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Planner: don't return static data in fake_dc()

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fake_dc() used to return a statically allocated dc with statically
allocated samples. This is of course a questionable practice in
the light of multi-threading / resource ownership. Once these
problems were recognized, the parameter "alloc" was added. If set
to true, the function would still return a statically allocated
dc, but heap-allocated samples, which could then be copied in
a different dc.

All in all an ownership nightmare and a recipie for disaster.
The returned static dc was only used as a pointer to the samples
anyway. There are four callers of fake_dc() and they all have access
to a dc-structure without samples. Therefore, change the semantics
of fake_dc() to fill out the passed in dc. If the caller does
not care about the samples, it can simply reset the sample number
to zero after work.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
This commit is contained in:
Berthold Stoeger 2018-05-05 19:26:48 +02:00 • committed by Lubomir I. Ivanov
parent 450f0992a0
commit 920ff15f71
7 changed files with 39 additions and 40 deletions
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37
core/device.c
View file

@ -109,33 +109,29 @@ static void fill_samples_no_avg(struct sample *s, int max_d, int max_t, double s
}
}
struct divecomputer *fake_dc(struct divecomputer *dc, bool alloc)
void fake_dc(struct divecomputer *dc)
{
static struct sample fake_samples[6];
static struct divecomputer fakedc;
struct sample *fake = fake_samples;
alloc_samples(dc, 6);
struct sample *fake = dc->sample;
int i;
fakedc = (*dc);
if (alloc)
fake = malloc(sizeof(fake_samples));
fakedc.sample = fake;
fakedc.samples = 6;
dc->samples = 6;
/* The dive has no samples, so create a few fake ones */
int max_t = dc->duration.seconds;
int max_d = dc->maxdepth.mm;
int avg_d = dc->meandepth.mm;
memset(fake, 0, sizeof(fake_samples));
memset(fake, 0, 6 * sizeof(struct sample));
fake[5].time.seconds = max_t;
for (i = 0; i < 6; i++) {
fake_samples[i].bearing.degrees = -1;
fake_samples[i].ndl.seconds = -1;
fake[i].bearing.degrees = -1;
fake[i].ndl.seconds = -1;
}
if (!max_t || !max_d) {
dc->samples = 0;
return;
}
if (!max_t || !max_d)
return &fakedc;
/*
* We want to fake the profile so that the average
@ -149,10 +145,10 @@ struct divecomputer *fake_dc(struct divecomputer *dc, bool alloc)
* the user supplied data */
fill_samples_no_avg(fake, max_d, max_t, MAX(2.0 * max_d / max_t, 5000.0 / 60));
if (fake[3].time.seconds == 0) { // just a 4 point profile
fakedc.samples = 4;
dc->samples = 4;
fake[3].time.seconds = max_t;
}
return &fakedc;
return;
}
if (avg_d < max_d / 10 || avg_d >= max_d) {
avg_d = (max_d + 10000) / 3;
@ -167,7 +163,7 @@ struct divecomputer *fake_dc(struct divecomputer *dc, bool alloc)
* rate (5 meters per minute) and d_frac (1/3).
*/
if (fill_samples(fake, max_d, avg_d, max_t, 5000.0 / 60, 0.33))
return &fakedc;
return;
/*
* Ok, assume that didn't work because we cannot make the
@ -175,7 +171,7 @@ struct divecomputer *fake_dc(struct divecomputer *dc, bool alloc)
* followed by a much shallower region
*/
if (fill_samples(fake, max_d, avg_d, max_t, 10000.0 / 60, 0.10))
return &fakedc;
return;
/*
* Uhhuh. That didn't work. We'd need to find a good combination that
@ -183,10 +179,9 @@ struct divecomputer *fake_dc(struct divecomputer *dc, bool alloc)
* slopes.
*/
if (fill_samples(fake, max_d, avg_d, max_t, 10000.0, 0.01))
return &fakedc;
return;
/* Even that didn't work? Give up, there's something wrong */
return &fakedc;
}
static void match_id(void *_dc, const char *model, uint32_t deviceid,