[rtems commit] pipe: Use condition variables
Sebastian Huber
sebh at rtems.org
Wed Dec 11 16:46:23 UTC 2019
Module: rtems
Branch: master
Commit: b1b6dd71d0d4609e81e14cbc94ef3dafa06712ba
Changeset: http://git.rtems.org/rtems/commit/?id=b1b6dd71d0d4609e81e14cbc94ef3dafa06712ba
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Wed Dec 11 16:45:37 2019 +0100
pipe: Use condition variables
Use self-contained condition variables instead of Classic API barriers.
This simplifies the implementation and configuration.
Update #3840.
---
cpukit/include/rtems/confdefs.h | 22 +---------
cpukit/include/rtems/pipe.h | 4 +-
cpukit/libfs/src/pipe/fifo.c | 66 ++++++++--------------------
testsuites/sptests/spfifo02/init.c | 75 +++-----------------------------
testsuites/sptests/spfifo02/spfifo02.doc | 1 -
5 files changed, 28 insertions(+), 140 deletions(-)
diff --git a/cpukit/include/rtems/confdefs.h b/cpukit/include/rtems/confdefs.h
index 922e4d7..2e48af3 100644
--- a/cpukit/include/rtems/confdefs.h
+++ b/cpukit/include/rtems/confdefs.h
@@ -213,17 +213,6 @@ extern rtems_initialization_tasks_table Initialization_tasks[];
#define CONFIGURE_MAXIMUM_PIPES 0
#endif
-/*
- * This specifies the number of barriers required for the configured
- * number of FIFOs and named pipes.
- */
-#if CONFIGURE_MAXIMUM_FIFOS > 0 || CONFIGURE_MAXIMUM_PIPES > 0
- #define _CONFIGURE_BARRIERS_FOR_FIFOS \
- (2 * (CONFIGURE_MAXIMUM_FIFOS + CONFIGURE_MAXIMUM_PIPES))
-#else
- #define _CONFIGURE_BARRIERS_FOR_FIFOS 0
-#endif
-
/**
* @defgroup ConfigFilesystems Filesystems and Mount Table Configuration
*
@@ -2041,13 +2030,6 @@ extern rtems_initialization_tasks_table Initialization_tasks[];
#define CONFIGURE_MAXIMUM_BARRIERS 0
#endif
-/*
- * This macro is calculated to specify the number of Classic API
- * Barriers required by the application and configured capabilities.
- */
-#define _CONFIGURE_BARRIERS \
- (CONFIGURE_MAXIMUM_BARRIERS + _CONFIGURE_BARRIERS_FOR_FIFOS)
-
#ifndef CONFIGURE_MAXIMUM_USER_EXTENSIONS
/**
* This configuration parameter specifies the maximum number of
@@ -2737,8 +2719,8 @@ struct _reent *__getreent(void)
_CONFIGURE_IDLE_TASKS_COUNT + _CONFIGURE_MPCI_RECEIVE_SERVER_COUNT
);
- #if _CONFIGURE_BARRIERS > 0
- BARRIER_INFORMATION_DEFINE( _CONFIGURE_BARRIERS );
+ #if CONFIGURE_MAXIMUM_BARRIERS > 0
+ BARRIER_INFORMATION_DEFINE( CONFIGURE_MAXIMUM_BARRIERS );
#endif
#if CONFIGURE_MAXIMUM_MESSAGE_QUEUES > 0
diff --git a/cpukit/include/rtems/pipe.h b/cpukit/include/rtems/pipe.h
index 083e134..eb016ed 100644
--- a/cpukit/include/rtems/pipe.h
+++ b/cpukit/include/rtems/pipe.h
@@ -47,8 +47,8 @@ typedef struct pipe_control {
unsigned int readerCounter; /* incremental counters */
unsigned int writerCounter; /* for differentiation of successive opens */
rtems_mutex Mutex;
- rtems_id readBarrier; /* wait queues */
- rtems_id writeBarrier;
+ rtems_condition_variable readBarrier; /* wait queues */
+ rtems_condition_variable writeBarrier;
#if 0
boolean Anonymous; /* anonymous pipe or FIFO */
#endif
diff --git a/cpukit/libfs/src/pipe/fifo.c b/cpukit/libfs/src/pipe/fifo.c
index f7f186c..b64c0d9 100644
--- a/cpukit/libfs/src/pipe/fifo.c
+++ b/cpukit/libfs/src/pipe/fifo.c
@@ -27,8 +27,6 @@
#include <rtems.h>
#include <rtems/libio_.h>
#include <rtems/pipe.h>
