summaryrefslogtreecommitdiffstats
path: root/src/pulsecore/atomic.h
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/pulsecore/atomic.h683
1 files changed, 683 insertions, 0 deletions
diff --git a/src/pulsecore/atomic.h b/src/pulsecore/atomic.h
new file mode 100644
index 0000000..e5c1401
--- /dev/null
+++ b/src/pulsecore/atomic.h
@@ -0,0 +1,683 @@
+#ifndef foopulseatomichfoo
+#define foopulseatomichfoo
+
+/***
+ This file is part of PulseAudio.
+
+ Copyright 2006-2008 Lennart Poettering
+ Copyright 2008 Nokia Corporation
+
+ PulseAudio 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 2.1 of the
+ License, or (at your option) any later version.
+
+ PulseAudio 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 Lesser General Public
+ License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <pulsecore/macro.h>
+
+/*
+ * atomic_ops guarantees us that sizeof(AO_t) == sizeof(void*). It is
+ * not guaranteed however, that sizeof(AO_t) == sizeof(size_t).
+ * however very likely.
+ *
+ * For now we do only full memory barriers. Eventually we might want
+ * to support more elaborate memory barriers, in which case we will add
+ * suffixes to the function names.
+ *
+ * On gcc >= 4.1 we use the builtin atomic functions. otherwise we use
+ * libatomic_ops
+ */
+
+#ifndef PACKAGE
+#error "Please include config.h before including this file!"
+#endif
+
+#ifdef HAVE_ATOMIC_BUILTINS
+
+/* __sync based implementation */
+
+typedef struct pa_atomic {
+ volatile int value;
+} pa_atomic_t;
+
+#define PA_ATOMIC_INIT(v) { .value = (v) }
+
+#ifdef HAVE_ATOMIC_BUILTINS_MEMORY_MODEL
+
+/* __atomic based implementation */
+
+static inline int pa_atomic_load(const pa_atomic_t *a) {
+ return __atomic_load_n(&a->value, __ATOMIC_SEQ_CST);
+}
+
+static inline void pa_atomic_store(pa_atomic_t *a, int i) {
+ __atomic_store_n(&a->value, i, __ATOMIC_SEQ_CST);
+}
+
+#else
+
+static inline int pa_atomic_load(const pa_atomic_t *a) {
+ __sync_synchronize();
+ return a->value;
+}
+
+static inline void pa_atomic_store(pa_atomic_t *a, int i) {
+ a->value = i;
+ __sync_synchronize();
+}
+
+#endif
+
+
+/* Returns the previously set value */
+static inline int pa_atomic_add(pa_atomic_t *a, int i) {
+ return __sync_fetch_and_add(&a->value, i);
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_sub(pa_atomic_t *a, int i) {
+ return __sync_fetch_and_sub(&a->value, i);
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_inc(pa_atomic_t *a) {
+ return pa_atomic_add(a, 1);
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_dec(pa_atomic_t *a) {
+ return pa_atomic_sub(a, 1);
+}
+
+/* Returns true when the operation was successful. */
+static inline bool pa_atomic_cmpxchg(pa_atomic_t *a, int old_i, int new_i) {
+ return __sync_bool_compare_and_swap(&a->value, old_i, new_i);
+}
+
+typedef struct pa_atomic_ptr {
+ volatile unsigned long value;
+} pa_atomic_ptr_t;
+
+#define PA_ATOMIC_PTR_INIT(v) { .value = (long) (v) }
+
+#ifdef HAVE_ATOMIC_BUILTINS_MEMORY_MODEL
