DPDK  20.11.0
Data Structures | Macros | Functions
rte_atomic.h File Reference
#include <stdint.h>
#include <rte_common.h>

Go to the source code of this file.

Data Structures

struct  rte_atomic16_t
 
struct  rte_atomic32_t
 
struct  rte_atomic64_t
 
struct  __rte_aligned
 

Macros

#define rte_compiler_barrier()
 
#define RTE_ATOMIC16_INIT(val)   { (val) }
 
#define RTE_ATOMIC32_INIT(val)   { (val) }
 
#define RTE_ATOMIC64_INIT(val)   { (val) }
 

Functions

static void rte_atomic_thread_fence (int memorder)
 
static int rte_atomic16_cmpset (volatile uint16_t *dst, uint16_t exp, uint16_t src)
 
static uint16_t rte_atomic16_exchange (volatile uint16_t *dst, uint16_t val)
 
static void rte_atomic16_init (rte_atomic16_t *v)
 
static int16_t rte_atomic16_read (const rte_atomic16_t *v)
 
static void rte_atomic16_set (rte_atomic16_t *v, int16_t new_value)
 
static void rte_atomic16_add (rte_atomic16_t *v, int16_t inc)
 
static void rte_atomic16_sub (rte_atomic16_t *v, int16_t dec)
 
static void rte_atomic16_inc (rte_atomic16_t *v)
 
static void rte_atomic16_dec (rte_atomic16_t *v)
 
static int16_t rte_atomic16_add_return (rte_atomic16_t *v, int16_t inc)
 
static int16_t rte_atomic16_sub_return (rte_atomic16_t *v, int16_t dec)
 
static int rte_atomic16_inc_and_test (rte_atomic16_t *v)
 
static int rte_atomic16_dec_and_test (rte_atomic16_t *v)
 
static int rte_atomic16_test_and_set (rte_atomic16_t *v)
 
static void rte_atomic16_clear (rte_atomic16_t *v)
 
static int rte_atomic32_cmpset (volatile uint32_t *dst, uint32_t exp, uint32_t src)
 
static uint32_t rte_atomic32_exchange (volatile uint32_t *dst, uint32_t val)
 
static void rte_atomic32_init (rte_atomic32_t *v)
 
static int32_t rte_atomic32_read (const rte_atomic32_t *v)
 
static void rte_atomic32_set (rte_atomic32_t *v, int32_t new_value)
 
static void rte_atomic32_add (rte_atomic32_t *v, int32_t inc)
 
static void rte_atomic32_sub (rte_atomic32_t *v, int32_t dec)
 
static void rte_atomic32_inc (rte_atomic32_t *v)
 
static void rte_atomic32_dec (rte_atomic32_t *v)
 
static int32_t rte_atomic32_add_return (rte_atomic32_t *v, int32_t inc)
 
static int32_t rte_atomic32_sub_return (rte_atomic32_t *v, int32_t dec)
 
static int rte_atomic32_inc_and_test (rte_atomic32_t *v)
 
static int rte_atomic32_dec_and_test (rte_atomic32_t *v)
 
static int rte_atomic32_test_and_set (rte_atomic32_t *v)
 
static void rte_atomic32_clear (rte_atomic32_t *v)
 
static int rte_atomic64_cmpset (volatile uint64_t *dst, uint64_t exp, uint64_t src)
 
static uint64_t rte_atomic64_exchange (volatile uint64_t *dst, uint64_t val)
 
static void rte_atomic64_init (rte_atomic64_t *v)
 
static int64_t rte_atomic64_read (rte_atomic64_t *v)
 
static void rte_atomic64_set (rte_atomic64_t *v, int64_t new_value)
 
static void rte_atomic64_add (rte_atomic64_t *v, int64_t inc)
 
static void rte_atomic64_sub (rte_atomic64_t *v, int64_t dec)
 
static void rte_atomic64_inc (rte_atomic64_t *v)
 
static void rte_atomic64_dec (rte_atomic64_t *v)
 
static int64_t rte_atomic64_add_return (rte_atomic64_t *v, int64_t inc)
 
static int64_t rte_atomic64_sub_return (rte_atomic64_t *v, int64_t dec)
 
static int rte_atomic64_inc_and_test (rte_atomic64_t *v)
 
static int rte_atomic64_dec_and_test (rte_atomic64_t *v)
 
static int rte_atomic64_test_and_set (rte_atomic64_t *v)
 
static void rte_atomic64_clear (rte_atomic64_t *v)
 
static __rte_experimental int rte_atomic128_cmp_exchange (rte_int128_t *dst, rte_int128_t *exp, const rte_int128_t *src, unsigned int weak, int success, int failure)
 
