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BrunoLevyBrunoLevy
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reverted PR #123 (atomic refactors), breaks compilation and some tests
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‎src/lib/geogram/basic/atomics.h

+303-1
Original file line numberDiff line numberDiff line change
@@ -40,7 +40,309 @@
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#ifndef GEOGRAM_BASIC_ATOMICS
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#define GEOGRAM_BASIC_ATOMICS
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// Obsolete due to switching to std::atomics
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#include <geogram/basic/common.h>
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#include <geogram/basic/numeric.h>
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/**
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* \file geogram/basic/atomics.h
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* \brief Functions for atomic operations
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*/
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#ifdef GEO_OS_LINUX
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# if defined(GEO_OS_EMSCRIPTEN)
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# define GEO_USE_DUMMY_ATOMICS
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# elif defined(GEO_OS_RASPBERRY)
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# define GEO_USE_ARM32_ATOMICS
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# elif defined(GEO_OS_ANDROID)
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# define GEO_USE_ANDROID_ATOMICS
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# else
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# define GEO_USE_X86_ATOMICS
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# endif
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#endif
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#if defined(GEO_USE_DUMMY_ATOMICS)
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inline void geo_pause() {
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}
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inline char atomic_bittestandset_x86(volatile unsigned int*, unsigned int) {
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return 0;
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}
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inline char atomic_bittestandreset_x86(volatile unsigned int*, unsigned int) {
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return 0;
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}
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#elif defined(GEO_USE_ANDROID_ATOMICS)
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/** A mutex for Android */
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typedef GEO::Numeric::uint32 android_mutex_t;
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inline void lock_mutex_android(volatile android_mutex_t* lock) {
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while(__sync_lock_test_and_set(lock, 1) != 0);
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}
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inline void unlock_mutex_android(volatile android_mutex_t* lock) {
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__sync_lock_release(lock);
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}
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inline unsigned int atomic_bitset_android(volatile unsigned int* ptr, unsigned int bit) {
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return __sync_fetch_and_or(ptr, 1u << bit) & (1u << bit);
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}
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inline unsigned int atomic_bitreset_android(volatile unsigned int* ptr, unsigned int bit) {
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return __sync_fetch_and_and(ptr, ~(1u << bit)) & (1u << bit);
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}
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inline void memory_barrier_android() {
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// Full memory barrier.
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__sync_synchronize();
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}
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inline void wait_for_event_android() {
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/* TODO */
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}
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inline void send_event_android() {
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/* TODO */
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}
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#elif defined(GEO_USE_ARM32_ATOMICS)
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/** A mutex for ARM processors */
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typedef GEO::Numeric::uint32 arm32_mutex_t;
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/**
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* \brief Acquires a lock (ARM only)
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* \param[in,out] lock the mutex to lock
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*/
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inline void lock_mutex_arm32(volatile arm32_mutex_t* lock) {
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arm_mutex_t tmp;
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__asm__ __volatile__ (
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"1: ldrex %0, [%1] \n" // read lock
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" cmp %0, #0 \n" // check if zero
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" wfene \n" // wait for event if non-zero
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" strexeq %0, %2, [%1] \n" // attempt to store new value
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" cmpeq %0, #0 \n" // test if store succeeded
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" bne 1b \n" // retry if not
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" dmb \n" // memory barrier
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: "=&r" (tmp)
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: "r" (lock), "r" (1)
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: "cc", "memory");
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}
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/**
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* \brief Releases a lock (ARM only)
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* \param[in,out] lock the mutex to unlock
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*/
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inline void unlock_mutex_arm32(volatile arm32_mutex_t* lock) {
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__asm__ __volatile__ (
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" dmb \n" // ensure all previous access are observed
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" str %1, [%0] \n" // clear the lock
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" dsb \n" // ensure completion of clear lock ...
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" sev \n" // ... before sending the event
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:
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: "r" (lock), "r" (0)
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: "cc", "memory");
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}
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/**
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* \brief Atomically tests and sets a bit (ARM only)
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* \details Sets the bit \p bit of the *\p ptr.
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* The function is atomic and acts as a read-write memory barrier.
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* \param[in] ptr a pointer to an unsigned integer
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* \param[in] bit index of the bit to set in *\p ptr
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* \retval a non-zero integer if the bit was previously set
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* \retval 0 if the bit was previously not set
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*/
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inline unsigned int atomic_bitset_arm32(volatile unsigned int* ptr, unsigned int bit) {
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unsigned int tmp;
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unsigned int result;
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unsigned int OK;
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__asm__ __volatile__ (
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"1: ldrex %1, [%5] \n" // result = *ptr
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" orr %0, %1, %6, LSL %4 \n" // tmp = result OR (1 << bit)
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" strex %2, %0, [%5] \n" // *ptr = tmp, status in OK
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" teq %2, #0 \n" // if !OK then
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" bne 1b \n" // goto 1:
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" and %1, %1, %6, LSL %4 \n" // result = result AND (1 << bit)
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: "=&r" (tmp), "=&r" (result), "=&r" (OK), "+m" (*ptr)
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: "r" (bit), "r" (ptr), "r" (1)
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: "cc"
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);
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return result;
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}
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/**
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* \brief Atomically tests and resets a bit (ARM only)
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* \details Resets the bit \p bit of *\p ptr.
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* The function is atomic and acts as a read-write memory barrier.