+
+/* __atomic based implementation */
+
+static inline void* pa_atomic_ptr_load(const pa_atomic_ptr_t *a) {
+ return (void*) __atomic_load_n(&a->value, __ATOMIC_SEQ_CST);
+}
+
+static inline void pa_atomic_ptr_store(pa_atomic_ptr_t *a, void* p) {
+ __atomic_store_n(&a->value, (unsigned long) p, __ATOMIC_SEQ_CST);
+}
+
+#else
+
+static inline void* pa_atomic_ptr_load(const pa_atomic_ptr_t *a) {
+ __sync_synchronize();
+ return (void*) a->value;
+}
+
+static inline void pa_atomic_ptr_store(pa_atomic_ptr_t *a, void *p) {
+ a->value = (unsigned long) p;
+ __sync_synchronize();
+}
+
+#endif
+
+static inline bool pa_atomic_ptr_cmpxchg(pa_atomic_ptr_t *a, void *old_p, void* new_p) {
+ return __sync_bool_compare_and_swap(&a->value, (long) old_p, (long) new_p);
+}
+
+#elif defined(__NetBSD__) && defined(HAVE_SYS_ATOMIC_H)
+
+/* NetBSD 5.0+ atomic_ops(3) implementation */
+
+#include <sys/atomic.h>
+
+typedef struct pa_atomic {
+ volatile unsigned int value;
+} pa_atomic_t;
+
+#define PA_ATOMIC_INIT(v) { .value = (unsigned int) (v) }
+
+static inline int pa_atomic_load(const pa_atomic_t *a) {
+ membar_sync();
+ return (int) a->value;
+}
+
+static inline void pa_atomic_store(pa_atomic_t *a, int i) {
+ a->value = (unsigned int) i;
+ membar_sync();
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_add(pa_atomic_t *a, int i) {
+ int nv = (int) atomic_add_int_nv(&a->value, i);
+ return nv - i;
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_sub(pa_atomic_t *a, int i) {
+ int nv = (int) atomic_add_int_nv(&a->value, -i);
+ return nv + i;
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_inc(pa_atomic_t *a) {
+ int nv = (int) atomic_inc_uint_nv(&a->value);
+ return nv - 1;
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_dec(pa_atomic_t *a) {
+ int nv = (int) atomic_dec_uint_nv(&a->value);
+ return nv + 1;
+}
+
+/* Returns true when the operation was successful. */
+static inline bool pa_atomic_cmpxchg(pa_atomic_t *a, int old_i, int new_i) {
+ unsigned int r = atomic_cas_uint(&a->value, (unsigned int) old_i, (unsigned int) new_i);
+ return (int) r == old_i;
+}
+
+typedef struct pa_atomic_ptr {
+ volatile void *value;
+} pa_atomic_ptr_t;
+
+#define PA_ATOMIC_PTR_INIT(v) { .value = (v) }
+
+static inline void* pa_atomic_ptr_load(const pa_atomic_ptr_t *a) {
+ membar_sync();
+ return (void *) a->value;
+}
+
+static inline void pa_atomic_ptr_store(pa_atomic_ptr_t *a, void *p) {
+ a->value = p;
+ membar_sync();
+}
+
+static inline bool pa_atomic_ptr_cmpxchg(pa_atomic_ptr_t *a, void *old_p, void* new_p) {
+ void *r = atomic_cas_ptr(&a->value, old_p, new_p);
+ return r == old_p;
+}
+
+#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <machine/atomic.h>
+
+#if __FreeBSD_version < 600000
+#if defined(__i386__) || defined(__amd64__)
+#if defined(__amd64__)
+#define atomic_load_acq_64 atomic_load_acq_long
+#endif
+static inline u_int atomic_fetchadd_int(volatile u_int *p, u_int v) {
+ __asm __volatile(