Memory Barrier
static void rte_mb (void)
 
static void rte_wmb (void)
 
static void rte_rmb (void)
 
SMP Memory Barrier
static void rte_smp_mb (void)
 
static void rte_smp_wmb (void)
 
static void rte_smp_rmb (void)
 
I/O Memory Barrier
static void rte_io_mb (void)
 
static void rte_io_wmb (void)
 
static void rte_io_rmb (void)
 

Detailed Description

Atomic Operations

This file defines a generic API for atomic operations.

Definition in file rte_atomic.h.

Macro Definition Documentation

#define rte_compiler_barrier ( )
Value:
do { \
asm volatile ("" : : : "memory"); \
} while(0)

Compiler barrier.

Guarantees that operation reordering does not occur at compile time for operations directly before and after the barrier.

Examples:
examples/performance-thread/common/lthread_tls.c.

Definition at line 118 of file rte_atomic.h.

#define RTE_ATOMIC16_INIT (   val)    { (val) }

Static initializer for an atomic counter.

Definition at line 196 of file rte_atomic.h.

#define RTE_ATOMIC32_INIT (   val)    { (val) }

Static initializer for an atomic counter.

Examples:
examples/kni/main.c.

Definition at line 479 of file rte_atomic.h.

#define RTE_ATOMIC64_INIT (   val)    { (val) }

Static initializer for an atomic counter.

Definition at line 761 of file rte_atomic.h.

Function Documentation

static void rte_mb ( void  )
inlinestatic

General memory barrier.

Guarantees that the LOAD and STORE operations generated before the barrier occur before the LOAD and STORE operations generated after.

static void rte_wmb ( void  )
inlinestatic

Write memory barrier.

Guarantees that the STORE operations generated before the barrier occur before the STORE operations generated after.

Examples:
examples/performance-thread/common/lthread.c, examples/performance-thread/common/lthread_sched.c, and examples/vhost_crypto/main.c.
static void rte_rmb ( void  )
inlinestatic

Read memory barrier.

Guarantees that the LOAD operations generated before the barrier occur before the LOAD operations generated after.

static void rte_smp_mb ( void  )
inlinestatic

General memory barrier between lcores

Guarantees that the LOAD and STORE operations that precede the rte_smp_mb() call are globally visible across the lcores before the LOAD and STORE operations that follows it.

Examples:
examples/vhost_blk/vhost_blk.c.
static void rte_smp_wmb ( void  )
inlinestatic

Write memory barrier between lcores

Guarantees that the STORE operations that precede the rte_smp_wmb() call are globally visible across the lcores before the STORE operations that follows it.

Examples:
examples/eventdev_pipeline/main.c, and examples/vhost/virtio_net.c.
static void rte_smp_rmb ( void  )
inlinestatic

Read memory barrier between lcores

Guarantees that the LOAD operations that precede the rte_smp_rmb() call are globally visible across the lcores before the LOAD operations that follows it.

Examples:
examples/vhost/virtio_net.c.
static void rte_io_mb ( void  )
inlinestatic

General memory barrier for I/O device

Guarantees that the LOAD and STORE operations that precede the rte_io_mb() call are visible to I/O device or CPU before the LOAD and STORE operations that follow it.

static void rte_io_wmb ( void  )
inlinestatic

Write memory barrier for I/O device

Guarantees that the STORE operations that precede the rte_io_wmb() call are visible to I/O device before the STORE operations that follow it.

static void rte_io_rmb ( void  )
inlinestatic

Read memory barrier for IO device

Guarantees that the LOAD operations on I/O device that precede the rte_io_rmb() call are visible to CPU before the LOAD operations that follow it.

static void rte_atomic_thread_fence ( int  memorder)
inlinestatic

Synchronization fence between threads based on the specified memory order.

static int rte_atomic16_cmpset ( volatile uint16_t *  dst,
uint16_t  exp,
uint16_t  src 
)
inlinestatic

Atomic compare and set.

