes are
* currently blocked is undefined.
@@ -290,6 +275,7 @@ int nxsem_trywait(FAR sem_t *sem);
* expired.
* EDEADLK A deadlock condition was detected.
* EINTR A signal interrupted this function.
+ * ECANCELED May be returned if the thread is canceled while waiting.
*
****************************************************************************/
@@ -316,8 +302,10 @@ int nxsem_timedwait(FAR sem_t *sem, FAR const struct timespec *abstime);
* Returned Value:
* This is an internal OS interface, not available to applications, and
* hence follows the NuttX internal error return policy: Zero (OK) is
- * returned on success. A negated errno value is returned on failure.
- * -ETIMEDOUT is returned on the timeout condition.
+ * returned on success. A negated errno value is returned on failure:
+ *
+ * -ETIMEDOUT is returned on the timeout condition.
+ * -ECANCELED may be returned if the thread is canceled while waiting.
*
****************************************************************************/
@@ -528,8 +516,8 @@ int sem_setprotocol(FAR sem_t *sem, int protocol);
* Name: nxsem_wait_uninterruptible
*
* Description:
- * This function is wrapped version of nxsem_wait(), which is uninterruptible
- * and convenient for use.
+ * This function is wrapped version of nxsem_wait(), which is
+ * uninterruptible and convenient for use.
*
* Parameters:
* sem - Semaphore descriptor.
@@ -578,6 +566,7 @@ int nxsem_wait_uninterruptible(FAR sem_t *sem);
* ETIMEDOUT The semaphore could not be locked before the specified timeout
* expired.
* EDEADLK A deadlock condition was detected.
+ * ECANCELED May be returned if the thread is canceled while waiting.
*
****************************************************************************/
@@ -594,7 +583,7 @@ static inline int
ret = nxsem_timedwait(sem, abstime);
}
- while (ret == -EINTR || ret == -ECANCELED);
+ while (ret == -EINTR);
return ret;
}
@@ -621,14 +610,19 @@ int nxsem_timedwait_uninterruptible(FAR sem_t *sem,
* to sem_trywait().
*
* Returned Value:
- * Zero (OK) is returned on success. A negated errno value is returned
- * on failure. -ETIMEDOUT is returned on the timeout condition.
+ * This is an internal OS interface, not available to applications, and
+ * hence follows the NuttX internal error return policy: Zero (OK) is
+ * returned on success. A negated errno value is returned on failure:
+ *
+ * -ETIMEDOUT is returned on the timeout condition.
+ * -ECANCELED may be returned if the thread is canceled while waiting.
*
****************************************************************************/
#ifdef CONFIG_HAVE_INLINE
static inline int
- nxsem_tickwait_uninterruptible(FAR sem_t *sem, clock_t start, uint32_t delay)
+ nxsem_tickwait_uninterruptible(FAR sem_t *sem, clock_t start,
+ uint32_t delay)
{
int ret;
@@ -638,7 +632,7 @@ static inline int
ret = nxsem_tickwait(sem, start, delay);
}
- while (ret == -EINTR || ret == -ECANCELED);
+ while (ret == -EINTR);
return ret;
}
diff --git a/include/nuttx/sensors/lps25h.h b/include/nuttx/sensors/lps25h.h
index 6f30d61..615feb4 100644
--- a/include/nuttx/sensors/lps25h.h
+++ b/include/nuttx/sensors/lps25h.h
@@ -62,8 +62,8 @@ typedef struct lps25h_temper_data_s
typedef struct lps25h_pressure_data_s
{
- uint32_t pressure_int_hP;
- uint32_t pressure_Pa;
+ uint32_t pressure_int_hp;
+ uint32_t pressure_pa;
uint32_t raw_data;
} lps25h_pressure_data_t;
diff --git a/sched/semaphore/sem_tickwait.c b/sched/semaphore/sem_tickwait.c
index 120e857..83f132e 100644
--- a/sched/semaphore/sem_tickwait.c
+++ b/sched/semaphore/sem_tickwait.c
@@ -1,35 +1,20 @@
/****************************************************************************
* sched/semaphore/sem_tickwait.c
*
- * Copyright (C) 2015-2017, 2020 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gn...@nuttx.org>
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
*
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
+ * http://www.apache.org/licenses/LICENSE-2.0
*
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
*
****************************************************************************/
@@ -176,6 +161,7 @@ errout_with_irqdisabled:
rtcb->waitdog = NULL;
return ret;
}
+
/****************************************************************************
* Name: nxsem_tickwait_uninterruptible
*
@@ -194,8 +180,12 @@ errout_with_irqdisabled:
* to sem_trywait().
*
* Returned Value:
- * Zero (OK) is returned on success. A negated errno value is returned
- * on failure. -ETIMEDOUT is returned on the timeout condition.
+ * This is an internal OS interface, not available to applications, and
+ * hence follows the NuttX internal error return policy: Zero (OK) is
+ * returned on success. A negated errno value is returned on failure:
+ *
+ * -ETIMEDOUT is returned on the timeout condition.
+ * -ECANCELED may be returned if the thread is canceled while waiting.
*
****************************************************************************/
@@ -211,7 +201,7 @@ int nxsem_tickwait_uninterruptible(FAR sem_t *sem, clock_t start,
ret = nxsem_tickwait(sem, start, delay);
}
- while (ret == -EINTR || ret == -ECANCELED);
+ while (ret == -EINTR);
return ret;
}
diff --git a/sched/semaphore/sem_timedwait.c b/sched/semaphore/sem_timedwait.c
index 2eef642..6e8c350 100644
--- a/sched/semaphore/sem_timedwait.c
+++ b/sched/semaphore/sem_timedwait.c
@@ -1,35 +1,20 @@
/****************************************************************************
* sched/semaphore/sem_timedwait.c
*
- * Copyright (C) 2011, 2013-201, 2020 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gn...@nuttx.org>
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
*
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
+ * http://www.apache.org/licenses/LICENSE-2.0
*
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
*
****************************************************************************/
@@ -232,6 +217,7 @@ errout_with_irqdisabled:
* ETIMEDOUT The semaphore could not be locked before the specified timeout
* expired.
* EDEADLK A deadlock condition was detected.
+ * ECANCELED May be returned if the thread is canceled while waiting.
*
****************************************************************************/
@@ -247,7 +233,7 @@ int nxsem_timedwait_uninterruptible(FAR sem_t *sem,
ret = nxsem_timedwait(sem, abstime);
}
- while (ret == -EINTR || ret == -ECANCELED);
+ while (ret == -EINTR);
return ret;
}
@@ -285,6 +271,7 @@ int nxsem_timedwait_uninterruptible(FAR sem_t *sem,
* expired.
* EDEADLK A deadlock condition was detected.
* EINTR A signal interrupted this function.
+ * ECANCELED May be returned if the thread is canceled while waiting.
*
****************************************************************************/