+ " " __XSTRING(MPLOCKED) " "
+ " xaddl %0, %1 ; "
+ "# atomic_fetchadd_int"
+ : "+r" (v),
+ "=m" (*p)
+ : "m" (*p));
+
+ return (v);
+}
+#elif defined(__sparc__) && defined(__arch64__)
+#define atomic_load_acq_64 atomic_load_acq_long
+#define atomic_fetchadd_int atomic_add_int
+#elif defined(__ia64__)
+#define atomic_load_acq_64 atomic_load_acq_long
+static inline uint32_t
+atomic_fetchadd_int(volatile uint32_t *p, uint32_t v) {
+ uint32_t value;
+
+ do {
+ value = *p;
+ } while (!atomic_cmpset_32(p, value, value + v));
+ return (value);
+}
+#endif
+#endif
+
+typedef struct pa_atomic {
+ volatile unsigned long value;
+} pa_atomic_t;
+
+#define PA_ATOMIC_INIT(v) { .value = (v) }
+
+static inline int pa_atomic_load(const pa_atomic_t *a) {
+ return (int) atomic_load_acq_int((unsigned int *) &a->value);
+}
+
+static inline void pa_atomic_store(pa_atomic_t *a, int i) {
+ atomic_store_rel_int((unsigned int *) &a->value, i);
+}
+
+static inline int pa_atomic_add(pa_atomic_t *a, int i) {
+ return atomic_fetchadd_int((unsigned int *) &a->value, i);
+}
+
+static inline int pa_atomic_sub(pa_atomic_t *a, int i) {
+ return atomic_fetchadd_int((unsigned int *) &a->value, -(i));
+}
+
+static inline int pa_atomic_inc(pa_atomic_t *a) {
+ return atomic_fetchadd_int((unsigned int *) &a->value, 1);
+}
+
+static inline int pa_atomic_dec(pa_atomic_t *a) {
+ return atomic_fetchadd_int((unsigned int *) &a->value, -1);
+}
+
+static inline int pa_atomic_cmpxchg(pa_atomic_t *a, int old_i, int new_i) {
+ return atomic_cmpset_int((unsigned int *) &a->value, old_i, new_i);
+}
+
+typedef struct pa_atomic_ptr {
+ volatile unsigned long value;
+} pa_atomic_ptr_t;
+
+#define PA_ATOMIC_PTR_INIT(v) { .value = (unsigned long) (v) }
+
+static inline void* pa_atomic_ptr_load(const pa_atomic_ptr_t *a) {
+#ifdef atomic_load_acq_64
+ return (void*) atomic_load_acq_ptr((unsigned long *) &a->value);
+#else
+ return (void*) atomic_load_acq_ptr((unsigned int *) &a->value);
+#endif
+}
+
+static inline void pa_atomic_ptr_store(pa_atomic_ptr_t *a, void *p) {
+#ifdef atomic_load_acq_64
+ atomic_store_rel_ptr(&a->value, (unsigned long) p);
+#else
+ atomic_store_rel_ptr((unsigned int *) &a->value, (unsigned int) p);
+#endif
+}
+
+static inline int pa_atomic_ptr_cmpxchg(pa_atomic_ptr_t *a, void *old_p, void* new_p) {
+#ifdef atomic_load_acq_64
+ return atomic_cmpset_ptr(&a->value, (unsigned long) old_p, (unsigned long) new_p);
+#else
+ return atomic_cmpset_ptr((unsigned int *) &a->value, (unsigned int) old_p, (unsigned int) new_p);
+#endif
+}
+
+#elif defined(__GNUC__) && (defined(__amd64__) || defined(__x86_64__))
+
+#warn "The native atomic operations implementation for AMD64 has not been tested thoroughly. libatomic_ops is known to not work properly on AMD64 and your gcc version is too old for the gcc-builtin atomic ops support. You have three options now: test the native atomic operations implementation for AMD64, fix libatomic_ops, or upgrade your GCC."