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* \param[in] ptr a pointer to an unsigned integer
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* \param[in] bit index of the bit to reset in *\p ptr
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* \retval a non-zero integer if the bit was previously reset
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* \retval 0 if the bit was previously not reset
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*/
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inline unsigned int atomic_bitreset_arm32(volatile unsigned int* ptr, unsigned int bit) {
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unsigned int tmp;
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unsigned int result;
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unsigned int OK;
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__asm__ __volatile__ (
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"1: ldrex %1, [%5] \n" // result = *ptr
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" bic %0, %1, %6, LSL %4 \n" // tmp = result AND NOT(1 << bit)
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" strex %2, %0, [%5] \n" // *ptr = tmp, status in OK
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" teq %2, #0 \n" // if !OK then
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" bne 1b \n" // goto 1:
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" and %1, %1, %6, LSL %4 \n" // result = result AND (1 << bit)
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: "=&r" (tmp), "=&r" (result), "=&r" (OK), "+m" (*ptr)
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: "r" (bit), "r" (ptr), "r" (1)
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: "cc"
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);
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return result;
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}
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/**
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* \brief Issues a memory and compiler barrier (ARM only)
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*/
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inline void memory_barrier_arm32() {
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__asm__ __volatile__ (
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"dmb \n"
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: : : "memory"
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);
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}
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/**
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* \brief Waits for an event (ARM only)
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*/
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inline void wait_for_event_arm32() {
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__asm__ __volatile__ (
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"wfe \n"
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: : :
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);
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}
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/**
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* \brief Sends an event (ARM only)
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*/
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inline void send_event_arm32() {
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__asm__ __volatile__ (
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"dsb \n" // ensure completion of store operations
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"sev \n"
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: : :
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);
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}
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#elif defined(GEO_USE_X86_ATOMICS)
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# define GEO_USE_X86_PAUSE
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# ifdef GEO_USE_X86_PAUSE
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/**
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* \brief Issues a processor pause (INTEL only)
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*/
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inline void geo_pause() {
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__asm__ __volatile__ (
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"pause;\n"
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);
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}
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# else
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# ifdef __ICC
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# define geo_pause _mm_pause
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# else
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# define geo_pause __builtin_ia32_pause
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# endif
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# endif
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/**
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* \brief Atomically tests and sets a bit (INTEL only)
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* \details Sets bit \p bit of *\p ptr and returns its previous value.
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* The function is atomic and acts as a read-write memory barrier.
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* \param[in] ptr a pointer to an unsigned integer
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* \param[in] bit index of the bit to set in *\p ptr
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* \return the previous value of bit \p bit
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*/
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inline char atomic_bittestandset_x86(volatile unsigned int* ptr, unsigned int bit) {
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char out;
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#if defined(__x86_64)
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__asm__ __volatile__ (
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"lock; bts %2,%1\n" // set carry flag if bit %2 (bit) of %1 (ptr) is set
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// then set bit %2 of %1
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"sbb %0,%0\n" // set %0 (out) if carry flag is set
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: "=r" (out), "=m" (*ptr)
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: "Ir" (bit)
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: "memory"
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);
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#else
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__asm__ __volatile__ (
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"lock; bts %2,%1\n" // set carry flag if bit %2 (bit) of %1 (ptr) is set
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// then set bit %2 of %1
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"sbb %0,%0\n" // set %0 (out) if carry flag is set
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: "=q" (out), "=m" (*ptr)
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: "Ir" (bit)
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: "memory"
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);
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#endif
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return out;
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}
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/**
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* \brief Atomically tests and resets a bit (INTEL only)
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* \details Resets bit \p bit of *\p ptr and returns its previous value.
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* The function is atomic and acts as a read-write memory barrier
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* \param[in] ptr a pointer to an unsigned integer
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* \param[in] bit index of the bit to reset in \p ptr
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* \return the previous value of bit \p bit
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*/
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inline char atomic_bittestandreset_x86(volatile unsigned int* ptr, unsigned int bit) {
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char out;
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#if defined(__x86_64)
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__asm__ __volatile__ (
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"lock; btr %2,%1\n" // set carry flag if bit %2 (bit) of %1 (ptr) is set
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// then reset bit %2 of %1
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"sbb %0,%0\n" // set %0 (out) if carry flag is set
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: "=r" (out), "=m" (*ptr)
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: "Ir" (bit)
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: "memory"
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);
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#else
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__asm__ __volatile__ (
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"lock; btr %2,%1\n" // set carry flag if bit %2 (bit) of %1 (ptr) is set
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// then reset bit %2 of %1
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"sbb %0,%0\n" // set %0 (out) if carry flag is set
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: "=q" (out), "=m" (*ptr)
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: "Ir" (bit)
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: "memory"
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);
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#endif
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return out;
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}
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#elif defined(GEO_OS_APPLE)
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#include <libkern/OSAtomic.h>
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#elif defined(GEO_OS_WINDOWS)
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#include <windows.h>
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#include <intrin.h>
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#pragma intrinsic(_InterlockedCompareExchange8)
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#pragma intrinsic(_InterlockedCompareExchange16)
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#pragma intrinsic(_InterlockedCompareExchange)
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#pragma intrinsic(_interlockedbittestandset)
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#pragma intrinsic(_interlockedbittestandreset)
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#pragma intrinsic(_ReadBarrier)
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#pragma intrinsic(_WriteBarrier)
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#pragma intrinsic(_ReadWriteBarrier)
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# ifdef GEO_COMPILER_MINGW
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inline void geo_pause() {
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}
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# endif
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#endif // GEO_OS_WINDOWS
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#endif
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