[PATCH] lib: acpica: fix semaphore counting by waiting for threads to complete
Keng-Yu Lin
kengyu at canonical.com
Mon Jul 23 05:33:44 UTC 2012
On Thu, Jul 19, 2012 at 4:44 PM, Colin King <colin.king at canonical.com> wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> When executing Notify() handlers ACPICA creates separate threads which
> we need to wait to complete before we do any semaphore usage accounting.
> This is because these threads can themselves use internal or AML semaphores
> which will be in an unknown state if we do the start doing semaphore
> usage accounted before we wait for them to terminate. This patch adds
> in an array to keep track of threads created by AcpiOsExecute and also
> a pthread join on these running threads before we start counting any
> used semaphores.
>
> Note that we have to deprecate the ACPICA verison of AcpiOsExecute and
> re-implement this in fwts to allow us to do the thread creation tracking.
>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
> src/acpica/Makefile.am | 3 +-
> src/acpica/fwts_acpica.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 108 insertions(+), 1 deletion(-)
>
> diff --git a/src/acpica/Makefile.am b/src/acpica/Makefile.am
> index e2213d5..6b3bfa5 100644
> --- a/src/acpica/Makefile.am
> +++ b/src/acpica/Makefile.am
> @@ -24,7 +24,8 @@ osunixxf_munged.c: $(ACPICA_OSL)/osunixxf.c
> sed 's/^AcpiOsDeleteSemaphore/__AcpiOsDeleteSemaphore/' | \
> sed 's/^AcpiOsVprintf/__AcpiOsVprintf/' | \
> sed 's/^AcpiOsSignal/__AcpiOsSignal/' | \
> - sed 's/^AcpiOsSleep/__AcpiOsSleep/' \
> + sed 's/^AcpiOsSleep/__AcpiOsSleep/' | \
> + sed 's/^AcpiOsExecute/__AcpiOsExecute/' \
> > osunixxf_munged.c
>
> #
> diff --git a/src/acpica/fwts_acpica.c b/src/acpica/fwts_acpica.c
> index cf9a4fe..08b012d 100644
> --- a/src/acpica/fwts_acpica.c
> +++ b/src/acpica/fwts_acpica.c
> @@ -32,6 +32,7 @@
> #include <pthread.h>
>
> static pthread_mutex_t mutex_lock_count;
> +static pthread_mutex_t mutex_thread_info;
>
> #include "fwts.h"
>
> @@ -54,11 +55,15 @@ static pthread_mutex_t mutex_lock_count;
> #define MAX_SEMAPHORES (1009)
> #define HASH_FULL (0xffffffff)
>
> +#define MAX_THREADS (128)
> +
> typedef struct {
> sem_t *sem; /* Semaphore handle */
> int count; /* count > 0 if acquired */
> } sem_hash;
>
> +typedef void * (*PTHREAD_CALLBACK)(void *);
> +
> BOOLEAN AcpiGbl_IgnoreErrors = FALSE;
> UINT8 AcpiGbl_RegionFillValue = 0;
>
> @@ -70,6 +75,16 @@ static sem_hash sem_hash_table[MAX_SEMAPHORES];
> static ACPI_TABLE_DESC Tables[ACPI_MAX_INIT_TABLES];
>
> /*
> + * Used to account for threads used by AcpiOsExecute
> + */
> +typedef struct {
> + bool used; /* true if the thread accounting info in use by a thread */
> + pthread_t thread; /* thread info */
> +} fwts_thread;
> +
> +static fwts_thread threads[MAX_THREADS];
> +
> +/*
> * Static copies of ACPI tables used by ACPICA execution engine
> */
> static ACPI_TABLE_XSDT *fwts_acpica_XSDT;
> @@ -133,6 +148,27 @@ void fwts_acpica_sem_count_get(int *acquired, int *released)
> *acquired = 0;
> *released = 0;
>
> + /* Wait for any pending threads to complete */
> +
> + for (i = 0; i < MAX_THREADS; i++) {
> + pthread_mutex_lock(&mutex_thread_info);
> + if (threads[i].used) {
> + pthread_mutex_unlock(&mutex_thread_info);
> +
> + /* Wait for thread to complete */
> + pthread_join(threads[i].thread, NULL);
> +
> + pthread_mutex_lock(&mutex_thread_info);
> + threads[i].used = false;
> + pthread_mutex_unlock(&mutex_thread_info);
> + }
> + pthread_mutex_unlock(&mutex_thread_info);
> + }
> +
> + /*
> + * All threads (such as Notify() calls now complete, so
> + * we can now do the semaphore accounting calculations
> + */
> for (i=0;i<MAX_SEMAPHORES;i++) {
> if (sem_hash_table[i].sem != NULL) {
> (*acquired)++;
> @@ -624,6 +660,74 @@ ACPI_STATUS AcpiOsReadPort(ACPI_IO_ADDRESS addr, UINT32 *value, UINT32 width)
> return AE_OK;
> }
>
> +typedef struct {
> + PTHREAD_CALLBACK func;
> + void * context;
> + int thread_index;
> +} fwts_func_wrapper_context;
> +
> +/*
> + * fwts_pthread_func_wrapper()
> + * wrap the AcpiOsExecute function so we can mark the thread
> + * accounting free once the function has completed.