+
+/* Adapted from glibc */
+
+typedef struct pa_atomic {
+ volatile int value;
+} pa_atomic_t;
+
+#define PA_ATOMIC_INIT(v) { .value = (v) }
+
+static inline int pa_atomic_load(const pa_atomic_t *a) {
+ return a->value;
+}
+
+static inline void pa_atomic_store(pa_atomic_t *a, int i) {
+ a->value = i;
+}
+
+static inline int pa_atomic_add(pa_atomic_t *a, int i) {
+ int result;
+
+ __asm __volatile ("lock; xaddl %0, %1"
+ : "=r" (result), "=m" (a->value)
+ : "0" (i), "m" (a->value));
+
+ return result;
+}
+
+static inline int pa_atomic_sub(pa_atomic_t *a, int i) {
+ return pa_atomic_add(a, -i);
+}
+
+static inline int pa_atomic_inc(pa_atomic_t *a) {
+ return pa_atomic_add(a, 1);
+}
+
+static inline int pa_atomic_dec(pa_atomic_t *a) {
+ return pa_atomic_sub(a, 1);
+}
+
+static inline bool pa_atomic_cmpxchg(pa_atomic_t *a, int old_i, int new_i) {
+ int result;
+
+ __asm__ __volatile__ ("lock; cmpxchgl %2, %1"
+ : "=a" (result), "=m" (a->value)
+ : "r" (new_i), "m" (a->value), "0" (old_i));
+
+ return result == old_i;
+}
+
+typedef struct pa_atomic_ptr {
+ volatile unsigned long value;
+} pa_atomic_ptr_t;
+
+#define PA_ATOMIC_PTR_INIT(v) { .value = (long) (v) }
+
+static inline void* pa_atomic_ptr_load(const pa_atomic_ptr_t *a) {
+ return (void*) a->value;
+}
+
+static inline void pa_atomic_ptr_store(pa_atomic_ptr_t *a, void *p) {
+ a->value = (unsigned long) p;
+}
+
+static inline bool pa_atomic_ptr_cmpxchg(pa_atomic_ptr_t *a, void *old_p, void* new_p) {
+ void *result;
+
+ __asm__ __volatile__ ("lock; cmpxchgq %q2, %1"
+ : "=a" (result), "=m" (a->value)
+ : "r" (new_p), "m" (a->value), "0" (old_p));
+
+ return result == old_p;
+}
+
+#elif defined(ATOMIC_ARM_INLINE_ASM)
+
+/*
+ These should only be enabled if we have ARMv6 or better.
+*/
+
+typedef struct pa_atomic {
+ volatile int value;
+} pa_atomic_t;
+
+#define PA_ATOMIC_INIT(v) { .value = (v) }
+
+static inline void pa_memory_barrier(void) {
+#ifdef ATOMIC_ARM_MEMORY_BARRIER_ENABLED
+ asm volatile ("mcr p15, 0, r0, c7, c10, 5 @ dmb");
+#endif
+}
+
+static inline int pa_atomic_load(const pa_atomic_t *a) {
+ pa_memory_barrier();
+ return a->value;
+}
+
+static inline void pa_atomic_store(pa_atomic_t *a, int i) {
+ a->value = i;
+ pa_memory_barrier();
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_add(pa_atomic_t *a, int i) {
+ unsigned long not_exclusive;
+ int new_val, old_val;
+
+ pa_memory_barrier();
+ do {
+ asm volatile ("ldrex %0, [%3]\n"
+ "add %2, %0, %4\n"
+ "strex %1, %2, [%3]\n"
+ : "=&r" (old_val), "=&r" (not_exclusive), "=&r" (new_val)
+ : "r" (&a->value), "Ir" (i)
+ : "cc");
+ } while(not_exclusive);
+ pa_memory_barrier();
+
+ return old_val;
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_sub(pa_atomic_t *a, int i) {
+ unsigned long not_exclusive;
+ int new_val, old_val;
+
+ pa_memory_barrier();
+ do {
+ asm volatile ("ldrex %0, [%3]\n"
+ "sub %2, %0, %4\n"
+ "strex %1, %2, [%3]\n"
+ : "=&r" (old_val), "=&r" (not_exclusive), "=&r" (new_val)
+ : "r" (&a->value), "Ir" (i)
+ : "cc");
+ } while(not_exclusive);
+ pa_memory_barrier();
+