-#include <rtems/rtems/barrierimpl.h>
-#include <rtems/score/statesimpl.h>
#define LIBIO_ACCMODE(_iop) (rtems_libio_iop_flags(_iop) & LIBIO_FLAGS_READ_WRITE)
#define LIBIO_NODELAY(_iop) rtems_libio_iop_is_no_delay(_iop)
@@ -46,18 +44,16 @@ static rtems_mutex pipe_mutex = RTEMS_MUTEX_INITIALIZER("Pipes");
#define PIPE_UNLOCK(_pipe) rtems_mutex_unlock(&(_pipe)->Mutex)
#define PIPE_READWAIT(_pipe) \
- ( rtems_barrier_wait(_pipe->readBarrier, RTEMS_NO_TIMEOUT) \
- == RTEMS_SUCCESSFUL)
+ rtems_condition_variable_wait(&(_pipe)->readBarrier, &(_pipe)->Mutex)
#define PIPE_WRITEWAIT(_pipe) \
- ( rtems_barrier_wait(_pipe->writeBarrier, RTEMS_NO_TIMEOUT) \
- == RTEMS_SUCCESSFUL)
+ rtems_condition_variable_wait(&(_pipe)->writeBarrier, &(_pipe)->Mutex)
#define PIPE_WAKEUPREADERS(_pipe) \
- do {uint32_t n; rtems_barrier_release(_pipe->readBarrier, &n); } while(0)
+ rtems_condition_variable_broadcast(&(_pipe)->readBarrier)
#define PIPE_WAKEUPWRITERS(_pipe) \
- do {uint32_t n; rtems_barrier_release(_pipe->writeBarrier, &n); } while(0)
+ rtems_condition_variable_broadcast(&(_pipe)->writeBarrier)
/*
* Alloc pipe control structure, buffer, and resources.
@@ -78,35 +74,19 @@ static int pipe_alloc(
pipe->Size = PIPE_BUF;
pipe->Buffer = malloc(pipe->Size);
- if (! pipe->Buffer)
- goto err_buf;
-
- err = -ENOMEM;
-
- if (rtems_barrier_create(
- rtems_build_name ('P', 'I', 'r', c),
- RTEMS_BARRIER_MANUAL_RELEASE, 0,
- &pipe->readBarrier) != RTEMS_SUCCESSFUL)
- goto err_rbar;
- if (rtems_barrier_create(
- rtems_build_name ('P', 'I', 'w', c),
- RTEMS_BARRIER_MANUAL_RELEASE, 0,
- &pipe->writeBarrier) != RTEMS_SUCCESSFUL)
- goto err_wbar;
+ if (pipe->Buffer == NULL) {
+ free(pipe);
+ return -ENOMEM;
+ }
+
+ rtems_condition_variable_init(&pipe->readBarrier, "Pipe Read");
+ rtems_condition_variable_init(&pipe->writeBarrier, "Pipe Write");
rtems_mutex_init(&pipe->Mutex, "Pipe");
*pipep = pipe;
if (c ++ == 'z')
c = 'a';
return 0;
-
-err_wbar:
- rtems_barrier_delete(pipe->readBarrier);
-err_rbar:
- free(pipe->Buffer);
-err_buf:
- free(pipe);
- return err;
}
/* Called with pipe_semaphore held. */
@@ -114,8 +94,8 @@ static inline void pipe_free(
pipe_control_t *pipe
)
{
- rtems_barrier_delete(pipe->readBarrier);
- rtems_barrier_delete(pipe->writeBarrier);
+ rtems_condition_variable_destroy(&pipe->readBarrier);
+ rtems_condition_variable_destroy(&pipe->writeBarrier);
rtems_mutex_destroy(&pipe->Mutex);
free(pipe->Buffer);
free(pipe);
@@ -241,10 +221,7 @@ int fifo_open(
err = -EINTR;
/* Wait until a writer opens the pipe */
do {
- PIPE_UNLOCK(pipe);
- if (! PIPE_READWAIT(pipe))
- goto out_error;
- PIPE_LOCK(pipe);
+ PIPE_READWAIT(pipe);
} while (prevCounter == pipe->writerCounter);
}
break;
@@ -265,10 +242,7 @@ int fifo_open(
prevCounter = pipe->readerCounter;
err = -EINTR;
do {
- PIPE_UNLOCK(pipe);
- if (! PIPE_WRITEWAIT(pipe))
- goto out_error;
- PIPE_LOCK(pipe);
+ PIPE_WRITEWAIT(pipe);
} while (prevCounter == pipe->readerCounter);
}
break;
@@ -314,10 +288,7 @@ ssize_t pipe_read(
/* Wait until pipe is no more empty or no writer exists */
pipe->waitingReaders ++;
- PIPE_UNLOCK(pipe);
- if (! PIPE_READWAIT(pipe))
- ret = -EINTR;
- PIPE_LOCK(pipe);
+ PIPE_READWAIT(pipe);
pipe->waitingReaders --;
if (ret != 0)
goto out_locked;
@@ -384,10 +355,7 @@ ssize_t pipe_write(