(atomic) equivalent to: if (*dst == exp) *dst = src (all 16-bit words)

Parameters
dstThe destination location into which the value will be written.
expThe expected value.
srcThe new value.
Returns
Non-zero on success; 0 on failure.
static uint16_t rte_atomic16_exchange ( volatile uint16_t *  dst,
uint16_t  val 
)
inlinestatic

Atomic exchange.

(atomic) equivalent to: ret = *dst *dst = val; return ret;

Parameters
dstThe destination location into which the value will be written.
valThe new value.
Returns
The original value at that location
static void rte_atomic16_init ( rte_atomic16_t v)
inlinestatic

Initialize an atomic counter.

Parameters
vA pointer to the atomic counter.
Examples:
examples/bbdev_app/main.c, and examples/performance-thread/common/lthread_sched.c.

Definition at line 205 of file rte_atomic.h.

static int16_t rte_atomic16_read ( const rte_atomic16_t v)
inlinestatic

Atomically read a 16-bit value from a counter.

Parameters
vA pointer to the atomic counter.
Returns
The value of the counter.
Examples:
examples/bbdev_app/main.c, examples/l2fwd-jobstats/main.c, examples/performance-thread/common/lthread_sched.c, and examples/performance-thread/l3fwd-thread/main.c.

Definition at line 219 of file rte_atomic.h.

static void rte_atomic16_set ( rte_atomic16_t v,
int16_t  new_value 
)
inlinestatic

Atomically set a counter to a 16-bit value.

Parameters
vA pointer to the atomic counter.
new_valueThe new value for the counter.
Examples:
examples/bbdev_app/main.c, examples/l2fwd-jobstats/main.c, and examples/performance-thread/common/lthread_sched.c.

Definition at line 233 of file rte_atomic.h.

static void rte_atomic16_add ( rte_atomic16_t v,
int16_t  inc 
)
inlinestatic

Atomically add a 16-bit value to an atomic counter.

Parameters
vA pointer to the atomic counter.
incThe value to be added to the counter.

Definition at line 247 of file rte_atomic.h.

static void rte_atomic16_sub ( rte_atomic16_t v,
int16_t  dec 
)
inlinestatic

Atomically subtract a 16-bit value from an atomic counter.

Parameters
vA pointer to the atomic counter.
decThe value to be subtracted from the counter.

Definition at line 261 of file rte_atomic.h.

static void rte_atomic16_inc ( rte_atomic16_t v)
inlinestatic

Atomically increment a counter by one.

Parameters
vA pointer to the atomic counter.
Examples:
examples/performance-thread/common/lthread_sched.c, and examples/performance-thread/l3fwd-thread/main.c.
static void rte_atomic16_dec ( rte_atomic16_t v)
inlinestatic

Atomically decrement a counter by one.

Parameters
vA pointer to the atomic counter.
Examples:
examples/performance-thread/common/lthread_sched.c.
static int16_t rte_atomic16_add_return ( rte_atomic16_t v,
int16_t  inc 
)
inlinestatic

Atomically add a 16-bit value to a counter and return the result.

Atomically adds the 16-bits value (inc) to the atomic counter (v) and returns the value of v after addition.

Parameters
vA pointer to the atomic counter.
incThe value to be added to the counter.
Returns
The value of v after the addition.

Definition at line 314 of file rte_atomic.h.

static int16_t rte_atomic16_sub_return ( rte_atomic16_t v,
int16_t  dec 
)
inlinestatic

Atomically subtract a 16-bit value from a counter and return the result.

Atomically subtracts the 16-bit value (inc) from the atomic counter (v) and returns the value of v after the subtraction.