+ return old_val;
+}
+
+static inline int pa_atomic_inc(pa_atomic_t *a) {
+ return pa_atomic_add(a, 1);
+}
+
+static inline int pa_atomic_dec(pa_atomic_t *a) {
+ return pa_atomic_sub(a, 1);
+}
+
+static inline bool pa_atomic_cmpxchg(pa_atomic_t *a, int old_i, int new_i) {
+ unsigned long not_equal, not_exclusive;
+
+ pa_memory_barrier();
+ do {
+ asm volatile ("ldrex %0, [%2]\n"
+ "subs %0, %0, %3\n"
+ "mov %1, %0\n"
+ "strexeq %0, %4, [%2]\n"
+ : "=&r" (not_exclusive), "=&r" (not_equal)
+ : "r" (&a->value), "Ir" (old_i), "r" (new_i)
+ : "cc");
+ } while(not_exclusive && !not_equal);
+ pa_memory_barrier();
+
+ return !not_equal;
+}
+
+typedef struct pa_atomic_ptr {
+ volatile unsigned long value;
+} pa_atomic_ptr_t;
+
+#define PA_ATOMIC_PTR_INIT(v) { .value = (long) (v) }
+
+static inline void* pa_atomic_ptr_load(const pa_atomic_ptr_t *a) {
+ pa_memory_barrier();
+ return (void*) a->value;
+}
+
+static inline void pa_atomic_ptr_store(pa_atomic_ptr_t *a, void *p) {
+ a->value = (unsigned long) p;
+ pa_memory_barrier();
+}
+
+static inline bool pa_atomic_ptr_cmpxchg(pa_atomic_ptr_t *a, void *old_p, void* new_p) {
+ unsigned long not_equal, not_exclusive;
+
+ pa_memory_barrier();
+ do {
+ asm volatile ("ldrex %0, [%2]\n"
+ "subs %0, %0, %3\n"
+ "mov %1, %0\n"
+ "strexeq %0, %4, [%2]\n"
+ : "=&r" (not_exclusive), "=&r" (not_equal)
+ : "r" (&a->value), "Ir" (old_p), "r" (new_p)
+ : "cc");
+ } while(not_exclusive && !not_equal);
+ pa_memory_barrier();
+
+ return !not_equal;
+}
+
+#elif defined(ATOMIC_ARM_LINUX_HELPERS)
+
+/* See file arch/arm/kernel/entry-armv.S in your kernel sources for more
+ information about these functions. The arm kernel helper functions first
+ appeared in 2.6.16.
+ Apply --disable-atomic-arm-linux-helpers flag to configure if you prefer
+ inline asm implementation or you have an obsolete Linux kernel.
+*/
+/* Memory barrier */
+typedef void (__kernel_dmb_t)(void);
+#define __kernel_dmb (*(__kernel_dmb_t *)0xffff0fa0)
+
+static inline void pa_memory_barrier(void) {
+#ifndef ATOMIC_ARM_MEMORY_BARRIER_ENABLED
+ __kernel_dmb();
+#endif
+}
+
+/* Atomic exchange (__kernel_cmpxchg_t contains memory barriers if needed) */
+typedef int (__kernel_cmpxchg_t)(int oldval, int newval, volatile int *ptr);
+#define __kernel_cmpxchg (*(__kernel_cmpxchg_t *)0xffff0fc0)
+
+/* This is just to get rid of all warnings */
+typedef int (__kernel_cmpxchg_u_t)(unsigned long oldval, unsigned long newval, volatile unsigned long *ptr);
+#define __kernel_cmpxchg_u (*(__kernel_cmpxchg_u_t *)0xffff0fc0)
+
+typedef struct pa_atomic {
+ volatile int value;
+} pa_atomic_t;
+
+#define PA_ATOMIC_INIT(v) { .value = (v) }
+
+static inline int pa_atomic_load(const pa_atomic_t *a) {
+ pa_memory_barrier();
+ return a->value;
+}
+
+static inline void pa_atomic_store(pa_atomic_t *a, int i) {
+ a->value = i;
+ pa_memory_barrier();
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_add(pa_atomic_t *a, int i) {
+ int old_val;
+ do {
+ old_val = a->value;
+ } while(__kernel_cmpxchg(old_val, old_val + i, &a->value));
+ return old_val;
