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Adding support for trickle writes to disk

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This commit is contained in:
Dave Smith 2008-12-11 11:51:55 -07:00
parent 3be9b64c30
commit cc7d95a5b7
1 changed files with 57 additions and 5 deletions
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62
c_src/bdberl_drv.c
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@ -39,6 +39,7 @@ static void* zalloc(unsigned int size);
static void signal_port(PortData* d);
static void* deadlock_check(void* arg);
static void* trickle_write(void* arg);
/**
* Global instance of DB_ENV; only a single one exists per O/S process.
@ -71,12 +72,25 @@ static int G_DATABASES_SIZE;
static ErlDrvRWLock* G_DATABASES_RWLOCK;
static hive_hash* G_DATABASES_NAMES;
/**
* G_DEADLOCK_* a
* Deadlock detector thread variables. We run a single thread per VM to detect deadlocks within
* our global environment. G_DEADLOCK_CHECK_INTERVAL is the time between runs in milliseconds.
*/
static ErlDrvTid G_DEADLOCK_THREAD;
static unsigned int G_DEADLOCK_CHECK_ACTIVE = 1;
static unsigned int G_DEADLOCK_CHECK_INTERVAL = 100;
static unsigned int G_DEADLOCK_CHECK_ACTIVE = 1;
static unsigned int G_DEADLOCK_CHECK_INTERVAL = 100; /* Milliseconds between checks */
/**
* Trickle writer for dirty pages. We run a single thread per VM to perform background
* trickling of dirty pages to disk. G_TRICKLE_INTERVAL is the time between runs in seconds.
*/
static ErlDrvTid G_TRICKLE_THREAD;
static unsigned int G_TRICKLE_ACTIVE = 1;
static unsigned int G_TRICKLE_INTERVAL = 60 * 15; /* Seconds between trickle writes */
static unsigned int G_TRICKLE_PERCENTAGE = 10; /* Desired % of clean pages in cache */
/**
*
@ -157,10 +171,14 @@ DRIVER_INIT(bdberl_drv)
erl_drv_thread_create("bdberl_drv_deadlock_checker", &G_DEADLOCK_THREAD,
&deadlock_check, 0, 0);
// Startup trickle write thread
erl_drv_thread_create("bdberl_drv_trickle_write", &G_TRICKLE_THREAD,
&trickle_write, 0, 0);
// Startup our thread pools
// TODO: Make configurable/adjustable
G_TPOOL_GENERAL = bdberl_tpool_start(5);
G_TPOOL_TXNS = bdberl_tpool_start(5);
G_TPOOL_GENERAL = bdberl_tpool_start(10);
G_TPOOL_TXNS = bdberl_tpool_start(10);
}
else
{
@ -245,6 +263,10 @@ static void bdberl_drv_finish()
bdberl_tpool_stop(G_TPOOL_GENERAL);
bdberl_tpool_stop(G_TPOOL_TXNS);
// Signal the trickle write thread to shutdown
G_TRICKLE_ACTIVE = 0;
erl_drv_thread_join(G_TRICKLE_THREAD, 0);
// Signal the deadlock checker to shutdown -- then wait for it
G_DEADLOCK_CHECK_ACTIVE = 0;
erl_drv_thread_join(G_DEADLOCK_THREAD, 0);
@ -986,3 +1008,33 @@ static void* deadlock_check(void* arg)
printf("Deadlock checker exiting.\n");
return 0;
}
/**
* Thread function that trickle writes dirty pages to disk
*/
static void* trickle_write(void* arg)
{
int elapsed_secs = 0;
while(G_TRICKLE_ACTIVE)
{
if (elapsed_secs == G_TRICKLE_INTERVAL)
{
// Enough time has passed -- time to run the trickle operation again
int pages_wrote = 0;
G_DB_ENV->memp_trickle(G_DB_ENV, G_TRICKLE_PERCENTAGE, &pages_wrote);
printf("Wrote %d pages to achieve %d trickle\n", pages_wrote, G_TRICKLE_PERCENTAGE);
// Reset the counter
elapsed_secs = 0;
}
else
{
// TODO: Use nanosleep
usleep(1000 * 1000); /* Sleep for 1 second */
elapsed_secs++;
}
}
printf("Trickle writer exiting.\n");
return 0;
}