Parameters
vA pointer to the atomic counter.
decThe value to be subtracted from the counter.
Returns
The value of v after the subtraction.

Definition at line 334 of file rte_atomic.h.

static int rte_atomic16_inc_and_test ( rte_atomic16_t v)
inlinestatic

Atomically increment a 16-bit counter by one and test.

Atomically increments the atomic counter (v) by one and returns true if the result is 0, or false in all other cases.

Parameters
vA pointer to the atomic counter.
Returns
True if the result after the increment operation is 0; false otherwise.
static int rte_atomic16_dec_and_test ( rte_atomic16_t v)
inlinestatic

Atomically decrement a 16-bit counter by one and test.

Atomically decrements the atomic counter (v) by one and returns true if the result is 0, or false in all other cases.

Parameters
vA pointer to the atomic counter.
Returns
True if the result after the decrement operation is 0; false otherwise.
static int rte_atomic16_test_and_set ( rte_atomic16_t v)
inlinestatic

Atomically test and set a 16-bit atomic counter.

If the counter value is already set, return 0 (failed). Otherwise, set the counter value to 1 and return 1 (success).

Parameters
vA pointer to the atomic counter.
Returns
0 if failed; else 1, success.
static void rte_atomic16_clear ( rte_atomic16_t v)
inlinestatic

Atomically set a 16-bit counter to 0.

Parameters
vA pointer to the atomic counter.

Definition at line 405 of file rte_atomic.h.

static int rte_atomic32_cmpset ( volatile uint32_t *  dst,
uint32_t  exp,
uint32_t  src 
)
inlinestatic

Atomic compare and set.

(atomic) equivalent to: if (*dst == exp) *dst = src (all 32-bit words)

Parameters
dstThe destination location into which the value will be written.
expThe expected value.
srcThe new value.
Returns
Non-zero on success; 0 on failure.
Examples:
examples/vm_power_manager/channel_monitor.c.
static uint32_t rte_atomic32_exchange ( volatile uint32_t *  dst,
uint32_t  val 
)
inlinestatic

Atomic exchange.

(atomic) equivalent to: ret = *dst *dst = val; return ret;

Parameters
dstThe destination location into which the value will be written.
valThe new value.
Returns
The original value at that location
static void rte_atomic32_init ( rte_atomic32_t v)
inlinestatic

Initialize an atomic counter.

Parameters
vA pointer to the atomic counter.

Definition at line 488 of file rte_atomic.h.

static int32_t rte_atomic32_read ( const rte_atomic32_t v)
inlinestatic

Atomically read a 32-bit value from a counter.

Parameters
vA pointer to the atomic counter.
Returns
The value of the counter.
Examples:
examples/kni/main.c.

Definition at line 502 of file rte_atomic.h.

static void rte_atomic32_set ( rte_atomic32_t v,
int32_t  new_value 
)
inlinestatic

Atomically set a counter to a 32-bit value.

Parameters
vA pointer to the atomic counter.
new_valueThe new value for the counter.

Definition at line 516 of file rte_atomic.h.

static void rte_atomic32_add ( rte_atomic32_t v,
int32_t  inc 
)
inlinestatic

Atomically add a 32-bit value to an atomic counter.

Parameters
vA pointer to the atomic counter.
incThe value to be added to the counter.

Definition at line 530 of file rte_atomic.h.

static void rte_atomic32_sub ( rte_atomic32_t v,
int32_t  dec 
)
inlinestatic

Atomically subtract a 32-bit value from an atomic counter.

Parameters
vA pointer to the atomic counter.
decThe value to be subtracted from the counter.

Definition at line 544 of file rte_atomic.h.

static void rte_atomic32_inc ( rte_atomic32_t v)
inlinestatic

Atomically increment a counter by one.

Parameters
vA pointer to the atomic counter.
Examples:
examples/kni/main.c.
static void rte_atomic32_dec ( rte_atomic32_t v)
inlinestatic

Atomically decrement a counter by one.

Parameters
vA pointer to the atomic counter.
Examples:
examples/kni/main.c.
static int32_t rte_atomic32_add_return ( rte_atomic32_t v,
int32_t  inc 
)
inlinestatic

Atomically add a 32-bit value to a counter and return the result.