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_sub(pa_atomic_t *a, int i) {
+ int old_val;
+ do {
+ old_val = a->value;
+ } while(__kernel_cmpxchg(old_val, old_val - i, &a->value));
+ return old_val;
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_inc(pa_atomic_t *a) {
+ return pa_atomic_add(a, 1);
+}
+
+/* Returns the previously set value */
+static inline int pa_atomic_dec(pa_atomic_t *a) {
+ return pa_atomic_sub(a, 1);
+}
+
+/* Returns true when the operation was successful. */
+static inline bool pa_atomic_cmpxchg(pa_atomic_t *a, int old_i, int new_i) {
+ bool failed;
+ do {
+ failed = !!__kernel_cmpxchg(old_i, new_i, &a->value);
+ } while(failed && a->value == old_i);
+ return !failed;
+}
+
+typedef struct pa_atomic_ptr {
+ volatile unsigned long value;
+} pa_atomic_ptr_t;
+
+#define PA_ATOMIC_PTR_INIT(v) { .value = (unsigned long) (v) }
+
+static inline void* pa_atomic_ptr_load(const pa_atomic_ptr_t *a) {
+ pa_memory_barrier();
+ return (void*) a->value;
+}
+
+static inline void pa_atomic_ptr_store(pa_atomic_ptr_t *a, void *p) {
+ a->value = (unsigned long) p;
+ pa_memory_barrier();
+}
+
+static inline bool pa_atomic_ptr_cmpxchg(pa_atomic_ptr_t *a, void *old_p, void* new_p) {
+ bool failed;
+ do {
+ failed = !!__kernel_cmpxchg_u((unsigned long) old_p, (unsigned long) new_p, &a->value);
+ } while(failed && a->value == (unsigned long) old_p);
+ return !failed;
+}
+
+#else
+
+/* libatomic_ops based implementation */
+
+#include <atomic_ops.h>
+
+typedef struct pa_atomic {
+ volatile AO_t value;
+} pa_atomic_t;
+
+#define PA_ATOMIC_INIT(v) { .value = (AO_t) (v) }
+
+static inline int pa_atomic_load(const pa_atomic_t *a) {
+ return (int) AO_load_full((AO_t*) &a->value);
+}
+
+static inline void pa_atomic_store(pa_atomic_t *a, int i) {
+ AO_store_full(&a->value, (AO_t) i);
+}
+
+static inline int pa_atomic_add(pa_atomic_t *a, int i) {
+ return (int) AO_fetch_and_add_full(&a->value, (AO_t) i);
+}
+
+static inline int pa_atomic_sub(pa_atomic_t *a, int i) {
+ return (int) AO_fetch_and_add_full(&a->value, (AO_t) -i);
+}
+
+static inline int pa_atomic_inc(pa_atomic_t *a) {
+ return (int) AO_fetch_and_add1_full(&a->value);
+}
+
+static inline int pa_atomic_dec(pa_atomic_t *a) {
+ return (int) AO_fetch_and_sub1_full(&a->value);
+}
+
+static inline bool pa_atomic_cmpxchg(pa_atomic_t *a, int old_i, int new_i) {
+ return AO_compare_and_swap_full(&a->value, (unsigned long) old_i, (unsigned long) new_i);
+}
+
+typedef struct pa_atomic_ptr {
+ volatile AO_t value;
+} pa_atomic_ptr_t;
+
+#define PA_ATOMIC_PTR_INIT(v) { .value = (AO_t) (v) }
+
+static inline void* pa_atomic_ptr_load(const pa_atomic_ptr_t *a) {
+ return (void*) AO_load_full((AO_t*) &a->value);
+}
+
+static inline void pa_atomic_ptr_store(pa_atomic_ptr_t *a, void *p) {
+ AO_store_full(&a->value, (AO_t) p);
+}
+
+static inline bool pa_atomic_ptr_cmpxchg(pa_atomic_ptr_t *a, void *old_p, void* new_p) {
+ return AO_compare_and_swap_full(&a->value, (AO_t) old_p, (AO_t) new_p);
+}
+
+#endif
+
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 18:53:39 +0000