> + */
> +void *fwts_pthread_func_wrapper(fwts_func_wrapper_context *ctx)
> +{
> + void *ret;
> +
> + ret = ctx->func(ctx->context);
> +
> + pthread_mutex_lock(&mutex_thread_info);
> + threads[ctx->thread_index].used = false;
> + pthread_mutex_unlock(&mutex_thread_info);
> +
> + free(ctx);
> +
> + return ret;
> +}
> +
> +ACPI_STATUS AcpiOsExecute(
> + ACPI_EXECUTE_TYPE type,
> + ACPI_OSD_EXEC_CALLBACK function,
> + void *func_context)
> +{
> + int ret;
> + int i;
> +
> + pthread_mutex_lock(&mutex_thread_info);
> +
> + /* Find a free slot to do per-thread join tracking */
> + for (i = 0; i < MAX_THREADS; i++) {
> + if (!threads[i].used) {
> + fwts_func_wrapper_context *ctx;
> +
> + /* We need some context to pass through to the thread wrapper */
> + if ((ctx = malloc(sizeof(fwts_func_wrapper_context))) == NULL) {
> + pthread_mutex_unlock(&mutex_thread_info);
> + return AE_NO_MEMORY;
> + }
> +
> + ctx->func = (PTHREAD_CALLBACK)function;
> + ctx->context = func_context;
> + ctx->thread_index = i;
> + threads[i].used = true;
> +
> + ret = pthread_create(&threads[i].thread, NULL,
> + (PTHREAD_CALLBACK)fwts_pthread_func_wrapper, ctx);
> + pthread_mutex_unlock(&mutex_thread_info);
> +
> + if (ret)
> + return AE_ERROR;
> +
> + return AE_OK;
> + }
> + }
> +
> + /* No free slots, failed! */
> + pthread_mutex_unlock(&mutex_thread_info);
> + return AE_NO_MEMORY;
> +}
> +
> /*
> * AcpiOsReadPciConfiguration()
> * Override ACPICA AcpiOsReadPciConfiguration to fake PCI reads
> @@ -802,6 +906,7 @@ int fwts_acpica_init(fwts_framework *fw)
> return FWTS_ERROR;
>
> pthread_mutex_init(&mutex_lock_count, NULL);
> + pthread_mutex_init(&mutex_thread_info, NULL);
>
> fwts_acpica_fw = fw;
>
> @@ -990,6 +1095,7 @@ int fwts_acpica_deinit(void)
>
> AcpiTerminate();
> pthread_mutex_destroy(&mutex_lock_count);
> + pthread_mutex_destroy(&mutex_thread_info);
>
> FWTS_ACPICA_FREE(fwts_acpica_XSDT);
> FWTS_ACPICA_FREE(fwts_acpica_RSDT);
> --
> 1.7.10.4
>
Acked-by: Keng-Yu Lin <kengyu at canonical.com>
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