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changed to malloc, added comment about adaptive compression level, and changed ternary operators

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This commit is contained in:
Paul Cruz 2017-07-12 17:10:58 -07:00
parent 954d999abf
commit b5b18cf664
1 changed files with 16 additions and 9 deletions
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25
contrib/adaptive-compression/adapt.c
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@ -130,12 +130,11 @@ static int freeCCtx(adaptCCtx* ctx)
static adaptCCtx* createCCtx(unsigned numJobs, const char* const outFilename) static adaptCCtx* createCCtx(unsigned numJobs, const char* const outFilename)
{ {
adaptCCtx* ctx = malloc(sizeof(adaptCCtx)); adaptCCtx* ctx = calloc(1, sizeof(adaptCCtx));
if (ctx == NULL) { if (ctx == NULL) {
DISPLAY("Error: could not allocate space for context\n"); DISPLAY("Error: could not allocate space for context\n");
return NULL; return NULL;
} }
memset(ctx, 0, sizeof(adaptCCtx));
ctx->compressionLevel = g_compressionLevel; ctx->compressionLevel = g_compressionLevel;
pthread_mutex_init(&ctx->jobCompressed_mutex, NULL); pthread_mutex_init(&ctx->jobCompressed_mutex, NULL);
pthread_cond_init(&ctx->jobCompressed_cond, NULL); pthread_cond_init(&ctx->jobCompressed_cond, NULL);
@ -216,16 +215,24 @@ static void waitUntilAllJobsCompleted(adaptCCtx* ctx)
pthread_mutex_unlock(&ctx->allJobsCompleted_mutex); pthread_mutex_unlock(&ctx->allJobsCompleted_mutex);
} }
/*
* Compression level is changed depending on which part of the compression process is lagging
* Currently, three theads exist for job creation, compression, and file writing respectively.
* adaptCompressionLevel() increments or decrements compression level based on which of the threads is lagging
* job creation or file writing lag => increased compression level
* compression thread lag => decreased compression level
* detecting which thread is lagging is done by keeping track of how many calls each thread makes to pthread_cond_wait
*/
static unsigned adaptCompressionLevel(adaptCCtx* ctx) static unsigned adaptCompressionLevel(adaptCCtx* ctx)
{ {
unsigned reset = 0; unsigned reset = 0;
unsigned const allSlow = ctx->adaptParam < ctx->stats.compressedCounter && ctx->adaptParam < ctx->stats.writeCounter && ctx->adaptParam < ctx->stats.readyCounter ? 1 : 0; unsigned const allSlow = ctx->adaptParam < ctx->stats.compressedCounter && ctx->adaptParam < ctx->stats.writeCounter && ctx->adaptParam < ctx->stats.readyCounter;
unsigned const compressWaiting = ctx->adaptParam < ctx->stats.readyCounter ? 1 : 0; unsigned const compressWaiting = ctx->adaptParam < ctx->stats.readyCounter;
unsigned const writeWaiting = ctx->adaptParam < ctx->stats.compressedCounter ? 1 : 0; unsigned const writeWaiting = ctx->adaptParam < ctx->stats.compressedCounter;
unsigned const createWaiting = ctx->adaptParam < ctx->stats.writeCounter ? 1 : 0; unsigned const createWaiting = ctx->adaptParam < ctx->stats.writeCounter;
unsigned const writeSlow = ((compressWaiting && createWaiting) || (createWaiting && !writeWaiting)) ? 1 : 0; unsigned const writeSlow = ((compressWaiting && createWaiting) || (createWaiting && !writeWaiting));
unsigned const compressSlow = ((writeWaiting && createWaiting) || (writeWaiting && !compressWaiting)) ? 1 : 0; unsigned const compressSlow = ((writeWaiting && createWaiting) || (writeWaiting && !compressWaiting));
unsigned const createSlow = ((compressWaiting && writeWaiting) || (compressWaiting && !createWaiting)) ? 1 : 0; unsigned const createSlow = ((compressWaiting && writeWaiting) || (compressWaiting && !createWaiting));
DEBUG(3, "ready: %u compressed: %u write: %u\n", ctx->stats.readyCounter, ctx->stats.compressedCounter, ctx->stats.writeCounter); DEBUG(3, "ready: %u compressed: %u write: %u\n", ctx->stats.readyCounter, ctx->stats.compressedCounter, ctx->stats.writeCounter);
if (allSlow) { if (allSlow) {
reset = 1; reset = 1;