Atomically adds the 32-bits value (inc) to the atomic counter (v) and returns the value of v after addition.

Parameters
vA pointer to the atomic counter.
incThe value to be added to the counter.
Returns
The value of v after the addition.

Definition at line 597 of file rte_atomic.h.

static int32_t rte_atomic32_sub_return ( rte_atomic32_t v,
int32_t  dec 
)
inlinestatic

Atomically subtract a 32-bit value from a counter and return the result.

Atomically subtracts the 32-bit value (inc) from the atomic counter (v) and returns the value of v after the subtraction.

Parameters
vA pointer to the atomic counter.
decThe value to be subtracted from the counter.
Returns
The value of v after the subtraction.

Definition at line 617 of file rte_atomic.h.

static int rte_atomic32_inc_and_test ( rte_atomic32_t v)
inlinestatic

Atomically increment a 32-bit counter by one and test.

Atomically increments the atomic counter (v) by one and returns true if the result is 0, or false in all other cases.

Parameters
vA pointer to the atomic counter.
Returns
True if the result after the increment operation is 0; false otherwise.
static int rte_atomic32_dec_and_test ( rte_atomic32_t v)
inlinestatic

Atomically decrement a 32-bit counter by one and test.

Atomically decrements the atomic counter (v) by one and returns true if the result is 0, or false in all other cases.

Parameters
vA pointer to the atomic counter.
Returns
True if the result after the decrement operation is 0; false otherwise.
static int rte_atomic32_test_and_set ( rte_atomic32_t v)
inlinestatic

Atomically test and set a 32-bit atomic counter.

If the counter value is already set, return 0 (failed). Otherwise, set the counter value to 1 and return 1 (success).

Parameters
vA pointer to the atomic counter.
Returns
0 if failed; else 1, success.
Examples:
examples/multi_process/client_server_mp/mp_server/main.c, and examples/server_node_efd/server/main.c.
static void rte_atomic32_clear ( rte_atomic32_t v)
inlinestatic

Atomically set a 32-bit counter to 0.

Parameters
vA pointer to the atomic counter.

Definition at line 688 of file rte_atomic.h.

static int rte_atomic64_cmpset ( volatile uint64_t *  dst,
uint64_t  exp,
uint64_t  src 
)
inlinestatic

An atomic compare and set function used by the mutex functions. (atomic) equivalent to: if (*dst == exp) *dst = src (all 64-bit words)

Parameters
dstThe destination into which the value will be written.
expThe expected value.
srcThe new value.
Returns
Non-zero on success; 0 on failure.
Examples:
examples/performance-thread/common/lthread.c, examples/performance-thread/common/lthread_mutex.c, and examples/performance-thread/common/lthread_tls.c.
static uint64_t rte_atomic64_exchange ( volatile uint64_t *  dst,
uint64_t  val 
)
inlinestatic

Atomic exchange.

(atomic) equivalent to: ret = *dst *dst = val; return ret;

Parameters
dstThe destination location into which the value will be written.
valThe new value.
Returns
The original value at that location
static void rte_atomic64_init ( rte_atomic64_t v)
inlinestatic

Initialize the atomic counter.

Parameters
vA pointer to the atomic counter.
Examples:
examples/performance-thread/common/lthread_mutex.c.
static int64_t rte_atomic64_read ( rte_atomic64_t v)
inlinestatic

Atomically read a 64-bit counter.

Parameters
vA pointer to the atomic counter.
Returns
The value of the counter.
Examples:
examples/performance-thread/common/lthread_mutex.c, and examples/vhost/main.c.
static void rte_atomic64_set ( rte_atomic64_t v,
int64_t  new_value 
)
inlinestatic

Atomically set a 64-bit counter.

Parameters
vA pointer to the atomic counter.
new_valueThe new value of the counter.
static void rte_atomic64_add ( rte_atomic64_t v,
int64_t  inc 
)
inlinestatic

Atomically add a 64-bit value to a counter.