/* Wait until there is chunk bytes space or no reader exists */
pipe->waitingWriters ++;
- PIPE_UNLOCK(pipe);
- if (! PIPE_WRITEWAIT(pipe))
- ret = -EINTR;
- PIPE_LOCK(pipe);
+ PIPE_WRITEWAIT(pipe);
pipe->waitingWriters --;
if (ret != 0)
goto out_locked;
diff --git a/testsuites/sptests/spfifo02/init.c b/testsuites/sptests/spfifo02/init.c
index 4fca304..89a9a77 100644
--- a/testsuites/sptests/spfifo02/init.c
+++ b/testsuites/sptests/spfifo02/init.c
@@ -19,63 +19,13 @@
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
-#include <rtems/libcsupport.h>
+#include <rtems/malloc.h>
const char rtems_test_name[] = "SPFIFO 2";
-/* forward declarations to avoid warnings */
-rtems_task Init(rtems_task_argument argument);
-void create_all_barriers(void);
-void delete_barrier(void);
-void create_fifo(void);
-void open_fifo(int expected, int flags);
-
-#define MAXIMUM 10
#define NUM_OPEN_REQ 26
-rtems_id Barriers[MAXIMUM];
-int BarrierCount;
-
-rtems_id Semaphores[MAXIMUM];
-int SemaphoreCount;
-
-void create_all_barriers(void)
-{
- rtems_status_code status;
- int i;
-
- BarrierCount = 0;
-
- memset( Barriers, 0, sizeof(Barriers) );
- for ( i=0 ; i<MAXIMUM ; i++ ) {
- status = rtems_barrier_create(
- rtems_build_name( 'B', 'A', 'R', 0x30+i ),
- RTEMS_BARRIER_MANUAL_RELEASE,
- 0,
- &Barriers[i]
- );
- if ( status == RTEMS_TOO_MANY ) {
- printf( "%d Barriers created\n", BarrierCount+1 );
- return;
- }
-
- directive_failed( status, "barrier create" );
- BarrierCount++;
- }
-}
-
-void delete_barrier(void)
-{
- rtems_status_code status;
-
- BarrierCount--;
- printf( "Deleting barrier id=0x%08x\n",
- (unsigned int)Barriers[BarrierCount] );
- status = rtems_barrier_delete( Barriers[BarrierCount] );
- directive_failed( status, "barrier delete" );
-}
-
-void create_fifo(void)
+static void create_fifo(void)
{
int status;
@@ -83,7 +33,7 @@ void create_fifo(void)
rtems_test_assert(status == 0);
}
-void open_fifo(int expected, int flags)
+static void open_fifo(int expected, int flags)
{
int fd;
@@ -98,35 +48,24 @@ void open_fifo(int expected, int flags)
}
}
-rtems_task Init(
+static rtems_task Init(
rtems_task_argument argument
)
{
- void *alloc_ptr = (void *)0;
+ void *p;
int num_opens = 0;
int index = 0;
TEST_BEGIN();
- puts( "Creating all barriers" );
- create_all_barriers();
-
puts( "Creating FIFO" );
create_fifo();
- alloc_ptr = malloc( malloc_free_space() - 4 );
+ p = rtems_heap_greedy_allocate(NULL, 0);
puts("Opening FIFO.. expect ENOMEM since no memory is available");
open_fifo(ENOMEM, O_RDWR);
+ rtems_heap_greedy_free(p);
- free(alloc_ptr);
- puts( "Opening FIFO.. expect ENOMEM (barrier-1 for pipe could not be created)" );
- open_fifo(ENOMEM, O_RDWR);
-
- delete_barrier();
- puts( "Opening FIFO.. expect ENOMEM (barrier-2 for pipe could not be created" );
- open_fifo(ENOMEM, O_RDWR);
-
- delete_barrier();
puts( "Opening FIFO in RDWR mode. Expect OK" );
open_fifo(0, O_RDWR);
++num_opens;
diff --git a/testsuites/sptests/spfifo02/spfifo02.doc b/testsuites/sptests/spfifo02/spfifo02.doc
index 32cac6d..b8d66ac 100644
--- a/testsuites/sptests/spfifo02/spfifo02.doc
+++ b/testsuites/sptests/spfifo02/spfifo02.doc
@@ -18,4 +18,3 @@ directives:
concepts:
+ memory allocation error cases
-+ resource allocation error cases
More information about the vc
mailing list