Parameters
vA pointer to the atomic counter.
incThe value to be added to the counter.
Examples:
examples/vhost/main.c.
static void rte_atomic64_sub ( rte_atomic64_t v,
int64_t  dec 
)
inlinestatic

Atomically subtract a 64-bit value from a counter.

Parameters
vA pointer to the atomic counter.
decThe value to be subtracted from the counter.
static void rte_atomic64_inc ( rte_atomic64_t v)
inlinestatic

Atomically increment a 64-bit counter by one and test.

Parameters
vA pointer to the atomic counter.
Examples:
examples/performance-thread/common/lthread_mutex.c, and examples/vhost/main.c.
static void rte_atomic64_dec ( rte_atomic64_t v)
inlinestatic

Atomically decrement a 64-bit counter by one and test.

Parameters
vA pointer to the atomic counter.
Examples:
examples/performance-thread/common/lthread_mutex.c.
static int64_t rte_atomic64_add_return ( rte_atomic64_t v,
int64_t  inc 
)
inlinestatic

Add a 64-bit value to an atomic counter and return the result.

Atomically adds the 64-bit value (inc) to the atomic counter (v) and returns the value of v after the addition.

Parameters
vA pointer to the atomic counter.
incThe value to be added to the counter.
Returns
The value of v after the addition.
static int64_t rte_atomic64_sub_return ( rte_atomic64_t v,
int64_t  dec 
)
inlinestatic

Subtract a 64-bit value from an atomic counter and return the result.

Atomically subtracts the 64-bit value (dec) from the atomic counter (v) and returns the value of v after the subtraction.

Parameters
vA pointer to the atomic counter.
decThe value to be subtracted from the counter.
Returns
The value of v after the subtraction.
static int rte_atomic64_inc_and_test ( rte_atomic64_t v)
inlinestatic

Atomically increment a 64-bit counter by one and test.

Atomically increments the atomic counter (v) by one and returns true if the result is 0, or false in all other cases.

Parameters
vA pointer to the atomic counter.
Returns
True if the result after the addition is 0; false otherwise.
static int rte_atomic64_dec_and_test ( rte_atomic64_t v)
inlinestatic

Atomically decrement a 64-bit counter by one and test.

Atomically decrements the atomic counter (v) by one and returns true if the result is 0, or false in all other cases.

Parameters
vA pointer to the atomic counter.
Returns
True if the result after subtraction is 0; false otherwise.
static int rte_atomic64_test_and_set ( rte_atomic64_t v)
inlinestatic

Atomically test and set a 64-bit atomic counter.

If the counter value is already set, return 0 (failed). Otherwise, set the counter value to 1 and return 1 (success).

Parameters
vA pointer to the atomic counter.
Returns
0 if failed; else 1, success.
static void rte_atomic64_clear ( rte_atomic64_t v)
inlinestatic

Atomically set a 64-bit counter to 0.

Parameters
vA pointer to the atomic counter.
static __rte_experimental int rte_atomic128_cmp_exchange ( rte_int128_t *  dst,
rte_int128_t *  exp,
const rte_int128_t *  src,
unsigned int  weak,
int  success,
int  failure 
)
inlinestatic

An atomic compare and set function used by the mutex functions. (Atomically) Equivalent to:

1 if (*dst == *exp)
2  *dst = *src
3 else
4  *exp = *dst
Note
This function is currently available for the x86-64 and aarch64 platforms.
The success and failure arguments must be one of the __ATOMIC_* values defined in the C++11 standard. For details on their behavior, refer to the standard.
Parameters
dstThe destination into which the value will be written.
expPointer to the expected value. If the operation fails, this memory is updated with the actual value.
srcPointer to the new value.
weakA value of true allows the comparison to spuriously fail and allows the 'exp' update to occur non-atomically (i.e. a torn read may occur). Implementations may ignore this argument and only implement the strong variant.
successIf successful, the operation's memory behavior conforms to this (or a stronger) model.
failureIf unsuccessful, the operation's memory behavior conforms to this (or a stronger) model. This argument cannot be __ATOMIC_RELEASE, __ATOMIC_ACQ_REL, or a stronger model than success.
Returns
Non-zero on success; 0 on failure.